VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: rodpaslow on October 11, 2011, 10:02:10 am
-
I have a vnt where my control cable came apart and I fixed it and was trying to set it when it hit 26 psi and the head gasket went poof. on the back side of the head leaking oil and engine will not run.
I've got all the good stuff, metal head gasket, arp head bolts to 110 ft.lbs.
I've heard of people going up to 30 lbs of boost. What have I missed, as I would like to stick with about 25 lbs of boost. Is it too high for the aluminum heads?
-
Boost levels aren't nearly as important as EGTs / coolant temperature. Do you have an EGT gauge?
Also you list a metal head gasket, are you running this on a 1.6TD or an AAZ? Do you know if your head was surfaced well enough for the metal gasket?
-
what vnt do u have? back pressure could have had a lot to do with it as well, especially if your vanes were not fully open at 26psi.
-
my head gasket left the engine at around 35psi.. on a 1.5D..
you have a VNT15 also, right?
making that much boost, the turbo is about ready to fly apart..
i run my vanes in the open position, and get about 18-20 psi if i leave my foot in it..
-
25 psi should not make any vw head gasket go poof instantly. something else is up.
also, with leaking hg, engine should run, sounds to me like rod made friends with block....
-
25 psi should not make any vw head gasket go poof instantly. something else is up.
also, with leaking hg, engine should run, sounds to me like rod made friends with block....
25 psi from a vnt15 is probably over 30 psi in the exhaust, or more especially if the veins are not entirely open. keep in mind what the exhaust side is doing. and at 25 psi vnt15 is blow lots of hot air, plus a *** load of back pressure, its not a good situation
-
Also there is a big difference between 26psi @ 2000rpm and 26psi @ 4000rpm (turbo efficiency, peak cylinder pressure, EGT) At what RPMs did you blow your HG?
-
ive never had a gasket blown soo bad that it wouldnt run..
even when i blew the head off my 1.5D and cracked 7 head bolt holes, i still drove it home the next day. it took 5 gallons of water to go 2 miles tho..
-
I certainly hope its nothing else than a head gasket. It would start and run for a few seconds, but I've had a head gasket go a while back on a 1.5 I had and it starts and has a thick/grey cloud like that 1.5. To me that means it using oil from the motor. There were a couple of oil spots on the ground from the back of the engine I saw after I had it towed home. It's a '92 1.6 td with a vnt15. Metal AAZ gasket. My egt was not working at the time, I have it in the wrong spot. I will be drilling an adding it to the right spot after taking the head off. As for setting of the VNT, vanes were mostly closed at this point as it was full throttle and I see I'm MUST need to add a boost can as it may have overshot 26 pounds...roughly 3200-3400 rpm at the time.
Coolant temp was right at normal, as I'm on boost it starts from about 200° and goes to 212-220° depending on how long I'm on boost. I never lost any coolant as that was the first thing I checked. Normal coolant pressure was being held even after the "poof".
Question I have too is if I add a boost can (vnt boost can reversed) as boost rises to a point the can starts to work, will not boost decrease as pressure rises?
Whats the easiest way to check if anything else had been damaged with the head off. Check that all pistons protrude roughly the same amount? That will ensure I haven't bent a rod?
-
yea, theres no way your METAL head gasket crapped the bed at 26psi..
my FIBER gaskets last better than that. i think something else is your problem..
-
Timing belt probably jumped a tooth on the injection pump.
I pegged the gauge on my 1.5D with a VNT,.. about 35psi, if I didn't have ARP studs it probably would have done the same as ROR's.
-
yup. something isnt right. that head gasket is fine.. i almost hit 26 psi yesterday on my 11mm stock n/a 1.6 (stock fiber gasket, and stretch bolts)
-
Well I was able to do some work on it last night. I have everything off the back of the engine except the turbo. What was weird is when I pulled the intake about 1/4 litre of oil poured out onto the floor (It was enough to coat most of the floor below the engine). Where would that oil come from? My first thought was the turbo. Once I take that off I will check the cool side and make sure it's not full of oil and I can check my intercooler as well. It they don't have any oil it had to come from the engine. If they have oil, is my turbo cooked? I have a spare vnt if I need it....
Well see what else I can fine tonight as an issue.
I was thinking I might pull the injectors out and turn the engine over before I pull the head. Clear any oil that may be in it, but the injectors back in and see if it will start. The more I read this the more I think its not the head gasket.
-
Wow, that's a lot of oil in the intake...
Generally oil in the intake is coming from the breather, but that sounds like WAY more than I'd expect. Any chance the turbo drain line was blocked somehow? What condition is this engine in otherwise?
Usually the turbo wouldn't puke that much oil out the cold side even if its seals were completely gone, since the cold side is pressurized most of the time whereas the oil drain is at atmospheric, so there shouldn't be any oil pressure there to leak out.
Hmm what kind of breather do you have going on?
-
And there wasn't much oil, I don't think any oil came out the hot side, there was just a bit on the outside of the turbo. I'll be removing it tonight so I'll know a bit more then. Then engine before this had about 15k miles on it, relatively new rebuild with no previous issues. I was just at full bore when this happened. 1.6 td with a vnt15, going hard on the throttle.
-
Yeah, that's definitely weird...
Sorry to ask again, but what kind of breather setup do you have?
-
I just have it coming from the valve cover with a 1" hose going to a Mann Provent filter unit and back into the intake side of the turbo. There certainly wasn't any excess oil in the intake or exhaust side of the turbo taking all the pipe connections off. I'm at a loss as to why all the oil...
-
We'll I just finished pulling the turbo off and I think that's were all the oil came from. You can move the shaft about 3/8 to 1/2" from side to side. That can't be a good thing...lol!
The next question is: can I pull the injectors out of the head and crank the engine over like you would to clear a flood from a gasser, in order to get oil out of the cylinders because there has to be a large amount of oil there too? I don't want to bend a rod or something like that from too much oil in a cylinder. I bet the head gasket is fine.
That's a load off as I just have to get the other vnt I have ready to go in.
-
Why? You are 99% of the way into removing the head, don't stop now for the price of a head gasket and bolts! Besides, if there is that much oil in the cylinders, you've probably already bent/broken something.
Ian
-
Why? You are 99% of the way into removing the head, don't stop now for the price of a head gasket and bolts! Besides, if there is that much oil in the cylinders, you've probably already bent/broken something.
Ian
This is my concern as well; if the intake was full of oil and the motor came to a slammin stop, and now won't run.. There's likely a bent rod somewhere
-
X2 on more damage inside.
Also if the shaft moves that far wouldn't the wheels be hitting the housings and thus producing metal of various sizes that would be going through the engine?
-
Yeah, your probably right. I think I will do that. I have a new head gasket ordered and I have ARP head studs so i don't need new ones. I might as well check everything. How will I know if I have a bent rod? Simply check piston heights?
This way I can start out with almost like new if all the oil and crap is cleaned out from the cylinders and striaghten any bend rods, if any...
-
If you do have anything bent/broken, let me know. I have rods/pistons/cranks for AAZs. just pm me.
Ian
-
Thanks for the offer, but it's a 1.6 td not a 1.9. I'd be looking for 1.6 rods. I'm hoping because it started after it had stopped initially that nothing is bent. I'll be posting this weekend if that's not the case..
-
Pulled the head off and I checked pistons heights and all were good within +/- .002" as best I could measure anyway. I think what saved me was as soon as I lost power I hit the clutch pretty fast. But there was enough oil in 2 of the cylinders had I tried to start it again I think it would have been a bad idea. I also found a bolt on the intermediate shaft pulley I had missed tightening. Oops, that could have been a catastrophe had it stopped turning.
So has any one else had a vnt turbo fail like this? I'm a bit worried they are not as robust as the T3 the vnt replaced? Luckily I had a spare one I traded the T3 for so I'm just getting it ready to put in...mak'in sure the egt is installed properly this time!
Will reduce pressure help longevity? Is the vnt 17 any better? I see they are a bit pricier than a new 15, but if it lasts it may be worth it? Also may be too large for a 1.6?
-
Sorry but I got confused (I have alot goin on lol)
The turbo took a dump and spewed the contents of your oil pan into the intake? Is that correct?
-
Yup, I think what happened is there must have been some movement, maybe from over-speed of turbo (I've read 18psi steady is about the mac a vnt 15 should be able to handle reliably). The seals must have gone as this overspeed happened and pushed about a litre and a bit into the intake and engine.
-
I hit 35psi on my VNT, a couple times and had no problem.
I had a good block vent.
-
I hit 35psi on my VNT, a couple times and had no problem.
I had a good block vent.
i hit OVER 35psi with a 1.5D that had a VNT bolted to it.. then shortly after, the head ALMOST left the block. 7 head bolt bosses were toasted. many cracked soo badly that they would not torque at all..
still drove the car home the next day with the head gasket blown in almost a dozen spots.. only took 5 gallons of water to drive 2 miles, im thinking i had some sort of a SMALL LEAK for it to use that much water.. lol..
retarded timing is the easiest way to over-boost these VNTs..
ever since ive had my engine timed good, its been hard to get the VNT out of its efficiency range..
-
Efficiency range being what psi? I think I will start with 18 and see how it works.
-
Efficiency range being what psi? I think I will start with 18 and see how it works.
im not EXACTLY sure what the specific numbers, but im gonna say that they are efficient to about 20-22psi or so..
-
Sounds good enough for a 1.6. What do you run yours up to?
-
with proper timing and fueling, i can only get mine to about 22 psi or so.. but my vanes are non-functional. when i had super retarded timing, i could hit 30+psi quite easily. around 26psi, the turbo would start screaming from overspeed.
-
The head gasket has been replaced and I made a few other changes, I have a boost can now to back off the boost, got rid of stock air box-changed to a larger open air filter, etc.
I started the car up yesterday, ran fine with the (1.6td) advance/fast idle lever pulled, with this off though it was kind of a lopey idle. I haven't re-adjusted the timing yet - would timing be the issue?
-
yeah sounds like u got it retarded
-
Tanks
-
the retarded timing would also cause your ridiculous amount of boost.. if your gonna be running that much boost, out of that small of a turbo, then i would rig up a exhaust manifold pressure gauge.. drive pressure goes sky high on these little VNTs in the upper RPMs/high boost levels..
excessive drive pressure vaporizes head gaskets, and sometimes blocks..
-
I don't plan on going over about 18 psi with the other vnt 15 now installed. I have since installed a boost can and a much better setup for vnt control than I originally had. I've been having trouble, for some reason, to get it to run properly since replacing the head gasket. Yesterday I re-timed it starting with the timing belt making sure everything was good there and did the dial gauge thing and it's set to 1.00mm right on the money. Like I said before it starts and runs properly with the high idle/advance lever on, but lopes for a couple minutes before the idle smooths out. I didn't have that issue before. The engine has a nice snap to it so I think timing is good now, maybe once I run it for more than a few minutes and get it to warm right up, this will disappear.
Next is just to save up for the vnt 17 hybrid so I can run 26 psi without blowing up the turbo.
-
glow plug?
maybe a burnt valve
-
I hit 35psi on my VNT, a couple times and had no problem.
I had a good block vent.
i hit OVER 35psi with a 1.5D that had a VNT bolted to it.. then shortly after, the head ALMOST left the block. 7 head bolt bosses were toasted. many cracked soo badly that they would not torque at all..
still drove the car home the next day with the head gasket blown in almost a dozen spots.. only took 5 gallons of water to drive 2 miles, im thinking i had some sort of a SMALL LEAK for it to use that much water.. lol..
retarded timing is the easiest way to over-boost these VNTs..
ever since ive had my engine timed good, its been hard to get the VNT out of its efficiency range..
I think why my little 1.5 survived 35psi and yours didn't is: mine had head studs. You still had the stock 11mm headbolts right?
-
I hit 35psi on my VNT, a couple times and had no problem.
I had a good block vent.
i hit OVER 35psi with a 1.5D that had a VNT bolted to it.. then shortly after, the head ALMOST left the block. 7 head bolt bosses were toasted. many cracked soo badly that they would not torque at all..
still drove the car home the next day with the head gasket blown in almost a dozen spots.. only took 5 gallons of water to drive 2 miles, im thinking i had some sort of a SMALL LEAK for it to use that much water.. lol..
retarded timing is the easiest way to over-boost these VNTs..
ever since ive had my engine timed good, its been hard to get the VNT out of its efficiency range..
I think why my little 1.5 survived 35psi and yours didn't is: mine had head studs. You still had the stock 11mm headbolts right?
yup, stock non-stretch bolts. shortest amount of threads out of any oem VW bolt. even the 11mm gasser stretch bolts had more bolt threading into the block..
-
I finally took mine for a run yesterday, but I think I need a boost controller to control my boost can as I can get maybe 5 psi held and if just slowly accelerating it drops off to 0 rather quickly. I almost thought I had a boost leak but everything is tight. I can hear something hissing, but i finally changed to an open element air filter and I think that's just the turbo pulling in air.
I might disconnect my boost controller and see if the boost comes up like it used to and maybe test it up to about 15 or 20 psi. Once I fit a boost controller I can bring it up slowly.
I certainly notice with the egts, on about 5 lbs of boost it runs up to 1100° quickly. I might have to back off the fueling at 15-18 psi it will be up to and past 1250° in no time at all...
So far so good with a newly installed old VNT...
-
My boost can nut that held to the controller came off and the vanes were full open that's why I was getting only 5 psi - I tried last night and it will put out 18-20 psi no problem.
Please can someone answer this - if you have an open cone style air filter-when the turbo is pulling in air like 10-15 psi or so, can you hear it doing this? I'm still concerned I have a boost leak somewhere, as that is almost what it sounds like.
-
i hear the exhaust more than the intake. i have a pod style filter.
only time ive had a loud intake, was when my filter was in the rain tray. and it was only at idle.
-
My boost can nut that held to the controller came off and the vanes were full open that's why I was getting only 5 psi - I tried last night and it will put out 18-20 psi no problem.
Please can someone answer this - if you have an open cone style air filter-when the turbo is pulling in air like 10-15 psi or so, can you hear it doing this? I'm still concerned I have a boost leak somewhere, as that is almost what it sounds like.
I hear mine doing this as well, sounds like a boost leak but i think its just the turbo moving air.
-
Yeah it sounds really off, at anything over 10 psi. Thanks.
I have to make a quick manual boost controller. (have to stop at B&T/Applied) and get a 3/8 dia steel ball the rest I can pick up at a local hardware store after hours. I make about 10 psi max now and it drops to about 5 once the boost can interjects. I'd like max to be about 18 psi.
I'm a bit concerned after blowing the last turbo, not to go over that. What do most people run for psi cruising? If I increase it using a boost controller I think my cruising psi will be higher as well as the boost can won't be getting any signal(have to try it and see if I can adjust the vnt control). I may have to add a solenoid that has a microswitch on the throttle that only cuts in the high manual boost controller at or near full throttle....
-
I have my vanes tied partially closed and run ~18psi max and cruising at around 70mph im making about 4psi.
-
I've ran it for about 1 hours drive and found I have oil in my coolant. Something in my headgasket change hasn't worked. ARP head bolts are torque to 100 ft lbs. I don't think going higher will help.
I'm thinking when I change it to go back to a fibre gasket as it will seal better. I'm sure the surface I cleaned before I installed this last one were near perfect. Everything was straight and flat, usually first thing I check.
I'm questioning aftermarket parts. Are OEM gaskets (meaning VW) going to be better quality for a head gasket? I know you pay through the nose, but I only want to do this one more time (cause it's cold now[below freezing] -8°C and lower).
The other thing is(I've read)will aviation gasket sealer or some kind of partially fluid material going to help the head gasket slightly move around and find it's place and help any tiny tiny leak? I've talked to some old timers and they tend to use something to help the head gasket move around a bit to 'find' its end location. Maybe whitch-craft of somekind?
-
Is the oil in the coolant definitely from a leak though, or is it just left over from the head gasket change itself? Are you loosing oil?
-
It's definitely oil leak with the head gasket as it runs beautifully. I ran it for about and hour (1/2 hour a couple times). I started it Saturday and noticed the coolant tank looked darker. I open it after just starting the car (was still cold) and dipped my finger in the tank and it had a good coating of oil. I had cleaned all the oil from the cylinders when I had the head off, so I'm sure the oil is new from a leak.
The question is, go back to a fiber gasket and/or use some form of sealer to help with sealing these little problem(eg aviation gasket sealer). As far as combustion goes, I could run it the way it is with no problems except for oil in the coolant. That's not satisfactory to me!
-
It's definitely oil leak with the head gasket as it runs beautifully. I ran it for about and hour (1/2 hour a couple times). I started it Saturday and noticed the coolant tank looked darker. I open it after just starting the car (was still cold) and dipped my finger in the tank and it had a good coating of oil. I had cleaned all the oil from the cylinders when I had the head off, so I'm sure the oil is new from a leak.
The question is, go back to a fiber gasket and/or use some form of sealer to help with sealing these little problem(eg aviation gasket sealer). As far as combustion goes, I could run it the way it is with no problems except for oil in the coolant. That's not satisfactory to me!
do you have a stock style oil cooler? (warmer)
-
No, I don't have a stock oil cooler. It's actual an 83 vintage GTI with the filter and has the outlets to an aftermarket oil cooler. No coolant runs through it.
-
I don't have any issues with mine at 100ft/lbs. I didn't run the engine before final torque. I stepped it up, but I plugged the block heater in for a day and let it cool and did it again. I think the combustion force is hard on these gaskets to make them want to leak. Did you check the head and block surfaces? I also covered mine in the hylomar sealant. 53willy's had trouble and took his studs to 120ft/lbs IIRC then they were ok
-
I did check both head and block surfaces for flatness - they were fine and I made sure they were very clean no residue left from the old head gasket in areas that contacted. the combustion areas were pretty clean too, I was impressed with that. But all areas that needed to be clean were clean before I started putting the head back on.
I have some work to do yet, I still have to take the turbo off and remove the lines and glow plug wire, a few other minor things and pull the head off again. I haven't decided what to buy yet - a proper vw 1.6 head gasket, if available or a 1.9 metal one and try again...?
I have to buy a new turbo too, as I think the vnt 15 I have as a second has a seal leaking as the little time I ran it, there is oil dripping from the exhaust connection. Maybe a VNT 17 this time so I can comfortably run 20+ psi.
-
Did you just use the Hylomar Blue? I think I'm going to get some of that stuff and use it too!
-
http://partsxks.com/i-6917664-17-0214-blue-hylomar-5-oz-aerosol-can.html
spray...its for lazy people :D
-
Thanks, I will be buying that, spray I think will make it much easier to be even. I've read over most of your build and noticed lately you've had a bit of a problem with boost. Hope you've got it sorted. Is that a vnt turbo as well or is it wastegated?
I had one question - you in the posts used some white, I think it was teflon to fill some holes in the mls head gasket. What was that for? Are you using a mechanical head not a hydraulic lifter head?
Thanks again.
-
Yep MLS on mech head and mech block. The stuff has been perfect and worked amazing, the white stuff is called teflon joint sealant tape. I know a guy that replaced a head gasket on a gasser with it for a while, yep, it will hold up to combustion for about a week.
It is the K24. I run out of air, so I am going to a 2256vk soon.
-
Well, I've finally got the head off again as I can work in the weather we have for a while( around 0 or 32°F). I cleaned it last night and will check straightness again just to make sure, and am waiting to receive my Hylomar yet.
I am going to buy a new turbo once everything is back together. It will either be VNT 17 or the hybid 17/22. Has anyone run this with a 1.6? I'm just wondering if the 17/22 will not boost as quickly if it's a 1.6 and not a 1.9? It's also another $400 above the 17.
I'd appreciate any info if anyone had run either of these and what kind of success they've had on a 1.6. I'm only planning on running around 20 psi at a max and the 15, might due fine, but I read the 17 has a better shaft,etc.
-
Well, I've finally got the head off again as I can work in the weather we have for a while( around 0 or 32°F). I cleaned it last night and will check straightness again just to make sure, and am waiting to receive my Hylomar yet.
I am going to buy a new turbo once everything is back together. It will either be VNT 17 or the hybid 17/22. Has anyone run this with a 1.6? I'm just wondering if the 17/22 will not boost as quickly if it's a 1.6 and not a 1.9? It's also another $400 above the 17.
I'd appreciate any info if anyone had run either of these and what kind of success they've had on a 1.6. I'm only planning on running around 20 psi at a max and the 15, might due fine, but I read the 17 has a better shaft,etc.
do you really need more boost than the VNT 15 is capable of? i think the VNT17 even has the same high end restrictions of the VNT15..
high drive pressure at high RPMs.
the VNT15 actually got added to the VNT17 line.. mines a GT1749VNT.. i dont think the extra cost will be worth it. ive been abusing a VNT15 (1749VNT) for almost 5 years now. and its still amazing how good it works. never had an issue with it.
yes, whatever turbo you use, will spool slower on a 1.6, rather than on a 1.9
-
I think the 1.6IDI vs the 1.9 TDI is a tough call. The TDI is more efficient then the IDI so less heat is wasted out the ex. BUT you loose .3L of displacement. Plus with the higher revs of a 1.6 you might be better with one of malone's 1852v than either of the 15, 17, or 17/22. For either engine. This is just a GUESS. We need someone who has unlimited ammount of resources to test all of our theories.
Robbed this off of our very own Malone's site:
The biggest advantages the GT1852v turbo has over the popular bolt-on VNT-17 and VNT-17/22 (aka GT1752v) turbos are lower EGT and EMP. The VNT-17/22 tends to struggle with EGT and EMP at 170+ whp and it tends to struggle with boost creep at 180+ whp with the manufacturer’s recommended 26 PSI (1.8 BAR) boost limit. The GT1852v can handle these power figures with ease. The rotationally fired exhaust manifold design allows the GT18v and larger turbos to build boost relatively quickly.
-
I think the 1.6IDI vs the 1.9 TDI is a tough call. The TDI is more efficient then the IDI so less heat is wasted out the ex. BUT you loose .3L of displacement. Plus with the higher revs of a 1.6 you might be better with one of malone's 1852v than either of the 15, 17, or 17/22. For either engine. This is just a GUESS. We need someone who has unlimited ammount of resources to test all of our theories.
Robbed this off of our very own Malone's site:
The biggest advantages the GT1852v turbo has over the popular bolt-on VNT-17 and VNT-17/22 (aka GT1752v) turbos are lower EGT and EMP. The VNT-17/22 tends to struggle with EGT and EMP at 170+ whp and it tends to struggle with boost creep at 180+ whp with the manufacturer’s recommended 26 PSI (1.8 BAR) boost limit. The GT1852v can handle these power figures with ease. The rotationally fired exhaust manifold design allows the GT18v and larger turbos to build boost relatively quickly.
finally, someone paid attention to drive pressure!!
drive pressure is a big problem on smaller VNTs at high boost levels.. a vnt15 will make enough drive pressure to blow a head almost off a block..
-
Yes he did. Also I think that the drive pressure is a cause of the boost creep. Even when the vanes are fully open there might be enough drive pressure to continue to spool the turbo. If he is buying a turbo then I would look into one of these. If he already had one then I would say run it. This is something I am making educated guesses on, but I am reading a lot of what guys have written about on this. Also, reading Malone's site is helping me get my head around it.
Maybe even a call to Malone would help. Most all of his setup's are for TDI's, but I am sure he is more learned on this subject than I.
-
finally, someone paid attention to drive pressure!!
drive pressure is a big problem on smaller VNTs at high boost levels.. a vnt15 will make enough drive pressure to blow a head almost off a block..
IF so called "drive pressure" is actually EMP (exhaust manifold pressure) then this can't be true. EMP is in the 10s of psi. Cylinder pressure (BMEP) is in the 1000s of psi in a typical diesel engine, so EMP is not significant. I do not know what wasted your motor, but it wasn't too much pressure in the exhaust manifold. High EMP is self limiting. Just like any other plugged exhaust. If we also experience a boost runaway that is also unlikely to cause the problems that you have had because BMEP is limited by the amount of fuel available. (AEBE)
-
The 1852V sounds awesome, although I don't know if I need 26 to 30 psi of boost as I'm sure I'm not anywhere close to 170+ bhp. I think it's comparable, maybe a bit higher than my 16V jetta so I might be 135-140 max. I have sent Malone an email to see if he offers it yet and $$. If it's comparably priced it seems like it will offer more if I ever decide to go to higher bhp or a 1.9 td.
-
Understood. I was just thinking if you were going the 17/22 route then you were looking for power. I think power is limited to our turbos to a point. I think the stock pump is capable of a lot. If you have a Giles pump then it is more. But I think you can attain close to 190 with a stock pump and a big old turbo. The reason you maybe less than that now is the turbo can't push enough cold air to clear the heat if you turned up the pump.
-
I think I have a motor capable of more, ARP fastners on all the important bits - rods, mains & head and a Giles pump, and probably less than 20 k miles on a fresh rebuild (pistons, rings, and all that). I do want some reliability (don't want to have to replace a turbo every so often, why I'm want new)- but if I can push 150-170 bhp, I wouldn't mind that either. Within reason anyway. I drive it pretty hard when accelerating, but otherwise cruising I think is relatively soft on it. I prefer it to be my DD - but I have an old golf n/a as backup I'm driving now....
trying not to beat around the bush, I guess I want to be able to handle a turbo that somewhat can handle more boost (bit better hp/torque) and not break the bank.
-
I think I have a motor capable of more, ARP fastners on all the important bits - rods, mains & head and a Giles pump, and probably less than 20 k miles on a fresh rebuild (pistons, rings, and all that). I do want some reliability (don't want to have to replace a turbo every so often, why I'm want new)- but if I can push 150-170 bhp, I wouldn't mind that either. Within reason anyway. I drive it pretty hard when accelerating, but otherwise cruising I think is relatively soft on it. I prefer it to be my DD - but I have an old golf n/a as backup I'm driving now....
trying not to beat around the bush, I guess I want to be able to handle a turbo that somewhat can handle more boost (bit better hp/torque) and not break the bank.
Rod, if I may respectfully inquire, why a VNT? Why not a new Garrett that has a known Map that you can match scientifically to your engines needs? If you have spent the money on a Giles Pump, it would seem worth knowing exactly where your tubo will work and have a simple and reliable control system for it.
BlueMule
-
finally, someone paid attention to drive pressure!!
drive pressure is a big problem on smaller VNTs at high boost levels.. a vnt15 will make enough drive pressure to blow a head almost off a block..
IF so called "drive pressure" is actually EMP (exhaust manifold pressure) then this can't be true. EMP is in the 10s of psi. Cylinder pressure (BMEP) is in the 1000s of psi in a typical diesel engine, so EMP is not significant. I do not know what wasted your motor, but it wasn't too much pressure in the exhaust manifold. High EMP is self limiting. Just like any other plugged exhaust. If we also experience a boost runaway that is also unlikely to cause the problems that you have had because BMEP is limited by the amount of fuel available. (AEBE)
high drive pressure = REALLY HIGH cylinder pressure..
the drive pressure never stays in check because like a restriction, there is a fixed (so to speak) supply of air to it, but with a turbo, the more the restriction, the harder the boost is pushing to get thru it.. drive pressure is not a fixed restriction like you say, its a variable restriction that goes up as boost goes up. DRIVE PRESSURE DOES KILL ENGINES.
drive pressure is the pressure between the exhaust valve, and turbine inlet.. drive pressure is what makes the turbo work.
if you dont believe me about drive pressure, look up people modifying 6.4L ford powerjokes.. they would often have 50psi boost, and 80-90psi drive pressure. that right there would keep the cylinder pressures higher than safe, and pop head gaskets on those engines also.
drive pressure is no secret, its been working on every turbo engine ever produced.. DRIVE PRESSURE blew the head off my 1.5D block.. you know why? cause high drive pressure means higher peak cylinder pressures (less exhaust evacuated) and higher pressure everywhere between the face of the intake valve, and the outlet of the turbine.. drive pressure makes all other pressures exponentially greater..
And BlueMule:
he wants a vnt because VNTs are SWEET. you know of a conventional turbo that will boost at low revs, and flow well at upper rpms? no, because you get one, or the other, not both..
a VNT is like having a variable sized turbo.. starts out small, like K03 sized, then as the vanes open, the turbo grows, and spools later and flows better..
-
ROR - You hit it perfectly. I love the fact even with the VNT 15, I can get boost starting at 1600-1800 rpm depending on how hard I step on it from stopped. And as RPM increases the vane control backs off and still provides good boost all the way up to 4000 and past.
In my opinion I think it's hard to beat. I haven't used new other turbos of sorts, but why would OEM manufacturers be moving to VNT if they weren't as good as others? I think they are the best of both worlds; plus the fact I've changed my exhaust over to fit the VNT, why would I change back. If the 1852V is better, I think it's worth the time to investigate.
I'm still waiting to receive my Hylomar Blue. I've cleaned both the block and cylinder head and checked the flatness, they are virtually perfect with a Mitutoyo stainless ruler. Once I get the Hylomar (next week) I can start putting the head back on and make a choice on what turbo to get. I'm taking a chance and putting a new MLS 1.9 head gasket back on....
-
Toby, This mysterious "drive pressure" is all the rage with the Pickumup modifiers. They even have gauges to read this ethereal pressure. Pros basically call it "Hey dummy, your choke point has been reached". Drive pressure is an indication that the turbos limit has been reached, with all of the wonderful symptoms of "barking", etc.
If you know, the following.
Engine size
RPM
Boost
Which will give you your Mass Flow Rate
Then you couple this with your pressure ratio, plot it on your Map, and you never have to worry about "drivepressure" because you have claculated were you "choke ". Science, don't leave home without it.
BlueMule
-
Toby, This mysterious "drive pressure" is all the rage with the Pickumup modifiers. They even have gauges to read this ethereal pressure. Pros basically call it "Hey dummy, your choke point has been reached". Drive pressure is an indication that the turbos limit has been reached, with all of the wonderful symptoms of "barking", etc.
If you know, the following.
Engine size
RPM
Boost
Which will give you your Mass Flow Rate
Then you couple this with your pressure ratio, plot it on your Map, and you never have to worry about "drivepressure" because you have claculated were you "choke ". Science, don't leave home without it.
BlueMule
thank you for confirming what i was saying 8)
-
I received an email from Malone - Mark, he says the 1852V is no longer available and is out of production. I was under the impression that he sold them, but he doesn't. The tuning side is his forte?
So where does a VNT 15 choke? Is 17 any better for choke and drive pressure issues? I'm going to be looking for this info - I see faq doesn't have any VNT maps. Any help is appreciated.
-
I've read a VNT 20 off a V6 (not sure of what car, likely passat or audi??) is producing over 300 ft.lbs on a m4 TDI. totally different setup than manifold combined like the VNT.
If I were to use our engine with say 5000 rpm max what is the max flow rate if I can find a useful map? Roughly 280 cfm @ 100% VE. At 5000 if I'm wanting a max of say 25 psi boost, what's my mass flow rate?
-
I received an email from Malone - Mark, he says the 1852V is no longer available and is out of production. I was under the impression that he sold them, but he doesn't. The tuning side is his forte?
So where does a VNT 15 choke? Is 17 any better for choke and drive pressure issues? I'm going to be looking for this info - I see faq doesn't have any VNT maps. Any help is appreciated.
AFAIK the vnt15 and vnt17 have the same size turbine, the 17 just has a slightly larger compressor so I would imagine the 17 wouldnt be any better for drive pressure.
-
The VNT 17 is not going to be much of an improvement over the 15 if the turbine section is the same size, other than at the same turbo speed it will be producing slightly more boost. I wonder, is the hybrid 17/22 the same? It uses the 17 turbine section and the 22 compressor?
-
The VNT 17 is not going to be much of an improvement over the 15 if the turbine section is the same size, other than at the same turbo speed it will be producing slightly more boost. I wonder, is the hybrid 17/22 the same? It uses the 17 turbine section and the 22 compressor?
correct..
-
from what i understand the 17 has a larger inducer on the compressor, it would in theory spool up a little slower because it is moving more air and doing more work on the intake side for every revolution, at higher rpms the 17 would be more efficient so at higher rpms the turbine would be doing less work to move the same amount of air at higher flow rates, creating less back pressure and robbing less energy from the engine to create the same amount of air flow.
-
Yeah I found some pictures showing the difference, the 15, 17 and 20 (this picture showed 20 not 22) and the compressor wheels just increased in size from one to the other- the VNT 15 has 33mm wheel, whereas the VNT-17 has a 1.435" (36.449mm) wheel and 20 is larger than that.
I have a feeling it will be hard to find a vnt that has the same inlet and outlet and same bolt pattern, etc to fit my car. I think I'm going to buy a VNT17, not the hybrid, and see how it works out. I don't plan on running much over 20 psi, so it will be a good match for that.
-
We had some awesome weather this weekend so I had a chance to work on it. I sprayed some of the hylomar onto the head gasket (sticky stuff after it partially sets) set it in place on the block and put the head on and step torqued it up to 100 ft.lbs. Then I quickly connected all the coolant stuff to the head and filled it with coolant so I could use the block heater (still -1°C or about 32°F) to heat the block. After block was warm to the touch I torqued all head bolts to 110 ft.lbs. (these are ARP head bolts).
I don't have the turbo yet to continue, but so far so good. This seemed easier - better be as it's second go round. I hope the Hylomar seals any minor difference in surface like a fibre head gasket would. I so much like the steel head gasket. It just seems better than any fibre gasket that originally came on a 1.6.
-
We had some awesome weather this weekend so I had a chance to work on it. I sprayed some of the hylomar onto the head gasket (sticky stuff after it partially sets) set it in place on the block and put the head on and step torqued it up to 100 ft.lbs. Then I quickly connected all the coolant stuff to the head and filled it with coolant so I could use the block heater (still -1°C or about 32°F) to heat the block. After block was warm to the touch I torqued all head bolts to 110 ft.lbs. (these are ARP head bolts).
I don't have the turbo yet to continue, but so far so good. This seemed easier - better be as it's second go round. I hope the Hylomar seals any minor difference in surface like a fibre head gasket would. I so much like the steel head gasket. It just seems better than any fibre gasket that originally came on a 1.6.
where is everyone finding BOLTS?! i thought ARP only had studs out for our engines?
-
Oops, I mean to say studs not bolts, my bad!
-
Oops, I mean to say studs not bolts, my bad!
its ok, i just keep seeing everyone talking about these ARP head bolts, and i wanted to figure out if it was just a small mistake, or if ARP actually did make some head bolts that i didnt know about..
thanks for clearing that up!
-
I finally bought a vnt 17 turbo and it's on its way.
I have received a couple AN -10 fittings and hose I want to install this weekend, I can use the turbo I blew up as a mockup and get the drain better than it was with just a hose and clamps. This way it always leaked a bit - the AN fitting and 350+° braided line hose should fix that. I will have to weld a -10 fitting to the tube that connects to the oil pan, but that shouldn't be too hard.
-
I finally bought a vnt 17 turbo and it's on its way.
I have received a couple AN -10 fittings and hose I want to install this weekend, I can use the turbo I blew up as a mockup and get the drain better than it was with just a hose and clamps. This way it always leaked a bit - the AN fitting and 350+° braided line hose should fix that. I will have to weld a -10 fitting to the tube that connects to the oil pan, but that shouldn't be too hard.
Thats what I used on mine as well, except I didnt have a turbo oil pan so I just welded a bung onto the pan. Has worked well so far. Is yours a GT1749VA?
-
No the one I bought (I think has arrived today) is a GT1749VB. It's too damn cold to do any work on the car right now (unheated garage). I hoping to use the stock drain with the -10 fittings. I wasn't counting on the fittings being as long as they are. I hope I have enough distance between the -10 JIC nipple I weld onto the stock tubing and the bottom of the turbo drain. Turbo drain side I just plan to tap a fitting onto it and then connect the AN fittings. We'll see how much hose I need, but I bet it won't be any more than about 5".
I'll post a picture once I unpack the turbo. I hope it warms up next week so I can install it.
-
I used something like this for the drain on my turbo, just measure the bolt hole spacing. It has worked well.
http://www.ebay.com/itm/Turbo-Oil-Return-Drain-Flange-Kit-AN10-1-2-PT-KKK-K03-K04-Audi-Mitsubishi-TD02-/120836120603?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item1c2264e01b
-
the one you posted won't fit a vnt. I'm 99% sure the spacing looks to narrow. However the JIC/AN fitting looks like the size I plan on using.
-
Well I used something like that, Im not sure that that is the exact one I used and mine is a vnt17 as well. I was just trying to say that something like that is an option.
-
I finished installing the turbo this weekend and may have a problem with the drain. I fitted a 3/8 npt fitting to -10 Jic/AN the turbo oil plate and to the oil pan (bought a new oil pan;old one is for sale cheap if someone needs one), I used an fittings to go to those fittings- I used a straight coming out of the turbo and a 90 deg going into the oil pan. It's very close to the drive shaft once installed. I fitted the shaft in place and lifted the right side of the car with my jack, and it gets within less than 1/8".
This is a bit close for comfort, maybe once I test it, it may be okay, but I don't think so. Is a 90 deg female -10 to male fitting less distance center to center than the 90 deg hose fitting I'm using?
-
Finally got everything running and I now have the problem to try and remove all the oil from the cooling system. I see many different ways of doing it on this forum, I think I will use a flush product and a bit of soap as they both seem to have good results. Any other info on flushing would be helpful as this is the first time I will have done it - vw's are pretty good in this country for not having crap in the cooling system from my experience.
One other issue is under full boost, (I have it set to about 14-16 psi for now) it will fluctuate between 14 and 16 psi going back and forth until I let off the go pedal a bit, then it stabilizes. I have a manual boost contoller going to the boost can (-reversed vacuum can -vnt 17 turbo). Will enlarging the leak hole in the boost controller reduce this, or would blocking the hole reduce in the manual boost controller reduce this? I like to figure out how to stabilize this before I do any higher with boost.
-
i wouldnt be worried about running flush AND soap in my cooling system..
maybe even a little simple green.. that stuff is safe on every metal ive used it on, including al13, brass, copper, iron, stainless, whatever..
as for your boost reg problems, when i built my boost controller, i made my orifice bigger than recomended, because were running about twice the boost thru these than most people are.. my boost controller doesnt let my boost fluctuate at all.. im actually surprised at how well it worked..
-
Do you remember what size of hole was in it? The one in mine might be 1/32" if that. I was just wondering if I need to go bigger for more bleed or smaller for less???
-
Couldn't be too bothered to read the whole thread (sorry) but i run 25+psi on an AAZ and previously on a 1.6td MF block and i absolutely had to use an MLS metal head gasket and ARP studs (because they dont stretch) otherwise i would destroy a head gasket everytime i even saw the boost gauge go anywhere near 20psi.
-
Couldn't be too bothered to read the whole thread (sorry) but i run 25+psi on an AAZ and previously on a 1.6td MF block and i absolutely had to use an MLS metal head gasket and ARP studs (because they dont stretch) otherwise i would destroy a head gasket everytime i even saw the boost gauge go anywhere near 20psi.
ive been running a K24 on my car, with a n/a bottom end, T/D head, RE-USED head gasket, RE-USED bolts, and stock manifolds..
im running on the same gasket as when i bought my rabbit!
run 20-25psi boost all the time, and my gasket is still fine..
-
I think it depends on a few variables - as far as boost. I had to take the head twice, I had an oil leak into the coolant with the first head gasket (metal) pulled the head off a second time and used some sealant (hylomar) between block and head gasket and head gasket and cyl head. I was just doing a coolant flush last night and stripped one bolt on the thermostat housing and now it's going to be a you know what, to change because I have to pull the injector pump because the top left hand bolt I can't get a wrench on because of the injector pump bracket! I have a spare housing so it won't cost me anything, just about 4-5 hours to change....
-
I've run it a bit more (again it's a vnt17) and I thinks it's capacity for boost is bit much for a 1.6. I can have the vanes fully open and mash the throttle and it will hit 18 psi and climb fast until I let off. In FAQ I read before, started by fspGTD had the same problem only he wasn't going as high of boost as I want. I want 18-20 max and I've had it easily at 25 psi and climbing with the vanes fully open. It is relatively fast climb like 3 seconds max to hit 25psi. I think the only solution to this is what he did - add a proper wastegate to bypass the turbo to limit it. I don't think anything else will limit boost properly.
-
I was just doing a coolant flush last night and stripped one bolt on the thermostat housing and now it's going to be a you know what, to change because I have to pull the injector pump because the top left hand bolt I can't get a wrench on because of the injector pump bracket! I have a spare housing so it won't cost me anything, just about 4-5 hours to change....
Pretty easy access, I'd helicoil the thermostat bolt hole before I'd go to all that work.
-
It wasn't as bad as I thought, I changed the waterpump, I just cut a 3/4 deep socket I had and I was able to get the bolt out and then it was easy to change the back half of the water pump. Like you said though, I bough some heli-coils to refurbish the one I took out so if I ever need it I can use it. Theme of the story - use the torque wrench tightening the thermostat housing!
-
Running it now I still have one other issue - After it's warmed right up and been running for a while, if I stop I can smell something that smells like it's burning- while idling at a stop light or stopped and idling. I noticed there is a bit of blue smoke coming out of the tail pipe and it has a bit of that smell to it. When I blew the turbo initially, the whole car smelled like that. Is the hot exhaust just removing some of the oil in exhaust pipe(not likely?), or is the head gasket leaking again or turbo seals? (turbo is new has maybe 200 miles on it). Engine has less than 20,000 mi on it since full rebuild. What may be causing this?
I've double checked timing - it's a giles pump set at just under 1.00 (.99 approx in dial gauge)
-
Got the using oil problem fixed - if you use a provent 200 and you have it dumping back into the oil pan above the oil level, it must have their check valve or it will pull oil into the engine like you wouldn't believe. Once the check valve added it's not using any at all.
Tool it on a 500 mi round trip and the smell of the burning/burnt smell is gone. It may have just been in the tail pipe and just needed to be pushed out the back.
It's still cold (about -7°c) and having a wee bit of starting problems, but I think it's needed a new battery for a while and a starter. Glow plugs are fine.
So the head is fixed, I am going to add a actual turbo wastegate to control boost and will report after that's put on, in a week or two.
Thanks for the replies!
-
I just thought I'd update - after honing and new rings, going back to a fiber head gasket, everything is back together and running well. I had one cylinder before this job that wouldn't start working till after a minute or so of running. New rings and proper head gasket has taken care of that.
I have the VNT 17 installed after taking it apart and all it needed was a good cleaning of the control and the turbine side had some cake of sooth on it that had started to restrict it from turning freely. It's actually pretty easy to take apart, not as much vodoo as I thought! I have also added a wastegate to control boost as it would overshoot to 30 psi + easily. The wastegate and vnt control work nicely together. I've been keeping it to about 10-12 psi until I break in the rings somewhat. Just wanted to say thanks for all the posts & help.
-
I do have one quick question the in IP. How do you set the residual fuel properly? Is it just a bit less so the idle doesn't hang? It a Giles pump and I should have left it were it was. I know where to adjust it, just not how it should be set.
-
To set the residual pressure, I would disconnect the high idle/cold start linkage rod, set the idle lever to the slow idle position and run out that stop screw all the way so the slow idle lever is resting on the pump lid. Then adjust the idle speed using the residual pressure screw until it is just below the idle speed you want. Bring the idle up to the proper speed using the idle lever's slow idle stop screw. Adjust the fast idle rod length.