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Engine Specific Info and Questions => TDI Engine -General Info => Topic started by: tunedbandit on April 24, 2012, 10:43:59 pm
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Hi guys as it says
can porting a diesel cylinder help in general performance
anyone have any info on this if they have done it :)
cheers Rick
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Hi guys as it says
can porting a diesel cylinder help in general performance
anyone have any info on this if they have done it :)
cheers Rick
there IS a RIGHT AND WRONG way to port a TDI head, so please wait till someone has a definitive answer!
im not the one with the answer tho :(
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tdi or not an engine will always benefit from a well ported head
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tdi or not an engine will always benefit from a well ported head
the TDI has swirl inducing runners tho, and there is a bump cast into the runner that NEEDS NOT BE REMOVED..
it will smoke like a train when its cold if you port the head, and dont know what your doing..
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dont know abot that,but its like i said,a WELL ported head.
out here most of the +300hp tdi“s have ported heads,thats for sure.
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thanks for all your advice guys,,,iam not planning on doing the porting myself it will go to a cylinder head specialist
i was just wondering if any you guys have ported heads :)
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I don't have a TDI with a ported head, but my TD was and will be again soon. Big difference.
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thanks for all your advice guys,,,iam not planning on doing the porting myself it will go to a cylinder head specialist
i was just wondering if any you guys have ported heads :)
take it to a guy that has DONE TDI HEADS BEFORE..
these are nothing like gasser heads, if you go too big on the port shape, and shave the swirl inducing bump out of the port, then it will be a cold blooded pig. it will smoke and run rough if the head is ported by someone who has no idea what they are doing, ive seen this exact thing happen before.. somebody RUINED a perfectly good TDI head because they didnt know what they were doing..
(and heads are NOT cheap)
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My aaz head had a "swirl bump" I attributed to Chinese casting. Removed it and the thing ran awesome. Heavily modified though...
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Yeah, that would just be a casting flaw as you said. TDI's have a very obvious intake port shape that is crucial to proper combustion. IDI's are almost like gassers as far as porting goes.
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I remember a while back Dave at pp was experimenting with tdi head porting he said if you took too much of the swirl part out they'd smoke white down low but run better up top I guess there is enough turbulence at higher rpms for combustion to happen correctly. It's probably easy to figure out just by checking out what cummins guys do
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what power were you thinking of , i think a std head good for round 220hp but some may no beter
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I did this myself on this 1Y (same as AAZ) head:
(http://i167.photobucket.com/albums/u139/gldgti/P1010476.jpg)
goes to
(http://i167.photobucket.com/albums/u139/gldgti/P1010477.jpg)
and
(http://i167.photobucket.com/albums/u139/gldgti/P1010485.jpg)
(http://i167.photobucket.com/albums/u139/gldgti/P1010484.jpg)
(http://i167.photobucket.com/albums/u139/gldgti/P1010486.jpg)
not much, just took the ridge off the inside of the port near the valve and opened up the manifold connections to the same size as the manifolds.
Made a noticable difference to driveability.
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I did very similar to my AAZ head. I went all the way to the valve stems and then removed any part of the stem that stuck out. Matched the ports to the gasket and then on the other size i opened the ports up all the way to the valve seats.
Resulted in incredible mileage and super torque under 0 boost. Flowed amazing. Looking forward to selling my head to someone who will use it well.
I was so happy with the results i will definitely be looking into doing some head work on the ALH I just got.
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I did very similar to my AAZ head. I went all the way to the valve stems and then removed any part of the stem that stuck out. Matched the ports to the gasket and then on the other size i opened the ports up all the way to the valve seats.
Resulted in incredible mileage and super torque under 0 boost. Flowed amazing. Looking forward to selling my head to someone who will use it well.
I was so happy with the results i will definitely be looking into doing some head work on the ALH I just got.
Yup, I don't like to overstate it but it does make a huge difference to torque off boost.
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Bit of a long shot, but does anyone have a dyno comparison of before and after porting?
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id be interested in seeing why and how to properly port a TDI head, as i have ported and polished many many petrol heads for gti8v's and vr6's etc, but have never done a diesel. however im going to be rebuilding my 1Z tdi in a couple of months, and was thinking of doing it whilst im rebuilding the head.
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i ported the head on my first 1z and could feel a benefit,
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did you open the ports up then or just match them to the manifold and gasket etc, then port match the inlet? Or did you remove lots of material from inside the ports and make the ports a larger volume internally?? have you any pics??
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did you open the ports up then or just match them to the manifold and gasket etc, then port match the inlet? Or did you remove lots of material from inside the ports and make the ports a larger volume internally?? have you any pics??
i opened up the ports about1 to 2mm each side , mached the manifolds ,and smooth off the throat and cleened up the swirel bump at the bottom of the inlet throat , and 3 angled the inlet valves , left the exhaust valves stock, and then polished the 8 off them , no pics sorry . i still got the engine (pump settings wrong and over reved = bent valves 5 year a go) its sitting in my shed so i will take a pic of the ports from the back of the head , i pick up a nother engine cheap so did not bother fixing up .
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excellent, some pics would be awesome if you could :-) when you say cleaned the swirl bump up, do you mean removing it, or just polishing it up a bit??
Im hopefully gonna be removing the engine this weekend, and will split it, and start the work fter the weekend hopefully :-)
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I would tread lightly on that swirl bump. One guy had a head ported for his TDI and it had white smoke all the time at idle. It was a few years ago on here and the guy tried tons of stuff, eventually put a new head on and all the smoke was gone. From what I gather from my engine machinist, bigger isn't better. Better velocity into the cylinder is better, and with the TDI you need a little turbulance aparently.
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Did he check compression. I remember reading about the first AAZ head on a 1.6 block and the guy was convinced it was a terrible idea because the motor was fine before doing the head swap. He did a compression test and was very low on compression.
I'm not saying that the bump can safely be removed, but one guy's experience shouldn't be taken as fact unless he went about it and covered all his bases.
I haven't seen the thread in question, so I'm just asking.
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Remember, it was the TDI in a van. It went finally to Colorado or something where the new ower put a new head on. It checked out fine otherwise. I think Libby may have even looked at it.
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If you are building a huge turbo, high-revving, massive flow, track-only tdi, than removing the swirl hump can help. For any kind of daily-driver you need to keep it.
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Did he check compression. I remember reading about the first AAZ head on a 1.6 block and the guy was convinced it was a terrible idea because the motor was fine before doing the head swap. He did a compression test and was very low on compression.
I'm not saying that the bump can safely be removed, but one guy's experience shouldn't be taken as fact unless he went about it and covered all his bases.
I haven't seen the thread in question, so I'm just asking.
i think i remember that, the head he put on had bent valves or something.I would tread lightly on that swirl bump. One guy had a head ported for his TDI and it had white smoke all the time at idle. It was a few years ago on here and the guy tried tons of stuff, eventually put a new head on and all the smoke was gone. From what I gather from my engine machinist, bigger isn't better. Better velocity into the cylinder is better, and with the TDI you need a little turbulance aparently.
if i was doing a tdi head, i would gasket match the ports and manifolds, and yeah port it out down to the swirl bump thing, i dont think i'd touch the swirl bump, maybe clean off any casting imperfections so they are all even, and maybe even polish them up, but not really remove any material. and then flip the head over and open up the ports around the valve seats so they match the seat and continue that up in to the bowl/radius area and clean up the bowl, on the exhaust side u can try and make that turn not so harsh, i don't think i'd mess with the turn on the intake side because the swirl bump is in that area. i think cleaning up around the valve seats will make the biggest difference, but u have to keep in mind also that the seat is off set a bit from the port and this one done intentionally to even out the air flow around the valves, instead of all the air flowing towards the more open side of the valve. Before i did my head i did alot of reading, there is an old write up on how to port 8v heads, its a few pages long and has been posted here and on vortex. i think it'd be awesome to mess with the swirl port, but with out more information on how it works and whether it can be modified i wouldn't touch it, i think gasket matching, cleaning up the ports, and opening up around the valve seats will make a good enough difference, enough for an amateur like me anyway
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cheers for your reply's, especially trev0rby, makes alot of sense. I think i may well go down the route or cleaning and smoothing, rather than porting as such. Make irflow easier rather than more of it, as i;ve read the heads are good for well over the power output i want anyway, so i just want to make it easier and better flowing.
I also never "polish" a head on anything, i smooth it out using some emery paper on a flap bit ive made for my die grinder, but i never go more than 120 or 180 grit, as a polished port actually slows air down, and causes fuel to stick to it, meaning worse combustion, where as a slightly rough surface causes aggitations and swirls of its own. I know is fuel issue isnt a problem on the tdi as they are direct injection, but as i say, ive only ever done 8v gti's and the like, where the injector injects into the inlet.
I'll keeplooking for an explanation on the swirl bump, and for sme pics.......
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Yes if I said the word polish I meant just to sand smooth not to literally create a mirror finish. I have read the most important part of head porting is 1-2" before and after the valve seat. Which doesn't apply that much for use since the valves are basically on the head surface but I would bet there are small gains to be had from doing some kind of bevelling the head around the valve seat on the deck, I know Malone and Dave at pp had discussed this and on one picture of Dave's head it looks like had done it to his aaz head
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180 is almost polished LOL. From what I gather since we do not have the fuel and air in mix. On all the gassers I have ported I think I stopped at 80grit.
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I've seen lots of pictures of TDI ports without the swirl bump, one I drove and it drove just fine. All of these were done with use of a flow bench and either by shops or people I know who know what they're doing.
With that said, I removed the swirl bump on mine, and only opened the intake bowls slightly, smoothed them out quite a bit and I opened and cleaned up the exhaust ports quite a bit. I'm surfacing and doing a valve job on Saturday and hopefully can install the head soon, will report back.
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I'll keeplooking for an explanation on the swirl bump, and for sme pics.......
It's just an asymmetry in the intake port that closes off one side of the port between the wall and valve guide. It's quite obvious. It forces the air to increase in velocity and vortex around as it enters the cylinder.
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hey i am an expert googler
http://www.competitiondiesel.com/forums/showthread.php?t=139276
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yeah, its 120 i've got, not 180, lol.....just checked ha ha, its been a while since i done one and couldnt remember.
Will wait to see how you get on with your head once its refitted, be nice to see some pics of the ports etc :-)
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When I did mine I used 120 for the final then the shop that did all the valve work sand blasted the ports
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Remember, it was the TDI in a van. It went finally to Colorado or something where the new ower put a new head on. It checked out fine otherwise. I think Libby may have even looked at it.
That rings some bells. If Libby checked it over, I'm pretty sure he covered the bases. Thanks
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I did deal with the smokey TDI van. Swirl bumps were not the issue. Although the head was ported some, the swirl bumps were present and accounted for. I still do not know what the issue was. The owner did not want to replace the head which was the next step I would have taken and instead sold the van. The new owner did replace the head and the smoke issues went away. Again, the swirl bumps were not the issue.
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My bad, I thought the guys said the swirl bumps were taken out with the porting. If not the velocity must have been down and not mixing with the diesel well for some reason. Wasn't the HG replaced too and then a new head after that? If so the head was the culprit, I just thought the swirls were gone.
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excellent, some pics would be awesome if you could :-) when you say cleaned the swirl bump up, do you mean removing it, or just polishing it up a bit??
Im hopefully gonna be removing the engine this weekend, and will split it, and start the work fter the weekend hopefully :-)
I took 1mm off the bumps and smooth off the edges , i did not polish any of the ports the exhaust ports were finnish of the smoothest tho , and i forgot to take some pics but get them for next week ::)
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I just finished my head rebuild with porting. I didn't do any flow bench stuff, all ported by feel and pictures of other porting jobs.
(http://stuff.jfettigmachines.com/tdi/Porting/tn_IMAG0397.jpg)
(http://stuff.jfettigmachines.com/tdi/Porting/tn_IMAG0398.jpg)
(http://stuff.jfettigmachines.com/tdi/Porting/tn_IMAG0399.jpg)
(http://stuff.jfettigmachines.com/tdi/Porting/tn_IMAG0400.jpg)
(http://stuff.jfettigmachines.com/tdi/Porting/tn_IMAG0401.jpg)
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Very nicely done jfettig. I love the sharp angle of the ends of the swirl steps and the exhaust ports are massive! Do you plan on running a stock cam or something a little more aggressive to compliment those ports?
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I am running a Colt Stage 2 cam and will continue to run that. I could get a Colt Stage 3 cam but I've spent enough money recently :)
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beautiful port job! certainly more consistent than i have the patience for, looks great, like a robot did it
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Thanks :)
I can't believe the hours I spent on it, it was quite the learning experience. I mostly used 3/8" and 5/16" rounded end burs as well as a 1/4" for a little bit of it. I also used sanding rolls. next time I do it, I'm going to get a more course grit sanding roll, probably around 80. I think I was using 120.
Burs should be 2-4" long. I had a 6" that I shortened up because it was just too much.
I plan to tune my new turbo/injector setup with the old head then do an after comparison. Hopefully I don't loose any part of the RPM range.
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A comparison between a stock head and a ported head would be awesome. I'll be waiting patiently for results. ;D
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Awesome job. I'm going to do the same when i inevitably have to take it apart to clean out all the EGR crap.
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I feel like I shouldn't update this because I haven't sorted it completely.
I installed my ported head 3200 miles ago. At the same time I upgraded rods and pistons, resealed my injection pump and re-did my glow plug harness(used proper 4 wire harness).
The most important thing to mention first is that us two non engine machinists did the valve job.
First off it pulls really nice, I gained 200rpm on the low end. My turbo ran out of breath on the top end because it was so small and flowed so good, I had to cut boost earlier but it still pulled as good. Now I have a bigger turbo and it pulls nicely to 5500rpm, or higher(vcds only reads to 5355rpm).
Overall performance increases are awesome.
Now the bad - its most likely my change to the glow system, but it could be my valve job or reduction in swirl. It doesn't start nice with the stock glow plug duration, if I glow it multiple times it starts great, if I unplug the CTS and glow it longer, it starts great, boom its on, no excess cranking. Otherwise, it takes some effort to start.
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what kind of cold temps are we talking about here?
how is mpg?
any white smoke?
and perhaps describe what u did to the valves and and another machinist who speaks the machinist language can say if any of that could be a problem. maybe even just doing a compression test would give you a good idea.
sounds promising tho, if a tdi can make good power to 5500 and peak power near or above 5k u could make some serious power at relatively low boost and less stress on the engine. what turbo are you now running?
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Anywhere from +40F to -10F is about what I'm experiencing now. +40 it will start with a little more cranking than normal, just a little glow(unplugged CTS) and it'll fire right up. I have a new tune waiting to go into the car tomorrow morning with a different glow map which should glow for a few seconds at +40 and increase duration all the way down.
Only white smoke I get is right away on a hard start, if I glow it long enough, no white smoke. On a hard start it probably lasts 10-30 seconds.
MPG is +2-3mpg from a year ago, roughly 42mpg vs 40mpg
Based on a couple opinions, I did not lap the valves, we just cut the seats with a carbide cutter and ground the valves with a valve grinder. Also back cut them. They all held vacuum when tested(I forget what the actual # was)
I am running a GTB2056VL now, at 5500rpm I'm only making around 18psi. This was calculated based on a GT2056 map from turbobygarrett.com - not sure if its right but its happy. At 5000rpm I am still making 25psi
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will do a compression check soon - my new tester is defective.
Additional glow and it starts much better. Not as good as before but it'll start up first try.
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I would be very careful touching the swirl bump on a PD head, part of the injector seat is there.
here is some other useful info
PD130/150 Port molds
http://forums.tdiclub.com/showthread.php?t=300245&highlight=cross+sections
PD Cylinder head cross section
http://forums.tdiclub.com/showthread.php?t=374419&highlight=PD+Head
cylinder head swirl & flow data
http://forums.tdiclub.com/showthread.php?t=307098&highlight=cross+sections