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Engine Specific Info and Questions => TDI Engine -General Info => Topic started by: whoabeats on August 11, 2012, 08:31:12 pm
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Hey guys I've been lurking here for awhile. Really wish I was more of a contributor so this is a step in the right direction. I have been a diesel junkie for the past 4 years. I have been modding and daily driving my cummins for the last few years, and got my gf to buy a 98 jetta tdi 2 years ago. That car was taken off the road though because it was starting to get real sketchy. I ended up with all the parts though and am looking to do a full rebuild and a swap into an audi a4 of similar year as the engine. Brief Plans for build. 98 ahu M-Tdi based off cummins 12mm pump ( I have a few others around including an alh auto pump). gt2052 turbo, water methanol injection, and a big custom exhaust. I want a quick car that will save me a lot on fuel compared to my trusty 12v, drive nice, and must have ac ;D.
So right now I have a ton of parts flooded in my garage the engine is completely torn down. My next step is to clean up the block. The block is in great shape my plans for it are to magnaflux it, check the block for flatness, and paint it up real purdy. But problem number one how do I remove the rust and clean it to look as good as new? Can I make my own simple solvent, do I need to have a machine shop do it, what do you guys have experience with?
Then my next step is have the head checked. I had to drill out one of the glow plugs and I may have strayed slightly whilst doing that. So I plan to have the machine shop put in the replacement threads for me and make sure all is well. I mean worst case scenario I find another head in the mean time yes thats expensive but the car was free so who am I to complain. Then I can send it to someone like Frank06 to fix it for me. That should be fairly cheap compared to the usual stuff he gets in.
Besides this stuff what should i have the machine shop do? I was gonna research porting the head myself I have a die grinder and a dremel. I dont plan to do too crazy of rpms boost will be limited at like 25 maybe 30 so stock valve springs should be ok? I am debating lowering the cr of the engine, but I know that is where stuff will start getting trickier.
Pretty much what you guys can think of just throw it out there. Im using this post to help motivate me to get going. It will be a slow build because I plan to buy my first home in the next few months, and I actually wont buy the car til the engine is rebuilt and running. But I need to get started somewhere.
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Awful quiet...
(http://desmond.imageshack.us/Himg142/scaled.php?server=142&filename=crickets.gif&res=landing)
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is yon cricket helping you with the build , that kinda sucks , could allways glue him to the top off rocker cover , are you and the cricket going to Mtdi this engine , how you going to run your vnt E or M
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I was planning mechanical setup for the turbo. I was not going to worry about that for awhile though there is plenty of work to be done before then. And I dont think the cricket is going to be much help, just thought it would be an interesting place keeper for the thread.
I've done a lot of research as far as the mtdi pump as well. I have already machined my alh pulley, and clearanced the timing belt metal shroud. I think I need to add one thin washer to each hub bolt in between the hub and the pulley to mount the pulley perfectly in line with the cam pulley. I also am planning as of now to use the pump top off of my old rabbit ve pump. The cummins pump as many of you know have one governor spring, while the vw pumps have the caged multiple springs. I plan to shim one of them off hand I cant remember which one it is, but I'll go back and look before I do that. I would use my shiny cummins pump top with the vw governor, but that would be too easy; they do not line up. The things I still have to figure out is what else I need to switch out in order to get that pump to run right. I'd like to get 5k rpm out of it, but I also want to keep it alive so I am willing to settle so I have something reliable. Im thinking to get high rpms I will have to use the less aggressive alh camplate, but then again Im not entirely sure Im looking for insight from the experienced members.
Don't shun the newbie though I've done my hw prior to seeking help and I'd be more than happy to give anyone insight or advice about cummins engines if they need it.
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Lurkers are required to wait 48 hours before getting a response are they not? Once a contributing member then penalty time is reduce per post.
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A little more research on the 12mm bosch pump head and you will see why 5000rpms will be pushing it pretty far in to the no go zone. That is 2500 pump rpm, and i am pretty sure they only like to be 2250 tops.. And even then you risk seizing the head.
There really will be no need to spin an AHU/ALH 5000rpms as with these you make low end torque as opposed to high end horesepower. But if you feel the utmost need, i suggest an 11mm head.
The engine itself will hold up to 5k no problem, after all.. It didd alright stock ;).
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Hmm. ???I thought that the cummins pumps were better than that. And I do like low end torque, but at the same time I was aiming to raise the torque curve on the engine a bit to make life easier on all the parts. I have met a veteran member of this forum in person before at a meet who has given me some info. He recommended that I have a lift pump for a cummins pump. That way there is adequate fuel in the pump at all times to cool and lubricate it. Truck wise I know ve pumps are good for at least 3200 rpm. I think someone might even carry a 3800 rpm spring now. I'm sure like everyone else I'll have to experiment with pump parts once I get it going.
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Hmm. ???I thought that the cummins pumps were better than that.
A Bosch VE pump is a Bosch VE pump ;)
And I do like low end torque, but at the same time I was aiming to raise the torque curve on the engine a bit to make life easier on all the parts.
Simple, the reason they make SO much low end torque is the turbo. 1Z had the GT15, AHU had the K03, and the ALH got the VNT15(? 17 ?). They all have the ability to get the boost up QUICK, and with that the engine has the ability to DUMP the fuel in really early. Bam, a butt-ton of low end torque. Being that the fuel is injected in to a cup in the piston, and with a much more efficient injector nozzle the fuel gets a way better burn resulting in more torque over an IDI of the same displacement.
I have met a veteran member of this forum in person before at a meet who has given me some info. He recommended that I have a lift pump for a cummins pump. That way there is adequate fuel in the pump at all times to cool and lubricate it.
Lift pumps are always a good idea, I have installed an electric pump in the engine bay of every car I have worked on that didn't have one stock already. ALL my VW diesels have gotten one from me, as well as my old carb vehicles no more dry bowls and 10 years of cranking! lol
Truck wise I know ve pumps are good for at least 3200 rpm. I think someone might even carry a 3800 rpm spring now. I'm sure like everyone else I'll have to experiment with pump parts once I get it going.
Ok but even 3800 is only 1900 pump RPM. That is obviously still a safe rpm as you don't hear of Cummins trucks having seized pumps. It helps that their engines don't want to spin any more revs than that too.. ;). 2250 pumps RPM is 4500 engine RPM, and I am sure you will find that is enough unless you run a REALLY big turbo. What is the point though? is this a race engine? :P A 12mm Bosch head is worth a lot of money, too much to be experimenting with. For that part, get it in theory first lol
Well on your way to building an M-TDI pump for sure. Have you looked in to Land Rover pumps at all? The 1ZAHU block has been known to withstand 300ft.lbs without issue. The soon you can make that all come on, the better! lol I am sure with a VNT you will have A LOAD of playable area between 1500-4500RPM :).
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Ah alright Haha. I see what you did there with pump rpms. You can see why I was worried when you said 2500 rpm, I just immediately assumed engine rpm. I appreciate you laying out all that information for me. I'm hoping to get my garage finished up this week and I can show you guys some pictures. Cuz what car guy doesn't love garage build pics? Thinking back on it now I really wish I called my local machine shop Monday, my first day off in forever. Oh well I will get this ball rolling.
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I rev my mTDI with Cummins 4BTA pump over 4,000 rpms (engine) routinely and haven't had any issues. I've cruised it on the freeway over 3500 rpms for hours at a time. I wouldn't want to rev it to 5K anyway as the TDI combustion properties stink when turning that fast.
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I rev my mTDI with Cummins 4BTA pump over 4,000 rpms (engine) routinely and haven't had any issues. I've cruised it on the freeway over 3500 rpms for hours at a time. I wouldn't want to rev it to 5K anyway as the TDI combustion properties stink when turning that fast.
Surely you have heard of the seizure issues? It would seem there are a few different types of 12mm Bosch head, and only one or two of them are actually capable of 2500 pump rpms.
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I'm building an AHU with a LR 300TDi pump, what are they like in comparison?
Also how do you plan on attaching the turbo? i got my GT20 off an A4 2.5TDi over here for £60, but they're not a straight fit on any manifolds as far as i know. As such i'll be making an adaptor from a trapezoid 4 bolt manifold to the rectangular 4 bolt Garrett flange. If you want a pair of flanges, or the CAD drawings for them, let me know. will be getting them laser cut in work soon. Also curious as to how you intend to control it. I've a method in mind but have no idea how it'll perform in day to day driving to be honest
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I rev my mTDI with Cummins 4BTA pump over 4,000 rpms (engine) routinely and haven't had any issues. I've cruised it on the freeway over 3500 rpms for hours at a time. I wouldn't want to rev it to 5K anyway as the TDI combustion properties stink when turning that fast.
Surely you have heard of the seizure issues? It would seem there are a few different types of 12mm Bosch head, and only one or two of them are actually capable of 2500 pump rpms.
I have heard of pump rotor seizure issues with aftermarket rotor/head assemblies (read Prothe), but have not heard of any firsthand accounts of issues with actual Bosch units. I feel absolutely no concern about running a Bosch 12mm plunger for the whole rpm range that the TDI motors are comfortable.
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8v... i push my rover pumped ahu to 6k+ its 11mm..
why..... 78mph in 3rd.... 18-21psi on little crappy turbo...
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6k is fine for an 11mm, 5k is fine for a 12mm. I don't think they 12mm would like much of 6k.
However I stand by Andrews statement;
I feel absolutely no concern about running a Bosch 12mm plunger for the whole rpm range that the TDI motors are comfortable.
They aren't comfortable over 5k anyhow ;)
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I'm building an AHU with a LR 300TDi pump, what are they like in comparison?
Also how do you plan on attaching the turbo? i got my GT20 off an A4 2.5TDi over here for £60, but they're not a straight fit on any manifolds as far as i know. As such i'll be making an adaptor from a trapezoid 4 bolt manifold to the rectangular 4 bolt Garrett flange. If you want a pair of flanges, or the CAD drawings for them, let me know. will be getting them laser cut in work soon. Also curious as to how you intend to control it. I've a method in mind but have no idea how it'll perform in day to day driving to be honest
I am actually leaning more towards a non vgt turbo at this point and getting a traditional wastegated unit. Not entirely sure yet though. As far as manifold I plan to run a cast turbo 8v manifold from ebay. http://www.ebay.com/itm/VW-8V-CAST-IRON-TURBO-EXHAUST-MANIFOLD-GOLF-JETTA-PASSAT-BEETLE-CABRIO-MK3-T3-/280939833590?pt=Motors_Car_Truck_Parts_Accessories&hash=item416951a8f6&vxp=mtr#ht_1651wt_1037
And while I do trust genuine bosch parts. I'd rather take it easy with expensive pumps. Especially on interference timing belt engines. That part always makes me nervous.
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If the plunger seizes it won't do anything to the timing belt. The plunger will snap before the engine jumps time. All that happens is the engine stops running. It doesn't cause damage outside the pump.
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I guess that makes sense because why would the plunger stop the rotating assembly of the pump? I dont know, I know timing belts are pretty tough and they are nice because they are quiet, but having everything timed with gears just lets me sleep good at night haha.
So to those people that have seized a pump what happens? The engine just loses capability to maintain rpms and eventually stalls out? Im picturing much more catastrophic things in my head :o
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I guess that makes sense because why would the plunger stop the rotating assembly of the pump? I dont know, I know timing belts are pretty tough and they are nice because they are quiet, but having everything timed with gears just lets me sleep good at night haha.
So to those people that have seized a pump what happens? The engine just loses capability to maintain rpms and eventually stalls out? Im picturing much more catastrophic things in my head :o
the engine just stops like you have turned of the key as it can not pump any fuel to the injectors , what power you looking for out of your build
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I'd like to get the max I can without worrying about the stock bottom end. I dont want to throw in the added cost of rosten rods or a girdle at this time. So what does that put me at 230hp maybe 250hp? I am definitely considering getting the pistons machined down so that I can safely throw a little more boost at it. I also plan to do water/methanol injection so I will have high peak cylinder pressures. Hopefully a lower cr will help with that as well. At some point depending on what people who have done it think, I will want a cam and possibly valve train upgrades.
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Lurkers are required to wait 48 hours before getting a response are they not? Once a contributing member then penalty time is reduce per post.
This is true.
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IMO u should do the rods to make 230-250hp on a tdi it puts a lot of stress on those parts because all the power is in the lower rpms
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Well maybe I just need to aim at a lower power level. I just cant justify all that money yet. Because if I do rods I might as well do a girdle and some other stuff too. And I just bought a prefabbed garage and am working on buying my first home. I have driven an alh that only had a good exhaust, small nozzles (slightly bigger than stock), and a mild tune and I was happy with the power. There is no reason my big pump, big sticks, exhaust, big turbo cant feel like a speed demon compared to that and by using a bigger turbo it will have a little more boost lag and cause a lot less stress on the bottom end. At least that is the plan.