Author Topic: Establishing a base of information (swapable parts) (Read 3659 times)

GEMorris · « **on:** January 11, 2006, 10:49:29 pm »

Hi, first I would like to say hello and thank you for providing a board that is not simply a platform for vendors, but an area where people can learn about the true inner workings of their engines. Before buying my 03 TDI Golf I was a member over at turbobricks.com and they showed a DIY spirit and technical ability that was definitely lacking on other tdi message boards.

What I would like to do with this post is to consolidate some basic information about equipment swapability between different vw and audi engine models. The more we know we have to work with, the easier finding a solution is.

I'd like to start with manifolds. I have heard that all the diesel intake and exhaust maniflds bolt up to all the diesel heads (IDI and TDI). Is this true?

Do any of the gas intake and exhaust manifolds bolt up to the diesel heads? Any of the audi stuff? Can we take advantage of the aftermarket parts for the 2.0 and 1.8T?

Secondly I am interested in internal swapability. Will a 1.6 crank fit in a tdi? Is that a valid way to destroke a TDI or are we looking at a custom crankshaft not to mention rods etc. And what about rods? Any chance gasser rods will fit the TDI or IDI engines? There are volvo guys using chevy aftermarket forged pistons and rods because they discovered the measurements were almost exactly the same but the chevy rods and pistons were much cheaper due to aftermarket support.

I appreciate any knowledge and experience anyone can offer.

vwmike · « **Reply #1 on:** January 11, 2006, 11:43:09 pm »

Exhaust Manifolds - All of the 8v exhaust manifolds share the same bolt pattern, both gas and diesel. The ports are actually larger on the 2L crossflow gas engines though. I use the larger gaskets are a base for porting the counterflow heads.

Intake manifolds - They are not all created equal. The bolt pattern is the same on all but the 1.9L ports are larger and more square shaped. They are commonly referred to as the D-shaped ports. Crossflow intake manifolds are much different and will not swap. Audi 2L "bubble block" 3A engines have the injectors in the intake manifold so they will not fit on any other heads.

16v's and 20v's share no readily swappable manifold parts.

Cranks- The 1.6 crank will swap into any of the MK3 style blocks including the TDI engine. They changed the block design later and as a result the oil pump is chain driven. The crankshaft got slightly longer when they did this.

Rods - Gas rods are different for the most part. They are the same length in the 1.6's but I beleive only the 1.5 shared the gas wrist pin diameter. I think they should all be 136mm like the VW 1.5/1.6/G60 rods. The 1.8's with the exception of the G60 used 144mm rods, and the ABA used 159mm rods. All of them had much smaller wrist pins. I'm not sure what the length is of the AAZ/TDI rods, but word is they are interchangeable with the TDI rods lacking a counterweight on the bearing cap.

I'd love to find budget aftermarket rods but as of yet I haven't come up with anything. When you're dealing with these engines you have to be very careful. Tolerances are extremely important so close isn't really going to cut it.

I hope that helps you out

GEMorris · « **Reply #2 on:** January 12, 2006, 12:26:04 pm »

Thanks for the info vwmike.

If the gas rod pins are smaller than the diesel pins, then couldn't we simply have our cranks turned down to the gas pin size? By a competent machine shop that is. This is what the aforementioned volvo/chevy combo did.

Slave2School · « **Reply #3 on:** January 12, 2006, 10:05:29 pm »

This might be a really stupid question but...

What would be involved in getting the turbo on the 1.6td to bolt up and run nicely in place of the VNT-15 on the tdi? I am guessing the comptuer would freak out about the boost not matching requested etc, but maybe someone knows something more aobut that end of things than I...not too familiar with the wastegated turbos.

vwmike · « **Reply #4 on:** January 13, 2006, 03:03:52 am »

Thw wrist pins are bigger. That would be on the small end of the rod, up at the piston. I don't recall what the crank journal diameters are off hand though.

Replacing a VNT with the standard VW turbo is fairly easy as the manifold will bolt up, You would have to do some work on the oil lines though. I beleive it was Deo that did this and said it caused a lot of problems with the computer throwing CEL's. Some of the earlier TDI's didn't use VNT's - Perhaps it would be better get the harness and ecu out of one of those cars if you want to ditch the VNT.

Slave2School · « **Reply #5 on:** January 13, 2006, 11:21:34 am »

Thanks for the info, you learn something new everyday! For all the hassle it seems when I need a more robust solution I'll try to get a vnt-17 from someone.

malone · « **Reply #6 on:** January 13, 2006, 12:43:34 pm »

Quote from: "vwmike"

Replacing a VNT with the standard VW turbo is fairly easy as the manifold will bolt up,

caused a lot of problems with the computer throwing CEL's.

Perhaps it would be better get the harness and ecu out of one of those cars if you want to ditch the VNT.

That, or simply have the ECU flashed with software that accepts the wastegated turbo. I'm not trying to sell a product here, but my custom software (chip) is approximately $400 USD (could be less, it depends on the vehicle's modifications). Compare that to purchasing & swapping the entire wiring harness with no easy chance of running a VNT turbo again. Of course a chip is needed anyway to adjust the stock fuel maps, right? It's nicer to have an all-in-one solution within the original ECU.

There may be other chip tuners besides me in NA that is capable of doing such software work as well.

Slave2School · « **Reply #7 on:** January 13, 2006, 05:57:53 pm »

Don't worry, I'm not offended. I did ask for answers and that is what this place is all about...right?

I'll be keeping everything in mind if (when) my turbo grenades

I'll lokely go the cheapest route/bang for the buck vnt-17 route though when the time comes.

therabbittree · « **Reply #8 on:** January 18, 2006, 12:47:18 pm »

yeah my kkk 24 swap on to a tdi electronic was in a not vnt car... I rans great but teh problem was the ecu would need acustom chip to work corrdctly i tryed afew chips in tehre ..for a'98 jetta and non could control the boost with out going into limp mode..i have the waste gate connected to the n75 valve...it would be a great setup i plan on trying again if i can get some one to do a custom chip that works this way.. i'd like 30-35 psi max....
thanks
Deo