Autodelta V6 information

[ToonRboy]

Small tangent,

I brought up the issue for those with the mechanical de-tensioner because it has a clutch-like mechanism (with itty-bitty axial spring). If the hydraulic de-tensioner is installed properly, I don't think there should be a problem. Going cclockwise for 1-rev. 'Course, after establishing TDC & degreeing-in the cams, I would then go round clockwise 3-4x to make sure belt is seated proper-like...

I didn't recognize that tensioner right off because, from my memory, when Zat was in business, his website depicted a different looking unit

(didn't have the plunger assy on there still, just a bracket, adjusting bolt, and roller). 115 INVENTORY. (no more performance parts page tho)

I ordered a rebuild kit from Alfissimo for my hydraulic de-tensioner (cost half as much as a mechanical POS). - also, I'll have to get a bolt machined down to create my own stop tool. It is imperative to use this tool as the de-tensioner stop. No doubt the reason for many a skipped belt.

I may also install a "splash shield" (in case it starts weeping again), just to keep any oil off the belt.

[Gabor K.]

Alfaparticle: The rule of direction of rotation of engine is independent of what kind of tensioner used and if you are using a fixed type really does not matter. I realize that you dont care about factory standards because you are operating with unoriginal parts.

Alfar 7: You are right I dont know much about Mr. Zat, but his products are not around any more? Never mind. A fixed tensioner does not compensate for belt slack like the original, so its not an ideal change. About good workmanship:with your attitude about quality standards and lacking knowledge, I really would avoid having any business with you! Well, no fear we manage very well here!

[ToonRboy]

For fear of re-hashing some very, very old BMW to Alfa L-Jet AFM swap stink, I refrained from pointing this out. Butt, here goes anyway.

Greg, you mention the BMW 535 AFM/Injectors/ECU on your web page but fail to provide the part numbers. The part numbers had been posted many moons ago on the digest (can't seem to locate 'em), but you pointed out in an earlier thread (last year?) that these were incorrect. Obviously, Bosch had moved on to Motronic in the late '70's with BMW, but Alfa was still on L-Jet until the late '80's.

Having seen many L-Jet AFM's, and, in fact Motronic AFM's - they look to be physically the same darn thing - save for size and innards. To get a larger AFM, couldn't one get an AFM from say a '70's 280Z or 928 and swap the guts from the Alfa? Naturally one would have to adjust the spring tension and swap to larger injectors (either Bosch 0280150151 or 152). Try these guys:
Bosch Injectors - Alfa Romeo, BMW, And others . These injectors run at the same psi and are low-z. Still, you'd be stuck with fixed parameters on the ECU.

Personally, I think the AFM chase is a waste of time without cams.

Question: Has anyone set their intake valve lash to .016 instead of .019 on their GTV6?
Potentially, you could pick up .003" lift and a teeny bit of duration.
Look at the previous post with Camshaft Timing Specs. The stock 2.5 and 3.0 with "S" cams are spec'd at .019 and the Verde 3.0 cams at .016 lash.

[karmat]

Quote:

Originally Posted by ToonRboy Having seen many L-Jet AFM's, and, in fact Motronic AFM's - they look to be physically the same darn thing - save for size and innards. To get a larger AFM, couldn't one get an AFM from say a '70's 280Z or 928 and swap the guts from the Alfa? Naturally one would have to adjust the spring tension and swap to larger injectors (either Bosch 0280150151 or 152). Try these guys Bosch Injectors - Alpha Romeo, Fiat & Jaguar Fuel Injectors. These injectors run at the same psi and are low-z. Still, you'd be stuck with fixed parameters on the ECU.

[karmat]

Oh, BTW, I have scans of two pages from the original Autodelta publication that I had stored away from who knows where in the past. Here they are if you want to read them. Bosch parts are quoted, but as Greg says, I don't know if they're correct:

http://www.matthias.org/gtv6/

[ToonRboy]

Karmat, thanx for the reply. Esp. for providing the data I was talking about. As you can see, the scan you provided states the following key components be used
Bosch 0280 150 152 injectors .
Bosch 0280 203 002 AFM
Bosch 0280 001 114 ECU
Cross referencing these parts will show that they are for the BMW Euro 528/535i. The other two major components (for the 2.5) are the Autodelta cams and 10.5:1 compression pistons (this is where the big $$ are, not to leave out any porting that might be done). Not rocket science. Just good 'ol fashioned basics.

As far as Greg and the highperformancestore, I commend him for revamping his site. Much more intuitive and now sports HP gain, dyno sheet, and costs (esp. with regard to the supercharger kit). Note: He no longer carries low-z injectors for the L-Jet.

[Alfar7]

GABORK:
I wouldn`t think you have a clue to my attention to detail and quality standards.
You haven`t made a comment but to quote manual information. Nothing based on tried and proven results.
Personally I hope your "de-tensioner teaches you a lesson!

Tooner:

Quote:

But obviously the Webcam article was written with the American V8 in mind.

[ToonRboy]

Gee Richard (or is it "Dick"),

I guess you must'ave woken-up from your nap eh? I have to say that you're about as useful as tits on a nun! If you spent as much energy criticising your web page instead of cherry picking mis-spokes by others, you might bring that thing into the '90's.

Why don't you go to your shop and sweep-up or something. God forbid you might put in some work on that GT-R.

so long,

[Gabor K.]

Don´t you worry Richard, I always hear problems with the home made systems. The factory racers went to 7900rpm with the original tensioner. The clue is of course changing the belt before its gets too much slack, otherwise you get problems regardless of tensioner type.

[Alfar7]

Quote:

Don´t you worry Richard, I always hear problems with the home made systems. The factory racers went to 7900rpm with the original tensioner.

[Alfar7]

GaborK: This involves "home made " modifications. Please do not read .

ToonR:

Quote:

Thus the question on milling the heads (to up the compression) and of course, this discussion on cam comparison (JUST the RJR28-744 vs Verde - which, if that's it on the lower exhibit, fairs quite well). My aim is to get another 20-30ft lbs of torque out of the 2.5L engine. My last question (due to the later closing of the intake valve on the Verde cam) is whether I can run the 3L cams in the 2.5 without swapping the spark box. - "holding my breath"

[Greg Gordon]

Ok, I was off line for a couple days for training at my real job.

Regarding the fixed tensioners (Zat or homemade units), these things flat out work. The belt will not skip regardless of which direction you rotate the engine. As probably the only person on this site that has intentionally run a fixed tensioner and left a timing belt on until it failed (remember we have non interference pistons here) I can say it doesn't seem to have any adverse effects on belt life. The belt lasted about 60,000 miles.

Greg Gordon,
hiperformancestore

[Greg Gordon]

Toonrboy:

I didn't post the Bosch part numbers for the ECU or injectors for a few reasons. First of all, they are not listed in the Autodelta 200hp 2.5 publication. They are listed in another publication regarding making a 3.0 out of a 2.5. Obviously that publication is now totally outdated because you can buy a factory built 3.0 for a lot less money. I was posting the publication as it was written.

Second, it's not really useful information. That L-Jet 535 ECU is essentially impossible to find. It's also not going to do any good on a stockish engine. If someone is going to go through the trouble to bump up the compression add cams and so on there are quite a few easier and better options.

The BMW AFM information I have written many times on forums. I should probably add a good L-Jet modification section to my website. In my book I do have detailed description on how to modify L-Jet for up to 230rwhp. I also have detailed instruction on my to make my "black box" which is pretty easy. It takes me a few hours, which is where the cost is, but anyone that can solder can make it easily.

Richard, is it cam design or high RPM that kills the early rockers? In other words, on a forced induction engine with stock cams will they be OK at 7500rpm?

Greg Gordon,
hiperformancestore

[Jim K.]

There are still some race gtv6 engines in Europe left over from the good old days. These have of course been rebuilt a few times but they still (of course) have to comply with the specs in the FIA homologation documents as long as they race officially. Some use the 6 carb setup (the original form of this engine requiring the corresponding heads with integrally cast intake manifolds) and some are L-Jetronic. They routinely rev to 7800 or more. Their weak point at these revs were the std rods, with cracks originating from the little oil squirt drilling. They were not allowed special rods so they resorted to getting the rods before the little hole was drilled, a solution greatly increasing engine longevity. Recently, they had the same problems until the gta rods finally appeared (no holes). As for tensioners, most were (and still are) using the std factory item in 'dry' form, with the oil supply plugged up. They also use std exhaust rockers, std diameter valves and 9mm stems (historics rules).
The forged pistons were made by Mahle and the spaghetti-type 3-into-1 exhaust manifolds (only in GpA) were a work of art, coming up over the heads and then curving downwards, in order to gain length (~650mm primaries) before exiting under the doors.
Regarding the mentioned BMW ECU and AFM, they won't give any more power in a std engine. They allow more air in a modified engine and its there you will gain. However, this is only a poor solution nowadays. If you want serious tunable power from your 2.5 or 3liter, your best bet is to look for the ECU, AFM and wiring harness from the 164 3liter Quadrifoglio (200hp, 1990) or at least the 75 Potenziato version (1990). These parts can be simply chipped for a std engine or dyno mapped for serious applications, allowing more than 240hp depending on what other engine mods have been made.
Early racers mostly used valve springs from the Fiat 128 SOHC engine (a very convenient problem-solver for many European tuners and competitors of the time) which allowed a billion revs but ate cam lobes quickly, but the tradeoff was acceptable at factory racing level.Today, excellent springs are available from Paul Spruell, Arricambi and others. With proper spring tension, modern oils and correct valve clearance, cam wear should be a thing of the past.
Regarding the 'Motronic' cams used in the Potenziato 75's, 164Q and SZ/RZ (p/n 60548163 and 60548164)they have intake lobe lift of 10.4mm and exhaust lobe lift of 6.5mm. If you look through most official AR literature (spec sheets, manuals) you will only read 10.1mm. Only in one manual (164 technical characteristics-second edition) you will see the true intake lift. I have two pairs of such cams here, almost new and they of course check out at 10.4mm. Gtv6 and first generation 3liter cams had 9.1mm intake lift. Its one of those AR DIASS clerical screwups (if you've ever been where those manuals originated, you'll have an idea how these thing happen).
Jim K.