Jim bailey - 928 International

for a six cylinder to have a 1,500 cc displacement.....a 3.25 bore with stroke of 1.87 is possible or 3 inch bore with a 2.2 stroke.... that is far from the 3.84 bore of a 5 literwith the stroke of 3.11 ....the photo shows bores nearly touching where the pistons on a 928 are about 25 mm away from each other !

Kevin Johnson

Yes, those and some other pics are the ones I am guesstimating with.

The stroke and bore of the TAG TTE-PO1 (at least one iteration of it) was: 47.3mm by 82mm.

The liners are missing but it still clear that the block is much more substantial than the pics of a bare Ferrari block that I have.

History of the engine tells us that Porsche did not have the funds to sponsor so TAG did so but Porsche relinquished some advertising. My guess is that Porsche thought they were in heaven and used some of the existing engineering they had done for the 928/944. It is simple enough to compress and meld elements of the design. Chevy did it with the 4.3.

Kevin Johnson

I loaded the drawing in and used boxes scaled to the studs (11-12mm). There is perspective error of course but the boxes can be stacked and then moved/tilted as a group. I measured the 928 block that I have here. The bore to bore elements (stud to stud) seemed close enough to suggest they were retained. The width of the deck definitely had changed.

Jim bailey - 928 International

So the bore was 3.23 x 1.86 pretty close to my 3.25 by 1.87 guesstimate but I did guess twice ! ....so yes the deck height should be much less given that the piston is moving one and 1/4 inches less on each cycle. you could shorten the rod considerably with out screwing up the rod angle. The constraints of chassis dimensions, weight and aerodynamics in F1 were such that an inch saved here or there were HUGE....they might have even ran smaller head studs just to save weight

Kevin Johnson

Herr Lerbs was kind enough to answer an email. I asked him about the relationship between the TAG engine and the 928/944, possible powdered rods etc. and he wrote that he would look into it but it would take a bit of time. I looked and Ti powder is used in sinter forging processes. It will be interesting to learn a bit more.


Some discussion of PM including specific mention of Ti rods:
http://www.epma.com/about_pm/web_pag...ural_parts.htm

Kevin Johnson

Herr Lerbs directed me to a site where parts from the F1 engine are being sold. There is a picture there of the powder forged connecting rod. It is obvious that the rod is derived from the general 928/944 rod design.

Persistence in research pays off.

Q.E.D.

Kevin Johnson

Oh, by the way, you can see that the F1 rod in the picture has a mismatched cap and beam.

My God, who could have possibly caught that from just looking at a picture.

Laugh.

Jim bailey - 928 International

Thanks for sharing that photo....looks like it has little to do with a 928 or 944 rod. Seeing any similarity is like saying most cars have 4 wheels therefore the Yugo is much like a Ferrari.... But wow those are some BIG NUTS....or is it just a very small rod that we are talking about

Kevin Johnson

Wow.


Author: Jonathan Swift
"There is none so blind as they that won’t see."
Polite Conversation. Dialogue iii.


Edit: But of course you would know better than the production manager of the company that made both rods, right?

ew928

Small rod probably hurs less when you're flailing around at 19,000 rpm.
Not sure about the large nuts tho.

Jim bailey - 928 International

Glad I could amuse you... But is seeing things which exist only in your mind a better condition ? Amuses me that you would waste your time researching a point which has absolutely no usefullness to anyone....even IF you were correct.

Kevin Johnson

Humour aside, in the 1980s subtract 7,000 to 9,000 rpm.

http://www.f1technical.net/articles/26

Jim bailey - 928 International

Right they were ONLY spinning 12,000 RPM ! makes sense they would use a rod design made for 6,000 RPM use ...

Kevin Johnson

Errr... If a person cannot see that cap does not match I would think he or she has absolutely no business working on these engines.


Well, that's exactly it. You don't get it.

If you're trying to do serious failure analysis then you carefully examine the evidence at hand. In the current cases, photos.

If someone is serious about building Porsche engines and they cannot fathom that a cap could be mismatched from the factory with a rod, despite serial numbers being used -- well, don't let them near a Formula 1 engine where the same thing can happen.

Yup.

You see, I don't consider it a waste of my time even though I don't own a 928. That is a difference between you and me. I take what I do very seriously and I am willing to take the time. And you called me a fool. Yeah, right.

Get a grip. Even the non-Titanium version in the 928 was designed to run 7200 rpms at a minimum. Yikes.

Jim bailey - 928 International

Good to see that you remembered the fool comment. But when someone makes foolish comments , and conclusions it is difficult to have any other opinion. It was quite funny when you felt the need to go back over all your posts and delete them thus depriving this forum all of your "expertise" . That was however one of your least foolish actions.... I think you might take yourself a bit too seriously. Now what was your original premise ....Oh right there was a factory tour going on and Hans distracted by the sight of a pretty lady dropped a numbered rod cap and when he picked it up fitted it to another rod with the same number a 1 in 998 odds happening at best assuming the rods are stacked in a bin with the caps not attached ....that was then assembled into an engine which ran fine for 20 years..... Then on a rebuild for a 300 hp "race" engine that same mismatched rod cap was re-installed with new bearings only to quickly fail ....in spite of the fact that it had one of your scrapers. Which lead to the statement that an F-1 engine was based on the 944 then became it used 944 rods, then sinter forged rods. Frankly anyone who sees a any real similarity between the 944 rod and the F-1 rod which is about 1/2 the size has gone beyond the absurd. And in the end what difference does it make how that F-1 rod was made? It has nothing to do with the fact that one engine with your scraper setup failed. Was it caused by the scraper ? nope....does the scraper fix the 2/6 oiling problem ? ....