As for the forged/sintered/cast rod debate, well how long will it go on for ? !!! The 944 guys sure are confused with their extra 'Turbo rod'. Well I do not work for Porsche nor was I there to see the rods made, but I studied Engineering at college & have built more than a few racing Mopar's & Chevy's . Based on the few Porsche Tech. manuals I have & my limited experience with 928 rebuilds (928 Euro S, 2x '87, '88SE, '89) & pics on this forum, I would say that ALL 928 & 944 rods are FORGED. Would Porsche use cast rods in any models ? I don't think so.
Forged v sintered rods. Sintered rods ARE FORGED. I think sintered rods are the rods some refer to as 'cast'. To the best of my knowledge 'forged sintered steel' rods are stronger than plain 'forged steel rods' & are used in current production Hi-Po cars from MB,Chevy & Ford.

As for the pic below, Forged Turbo 944 rod (bottom) v re-con 'turbo' rod, to me they look like the same rods except that the top one has been 'race prepped' (all sharp edges removed/smoothed & then shot-peened). Perhaps the factory did this for 1 or 2 years then dropped it to save money.


The Nos. on the rods are PRODUCTION Nos. NOT part Nos. Most of the time production Nos. match P/Ns. But some time the same part has extra machining & so acquires a different P/N. So do not treat them as a 100% match.

From what I have seen there are only 2 928 rods, the '78-'87 Forged sintered steel rod & the '88-'95 forged steel rod ( I have not seen a GTS rod but I am lead to believe they are the same as 88-91) .The 944 'turbo forged' rod seems to be the same as the 928 '78-'87 rod.

928 Int. & Devek, you must have seen rods from all MY 928's how about it ,only 2 ? (apart from weights)

Sorry for rambling on a bit, but there are still myths banded about by 'knowledgeable enthusiast's about 60-70's Hi-Po V8's which are completely untrue, so if I can help pin the 'forged rod' one down I will.

Of course if anybody REALLY knows , please comment.

 

the cover plate on the front of the sump was for the oil return hose from the oil seperator on the 16 valve engines .

 

Hi Martin, I'm a little confused about your post. The rods in that pic are both what the 944 folks are calling (rare) "forged" rods. The top one is from an '83 944 and the bottom one is from an '86 951 which are what the 944 people know as the only “forged” rods used in the 944. Perhaps you are splitting hairs over the definition of forged or perhaps we are all incorrect in calling these rods forged when they all may well be forged but their track record (no pun intended) has shown that these rods seem to be more resilient than other Porsche rods for the same motors making them desirable over the other factory rod choices. Did I miss something? Thanks, Joel

 

Forged rods have a forging line on the side.........take a pic of the rod side and I will tell you if it is forged or not.

As far as I know, no 5.0 or less 928 came with forged rods...

The oil squirters were discontinued due to causing more problems with hot oil pressure and oil windage.

Marc

 

Here are the rods/pistons out of my 87 944S. Sorry about the size.

Can you guess the rod that threw its bearing around?

http://www.erik27.com/pistons/

 

Thanks for posting the link Erik, your '87 944S had a different set of rods from the 1986 951, (sorry about your rod bearing, I lost a 944 motor the same way.) The rod in the pic that Adam posted that started this thread has the same casting number and looks just like the rods in the 1986 951 which are known (by 944 people) to be forged. I have searched the 944/951 list for a post of a side view of the rod for Marc to look at but I could not find one. I had a set setting around my garage for months but they went with my car when it sold.

 

I have found that sintered rods are not the same as forged rods. THey are suppost to be of comperable strength to cast rods.

Sintered forged rods on the other hand are suppost to be the P/M replacement for forged rods.

As far as I can read, sintered forged rods are suppost to be less dence than regular forgeings, but about as strong pound for pound.

Did I get that right?

 

According to the evidence presented, it appears that the 944.103.110.ORARST rods are indeed forged. So that means Adam has one, and there are 3 more S4's (..2 are '87's, 1 is an '88) here in Wisconsin with rods with the same number, which makes a confirmed 4.

It would be reasonable to assume that there are quite a bit more with the identical rod number; perhaps all the '87's do, and who knows how many of the '88's have them.

As Adam implies, apparently the 928 S4 engine is one robust engine straight from the factory; ...can I get a witness from the congregation?!?

The windage issue especially makes sense.

 

Here's a pic of the real deal crank sprayer, pretty cool!:

 

Interesting. So is this all in the cradle?

 

So Adam if you go and replace your main bearings with new ones you will loose this feature right ???

Chris

 

heinrich wrote:

Appears to be from the pic that Martin posted. I plan on extracting the crank soon and getting a thorough look at the oil feed off the crank.


Chris wrote:

Good observation Chris, I would think that you are right unless 1) stock replacements are still available for this particular feature or 2) I'd have to drill what is available.

My bigger concern is if the sprayer creates an inherent weakness at the base of the cylinder that may cause a potential issue when overboring?

Guess I'll just have to pop in the 951 pistons, slap on a supercharger, and save the stroker crank for the engine that's in my car now.

 

Both rods in Martins photo are sintered forged rods.....or "molded" forged rods, rather than pounded!

Due to the forging process, forged rods have a different "parting line" for reasons that I will not into here. Folks knowledgable about forging would tell you that those rods are not forged.

The forged rods from the 951 are very unique, and have no part or casting number on the rod beam, except for a cavity number. They have a "85" on the rod shank.

BTW, I have one in my hand right now.


Marc
DEVEK

 

Wrong.

The forged rods from a 951, which are the 110 part number, are forged, and they have a beam part number.

The Forged rods from the 83 944 also are forged with a part number on the beam, which is the 103 part number.

See here: http://boards.rennlist.com/upload/rods.jpg

and here: http://boards.rennlist.com/upload/83rod.jpg

 

Here is the issue:

Lets say you find, finally, a good set of forged 944 rods. YOu then need to have them all balanced and re-shot peened, and before that you will want some crack testing of some sort, as they are used. Then you spend another 500 dollars on some ARP bolts to keep the big end cap on. Also, you want to rebush the small end.

1000 dollars? Maybe more?

I touched on this in another thread entitled the Rod Discussion, but some aftermarket olivers are 2000, and they come with the required bolts, and they are new. Maybe lighter, maybe heavier. I really don't know. Yes, you still must balance the rotating assembly.

Its up in the air with that small of a difference with all the other money spent on an engine buildup