bigs

...Or was it engineered from a clean sheet of paper? If so, I'm even more impressed. It is such a great engine - seems to last eternally except for the very occasional TBF issue - I would find it amazing if they got it so right, right out of the box!

Rich9928p

The 928 V8 was a clean slate design, as was the rest of the car design.

It is't fair to say that Porsche didn't use any of their past learnings - it is fair to say that they didn't try to make it a flat aircooled 6 cylinder engine and they didn't pull a bunch of 911 parts off of the shelf to make the 928.

Read Projekt 928, you'll find out how things were done. It was a real ground-up project done with paper and pencil in those days.

There were many early bugs - the first 928s weren't the "best" of cars, but in those days it was a partnership between builder and buyer. Porsche was very pleased with the 928, they got a lot of world attention for a very small company. I know this is fact because Tony Lapine told me ;^)

Dennis Wilson

Bigs,

It had to be clean sheet. The open water jacket, crank journal configuration with the block (better than 4 bolt mains) and all aluminum were new for a V-8 engine. Buick had played with the all aluminum V-8 engine but had given it up (sold it to BL) when they discovered it had a tendacy to warp when overheated. That may be the reason Porsche over engineered the cooling system with a 17 quart capacity. As far as getting it right the first time, Porsche had 6 or 7 years to refine it before the first production vehicle hit the market.

Dennis

Herr-Kuhn

I agree it is amazing, since the whole design started sometime in the mid 70's. The biggest flaw in the 928 engine is the crankcase breather system, otherwise the motor is a nice piece of work. But I do hate doing a cam swap on the 16V units with the engine in the car.

jeff jackson

Herr Kuhn..you raise an interesting point, regarding the crankcase breather / evacuation system. Surely...the 928s oil lifting, and pulling oil into the intake system can and should be, retro engineered to solve this issue. Why is it not possible (by relieving internal pressure in the cam covers)...to enhance the production oil control system enough to prevent oil from being pulled into the intake ? Primitive solution would be to use independant breathers, mounted on both cam covers (shielded by a baffle on the underside)...and venting via differential pressure to the exhaust system downstream of the cats ? A bit off topic I know...and apologize.

Nicole

Apparently, Porsche Engineers had seen some new ideas when touring the facilities of potential customers for their engineering services. They incorporated some of these new ideas into their own design, but as far as I know they started the actual design from scratch, meanilng they did not design around any exisiting parts they had.

inactiveuser92616

that would give horrible HC emissions to vent to exhaust.

jeff jackson

True...but if it gets sucked back into the intake...and through the throttle body...guess where it ultimately ends up , my friend ??? BINGO...in the exhaust. if you dont' separate the oil from the gases...(hence my suggestion of a baffle under the breather inlet) ...in this case...no more oil vapor will end up in the tailpipe ..as the present system pulling oil through the intake does...I personally used a crankcase evacuation system like this on my 340 Demon...and it was not a "smoker" ...(out the exhaust anyway). YMMV.

bigs

I'm sure they took a few years for development, but still...

For a company that had a lifelong legacy of air-cooled, rear engine, flat sixes to, all in one fell swoop, build a front engine, water-cooled, aluminum block V8 with a transaxle... Well, that's pretty amazing. I don't know of any other automotive company that has ever attempted such a radical departure.

That'd be like asking the Rolling Stones to play Beethoven and get it right first time!

bigs

I also find the discussion of the oil breather system interesting. And... If the aluminum block is potentially subject to warping when overheated, is this an issue of concern in supercharged sharks?

PorKen

clic pic for larger

jeff jackson

Bigs...not sure if the heads and the block are of the same alloy, (but I kinda doubt it), so different expansion and contraction rates of different alloy metals often contribute to (#1)... a blown head gasket, as a result of overheating aluminum headed engines. (Or so I'm told)... So, a blown head gasket would be the primary result of a severely overheated engine, (epecially if it had been allowed to run more than a couple/few... minutes after "overheating" (i:e...the temperature guage is in the RED zone) , followed by (#2) cracked head or block due to steam pocket formations cutting through the soft and ductile aluminum alloy..

Porken...Not sure what exactly you are showing us...with those photos...Care to elaborate ???

Steve Cattaneo

The V8 Porsche engines have many similarities to the Mercedes V8 engines. If you open the hood on cars which used the Bosch CIS fuel systems, if you did not know, you couldn’t tell them apart.

Nicole

Haha - that might be the reason my car had been serviced by Mercedes mechanics while in posession of the previous owner (after all, they charged him a lot, so they must have been good).

Problem is, they had no clue about what to do... it cost me a lot of money to get things right again, but it had to be done to this poor baby.

bigs

So Steve, do you think the Porsche engineers used Mercedes engines as a "blueprint," so to speak, in the development of the 928 engine?