Great engine for a touring car. Not so great engine for a race car at leat not until you address the oiling issues.

 

Interesting. I appreciate all the comments.

Conclusion thus far: "Great" engine due to the power (especially for that point in time) and reliability.

The interference aspect of the 32V engines is something I'm sure we all wish we didn't have to live with, but I'm not sure if it's avoidable.

I did't think variable valve timing was fully developed in that era?

EZK isn't "electronic"? What are its limitations? If you're talking about a distributor-less direct ignition design, yeah, I'd absolutely want that.

If I were considering engine management, I'd add sequential fuel injection to the feature list. I'm not sure how much fuel that would really save, but hey, why not?

I suppose that's getting a little off track. I think my original thinking was spawned from the "early dyno test" thread which really is about the engineering of the engine's mechanicals. It's almost unfair to critique the engine based on the evolution of the electronics that simply wasn't available at that time.

 

I am sure Porsche could have sorted the oiling issues that we are seeing more understood recently. They sponsored a race car, found it had an oiling problem, but by that time the management had changed and they could see that the 928 was never going to replace the 911 so they didn't put in resources to solve the problem (which I am quite sure they could).

 

Hi

I have run my 16V engine at well over 8000 revs a few times with no noticeable effect, and its still my daily driver.....

So is it a strong engine ...YES

As far as the oil/bearing problem is concerned its never happened to me, but mine is driven at top speed and extremely high revs in straight lines (mainly)

Personally I think its an astounding engine, when I started adding Nitrous I said to myself, its high mileage and sooner or later it will either blow up or wear out....and I was perfectly happy to expect to replace it, and when I did I would rebuild the replacement engine with various parts to suit its Nitrous use.....

Well its now around 5 years later and the damn thing is still going strong , no matter what I throw at it.... lol

In my past I have built a lot of high hp engines but NONE that have lasted like this one

So yes its a great engine....

All the best Brett

 

Interesting discussion ... can't recall the specific output norms of the mid/late 80s. Thinking about my car, 345 hp from 5.4L = 63.9 hp/liter ... how many non-turbo engines bettered that in the day?

I think the resonance induction gave an unusually flat torque curve. And on GTS, 369 ft-lbs from 5.4 liters (68.3 per liter) must have been pretty darn good for that era.

As others point out, the GT application called for a design that was smooth, quiet and tractable in daily driving while still delivering a lot of HP and torque on the way to a very high top speed. I think Porsche at times bragged about minimal maintenance and relatively low fuel consumption, though it's hard to know what they might have been comparing to ... we take all that for granted now ...

 

In it's day it was a fantastic engine. Now, not so much. It's 200 lbs too heavy and has oiling issues.

 

I don't disagree with anything said above, but I think the 928 is more than the sum of it's parts. It's not just a good engine (for it's day) but a great handling car with good looks, comfortable ride for long distance drives, great brakes etc etc. The entire package is what keeps all of us here, improving or correcting the faults not addressed by the factory.

 

Porsche.

If you have to ask maybe you need a Chevy.. I hear the LS9 engine is state of the art. U can get a crate LS-9 for about 22k from chevy (more than some cars..), oh
but you will be stuck with Push Rods, but u get a dry sump and 600+ HP.. I guess to be fair u can add a poweradder to our motor. N/A vs N/A I would take the 928 DOHC any other V8 except for a Hemi (Oh noes.. Pushrods!). (hey u can use caveman tech and still make big power).

Oh as far as engine weights.. A little googling and I found this list :

CrateEngineDepot lists the shipping weight of

an LS3 as 415 lbs

the 4.4 L Northstar DOHC engine at 467 lbs.

Ford Racing lists the weight of their 4.6 L modular engine long block as 475 lbs, not including the intake.

The supercharged 5.4 liter SVT mustang crate engine lists as 837 lbs.

The GM ZZ572/620 Deluxe engine lists at 580 lbs.

Whats the weight of our motor (complete?)

 

Let us not forget Al Holbert's 1986 record setting run at Bonneville 171-172mph.
He set two records for a stock production auto in the red 1987 928 S4.

 

It's the whole package. Where else can you get a reliable 500chp car that looks great, sounds great, has practical trunk space and can fit 2 adults and 2 kids (or adults 5'6" or less) for $15k?

Dan
'91 928GT S/C 475hp/460lb.ft

 

Search for the book Project 928 for insights into design criteria and development. IMHO this design was top drawer for the time, but it is the execution really stands out. Despite all the well known (and chronicled on this list) Achille's heels, how many big OHC V8's do you know that consume LESS oil with more miles? That has been my experience at >160K miles, and others on this list have made the same comments. Wish they knew as much about plastics as metallurgy back then, but that's another thread. That notwithstanding, as Dan, Jim, and others have said, its the package, really, that's so amazing. Love/hate, to be sure, but mostly love, or mine would not still be in my driveway.

 

No question; no question the entire package is awesome and I stand with everyone here as a devotee and owner (twice over!).

Really the discussion starter was to attempt to gain some insights from those more knowledgeable than I to technically qualify the value of the engine design, not really introduce any self-doubt about the car. i.e., just how good of a job did the Porsche engineers do? I think you can only answer that question in comparison to what the competitors were able to put out, or by looking at some data.

I have to thank dcrasta for the pointer to crateenginedepot as a readily available source of some basic stats - HP, torque, displacement, weight, max rpm. If I can click the links and take down the data for a spreadsheet, it would be an interesting graph to see where the engines line up. Looks like I have some homework!

I think this is a fact I can hang my hat on!

 

The 928 was a great engine for its TIME..... There are many aspects of it that were the pinnacle of design in the 70's when it was conceived... It had the most modern engine control systems of its time...that still aren't bad by modern standards... It also is a true big block bore spacing allow much larger bores than any other V8 engine from Europe with overhead cams (Mercedes did have near big blocks)....

It was designed as a grand touring engine....and it delivers this role nicely.....it can cruise comfortably at high speed with ease & can live a very long life on the street with minimal maintenance

However there are downsides to this engine....most flaws come up under harsh conditions, like racing....which not many 928's get exposed too..... The oil starvation problem due to wetsump is well documented....the extra issue at high RPM is just now being understood, but surely contributed to many engine failures in hard lived 928 engines....Another downside is weight....for an aluminum engine it is flat heavy....

By far the biggest downside to modified 928 engines is COST....parts and the skill required cost at least double compared to other high performance engines..... Perfect example...a chevy LS7 engine 505hp bone stock with dry sump is around $13k..... An equally reliable 500hp 928 engine would be at least double that amount and still 150lbs heavier.....