Engine Upgrade

[cornishgrose]

Just wondering,what are the dimensions of a 944 2.5 engine and a 928 engine? Will the 928 engine fit into the 944 engine bay and engine mounts? Has anyone out there tried this and did it work? (for long!). Lastly, for a real discussion, would it go any better than a 944 turbo or S??

 

[sawood12]

Just been playing with the search function to try to find a thread from a couple of months ago where this came up in discussion but couldn't find it. The general thinking was that the 928 V8 is a pretty heavy lump and would probably upset the weight distribution of a 944 too much. I can't remember if it was never discussed whether or not it would actually fit. It was suggested that a V8 conversion utilising a smaller american V8 would be much more sutable as the weight of the enigne was roughly the same as the 4-pot 944 engine. In fact I think there is someone on this forum that has actually carried out the conversion.

 

[Fen]

The 944 engine is half a 928 engine. Based on that, how full the bay is with just half the engine and that it had to be fitted at an angle to allow the desired bonnet line I don't think a 928 engine would fit.

 

[944Turbo]

Isn't it at an angle cos its half a V8? (and to keep a low bonnet line)

If you look at a 928 engine the 2 banks are close to the same angle as our engine.

However there must be a difference because having seen them parked nose to nose I think it would be very tight between the suspension towers.

Tony

 

[Fen]

I don't think there is enough width to add another bank like we have already. Mind you the centreline of the crank much be in the centre of the bay so if the angle of the V is such that the banks sit as our 4 cylinders to then it should fit. That's quite a big V though and I expect the banks in a 928 are more upright so it would foul the bonnet.

 

[John Sims]

ORIGINAL: cornishgrose

........Will the 928 engine fit into the 944 engine bay and engine mounts? ......

Not wishing to be cruel, but I fail to see why anybody would want to. The 944 works very well with it's own engine, as does the 928. If you want a 928 engine, get a 928.

 

[Fen]

Can't argue with that. To answer Alexander's other question if it can be done it would go better than a Turbo or S (I assume you mean Turbo S as the 944S isn't really in the running in terms of "go") but it would be heavier in the nose. It would be less work to take a Turbo and make it up to the same power though (circa 300-350bhp IIRC) plus it would be easier to insure (I imagine) and would handle more like a standard 944 (so better I'm guessing).

 

[Diver944]

If you had a N/A 2.5 with a dead engine, it would be much easier to drop in one of the 5.7 litre Chevy short blocks, than to convert it to 944 Turbo spec.

Renegade Hybrids in the US already have a kit to do just that, and 350BHP with lots of low down grunt would be much easier to obtain. The weight of the engines are similar and lets face it, the exhaust note would be to die for.

I don't think it would exactly be economical at the petrol pump []

 

[John Sims]

I know I'm being all romantic and soft but it doesn't seem right. You wouldn't put a Buick engine in a Ferrari so why put a Chevy in a Porsche - you are, in effect, saying that the original engine isn't good enough.

I appreciate that by modifying an engine one is suggesting the same but, to my mind, one is only doing what Porsche might have done had the car continued in production, (eg Bigger Turbo, modern induction etc.). Modifying the original is still in the spirt of the car.

 

[cornishgrose]

Cheers for the replies. The point of putting a bigger and larger engine would be to improve an already classic car and also to be a bit different. Putting a nice big chevy engine in sounds nice, but would prefer to stick to Porsche. However, Mr sims, a lot of different manufacturers have mixed parts on/in one car (VW/ Porsche being one that springs to mind!?) and may I add, aids our search for affordable, suitable parts.
If the 2.5 is half the 928 block at an angle, the other half should fit aound where the air filter is situated, roughly. If the engine is too high, the bonnet could be raised slightly to give a V8 type bulge.
Inspire me. Cheers

 

[Fen]

Remember that between even a few of us on here we have 20+ years of 944 experience. I haven't heard of this being done, ever, despite it coming up on a different forum just last week and despite having see 944 diesels and a 944 with an electric motor. None of the others have either by the sound of it and that suggests to me it can't be done. Join Rennlist if you haven't already and search on there. If nobody on Rennlist knows for sure or nobody knows of it being done then I think it's fair to say it can't be.

 

[944Turbo]

oooh I think I have seen two electric 944's one with a motor where the engine was and one with 2 in the rear - excellent future proofing
Haven't seen a 928 engined one either but cost and complexity of the 928 lumps might be an issue
Tony

 

[sawood12]

Am I alone in my views here?.... V8's are romantic and tempting but in my view it's all a bit too easy. Surely the challenge, at least from a pure engineering challenge, is to mod the good old 4-pot. 350 bhp is 350 bhp in whatever form it takes but it's far more challenging to drive and get the best out of a 4-pot 350bhp motor. Where's the fun in just putting your foot down and letting the engine do all the work. Maybe i'm missing the point!

If your going to shoe-horn in a 928 V8 you might as well shoe-horn in the auto gearbox and if you're going to go to all that trouble you might as well get a 928.

 

[Fen]

OK, I did the legwork. Here is a thread: http://forums.rennlist.com/rennforums/showthread.php?t=218053&referrerid=13813 Answer is it doesn't fit* The 928 engine is a 90 degree V so each bank has to sit at 45 degrees centred on the crank. I forget the angle the 944 engine is slanted at but it's less than 45 degrees I believe. *It has been done once before using a spaceframed race 944 with the body cut off in front of the bulkhead and a complete fabrication to hold the 928 engine. Click on the hotlink "Race" here: http://www.kellymoss.com/

 

[John Sims]

ORIGINAL: Fen

.......... Click on the hotlink "Race" here: http://www.kellymoss.com/

Damn, another purveyor of 944 tunning goodies. Will my credit card ever be safe? [&:]

 

[mik_ok]

Forum member "Blease" is persuing the Rengade V8 conversion ~

I just got back from Las Vegas where I visited the Renegade Hybrid workshops to check out the conversion in the flesh. I'm writing it up for Porsche Post or a non PCGB publication if PP feel its not suitable. They look good and sound unbelievable.

The above was posted back in January05, so I hope he's quietly progressing with it (?) []

I think it sounds rather interesting to be honest. Despite the 944 making one of the nicest 4-pot blares I've heard, it's simply not tuneful like a 6 or an 8 can be (or even a warbly 5), and is definately one of the 944 "negatives".

Following this route, you lose originality, but gain modded-turbo power levels, glorious engine note and (in theory) far better throttle response than you'd ever get from a big turbo car. No weight penalty, and you'd have something "unique" too. And as I "said" to Blease ~ it would save me making V8 noises as I drive along.

No idea what this would do the the resale value / insurablilty, but it's probably not dissimilar to a highly modded turbo in that respect*

* Based entirely on my speculation with zero factual evidence to support []

 

[cornishgrose]

Ok, OK. So it is posible, but for a lot more hassle than it is worth. Cheers for the links Fen, that kelly moss front looks really rough and still shark-like. So if I go back to the 944 engine, what can be done to get 350bhp out of it? Surely that must include air induction kit, twin turbos and a ported, polished, rebored and revalved engine. Also with the drive train being uprated to give a better gear ratio? Is the twin turbo idea possible? and surely it would have to have staged turbos, a small and a large one. Also has anyone discovered that damn elusive money plant yet, i am getting tired of looking?!

 

[sawood12]

I'm sure Fen and Rick Cannell will be more than happy to indulge you in that question but just to give you an idea of what's achievable with an essentially standard engine and sub £1k there were a number of people with the Promax level 2 kit that got over 300bhp at the Weltmiester rolling road event a few months ago. Of course due to the law of diminishing returns that extra 50bhp will cost a whole lot more both in terms of money and effort. But not as much effort as squeezing in a 928 engine!

 

[944Turbo]

250 Turbo + guru or promax chips + 3 bar FPR + Tial wastegate + Electronic boost controller + Siemens 55lb injectors = 320ish welmeister BHP and over 350ftlbs of torque

Add wideband and boost guage for monitoring to make sure its safe.

Add bigger ball raced turbo and MAP or MAF for the full 350bhp

Relax

The temptation for me with the US V8 is tuning parts are very cheap.

Tony

 

[eastendr]

I think you should meet 'Ben Sideways Bert' on the Titanic 944 forum

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