944 turbo 220 or 250

[colin944]

Can anyone tell me what the differences are between a 220 and a 250 turbo engine? is it just the turbo or is it alot more complicated. Can you get big power from a 220 as easily as you can from a 250. Also what is the easiest way to work out which is which. I always thought cars after 89 were 250 and before were 220 apart from silver rose. Is that right? I am sorry if this is easy stuff but I am a S2 guy and am only looking as I want to build a carrera gt rep for my next project and was offered a turbo 87 e reg so a 220 I think for not alot of money but the body is rotten even by my standards. So I thought transplant running gear into 924 shell and do a gt rep.Spannering and fabrication are not a prob,but I just don't want to buy a car that might not be as good a donner as I had hoped.

 

[944 man]

Itll be more than adequate! Itll all fit, even the intercooler: if you have a dremel... A 220 is superior although the 250 will have a better transmission and brakes.

Ive been trying to buy just such a car myself, to transplant into my 924S.

Simon

 

[Fat Albert]

I have an '89 220 with a Promax Boost enhancer that basically takes it up to the level of a 250, I have no complaints!

 

[Lowtimer]

Your 87 / E car is a 220.

How much power do you want? The smaller turbocharger housing on the 220 is a constraining factor for top-end power but gives less lag. An inexpensively tweaked 220 can give 250 reliable horsepower and is in no way slow. A 1986 220 Turbo has a forged crank and rods, making it the bottom end of choice if you want to go to really enormous power levels whilst retaining a 2.5 litre capacity (400 bhp+) but even the standard internals used on the later Turbos are hugely, massively strong.

In addition to the brake and suspension differences mentioned above, the 250 has hardened first and second gears, a transmission cooler which most 220s don;t have., and a standard limited slip diff.

I think you will find a mechanically fit 220 is an excellent donor for a 924 transplant.

 

[pauly]

ORIGINAL: Lowtimer
A 1986 220 Turbo has a forged crank and rods,

Thought it was only the forged rods some 250 bhp cars lost.

 

[pauly]

ORIGINAL: Fat Albert

I have an '89 220 with a Promax Boost enhancer that basically takes it up to the level of a 250, I have no complaints!

Are you sure ?.

 

[Lowtimer]

ORIGINAL: pauly

ORIGINAL: Lowtimer
A 1986 220 Turbo has a forged crank and rods,

Thought it was only the forged rods some 250 bhp cars lost.

Just did a bit more digging and based on some comments from Jon Mitchell over on Pistonheads you're right: they all have the forged crank, it's just the rods that changed.

 

[pauly]

ORIGINAL: Lowtimer

ORIGINAL: pauly

ORIGINAL: Lowtimer
A 1986 220 Turbo has a forged crank and rods,

Thought it was only the forged rods some 250 bhp cars lost.

Just did a bit more digging and based on some comments from Jon Mitchell over on Pistonheads you're right: they all have the forged crank, it's just the rods that changed.

No problem, reading posts from people that know what they're talking about on RL the switch from forged to cast rods wasn't related to bhp either.

 

[Lowtimer]

From what I've read they just eventually realised the forged rods were massive overkill. In fact the whole engine project throughout its life seems to have been the product of extreme caution and conservatism. Michal Cotton reckoned that the whole 250 hp project was beset by engineers sucking their teeth and saying "it wouldn't be prudent for us to guarantee that level of power in a production engine", and it took boardroom-level backside-kicking to push the 250 hp road car through. Yet as we, and they, have seen seen ever since then, the bottom end is REALLY hard to blow up through sheer power, and providing you avoid lubrication failures from oil surge under race conditions, pretty much bullet-proof.

And of course there was all the internal politicking about whether a front-engined four cylinder car should be allowed to outshine a rear-engined six-cylinder one.

 

[simkin911]

Take your turbo and this...

http://www.gumtree.com/p/cars-vans-motorbikes/porsche-carrera-gt-conversion-fsh-25-engine/82487534

Job done! []

Colin, 5 mins away from me if you were serious and wanted me to look at it.

 

[sawood12]

All cranks are forged. There is no feasible alternative way to make a crank. The move to cast con rods was undoubtedly for cost reduction - there is no other reason for moving from cast to forged methods. However there has been occasions where tuned cars with cast rods have broken rods and put holes in blocks. For a tuned engine a forged rod engine is preferable, but there are plenty of tuned 250 engines out there running perfectly reliably, so maybe it isn't too important and you should target the best engine you can within your budget.

I'd love to do the 924 based CGT replica Thing. Promax were working on one. Anyone know where it's at? I last saw it about 4 or 5 yes ago when my car was receiving the KWv3's, where it was a bare shell with the genuine square-flared rear arches had been fitted and the shell sprayed in white.

ORIGINAL: pauly

ORIGINAL: Lowtimer

ORIGINAL: pauly

ORIGINAL: Lowtimer
A 1986 220 Turbo has a forged crank and rods,

Thought it was only the forged rods some 250 bhp cars lost.

Just did a bit more digging and based on some comments from Jon Mitchell over on Pistonheads you're right: they all have the forged crank, it's just the rods that changed.

No problem, reading posts from people that know what they're talking about on RL the switch from forged to cast rods wasn't related to bhp either.

 

[Frenchy]

Appaerently they went to cast for cost savings, deeming the cast items well up to the job ?
A 220 can be modded to give and easy 275 bhp and a lot more depending on wallet !

 

[colin944]

It looks good,and yes it would be an easy job. But I am looking for my next project and will start on it after my S2 is done which should be fairly soon. I want to start over the winter and would idealy like a 1980 924 perf without a sunroof.I don't know why but it would just look better on a 80 car. I am still looking for my old 924 which I belive is still local and sitting sleeping in a garage. It was a 1980 car with no sunroof and with a bigger rear rubber spoiler. It would be perfect for conversion.I am not looking for an easy conversion but in saying that I don't want as much body work to do as I did to the S2.I would hope to get the thing on the road for not alot of cash probs 2-3 k. £500 for 924,£1500 for doner 944 and £1k for wheels, bucket seats,cage a couple of litres of paint and a wee bit for consumables.I can't justify spending more than that at the moment due to various constraints no 1 being the wife who thinks (why when youve nearly finnished the one you have).So I will have to be clever get a few bits from e-bay etc. I just want to build a raw fast car for my own enjoyment and maybe the odd track day.

 

[pauly]

ORIGINAL: sawood12

All cranks are forged. There is no feasible alternative way to make a crank.

OK, are 944 cranks steel or iron ?. A quick google suggests cranks can be machined from a billet also.

 

[Catamax944]

It looks good,and yes it would be an easy job. But I am looking for my next project and will start on it after my S2 is done which should be fairly soon. I want to start over the winter and would idealy like a 1980 924 perf without a sunroof.I don't know why but it would just look better on a 80 car. I am still looking for my old 924 which I belive is still local and sitting sleeping in a garage. It was a 1980 car with no sunroof and with a bigger rear rubber spoiler. It would be perfect for conversion.I am not looking for an easy conversion but in saying that I don't want as much body work to do as I did to the S2.I would hope to get the thing on the road for not alot of cash probs 2-3 k. £500 for 924,£1500 for doner 944 and £1k for wheels, bucket seats,cage a couple of litres of paint and a wee bit for consumables.I can't justify spending more than that at the moment due to various constraints no 1 being the wife who thinks (why when youve nearly finnished the one you have).So I will have to be clever get a few bits from e-bay etc. I just want to build a raw fast car for my own enjoyment and maybe the odd track day.

WARNING! You need a 924S for this coversion , 951 drivetrain will not bolt on to regular 2.0 924 chassis .

 

[944 man]

'Forged' cranks are machined from a forged billet. Cheaper cranks are machined up from a casting.


Simon

 

[colin944]

WARNING! You need a 924S for this coversion , 951 drivetrain will not bolt on to regular 2.0 924 chassis

Why? Is there really that much of a difference. I was going to cut out the battery try on the 24 and weld in 44's panel and fuse box. Then use battery mount fron 44 in the back of the 24.Also instal plastic tank from 44 and whole rear end onc torsion bar housing.torque tube. gearbox engine etc. Is the 24's shell really different in regards to mounting points or can I use the bits of the 44 shell and weld onto 24 shell.

 

[944 man]

Theres little you cant do with the time, skill, equipment and money..... Id suggest starting with a 924S too. The 924S is far closer to being a 944 series one, than it is a 924.

Id also leave the battery in the cabin, as opposed toin the 944 series twos position. This wasnt ideal, it was the only place they could fit it on a right hand drive car. The battery positive cable weighs a lot and the voltage drop is the reason that series two cars struggle to tun over. The ideal position is either on the floor where the rear seat passengers feet go, or on the passenger side floor butted up against the crossmember, if you arent installing a second seat (both positions in a battery box).


Simon

 

[sawood12]

For a production car machining from solid is not cost effective. You can cast and machine, but not for powerfull performance cars I'd have thought - cast metal has very poor tensile and torsional properties, which is just what you need for a crankshaft. Cast metal is better for compressive stresses, which is why you can get away with casting con rods as the stresses are primarily compressive. The beauty of forging is that the granular structure is very dense and flows in a preferable direction along the length of the component enhancing the strength in the direction you want it, ultimately leading to a lighter component. The tooling costs are high, but this can be ammortised over a long production run, and the production process times are much shorter once you've got the tooling.

ORIGINAL: pauly

ORIGINAL: sawood12

All cranks are forged. There is no feasible alternative way to make a crank.

OK, are 944 cranks steel or iron ?. A quick google suggests cranks can be machined from a billet also.

 

[barks944]

The crank on all the 944's is immense, having recently stripped a turbo, a 2.5 and a 2.7 engine I have seen that they are all almost identical and are monstrous. They really are huge, I took my crank to be cleaned and all the people in the shop were asking what the hell it was from! It weighs an absolute ton! I've seen 2.8 strokers that put down 500lbft of torque so I wouldnt worry about the crank at all! Rogue_ant from rennlist ran a stock 2.5 NA engine with a turbo and made 400hp with E85 and it was running daily for 9 months before it gave up.