16 valve 3 Litre Turbo

[appletonn]

ORIGINAL: zcacogp

You called, sir?

I'm actually thinking that I'm not going to bother to say it so much. I mean, that fact is practically part of the zeitgeist here, isn't it? In much the same way as I don't bother to repeatedly say "The sun rises in the morning", "Petrol is overpriced" or "Gordon Brown is a sour-faced Scottish idiot", I'm not sure it's worth saying "S2's are the best".

However, I am slightly worried that Nick (Appletonn) may be trying to send me a turbo - on delivery number 34230824. I've checked with Nightfreight (and DHL, Parcelforce, UPS and the rest of them) and none of them have any record of it, but if it is a turbo, how do I politely say 'No'? []


Oli.

P.S. Worse still, it might be a red one. Ugh!

It's on a van heading your way today...!

Might be a turbo (-charger, as opposed to the whole car!) or might just be some official Porsche sealant on a roll![]

Coming via Nightfreight in Basildon - tel 01268 728484

 

[333pg333]

One day Olli, you'll leave the 'Flat Earth Society' and get with the strength!!

Great to see Barry continue this project of his and nice to see some US feedback and possibly involvement.

 

[zcacogp]

Nick,

Ah! Thanks ... I thought you were joking (from my earlier post) so I wasn't quite being serious in response ...

If that's the case tho' then many thanks. Beer owing. I'll let you know when it arrives.


Oli.

 

[Diver944]

ORIGINAL: 333pg333


Great to see Barry continue this project of his and nice to see some US feedback and possibly involvement.

It's just a shame he hasn't been back online yet to update us a bit more.

It should stop us talking about V8's at least []

 

[morris944s2john]

Sorry if I missed this thread as I am a sporadic poster/reader of this forum, but... what was the issue that caused 3.0L 16v turboed S2 engines to blow up?? Can a solution not be found? If so you would think huge power is possible from the S2 lump.

 

[333pg333]

It depends on what components you use. If you change the S2 piston and rods and of course tune the car properly then there's no reason for them to blow up. There was a guy who used stock components and got over 500hp out of his, but that did blow up eventually. Speedforce racing even have an inlet available for them. You could go a full standalone kit, or perhaps get someone like Vitesse to build you a kit that runs off a Piggyback.

 

[333pg333]

ORIGINAL: Diver944

ORIGINAL: 333pg333


Great to see Barry continue this project of his and nice to see some US feedback and possibly involvement.

It's just a shame he hasn't been back online yet to update us a bit more.

It should stop us talking about V8's at least []

Paul, you know the V8 thing really is tempting in many ways having seen and spoken to Tony G about his. Don't forget that he had built many high hp i4 motors before making the change to the V8. I know I am not the person to be extolling the virtues of V8s as I've never done it, but all that simplicity and reliability does have it's charms. I don't mind the burble either. Thing is, it isn't a real Porsche and until I finish what I've started, I will continue to beat my head and maintain the course.

I think something like your motor is directly comparable to a V8 and really if it's not pushed very hard on the track and often, you should have many years of golden service. Not to say it's unreliable as a race motor, but I would think you'd need to improve some of the ancillaries to help it cope. Be nice to see some more video of it too just quietly!!!

 

[morris944s2john]

Aha! so it was the pistons/ con rods and possibly crankshaft that let go.

I guess that is the problem, one of economics, as to have stronger engine internals made would cost many thousands. Custom billet steel crank and con-rods cut on a C and C machine and then toughened would cost many £1000's. One for a lottery win perhaps!

But a 5-600BHP 944 S2 would be a handful. Would then need the rest of the car upgrading, at which point you ask- why not just spend the £x10,000 on a car that is faster to begin with??

 

[morris944s2john]

If I was to fit a V8, it would be a Rover 3.5 or 4.0 as used in TVR's etc, with a supercharger!

 

[333pg333]

ORIGINAL: morris944s2john

Aha! so it was the pistons/ con rods and possibly crankshaft that let go.

I guess that is the problem, one of economics, as to have stronger engine internals made would cost many thousands. Custom billet steel crank and con-rods cut on a C and C machine and then toughened would cost many £1000's. One for a lottery win perhaps!

But a 5-600BHP 944 S2 would be a handful. Would then need the rest of the car upgrading, at which point you ask- why not just spend the £x10,000 on a car that is faster to begin with??

Now that would just be plain sensible John. []

There are steps you can take, and you don't have to go for the full 600hp Welly model. You could keep a higher compression ratio and tune it for a lower boost level and just have a very nice responsive 400hp sort of thing....but yes you'll still need to make some other changes which do add up! []

 

[morris944s2john]

To be honest, considering the fairly light weight of the 944 compared to modern sports coupe's, even a moderate increase to 300BHP or thereabouts would be great! I would also want the car car to remain usable, so 30+mpg on a run that i currently get, I would still want to see decent fuel consumption figures and drivabillity.

 

[333pg333]

Ahh, so you only want.....EVERYTHING...[]

In all likeliness, when you're getting 30mpg in a turbo you are driving very sedately. You could probably get half decent mileage if you tread lightly with a V8 as well.

Oh and b.t.w. it's a 'HOLDEN MONARO' born and bred Down Under. []

 

[Barry Hart]

This thread is rolling all over the place.

To update you on a few points raised, the block is a 2.5 modified to fit a 968 head - chosen because it has almost twice as deep coolant channels that will keep the engine cooler and lower the oil temperature (don't forget - although a bigger oil cooler will lower it - the heat still soaks into the oil at the higher temperature before it is lowered by the cooler with a greater temperature gradient drop - so the oil on the surface is still hotter with the 104mm block).

The 2.5 block also has two coolant inlets whereas the 104mm block only has one. We have managed to make the cylinders split the coolant flow through these two inlets to keep the block cooler as well. There is nothing wrong with the 104mm block for cooling up to say 250- 300 bhp but it was not designed for 500bhp and if you ever see a seized S2 (as we have many times) it is always the lower cylinder area (where there is no adjacent coolant) that has seized. The 100mm block in normal use - possibly has too deep a coolant housing and runs perhaps a little too cool as a result (as many earlier engines did before designers realised it was uneccessary) - but it is ideal for a turbo or higher bhp set ups.

For road use you cannot drive flat out almost continually for several minutes like you do on a track and so for road use the 104mm block is just fine but it is a very different story when you put such an engine ona track where apart from a brief bit of braking the engine is absolutely flat out most of the time. Fitting bigger oil coolers lowers the oil temperature but the temperature rise is then still very high, the oil being too cool on entry and too hot on exit - much better to keep temperature differences as low as possible.

The S2 pistons do not have enough taper to run with high bmep without expanding too much but several manufacturers now offer more suitably tapered pistons for such a conversion.

The problem with tuning a 104mm block is that by doubling the heat in the cylinder you need better cooling and the 104mm block not only does not provide this but even shrouds the lower cylinder in a space cut off even from oil cooling by the lower plates (put in to stop the oil from lifting too far up in the block from the crakshaft throw).

The 968 head will flow better and more importantly allow us to experiment with different cam timing (without machining lots of single cam profiles) and then if we discover that the best set up would require a change in the timing of one of the cams we can alter the variocam system to advance or retard the inlet or exhaust cam accordingly to maximise the output.

I will send Diver some pictures (he is better at putting them on the internet than me) of progress to date to show more of what I mean.

Baz

 

[andye]

ORIGINAL: Barry Hart

This thread is rolling all over the place.

I know - I started a new one about the V8!

 

[Suffolk944]

ORIGINAL: Barry Hart

This thread is rolling all over the place.

Welcome to the world of the 944 forum ! []

 

[TTM]

ORIGINAL: Barry Hart
The 2.5 block also has two coolant inlets whereas the 104mm block only has one.

Are you refering to the passages in the block where the water pump sits?

 

[Diver944]

ORIGINAL: Barry Hart

I will send Diver some pictures (he is better at putting them on the internet than me) of progress to date to show more of what I mean.

Baz

Here's the pics that Barry sent me. I have no idea what they show so hopefully he will logon today and explain

 

[zcacogp]

I think they're bits of a car, Paul. In fact, I'm pretty sure they are. I've seen them before, and that's what they are.

(Looks like a machined out block and some new liners, which is what Barry talks about a lot in his thread. Although the detail from him would be good.)


Oli.

 

[333pg333]

It's actually an interesting process that has been around for some time. If you look at the 4th pic that Paul has posted you can see a 3L block on the LHS. You can tell that it's a 3L as the cylinders have 'siamesed bores' or joined, unlike our 2.5L blocks where they are completely separated from one another. Pros and cons of both would be that the 2.5L may have better all round cooling, the 3L would have better structural integrity. See on the RHS block how they've machined virtually all the top part of the cylinder away and then they insert the sleeves.

What I'd be interested to hear from Barry is what is the process of the 'insertion'? Do they pre heat the block up? Once installed do they hone with a deck plate? I assume that these interlock like the Darton MIDs?
I think these are Nikasil treated, yes? Do they require smaller, stock, or larger clearances with the rings and pistons? How many miles have been tested with these in terms of longevity of coatings?

Above all, it can be a great way of bringing a damaged block back from the brink. Better than having to buy a new motor in many cases.

 

[TTM]

ORIGINAL: 333pg333
the 2.5L may have better all round cooling, the 3L would have better structural integrity.

Yup, and the second, lower coolant inlet behind the water pump doesn't exist on the 104mm block as the coolant chamber is only half that of the 100mm block - I'm wondering how Baz added a second coolant inlet as this may mean increasing the size of the coolant chamber around cylinders?