964TT

Thanks everybody, nice to get some feedback! I just read everything, got back form a small trip.

I need to make some decisions on how to get this thing back on track...

1. Compression ratio
2. Would love to upgrade the liquid intercooler, not easy with space restrictions
3. Right cams

Just came back from the workshop and the guys who pulled the engine out. We exchanged some ideas but I am not really convinced which way to go.

I guess one option they offered makes sense:
Get turbo pistons from Mahle to match the Mahle 3.8 cilinders and have the right 8.5:1 compression or so.

According to them it is for sure NOT an oil problem. They say it is the high compression and high power that just consumed the bearing after a while. If it was an oil problem there would have been clear blue marks, and they were not there.
So if this is true I should drop the power a bit.

It is a bit of a headache at the moment, trying to figure it all out. My current Porsche specialist won't mind putting it back together but they won't give me any warranty...

I got myself in a real mess having the engine built somewhere and then modifying it again and again with others. Not smart.

These are some serious luxury problems!

964TT

The car runs on E85 but it is not really available anymore. Not in The Netherlands and Germany just stopped as well. Slowly it will only be available on special order, expensive!

Damn straight!
I'll keep it NB!

This I need to figure out. No idea if the cam has been altered, we are checking it this week. The number on the cam says stock.

evoderby

Hi Thomas,

If the bearing failure is due to the torque the engine is making just lower the boost you're running at....easiest, cheapest and most effective.

The absence of blue heat marks on your bearings indeed point towards bearing overload.
High compression in itself doesn't kill bearings, detonation leads to bearing overload but I see no signs of that on your pistons / combustion chambers. Fuel diluted oil leads to bearing overload, as does placing the engine under high loads at low revs (when oil pressure is relatively low).

See Mahles guide on bearing failure analysis: http://www.mahle-aftermarket.com/med...s-brochure.pdf

I have to say a 50.000km life is quite acceptable at the power you're running. With 5000km oil intervals to reduce the effects of fuel dilution and running coated bearing I'm sure this can be improved upon!

Here's some ready to use Calico coated bearings: http://www.patrickmotorsports.com/pa...icant-coating/

http://www.calicocoatings.com/bearings/

If I were you I'd rebuild the engine in the exact configuration it is now, enjoy the hell out of it and perform a bearing change after the next 50K.

964TT

Thats solid info! Great!

You are right, just drive it like this and enjoy it for another 50K km... Bit more oil changes, better oil quality, etc. should all help.

I'm going to read that Mahle info.

Cazzo Super Velo

50K km for a highly-stressed and well-used engine is not bad at all.
I would leave it unchanged, change oil more frequently and replace the conrod bearings at 40K km to be on the safe side.
And maybe invest in a trailer for the long and boring autobahn sections to keep milage down.

964TT

So here's whats happening:

- Sourced a GT3cup crank though one very helpful Rennlist member. WOW

Also Buying:
- Pauter conrods
- Coated Clevite rod bearings
- GT3 main bearings
- 127mm crank pulley

Keeping same 10:1 compression, engine ran fantastic.
We are looking at more options for the chargecooler. BMW is making a good one and there are some barrel type coolers which caught my attention.
But at the same time we're looking into getting better cooling in the front at the radiator. There is just very little flow, so possibly there is a lot to gain if we can get some more air behind the front bumper.

Lets get this thing on the road again!

hockenheimr

Any idea of the differences between a GT3cup and regular GT3 crank?

My GT3 crank came out of a low mileage Cup car.

evoderby

Damn Thomas, da's nog eens doorpakken!

On the subject of Pauter, have you seen their DLC coated rockers tested @ 10.5K RPM? http://pauter.com/parts/porsche-specific/

Just add a GT3 oil pump and strong enough valve springs/titanium caps and your engine is able to safely run at least 8500RPM. Sorry...shouldn't be messing with your head ;-)

964TT

I was already running a GT3 oil pump.
But those bits look very nice... They wouldn't fit my engine though, I don't need high rpm.
If there is anything I need, its more durability and lower inlet temp. This is what I am figuring out.
We have some options we are looking at, lets see.

On the track I was loosing power when things heated up and lost maybe 50-75hp. It would be great if I can keep the 600hp solid.

BLACK-BETTY

Exciting times.

The GT3 crank will surely help. I agree with a boosted engine you just don't need high RPMs.

You've already got the boat tailed case, GT3 pump, forged rods, titanium springs, retainers so all good there. Remind us what heads your using, original ported with valves or uprated?

Personally, and you're not gonna like this... There is no substitute for an air to air intercooler. That's really the most efficient way of keeping the intake temps down!

JJJMCD

How about two air-to-air intercoolers in the rear fender wells like the Ruf CTR? See:

https://rennlist.com/forums/993-turbo-forum/545388-my-stupid-question-of-the-week-can-the-intercoolers-be-relocated-2.html

And

https://rennlist.com/forums/911-turbo-930-forum/338649-ruf-ctr-pictures.html

964TT

Sorry but that's just not true. Let me make is simple for you, if you wanted to cool down a hot object, would you wave it around in the air or stick it in water?

Chargecoolers are used in a lot of different applications, from F1 to the 918, BMW M engines, Veyron, etc.

My system is aftermarket and not built well enough for my application. To be fair, I'm asking more of it than originally intended.


I can improve airflow through the front radiator, which is situated really lousy. But it's not easy to find a smart way to do it.

Secondly the chargecooler itself is quite old fashioned. I'm surprised it even cools as it is. With a modern barrel type charger there is much to gain I think. Or maybe a BMW cooler, those work very well I hear but we would have to fabricate something to make it fit.

The available space is the main problem.

964TT

Regular heads, I don't think there is much to gain here with a blown engine. I'm looking into it a bit. I am using 993 GT1 EVO cams, also something to look into.

I am carefully reconsidering all the parts before we put it back together.

I bought a new GT3 pump actually, don't really trust cleaning the old one. If metal pieces went through, there should be damage anyway...

I'm also changing from Castrol Edge 10/60 to Motul 20/60 (300V leMans)

Having the cilinders honed and a new set of piston rings.

964TT

Current state of being... 600hp in a box

964TT

Somehow these didn't come along in the previous post...