220 turbo engine bores scored

[Dave MGT]

Well after 8-9 months of waiting and finishing jobs on the 944 turbo I bought off a friend last year, I finally got it on the road the other week. Only to take it off again a week later. The fans were cutting in and staying on (rad stayed cold) I though to myself try bleeding it 1st. But as I had to do the belts and tentioners and check waterpump there wouldnt be much point. So removed belts and waterpump which was ok, so was the radiator. I then decided as I want about 300bhp It would be worth doing the headgasket at the same time........WOW glad I took the head off!! Gasket was fine but check out the bores

Only seen cylenders 2 and 3 as its still timed up. But you can clearly see the scoring on half of each cylender wall. (no lip at the top of bores though) Was very shocked to find this as it has only done 123k and runs like a dream with no smoking etc....
It it quite normal for these engines to wear big/small ends ....?
Currently weighing up what to do with it. Think I will end up getting a good 2nd hand engine?
Does anyone know the price of piston rings and bearings? or the best place to get them?

 

[Alexw]

I've not heard of these engine wearing out the bearings abnormally. The bores can be fixed try EMC, I had my pistonrings replaced a long with top and bottom end rebuild and they mentioned on minor damage you just give the bores a polish and fit oversize piston rings IIRC. If it holds compression ok it should be fine though?
Probably the best place to get the rings and bearings is from Porsche themselves to be honest. But you can try a few other places like frazerpart.com, partsforporsche.co.uk or www.promaxmotorsport.com.


EDIT: Its not polish, its hone! Thanks to Simon

 

[944 man]

If theres no lip then surely they can be honed? I know that Kev Eacock can hone them; but its quite a specilised job, needing a special tool; as they high silicone content alloy will shred most honing tools.


Simon

 

[Dave MGT]

ORIGINAL: 944 man

If theres no lip then surely they can be honed? I know that Kev Eacock can hone them; but its quite a specilised job, needing a special tool; as they high silicone content alloy will shred most honing tools.

Yes I could hone it but the thing that concerns me is the pistons must be tilting as only half of each bores are scored, so its going to need bearings etc.....?

 

[barks944]

Is that normal for them to push to one side on the power stroke? Maybe the angle of the con rod causes that?

 

[Dave MGT]

ORIGINAL: barks944

Is that normal for them to push to one side on the power stroke? Maybe the angle of the con rod causes that?

Never considered that before....very good point!
I will have a closer look at the marks tomorow
Thanks guys

 

[944 man]

Id speak to EMC or Hartech in the first instance - you need to be sure that youre getting proper information (otherwise itd be like asking on a forum! []).


Simon

 

[zcacogp]

ORIGINAL: Dave MGT

ORIGINAL: barks944

Is that normal for them to push to one side on the power stroke? Maybe the angle of the con rod causes that?

Never considered that before....very good point!
I will have a closer look at the marks tomorow
Thanks guys

Yes, there is always a 'thrust' side to the bore which wears more quickly.

Also bear in mind that (I don't think) the pistons travel vertically on a 944 - the bores are at an angle. This will mean that one side (the bottom side) wears more than the top due to gravity as well. (UR-Quatts were notorious for this - a well-driven one will have noticeably oval bores.)


Oli.

 

[Mike_Pollock]

I've just stripped a 165K + 2.5 N/A but has no obvious wear or marks. would it be due to the extra forces in a supercharged engine?

+1 for talking to Kev at EMC, hes knows these engines!

 

[Dave MGT]

ok checked number 1 and 4 today and it doesnt look good! they both have scoring not just on the thrust side and number 1 is very rough.
Theres quite a lip at the top of the bores as well. Im sure this engines done more than 123k

 

[Mike_Pollock]

I have a good looking block......

 

[DivineE]

I would take Mike's block and save yourself a world of pain (seriously I've been here many times).. or go to Serdi in london and get them to make it like new (but that means buying oversize pistons so add £1000).

So many 944 engines going around are scored and don't know it. They'll just keep going and going with very litttle fuss. I know of cars out there today with owners who have chosen to ignor it until it fails properly. Perhaps that's what I should have done in retrospect!

Be very careful who you take it to though. I've had some bad experiences and seen worse. Contact me off list if you decide on a place and I may be able to advise you more honestly.

Regards,

Ben

 

[Dave MGT]

Thanks Ben!