choosing piston

[chucai]

Hi there,

I have a 1983 930 3.3L Porsche. Unfortunately i have fried 2 pistons. Therefor i am looking to get the piston change. There are few options that i can go for now. 1st is to replace them with the OEM piston. 2nd- to get after-market piston. and 3rd oversize-- 3.4 litre piston.
I am really interested to go for the 3rd option. But i am not sure which pistons are the best one to get... andial, ******** or JE (if they do one) and the right compression to go for. I am just looking for some good reliability and the ease to get them rebuilt.
Hope you guys,..expertises... can help me abit here...!! THANKS VERY MUCH ...!! and any other advise / tips given are greatly appreciated..!!!

REgards.
Ernest (Malaysia)

[Steve@Rennsport]

Ernest:

If you are looking for reliability & longevity, then your best choice would be Mahle's; either stock 97mm or the 98mm (3.4 litre) ones. JE's and others do not come close in this regard.

I would NOT recommend a big boost in compression ratio (or boost pressure) unless you take measures to enrichen the fuel mixture.

[78P930]

Ernest,
In the interest of preventing others from doing the same hwo do you think you fried your pistons and what's your setup?

Thanks,
Pat

[sand_man]

Originally posted by 78P930
Ernest,
In the interest of preventing others from doing the same hwo do you think you fried your pistons and what's your setup?

Thanks,
Pat

I agree. What caused the failure? Too lean, ignition timing, age/mileage, too much boost (after market boost spring), etc., etc.

[78P930]

hwo=,how

[chucai]

Thanks guy. I dotn really know why exactly i fried the 2 piston. There are 2 obvious possibillity , 1st. My oil tank is too dirty (rust) and caused the car to run inadequate of fuel or 2nd. No engine oil .

I have the 1st problem since few months back and always have no chance to solve it. MY car will sometimes stop or cant rev up due to the lack of fuel. I have to then wash the fuel filter in order to make it work. Infact i really dont know what caused it to fail . vae you guys got any idea too ?

Thank guys, Steven where is the best place for me to get the 98 mm Mahle piston and does it require any modification to get it fitted and does it give significance power increase compaired to the original 3.3.

Thanks again everyone.

regards,
Ernest

[sand_man]

The Mahles are HELLA expensive, but it's good stuff! Before you end up dropping some serious $$$$ on them, you really need to find the culprit, or you'll be back in the same boat, only with your wallet close to US$4K lighter! Also, the 98mm are "bolt-on"...no other mods needed to make them fit in a 3.3.

[sand_man]

One other thing, Ernest, what's the story on this engine? I mean are you just planning on dropping in new pistons and cylinders and calling it a day, or are you looking at a total rebuild? Depending on the health of this engine, you might be advised to evaluate the bottom end and the rest of the top end before thinking about pistons and cylinders. Unfortunately with these engines there's more involved than just replacing the part that's "fried"...