Azztrix Posted September 30, 2016 Share Posted September 30, 2016 (edited) rb25 86.5 mm bore and Genuine head gasket???? Can anyone tell me if using a genuine head gasket on a 86.5 mm bore will be ok? I know the gaskets aren't spot on but just unsure and would rather use genuine all round then Anything else especially with the tolerance issues that come with metal gaskets Edited September 30, 2016 by Azztrix Link to comment https://www.sau.com.au/forums/topic/467057-rb25-865-mm-bore-and-genuine-head-gasket/ Share on other sites More sharing options...
89CAL Posted October 1, 2016 Share Posted October 1, 2016 AFAIK, the stock gasket is designed to work up to the maximum over-size bore allowance. So as long as its not above maximum spec (40 thou over I think) the gasket should be fine. Are you just doing a stock rebuild? Link to comment https://www.sau.com.au/forums/topic/467057-rb25-865-mm-bore-and-genuine-head-gasket/#findComment-7780111 Share on other sites More sharing options...
Azztrix Posted October 1, 2016 Author Share Posted October 1, 2016 Thanks bro legend All forged bottom end Standard head Gt35 turbo ar50 front 0.63 rear Hks 80mm throttle body 850cc injectorsProbably good for 400-450hp I am guessing and hoping Link to comment https://www.sau.com.au/forums/topic/467057-rb25-865-mm-bore-and-genuine-head-gasket/#findComment-7780120 Share on other sites More sharing options...
89CAL Posted October 1, 2016 Share Posted October 1, 2016 So why not MLS gasket? Just curiousMine is 87mm bore with the cometic MLS and no dramas. But im fairly sure I did alot of mock up etc with the standard gasket and all seemed ok 1 Link to comment https://www.sau.com.au/forums/topic/467057-rb25-865-mm-bore-and-genuine-head-gasket/#findComment-7780257 Share on other sites More sharing options...
Azztrix Posted October 1, 2016 Author Share Posted October 1, 2016 Just have always liked genuine gear and I can get a full engine genuine gasket kit for 350 bucks But I'll stew on it a little more.... If I do go cosmetic or another then I'll have to get the head decked too I guess hey? Another question if you know the answer what's the go with gtr pumps on 25's? Worth doing? Do they need restrictors in the head or no? I can get gtr genuine pump for 350$ or a 25 pump is bloody Close to 500$ Link to comment https://www.sau.com.au/forums/topic/467057-rb25-865-mm-bore-and-genuine-head-gasket/#findComment-7780261 Share on other sites More sharing options...
89CAL Posted October 2, 2016 Share Posted October 2, 2016 MLS gaskets require a better surface finish then std gaskets. If the head and block were surface finished they may be O.K but if not I would def go with the std gasketI have an N1 pump with billet gears. Best to fit oil restrictors etc. Check the oil control thread in forced induction 1 Link to comment https://www.sau.com.au/forums/topic/467057-rb25-865-mm-bore-and-genuine-head-gasket/#findComment-7780407 Share on other sites More sharing options...
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