lol4fun 0 Posted August 30, 2017 Report Share Posted August 30, 2017 As per the title really, has anyone rebored a v6 4mo block (81mm bore) to take r32 pistons and rods (84mm) i have both in my possession and work for an engine reconditioner so can rebore it for free in my own time. I've done a bit of research and the rods are the same length, also the big end bearings are the same. but apparently the r32 pistons have a lower piston height to allow for a bigger stroke from the r32 crank which i haven't got. For reference the engine codes ive been using are below: BDE for the v6 4mo BML for the R32 Link to post Share on other sites
Flylow 2 Posted August 31, 2017 Report Share Posted August 31, 2017 The R32 crank has a longer stroke. So you need that to complete the bottom end or get longer rods but then it won't be 3.2 Link to post Share on other sites
lol4fun 0 Posted August 31, 2017 Author Report Share Posted August 31, 2017 I know it wont be a full 3.2 but going from 81mm to an 84mm bore will gain quite a bit of capacity gained. Link to post Share on other sites
mks2310 10 Posted August 31, 2017 Report Share Posted August 31, 2017 Buy a crash damaged car for every thing Link to post Share on other sites
mks2310 10 Posted August 31, 2017 Report Share Posted August 31, 2017 Link to post Share on other sites
Flylow 2 Posted September 1, 2017 Report Share Posted September 1, 2017 I know it wont be a full 3.2 but going from 81mm to an 84mm bore will gain quite a bit of capacity gained. Yep but the pistons won't reach the deck height because the pistons are shorter from pin to crown. Check that out 1st. The R32 crank stroke is longer and the rods are the same length for both engines therefore the crown height on the pistons should be shorter on the R32. So if you use a 2.8 crank the pistons won't reach they deck height. It would have low comp. Maybe you can turbocharge then. Link to post Share on other sites
lol4fun 0 Posted September 1, 2017 Author Report Share Posted September 1, 2017 (edited) As much as id love to turbo it i cant afford that. I can deck the block to give me the correct compression ratio again thats not a problem. Also the combustion bowl in the r32 pistons is more than twice as big. Edited September 1, 2017 by lol4fun Link to post Share on other sites
Flylow 2 Posted September 1, 2017 Report Share Posted September 1, 2017 What about offsetting the pin bush on the rods. That can give you about 1.5mm extra deck height. Link to post Share on other sites
lol4fun 0 Posted September 1, 2017 Author Report Share Posted September 1, 2017 I might get that right once or twice but not 6 times lol i think ill try and find a spare block so I've got something to fall back on should this go tits up Link to post Share on other sites
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