Thread: Big Bore Pistons Over 88mm
12-04-2008, 01:05 PM #1
Big Bore Pistons Over 88mm
I'm making a custom made big bore engine and would like to know who makes pistons sizes over 88mm?
So far I've found the Group-K big bore pistons in the 88.5 & 89mm sizes and the flat top piston from Japan made for the Fennec Group in the 88mm & 89mm sizes.
I'm just wondering if I have any other options out there and help would be appreciated.
12-04-2008, 02:41 PM #2
conntact HopatcongGPR from this forum he had 90mm pistons made for the GPR
12-04-2008, 03:22 PM #3
what motor platform are you working with ?
fentec is prob 62t based
the 87and up from everyone on here is gonna be gpr platform
12-04-2008, 05:57 PM #4
I'm very curious about those custom made pistons and that might be a good option.
It's going to be used in a 65U, 62T, 61X cylinders with custom made sleeves and possibly with a stroker crank setups.
The Fennec flat top pistons are very similar to the Riva or R&D flat tops and available from sizes 84mm to 89mm.
I just don't like having to spend 270 bucks per piston plus shipping for Japan and I'm searching for a cheaper option.
I've also hear some engine builders use the CR500 and 951 pistons in these engines.
What's the largest GPR piston available?
12-04-2008, 07:03 PM #5
12-04-2008, 07:14 PM #6
I think the 87mm is the going thing..... Easy availability and $150. Its all in porting aswell but most great #'s are done with stock stroke an 87's....
12-05-2008, 08:38 AM #7
just consider the piston pin size /bearing are different in the 65u and the 66v
be sure your buying what you need not just a big piston
12-05-2008, 10:41 AM #8
- Join Date
- Dec 2008
it may be small by you big builders standards, but what is out there for a 83-84.5MM piston..forged...and maybe a little more compression then the stock gpr1200 piston? something cheaper(cheap and forged..ya right..LOL)...i would settle for a good hyperutectic piston for cheap if i can find something. you guys are the experts..what is out there..thanks alot and ttyl
12-05-2008, 11:07 AM #9
I am running 85.5mm pistons in the 97 GP for now I will be going 86mm in the future.
On a 1200
Stock GP 1200 piston 84mm 1131cc
.060 over piston 85.5mm 1169cc (bore size now)
.080 over piston 86mm 1184cc
12-05-2008, 11:14 AM #10
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