0.040 over pistons

J

jdi

New member
I'm building a 1992 Integra GS-R to race in ITS. The B17A1 engine in it is pretty uncommon and I'm having a *very* hard time tracking down anybody who makes 0.040 (or even 0.030 or 0.020) over pistons that don't have a big dome for high compression or a dish for turbo applications.

The biggest overbore that Honda offers is a 0.010 over. I've tried a few OEMs (Topline & ITM Engine) that have pistons for the car listed in their catalog but none of them actually make the pistons.

Anybody know of a possible source for these that won't involve having them custom made?

Thanks
 
You are going to have a real problem. We have a B18C1 which is waayy more common and there is only 1 or 2 companies that I have been able to find that make .040 stock-like pistons.
 
is it legal to take something like a Wiseco high dome and do some simple machining to reduce the dome height to correct the CR?
 
JimLill said:
is it legal to take something like a Wiseco high dome and do some simple machining to reduce the dome height to correct the CR?
Click to expand...

Pistons need to be the exact as oem in every manner, even the rings too. If Honda doesn't make a .040 piston, how can the pistons you have made have anything to compare to? Will the rings and ring groves be identical? :017:
 
--------------------------------------------
Rule D.1.j. Engines may be bored to a maximum of .040 inch over standard
bore size. Factory replacement pistons or their equivalent
with the exception of diameter shall be used. Cast or forged
equivalent pistons shall provide the same dome/dish/valve relief
configuration, ring groove width and spacing, pin height relationship,
weigh no less than the factory standard bore pistons.
Piston rings are unrestricted.
--------------------------------------------

I don't think I could meet those requirements by machining one of the "usual" aftermarket pistons. Rings are free, so that at least is not a problem.

Thanks for pointing me at rivergate, Tom. I'll check them out.

Jeremy, would you mind letting me know what are the companies you've found that do 0.040 over B18C1 pistons? I'd like to at least try them and see if they've got a B17 application.

Thanks!
 
Dan--I think we went through the "exact" equivalent OEM GCR debate a couple years back when the issue was forged replacement for cast.

I do not think it is a GCR problem to use a close substitute; just a difficult search.
 
Send a complete piston to JE and they will build exact duplicates for somewhere around 185-200$ each. Any size you specify. Chuck
 
Jeremy Billiel said:
You are going to have a real problem. We have a B18C1 which is waayy more common and there is only 1 or 2 companies that I have been able to find that make .040 stock-like pistons.
Click to expand...

CP is a spin off of JE and make a series of pistons for sports compacts, including the B18 series. They also do custom pistons too, so you might try them too.

http://www.cppistons.com/

BTW, they have also made custom BMW pistons for VAC, which aren't in their catalog.
 
Might be easier to simply get another block? I'm sure you've thought that through though. Seems like the blocks wouldn't be too hard to get.
 
B17 blocks are pretty hard to find and are specific to that car. Honda made a 1.7 liter GSR "VTEC" version of the Integra from 90-93 (??)... they made very, very few of them compared to the later model GSR cars.
 
92-93. About 5000 of them in existence, so not the easiest things to find, but far from impossible.

Either way, the block doesn't need to be bored out due to damage. This is more of a "I want to rebuild it before I race it so I might as well max out the displacement while I've got it open" sort of thing.

At the prices quoted for custom pistons I'll probably just settle for the 0.010 over OEM ones and spend the money on some other aspect of the car.

Thanks for all the input so far.
 
Send a complete piston to JE and they will build exact duplicates for somewhere around 185-200$ each. Any size you specify. Chuck
Click to expand...

Will they really be exact? I've seen JE work for what was listed as "replacement" and they are far from 'exact'. Very nice work, but not a duplicate. Especially for weight.

This doesn't really help the guy who can't buy OE replacements of any kind. Not sure what he is left to do.
 
FWIW, and with full knowledge that this is not 100% kosher:

B16 pistons will work, but you will need to use a thicker head gasket to bring the compression back down (~1.5mm will keep you legal with JDM or USDM B16) but they have a dome. B18C1 pistons are dished slighly and will also fit. no compression worries there, but again, technically NOT the same as the B17, though very close. it should be easier to source B18Ci (GSR) and B16 (civic/del sol Si) pistons in various overbore sizes as they are far less rare than your B17.

if you don't run the ARRC nor a very competitive series, no one should be too unhappy about your using these parts so long as you keep the CR to 9.56 +0.5/-0.

Handy calculator at: http://www.zealautowerks.com/
 
A B17 is nothing more than a destroked B18...same bore as a B18 (81mm) - the difference is the crank (stroke) and rod length. You should be able to use a 0.040 B18 piston as long as the compression height between the two pistons are the same.

Kirk
 
I'm aware that pistons from either the B16 or B18 engines will physically fit in the B17 engine. They've also got different dish/dome configurations, so I will not use them.
 
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