275Performance

I was planning on having my combustion chamer on my b16a and b20b cylinders bores matched. I have very rarley seen people talking about doing this. Is it really needed them? I will have GE sleeves, Eagle Rods, Endyn pistons make to fit a b20b/b16a set up, port flow valve train and retainers, and ferra valves. What is everyone's opinion on matching the chambers?

eg6ajk

if you are doing a build up from scratch then defiantly worth doing, it will prevent any unwanted detonation and should in theory provide more relibilty to the setup.

Ruby Civic

been covered a few times before, but to quote Tom Fujita of Portflow - it makes no diff xpt that you lose compression points (~.4 or so). it does not change the detonation character of the motor and is not worth doing....i know doesn't make sense but Kurt Gordon of KG Precision Engineering says the exact same thing..

275Performance

Yeah after I posted this, I was able to find the post discussing Portflow's thoughts. Its staying as is. Thanks for the info.

dohcsideSi

i still don't understand portflow's comments, yes it does increase the size of the combution camber obv reducing comp but why does he say it has no effect on detonation??? please give us a link or something

Ruby Civic

you have to ask Tom Fujita or else Kurt Gordon, but detonation has more to do with the top of the combustion chamber shape which are hotter than the edges. i think he has even done tests to compensate by milling head to make up for o=lost compression and still no diff.\

even though it would have been money in his pocket to do mine he recommended against it....

allmtr

i have heard it refered to as spot-facing. it will add better flow to your engine.

Ruby Civic

my point was that Tom Fujita and Kurt Gordon, the one perhaps the best headwork man available and the other with a very good shop and reputation say that is NOT the case and recommend against it even in the case that they would make money by doing it....

C1V1C

This is taken from http://hybrid.honda-perf.org/tech/b20/b20tech.html

"The B20B/Z head looks to be the same as a B18B (P75) head. The combustion chamber bore is 81mm, while the block and head gasket are 84mm"


So if the stock b20 head has a 81mm chanber it must be fine.


[Modified by C1V1C, 6:33 PM 4/23/2002]