Sup all, I am planning on sleeving my B18C1 block to 84mm bore and I heard from a friend of mine that in order to do that, I will need to match port the chambers of the cylinder head so that I have less chance of detonation???? I'm confused now, I thought I can keep the GSR head stock w/ upgraded springs and retainers???? Please I need your input on this before I get my block sleeved. Also, I need to know if its the same with b16a? Thank you very much!

 

You can retain your stock head on that bore. We have a few cars using stock head on 84.5mm runnin 12s all motor

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TURBO4drTypeR &raquo;</TD></TR><TR><TD CLASS="quote">You can retain your stock head on that bore. We have a few cars using stock head on 84.5mm runnin 12s all motor </TD></TR></TABLE>
Thanks for your input Anybody else have this setup w/ turbo???

 

Spot-Facing the head will lower the compression...I know on a GSR Head, your going to be in the 43-44cc Range. I don't find this necessary on a FI Buildup.

 

What he says

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Suprdave &raquo;</TD></TR><TR><TD CLASS="quote">Spot-Facing the head will lower the compression...I know on a GSR Head, your going to be in the 43-44cc Range. I don't find this necessary on a FI Buildup.</TD></TR></TABLE>

 

Yup. It's one of those don't-have-to-but-you-can things.

I did on mine. I wanted lower compression.

 

Thanks!

 

so if I bore my b16 to 83mm, I don't have to port match the combustion chamber

 

I actually like having the cylinder a little larger than the chamber. I would suppose that some would disagree with me. I do think a little deshrouding around the valve is helpful however.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">I actually like having the cylinder a little larger than the chamber. I would suppose that some would disagree with me. I do think a little deshrouding around the valve is helpful however.</TD></TR></TABLE>

That and it might even improve flame travel.

 

thanks again.....anybody else???

 

Didn't need it done but the guys that did my headwork did it for me anyway. Got my head p & p'd, new valve seats, new o/s valves installed, new bronze guides, hondata IM gasket and chambers matched to the cylinders for $900 so I didn't argue. I guess it all depends on personal preference

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">I actually like having the cylinder a little larger than the chamber. I would suppose that some would disagree with me. I do think a little deshrouding around the valve is helpful however.</TD></TR></TABLE>

This is what Endyn did to my head for my larger bore D series.

 

It really depends your compression ratio and what you want. Matching the head will lower your compression ratio. I make 362hp @ the wheels on a stock unmodified head on 9:1 compression ratio. Also take into consideration if the pistons you are using are for a b18c or b16a because there is a difference. Swapping a b16a head from a b18c head will drop compression by about .2 making 9:1 pistons 8.8:1. Make sure if you sleeve the block to 84mm to get 84.5mm pistons so you can have a machine shop match them to your cylinders and you can get a proper seal. Everyone's tolerances for measurement are different and your pistons might be 83.97mm-84.04mm for example. Also make sure you get a head gasket that's 84.5mm or 85. It's ok to be a little too big but not too small.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jdm_boost &raquo;</TD></TR><TR><TD CLASS="quote">It really depends your compression ratio and what you want. Matching the head will lower your compression ratio. I make 362hp @ the wheels on a stock unmodified head on 9:1 compression ratio. Also take into consideration if the pistons you are using are for a b18c or b16a because there is a difference. Swapping a b16a head from a b18c head will drop compression by about .2 making 9:1 pistons 8.8:1. Make sure if you sleeve the block to 84mm to get 84.5mm pistons so you can have a machine shop match them to your cylinders and you can get a proper seal. Everyone's tolerances for measurement are different and your pistons might be 83.97mm-84.04mm for example. Also make sure you get a head gasket that's 84.5mm or 85. It's ok to be a little too big but not too small.</TD></TR></TABLE>
Very good info Thank you everyone!!! I appreciate it!!