Piston question

[GSRallmotorhatch]

I have a GSR, want to do a piston swap. My friend is selling his B16 head, should i buy the ctr cams and slap on a B16 head? or just put in the CTR pistons on GSR head.

Compression VS. Volume. what should i do?

 

[Kolumbo69]

Well this i know forsure is that a gsr head has less volume but will boost you compression which in turn will give you more power, other than that my know how stops here and i will turn it over to someone else.

 

[katman]

From what I've learned, its better to NOT run such a domed piston such as the CTR's. Its better to run a flat top domed piston instead, like any ITR or B16A piston(s). The reason is for a cleaner & more consistent combustion/explosion. You'll make just the same power as CTR slugs too, if not better.

My suggestion to you is keep your GSR head and run a set of either ITR or B16A pistons, your compression will be in the 10.6-11.1 range if you run JDM or US ITR/B16A pistons. If you want to run the B16A head, the compression will drop a couple points because of the B16A's raised combustion chamber area. A GSR head's combustion chamber is like a milled down B16A head (puts out more compression).

Its up to you though.

PS: Don't forget to take your ecu into account if you decide to go with a B16A head. B16A's intake manifold do not secondary butterflies, yet a GSR intake does and a GSR ecu reflects this by having an early VTEC crossover point ranging from (4700-5000rpm depending on throttle load). So, if you go w/a B16A head, you might want to (1) have the ecu reprogrammed with a higher VTEC crossover point or (2) run a VTEC contoller or (2) run a B16A ecu.

 

[Import Builders]

Hi Katman.

Just to let you know, that theory of running a smaller dome...

Its a myth. Bigger dome/more cc's with everything else being equal with any kind of decent dsign of valve pockets will make more HP.

Take my Ultimates for example. CTR piston is what, about 6.7 CC dome right.

Ultimates are almost 11 CC dome.

probably a good 30 WHP more same bore size. Almost 2x the dome.

Just take a look at any domestic pro drag race piston, and youll see what I mean.

Jeff

 

[MikeBergy]

Just keep in mind that with an increase in compression comes extra heat, so you are going to want to run a colder spark plug, and higher octane gasoline. Getting hondata and a tune while you are at it would also be a good idea. If you are already sinking at least a 1000 dollars into the block rebuild, yu might as well put a few hundred into some tuning while you are at it.