Sorry if this is a stupid question. What would be need to run an 84mm combustion chambered head on an 81.5mm block. Both are gsr found a great deal on a fully built head just want to make sure it's possible with out any issues. Thank you in advance.

 

WTF are you asking?

 

Sorry maybe I should make it a little more clear. I'm boosting my gsr but I found a head that has been fully built at a great price. The combustion chambers on the head are 84mm the block that I have is set to 81.5mm would I be able to run the head on my block with no issues and would I need anything different such as head gasket to be larger or what have you to run the head?

 

You are confused. The combustion chamber has nothing to do with the bore. Stock bore or bored out to the max the combustion chamber does not need altered.

 

The combustion chamber is already altered I'm not confused. Ill put the exact specs of the head in just a minute.

 

Endyn/rlz big port gsr head. 84mm combustion chambers. .020 mill stainless ferra valve. Supertech springs, retainers, keeper, guides. All brand new never used.

 

Sounds like it. Or at the very least you like to make things hard.

 

What seems to be confusing that I'm saying ill try to better explain it. Now I'm confused as to what could be hard to understand.

 

I know what your saying dude, the combustion chambers in the head have been machined out to 84mm to work better with a block that has 84mm sleeves.

 

I guess you could always search. At this stage of the game there's no question that hasn't been asked and answered previously.
https://honda-tech.com/forums/showthread.php?p=43513429

They talk about an F23 but the concept is the same. Pretty much.

 

I guess I was confused. I see what you are saying.

 

All you need to do is get an 84mm headgasket. This way the combustion chamber isn't obscured by a smaller gasket

The larger chamber means increased chamber cc which means lower compression but that's it

Of course there's the issue of the sleeves not being 84mm but there isn't much you can do

Run it and see what happens. That's all anyone can do really

 

Do you think there will be sufficient sealing using an 84mm gasket on a 81mm bore?

Also, isn't this the same concept as putting a p8r head onto a Ls block? Isn't the p8r non vtec head 84mm combustion chambers?