Question on nitro bore sleeves 4.187 bore

hi first what is the largest u can over bore a 4.187 sleeve? Next is what is the most compression you can make with a piston that is in a bore size with buying custom pistons. Stroke is 3.750 bore 4.187 bae fuel heads 180cc and not sure what rod lenght yet. Thx guys

 

. Ohh ok have t check rob, but what about the compression question? Thx

 

I have 4.490 OD sleeve. In a 4.187 bore, what can it be bored out to? If at all thx rob

 

on the sleeves I took that measurement. Can that sleeve be bored? If yes what’s the max? I need min 4:250! PS the newer top fuel blocks do they all come with 4.550 sleeves? Say a John force block?

 

PS not sure what block the 4.90 sleeves came frm?

 

have older KB dry and newer KB wet
But have two older 2000 Brad billet too. But will measure the registers after work thx rob

 

Go to the Darton website and check their sleeve sizes. There are all sorts of different sleeve sizes available, so it depends on your block and ultimately what wall thickness you will be left with. You'll most likely be better served buying new sleeves if the wall thickness is getting too thin. Lastly, you can always overbore the block to run a thicker wall sleeve. Structurally this is the more sound way to go if weight is not of concern.

 

oh fr sure, but I got a lot of 4.187 sleeves. And can get 4.250 bore high compression pistons fr my needs. If I can get away with that over bore? Thx

 

You are only talking about .063 over or .0315 per side.

 

Per my calcs, even with the thinnest wall 4.187 bore sleeve, you will be at .120" wall at 4.250 bore. That's as thin as Darton goes on a sleeve except for their big bore, short deck alcohol stuff where they go down to .104" wall. You can probably get away with it if you keep everything squared up. You just can cry about it if one fails.

 

. Thx dave

 

it will only be fr injection only, and small stroke. Non boosted.

 

and that’s on their blown short deck alcohol engine?

 

My sleeve thickness is .150 and need to bore them to 4.250, so I am left with .083 thick? Not sure if that’s good enough to run a injection motor?

 

yes that’s sound advice but not making a ton of hp. Un blown 900, blown if possible 1200?