Overbore a 440

[Sick0]

I need to over bore my 440 sleeve. is there a compnay thats makes these piston or can even go over a 440. I think I have read theres is but don't remember. thanks

u can go all the way to 532 i think it is...but that is gonna cost u around $2000 and a whole new top assembly for the huge cylinder...or u could always go with a watercooled 400 for $2000...lol either way...u can also bore to 465 i am pretty sure...that may just be a stroker...im not sure

[jerry-89-250R]

contact C&D racing "the site sponsor", they got me a over bore piston kit for my 440

[hondafox440]

I don't think you can bore a 440 (stock stroke) any further. You have to stroke it form there to gain displacement..

[sleeveslave]

Sure you can bore a 440 sleeve beyond 89mm....
provided the original manufacturer has allowed enough remaining wall thickness at the step to continue to properly support the larger piston.


Northwest Sleeve
Tech Staff

[hondafox440]

Right, but you cannot bore the 400EX engine further than 89mm without boring the cases as well. The standard 89mm sleeves are the same outer diameter as the stock sleeve, just thinner walls. If you bore it more, it becomes too thin. This is what I heard at least..

[pairanutz]

i have je piston thats 89.25 they make a 89.5 also -or they did a year ago

[mntly_imptnt]

yes you can go higher than a 440. there are a couple of companies that supposed to offer a 465 kit. no stroke needed. i only know of one though. that is curtis sparks. his piston is a j.e. 13 to 1, which is an alchol only piston for the 400ex. i am myself looking for this piston in a lower comp. the other thing is, that yes you have to go with a BIG BORE SLEEVE and your cases and your cylinder do have to bore out to accept the new sleeve. this is not something for the faint at heart, because once it is done there is no putting the cases back nor the cylinder back to original. BUT GO BIG OR EVEN BOTHER!!! hope this helps.

[jgfarmsracer]

you can clean the sleve up to a 90mm and JE piston has them up to there in .25 steps that stay in the 12-1 compression stage without having to bore the cases

as far as 13to1 compession pistons being alcohol only is wrong
i run 116 in my 13-1 440

[pnut420]

Here is a nice kit powroll has http://powroll.safeshopper.com/77/77.htm?152

[Chef]

I know for sure that you can go 92mm, 465cc, with the right sleeve. Provided enough money, you could go bigger with a custom sleeve and case machining, and cylinder boring for the bigger sleeve. ESR is making a billet cylinder for it now, so they could probably custom make something even bigger.

I run a 14:1 in my EX on 116-118, or oxygenated fuels. No problems yet.

[sleeveslave]

Just to be clear--the original question pertained to a "unknown source" big bore 440 sleeve. So, we do not know who the original manufacturer is nor if the sleeve is stepped or straight.

Assuming it is stepped, as a rule can you bore a 89mm sleeve out? Yes. Does that require case modification? No. Does that make the sleeve body OD too thin? No. Does that make the step wall thickness too thin? Maybe--that would depend on what you wanted to bore it to. We do not recommend boring beyond 89.5 on our standard 88 - 89mm sleeve. Anyone considering boring a "production" 89mm sleeve should verify with the manufacturer (not the retailer) of the sleeve what the body and step O.D. actually are.

Northwest Sleeve
Tech Staff

[Hotdog]

Chef - do you have any more info on the billet cylinder. I emailed ESR asking for some info and all they sent me was the flyer that is in the magizine

[Sick0]

ok. i'm not try to get any performance gain. the sleeve is a IMS 440 kit w/ a je piston 10.5. i think its a step style sleeve. i know the case wasn't bored. the sleeve just needs to be bored. who would carry this piston.

[pnut420]

Originally posted by Sick0
ok. i'm not try to get any performance gain. the sleeve is a IMS 440 kit w/ a je piston 10.5. i think its a step style sleeve. i know the case wasn't bored. the sleeve just needs to be bored. who would carry this piston.

http://powroll.safeshopper.com/77/77.htm?152

http://powroll.safeshopper.com/77/77.htm?152

[Chef]

Originally posted by Hotdog
Chef - do you have any more info on the billet cylinder. I emailed ESR asking for some info and all they sent me was the flyer that is in the magizine

I know as much as you do...I dont even know what colors it comes in!