440 big bore

[brewster426]

i recently bought a 400 ex and it has a 426 big bore kit now, but i was wanting to do the 440. will i need to trim the cases to put the kit in?? thanks

[bigbad400]

you dont need to do anything with the cases. its not a stroker is it? i have a 440 and i needed a sleeve and a piston. with the stroker you will use a custom 426 piston (i think) and a stroked crank but i dont know if you need to trim the cases on these motors i never done one. but just a big bore you dont need any case modifications.

[dariusld]

I thought on some of them, they do?

[bigbad400]

unless your stroking the motor out you wont need to do anything with the cases, i cant see any reason a bigger piston and a 440 head would need to even get into the bottom end. i rebuilt 2 of these now and i just cant see it. all you NEED for a 440 is a sleeve piston and rings. i would suggest some hd studs and a cooling fan. maybe you were looking at stroker kits and didnt realize it.


the only other way to get 440 besides what i just said is to do a smaller bore on a stroked crank. i think its a custom 426 piston and a +4mill stroker crank to get a 440 stroker.

[dariusld]

I'm not sure, I thought I heard it somewhere.But from your wording, you don't sound so sure of yourself."i cant see" is not a definite answer.

[Punkmaster Flex]

I think the 426 piston + 4mm crank gives a 450 or 460 if I'm correct? And a 416 piston + 4mm crank does a 440?

If I am right, then I would just go for the big bore cause a 460 stroker is going to require more than a SPAL fan to keep it cool, but god it's gonna haul! :D

[bigbad400]

there you go thats what it is, sorry i was off a little. i love my 440 it hauls *** anyhow, i walk all over stock 450s and even piped 450s sometimes. i raced a fully modded banshee and if he could have got grip he would have smoked me but on dune sand i took him.

[F-16Guy]

The cases shouldn't need to be clearanced unless you somehow got a hold of a straight sleeve. Most 440 sleeves are tapered at the bottom now.

I think some of you guys are confused about the strokers. In some cases with a stroker, depending on who makes the kit, you have to trim the piston skirt to clear the crank since the piston has more travel. Again, unless you ended up with a straight sleeve, you shouldn't need to clearance the case halves, but it's always a good idea to make sure that the sleeve isn't rubbing anywhere.

[MtnEX]

So those bolt-on 440 kits are really bolt-on kits then?

I can remember reading about needing to work on the cases. I guess that is now old info with the new sleeves?

[F-16Guy]

Originally posted by MtnEX
So those bolt-on 440 kits are really bolt-on kits then?

I can remember reading about needing to work on the cases. I guess that is now old info with the new sleeves?
Yeah, pretty much. Just bore the cylinder for the new sleeve. You always want to make sure the new sleeve doesn't touch the case halves, though. If it does, you need to trim a little. If it touches and creates a tight spot when things heat up, the piston could grab the sleeve and break the top lip off, causing the sleeve to drop down and hit the crank. Not good.

[bigbad400]

i never heard of anything like that on a ex, i have friends that have dif. brand kits and they were all the same except maybe the compression ratio was different. i know that on a blaster you can add a big ole stroker to it and all you have to do is get a stroker plate, made to add more stroke to the thing without touching the cases.

i was just saying that with a standard 440 you dont need to mess with that stuff, if your doing a 416 + the stroker you still get a 440 but you have to mill the cases.


good luck