350x topend swaps

[big_daddy124]

does anyone know what all is a direct bolt on top end. xr 500, nx 650 or what. im trying to go bigger since im tearing the motor down

[Vealmonkey]

I don't believe that there is a direct bolt on without alot of work. Check out SWIGIN's thread on the ascot 500 head swap.

[SWIGIN]

the only bolt on is the old trx foreman 350 top ends....but they are the same so no gain.

[atvmxr]

i thought at least the XR350 would bolt on...

[big_daddy124]

well i read somewhere that a 500 would bolt on but i think they are 2 carbs but maybe you could use the head off the 350. not sure

[oscarmayer]

www.theoldone.com

CNC porting and CNC valve seat cutting and valve jobs.

[SWIGIN]

well i read somewhere that a 500 would bolt on but i think they are 2 carbs but maybe you could use the head off the 350. not sure

no 500 head is a bolt on.... look at my thread where i did it

[atvmxr]

but if you bolted on the XR500 cylinder, then the head would bolt on, yes??

[beets442]

+1..... valve job!!!!

[SWIGIN]

but if you bolted on the XR500 cylinder, then the head would bolt on, yes??

but the cylinder is not a bolt on either

[The Goat]

don't ya just love when those smart ass comments bite ya in the ass.

I'm thinking that xr500 sleeve is looking better and better every day swigin. with stock valves, high lift cam, and porting...will it be alright? or will it not flow enough?

need a 3mm spacer plate or a shorter crank...right?

couldn't you just have your piston cut down 3mm? and take 3mm off the bottom of the sleeve? or no...

[SWIGIN]

the 500 sleeve is by far the way to go and my buddy who does my porting runs a 500 sleeved and stroked 350x with a fully ported 350x head and a megacycle xr500 cam......it KILLS built 450s.

he is the one i talked about in my ascot head swap thread.

shorter rod not crank....spacer would work too if the timing chain is long enough

[atvmxr]

so then why the ascot head instead of a worked over 350x head?

with a spacer and some rework can the xr500 cylinder be modded to bolt on? or how about just swapping the whole motor for a xr500 or 650?

[SWIGIN]

so then why the ascot head instead of a worked over 350x head?

with a spacer and some rework can the xr500 cylinder be modded to bolt on? or how about just swapping the whole motor for a xr500 or 650?

i guess you didnt see my ascot thread....i show how much larger the valves are and i just wanted to see if i could do it.

you would have to gat a xr500 cly and see for your self why it nots worth the effort.....why mor work then a simple sleeve swap in a 350x jug.

as for your last question, why do guys built up 90s and 110s?......because they can. anyone can throw a bigger motor in a chassis. besides, my custom RX chassis is built for a 350x motor and im NOT hacking it up.