Topic: 895 to 836 Will there be issues??

[aggiepike]

I'm planning on going from an 895 (67mm MTC pistons) to an 836 (65mm Wiseco pistons). Reason for this is the sleeve broke and ruined one of the pistons so have to replace them. I'm looking at the old MTC piston and the valve relief on the MTC piston is offset and the Wiseco appears to not be offset. My question is can these Wiseco's be run in it or is this going to cause an issue?  I bought the bike from a buddy that didn't know what kind of work had been done to it before it was taken apart. Now that the shop has gotten into it it appears it has had lots of work, big bore, rods, cam, not sure on the head or the crank yet, but will find out. Before I have the donor cylinder block bored that I got for these 65mm pistons I want to make sure I'm not wasting time and money doing it if I'm going to have to go w/ a bigger kit because of head work that may have been done.

I've attached a couple pics to show you what I'm talking about. 67mm MTC is the old one 65mm Wiseco is the new one.

Can you guys let me know any knowledge you have of this or any info you may need to be able to help me out. If you can tell me what I need to know or ask I'll find out if that will help with this.


Thanks,
Richard

[Sam Green Racing]

It won't be a problem Richard as long as the combustion chambers haven't been opened up to much.
The MTC pistons are handed, two left and two right. the Wiseco pistons can go in any of the four.

Sam.

[aggiepike]

You're the man Sam! Thanks for the quick response.

I'll see what the shop says on the combustion chamber. Any idea how big is too big?

Thanks again,
Richard

[cbr954]

If you have the old 895 head gasket, lay it on the head and see if the chamber was ground out bigger to match the head gasket size.  Or if you have a 836 gasket lay it on there and see if the chamber fits the sealing ring on the gasket.  If it was ground to fit the 895 then the 836 gasket might not see depending on how far it was opened up.