Jump to content
Sign in to follow this  

Help with my big bore project!!!!

Recommended Posts

Ok I'll try and keep this short. I'm doing a 94mm bore, on my 400S, through MT and running RHC cams so I can put in my stroker next year. The problem I have run into is that MT doesn't offer a Compression Ratio high enough to keep the bottom end on the bike with a 94mm kit. The 94mm comes with 12: 1 CR. I need 13 or 13.5: 1 to keep my bottom end for trails and run pump gas for all of the commute?. How can I get a good enough compression with the 94mm bore to keep the bottom end? Should I just go through Lukes and build the kit with individual components, adding the high compression piston?

How can I get the higher compression with the smaller bore? The 94.5 and 95.5mm bores come with a 13: 1 CR, but not the 94mm. Nate, Ed, somebody........ HELP!!! Reply to this message or email me at manfpc03@bellsouth.net or call me at 865-898-3590. Your help would be greatly appriciated in getting this matter ironed out so that I can build my motor.

Share this post


Link to post
Share on other sites

if you absolutely have to have the 13.5 to 1 you need to go 94.5mm or machine the cylinder base .020".

that will require cam degreeing.

Share this post


Link to post
Share on other sites

I don't absolutely need 13.5: 1. I just want to keep the bottom end on the bike. I do much trails in the mountans and lots of street commute on the highway. I want a better top end and to keep my bottom end with the 94mm bore. Next year I'll be having Dave do the work to an LTZ crank that I have for the stroker project.

Basically I want a compression that is going to be high enough to let me keep the bottom end and not so high that I run into a lot of money. SO the highest compression that I can run with a 94mm bore and RHC cams and no excess work.

Share this post


Link to post
Share on other sites

the big bore itself will keep plenty of bottom end.

i have a Athena kit for sale if your interested.it was on a motor,but never fired.

i will sell it for dealer cost.

Share this post


Link to post
Share on other sites

If KVO doesn't want it I might be interested.

PM sent Ed.

Share this post


Link to post
Share on other sites
the big bore itself will keep plenty of bottom end.

i have a Athena kit for sale if your interested.it was on a motor,but never fired.

i will sell it for dealer cost.

So the big bore with RHC cams will run a good bottom at what compression? Remember I still want to run 93 octaine.

Ed, I PM'ed you about the kit. I'll probably take it if the price is right. How will you do on a trade for an LTZ motor that I have dismanteled? I wrote a post about it a while back and you said it may have had an oiling problem. The Cylinder is what I have planned to send off and the crank was going to dave for the stroker work..........but............. if you want you can call me at the # I posted above. Also when I have the stroker built, You will do the work. As long as I can get one of those custom "built by burned" plates for it.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×