Cam size

[Evanguy]

I'm building a Honda gx200 clone, using a flat top wiseco piston at 0 deck height.

Valves are stock size 25/27 I may upgrade them but shouldn't effect PTV in the non hemi.

I'm looking at getting a custom cam from "smallenginecams" .

What is the max lift reasonable for one of these motors. I know duration effects PTV more then lift but is .380" lift with ratio rockers reasonable?

I'm thinking the .380" 256 duration 104 lsa. I also plan to use forced induction hence the cam choice

 

[bob58o]

I would tell you to message Tim @ Isky but he is probably busy. I messaged him once about cams. I did get a return phone call but at the time it took a few months for the reply. I think I forgot about it, then got a call out of the blue.

 

[Evanguy]

That's kind of what I was thinking. So I asked I the forum instead Incase anyone has some knows the limits on cam sizes and fitting in the block, cam not into the piston and not causing too much of an issue to deal with about binding..

 

[BrownStainRacing]

I'm building a Honda gx200 clone, using a flat top wiseco piston at 0 deck height.

Valves are stock size 25/27 I may upgrade them but shouldn't effect PTV in the non hemi.

I'm looking at getting a custom cam from "smallenginecams" .

What is the max lift reasonable for one of these motors. I know duration effects PTV more then lift but is .380" lift with ratio rockers reasonable?

I'm thinking the .380" 256 duration 104 lsa. I also plan to use forced induction hence the cam choice

It's gonna take a hellva head to work a .380" lift cam.

Stock heads with a lil port work and clean up, works great from .265" - .310" lift, any more lift is a waste of money and time unless you get a head thats capable of handling .380" lift.



All heads will start to fall off at a certain lift.

The isky BMJ is a stump pulling cam, it comes on fast and hard and still hits 6000+ rpm, the best all around cam i have seen in ANY build. Works excellent with 9.5:1- 10.5:1 CR on pump gas.

The isky BM is more of a mid range to high rpm, power cam. A very good cruiser, drag cam. Needs 10.5:1-12:1CR to really work. It will still pull hills, but it don't have the hole shot like the BMJ.

I suggest you try a BMJ, for experience, then maybe a custom later on down the road, after you learn what it takes to build these engine to run and last with a .380" lift cam.

 

[Evanguy]

Thanks for the reply..my plan is to force the head to flow.
I'm going to make a build thread for the motor and trike here soon. I'll have a few questions and then I can keep the convo in one thread.