Open clone motor questions

Bartlome27

New member
I just started running these clone motors. Don't know to much about them. Need to know some suggestions on what to run in my open clone motor. I am building it myself. My AKRA motors run with the big builders, but not sure what to do in the open class. Gas or alky? Cam? Rocker Arms? Head cc? Header or big pipe with muffler? valve springs?..... I have a worked over carb, .930 big pipe with muffler, A CL1i dyno cam, 18 pound valve springs (even though I should be running 28, but head is not milled yet, not knowing what to cc it to).
 
What do you want to build ? lots of ways to do it.
Do you want a full open or a limited mod ?

For starters you will need to pick a good cam
then decide what rocker you want.
Do you want to stroke it or stay stock stroke?
Fuel choice would be alky then pick a carb.
big valve or small? What rpm range you looking for ?
If you don't want to break the bank I would look at
a small open or in other words a limited mod.
and still make great power.

Just tossing stuff out here other thoughts may vary.

Tilly carb
cam with 308 or more
big valve but not always better.
14 18 22 cc heads milled to the compression your looking for.
dual valve springs or strong single in the 32-37 range
bore .030
ratio rockers 1:2 or 1:3 or stay with 1:1 if going big lift.
 

Rbb200183

New member
Alky all the way, your cam is for a stock class, not sure on your track size, nrracing.com sales a 274 cam that does great with 1.2 or 1.3.. Smallenginecams.com is a great place to buy parts also.. 18 pound springs ant going to cut it, 26s or more.. I have a oem 18cc head cut 90 thous maybe 9 or 10 ccs now?????..
 
Maybe 9 or 10 cc now ??????

I would check it if you don't know.
jmo but a 14cc head with big valves
and no milling would come in at 16cc
and also flow a little better again jmo


Old saying from a while back but still holds true

A head from stock to milled now is at 120 psi
yes you went up in compression but also went
backwards in hp the engine can make.
then take same motor but do a real good job
in porting and now it reads 140 psi your on you
way to making hp.got to have the best of both.
most will take flow over compression its a balancing act for sure.
 

Flash06

New member
I don't think you can make these little heads flow enough to get that kind of compression out! You have to be running into a compression block, jmo.
 

Yakattack

Member
I would talk to minidragbike over on old mini bike about that...
He could have got one from him.
Welded up and what not....to get that cc with the big valves...
Just sayin...
 
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