Non-Hemi build

maknwar

maknwar

Member
#1
#1
Im looking to build a non hemi predator with RTC-8 head. It's going to be put on a asphalt go kart that will be used for parking lots and maybe on the streets in a subdivision. I would also like to use pump gas. So far I'm thinking:

governor removal
ARC flywheel
308 cam (102 centerline) (I hear this has a wide power range?)
ARC rod std + .020
Hemi flat top piston
26# springs
S/A carb


I dont want to get the compression too high that it will run like crap on pump gas. Any suggestions?
 
maknwar

maknwar

Member
#3
#3
trinik7597 said:
26# springs may be a little light for the 308 . you can mill the head some like .50/.65 and still run well on 93 octane
Click to expand...
Would 32# be better? Would I need anything special beside heavier springs like better rockers?

Just to let you know, I really don't know much about valves and what needs to be done with them. Everything else I can do.
 
Last edited:
trinik7597

trinik7597

Active Member
#4
#4
Anything heavier than 26# I use champion rockers or roller rockers .. You will need retainers and locks even with the 26# springs unless your predator head has them stock .. Some do
 
trinik7597

trinik7597

Active Member
#8
#8
Sounds like you are on the right track !!! You may have to clearance the block for the 308 just make sure to check ...and 102lsa is better for low end torque and mid range than high end speed
 
maknwar

maknwar

Member
#9
#9
I'm glad you told me cause that is what I'm looking for since I don't think I will be able to get to max speed anyway. I'm thinking tight turns and get up to speed will be what I need.
 
maknwar

maknwar

Member
#11
#11
So I broke down the engine to measure the piston height. On one side, where my finger is, it's 0.028 and on the opposite side it it 0.040. Will this be a problem? Seems excessive to me but what do I know.

https://i.imgur.com/hc4fgJE.jpg

Sounds like if I use a +0.040 rod with the hemi flat top piston I will be .008 in the hole?
 
Last edited:
OND

OND

#12
#12
Ummm if its .028 on one side and .040 on the other....I think I would go with a .020 longer rod. But aren't you going to buy a flat top piston ? I would check it again with the new piston before I bought a longer rod....just my 2 cents.
 
CarPlayLB

CarPlayLB

Well-Known Member
#18
#18
maybe you should go back to the other piston then!

Trinik meant to say to mill the head .050, not .50! Half an inch is WAY too much! Trinik failed math as a kid and had to sit in the corner!
 
maknwar

maknwar

Member
#20
#20
CarPlayLB said:
maybe you should go back to the other piston then!

Trinik meant to say to mill the head .050, not .50! Half an inch is WAY too much! Trinik failed math as a kid and had to sit in the corner!
Click to expand...
lol, yea I had to look it up after he said that. Don't think half an inch would leave much left on the head.

As for the piston, I still have the stock rod so I can get a little closer.
 
You must log in or register to reply here.
Top