Max rpm

[6racer]

hey guys, im building a motor for my brother,hf 6.5, so far he has gotten the new flywheel, billet rod. 18lb springs, pushrods, gx160 head, intake adapter with airfilter, 275 cam, rejetted, and custom exhaust ,what you guys think the max safe rpm for this motor will be and also how hp will i end up with around?? thanks guys

Nick

 

[mmisterbungl]

you can probably get around 7K+ with no problems, it's all really up to the cam. Those cams are good for about 7500rpm and with the billet parts added you should have no worries pushing into that range. I'd guesstimate about 12HP

 

[845mx5]

You said he got the "new flywheel". Exactly what flywheel did he get? Is it a billet flywheel or just a new flywheel, possibly a new honda flywheel. If youve got the billet flywheel and rod then like already stated, 7 grand is safe, higher rpms are possible as well as safe, just limited by the cam. The faster you spin, the stiffer valve springs youll need in order to help floating valves. When they float they limit rpm. As a side note, he should have grabbed a flat top piston. It boosted compression and adds power. Not to mention they only cost about 20 bucks. When i built my motor i got the billet rod and flattop piston and installed them at the same time. He can still get and install one but he'll have to pull the motor apart again

 

[Strigoi]

the billet parts are considered safe up until the 10,000rpm range.