originally built my motor for a big shot of nos so rings r gapped for it, now that changed my direction and went wit a na cam and intake truck is down on power , it does have some blow by comong out of catch can breather, has anyone been threw this ? I ran truck at track and its like 5-6 tenths and am wondering if this could cause loss of power on motor, iam still gna put a 175 shot but was built for a 350,

 

absolutely, if the engine was built with a looser ring gap to accomidate a 300+ shot, it will suffer a lot NA.

 

Typically you don't see a big loss in power unless ring gaps are huge, like .050" or something. Skirt clearance should have been increased too. Sure, leakdown numbers will suffer a few percent, but it won't hurt the motor a lot. Blowby may increase but oil consumption shouldn't be much worse. I mean, heck, oil and nitrous is BAD, so loss of oil control in a nitrous motor is not acceptable.

I'd be more suspicious of cam selection, stall, compression, exhaust or tune for how it runs.

 

top ring .024 second 026 is this much? I do get a lil puff from catch can but no oil

 

Ya I wouldn't hit that with a 300.. It's too tight on a 4" bore I probly wouldn't do much over 200. Unless your on e85/c16 and pulling a ton of timing. But if your down on power and it's using oil you better run a compression test and see what's goin on.