Author Topic: Best Zinc additive?  (Read 4049 times)

Offline Blind Mule

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Best Zinc additive?
« on: March 19, 2013, 04:07:34 AM »
Best for breaking in a new flat tappet cam and also which oil has the most?

     Randy!

Offline Frontenginedragsters

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Re: Best Zinc additive?
« Reply #1 on: March 21, 2013, 06:33:11 PM »
Randy:
 We use Brad Penn racing oil and are very happy! :)
But, open valve spring pressure MUST be checked and mutiply x the rocker ratio.
Most people check seat pressure and thats it. We find most cam failures are a result of to much
open pressure. Typical small Chevy/Ford with 1.6 ratio x 350 open = 560LBs.
Failure happens on a flat tappet cam after about 625-650 lbs open @ the lifter.
If you were to order a cam from a good company try to request a P55 core. Its better material and lasts longer.
Break-in is just as important. Prime the oil pump just before starting. Set the timing as close as possible before starting.
When that motor fires you have to get it up to 3000-4000 RPM instantly and do not let it idle at all. This spins the lifters fast
and also puts the oil pump at a high volume rate. Run it for a couple of minutes at a time and check things over and let it cool down.
Repeat 3-5 times until you get about 15-20 minutes total. We build about 30 engines a year with flat tappet/solid lifters and this as worked good
for me for 25 years. ;)   Matt
Driving a Front Engine Dragster builds character and keeps you awake for a 1/4 mile at a time.
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Offline Blind Mule

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Re: Best Zinc additive?
« Reply #2 on: March 23, 2013, 02:14:15 PM »
I had a 302 coupla years ago that wiped 3 cams before I found out what was wrong it was the same lobes every time ??? Found out that the lifter bores had a tiny scar and the lifters didn't spin very much got me a brake cyl. hone and fixed that problem that was one of the best motors I ever had won lotsa bracket races with it wish I had it back too!

  Randy!