Panther

Good idea, I wish I did the same last year.

birdog

It sucks , dont It ?

All worth it in the end though....Or so they tell me

Whiteknuckle

formula31, you mean you are going to go roller in one engine and flat tappet in the other? I'm wondering if the GM additive that RMBuilder recommended for break in would be a supplement to use all the time?

formula31

Ok, nevermind. I went through finances and what this was gonna cost me and what I had to still spend (ive got both drives apart too) and chickened out. I ordered a replacement for the flat tappet. Im gonna use Rotella and eos. Im also gonna lean up the carbs a little this year. Comp Cams has some stuff too Im gonna look into. I may also groove the lifter bores to get better oiling of the lobes. The roller cam was gonna be another experiment as far as reversion and power and I am very happy with what I have now. Ill just hope the new casting is better than the last.

Panther

I've learned from my mistakes. Put a hyd. flat tappet cam in my 580's last winter. Lost a lifter and cam lobe within the first 2 hrs. Cost me $2K to fix the damage...

I still cross my fingers everytime I start up the motors.

jpclear

The first 2 hrs. was the break-in period. Guess you had real junk from the get-go or the break-in additives and/or proper procedures were not used. And, I DO prefer roller lifters. It's just that it's not really practical for everyone to convert; and done properly, flat taps will do the job! --- Jer

Panther

I wasn't there when the motor was first fired, so hopefully it wasn't run at an idle when it was first fired? We also found that the seat pressure was about 5 lbs off.

I think one of the lifters must have stopped turning. Second time around was good because someone with some sense put it together.

I still have my druthers and would rather go roller. Also, the dyno results were less than stellar with the flat tappet, I'm at least 75 hp off.

jpclear

Really shouldn't be 75 hp diff. with just the lifters; BUT, you can use a better (steeper ramp) cam with roller lifters and make more hp with less drag, heat, friction, and wear. If it's in the budget; GO FOR IT! --- Jer

formula31

Ive always had good success breaking them in but I follow all the rules. Except the one about spining the lifter by hand if it doesnt start spinning on its own. Ive never figured out how to accomplish that one.

The one I have to change apparently was a bad casting or bad heat treat. Lifters were fine and lobe peaks were not worn off, just missing pieces.

rdoactive

FYI, there's an article in Car Craft now. Crane Cams is also blaming thier lobe failurs on low zinc content of new oil formulations.
Gary