From the ripples in the top of my power curve I't seem's I'm getting valve float from my dyno gragh right before 6K RPM, I was expecting my power to peak around 6.2K RPM before this would happen. I have a TR224 cam,Comp R lifter's that I know are not the best for my combo,TR 7.4 Inch push rods,stock rockers,and stock out of the box 205 AFR heads. I'm thinking I have too much preload on the lifters and the valves may be hanging open.What do you all think? Too much preload on the lifers? Do you think ajustable rockers would be the fix. Thanx in advance.

 

Which 224 cam is it. The .551/.563/.581 lift version? What type of springs? Did you check the pre-load on the lifters? If you just installed the stock rockers at there normal setting, then there is deffinatlly to much pre-load. I would go to Lowe's or Home depot and get you some 5/16 or 8mm flat washers that are about .045" thick and place them under the rocker shaft. That will relieve alot of the pre-load, but you should deffinatlly check it. Place your #1 piston at TDC, tighten the rocker bolt until all play is removed between the pushrod and lifter, then see how far around it is until 22 ft lbs. I would want about a 1/4 turn at most on those lifters. You can play around with diffrent washer thicknesses to get the load where you want it.

 

The cam is a TR 224 with a .562 of an inch lift, I was told by AFR that the springs are most likley Patriot golds, I'm not shure how much preload I used, I just put in comp R's in and tighend down the stock rockers. I was told the comp R's would work. Thanx for the info, I'm gonna try shiming my stock rockers.I really hope I didn't slightly ding my pistons because I have reved past 6.5K RPM.

 

Be sure and check the thickness of the shims. The washers I used varied a bit in thickness, so I had to carry my caliper to the store with me to get 16 that were within a few thousandths of each other.

 

Just get comp pro magnum rockers..adjust preload .008-.010 (1/5turn) like its supposed to be done...clearance your valvecovers...check the pushrod length...do it right and dont guess.

 

Not enough spring rate does the same thing

Dave

 

You need adjustable rockers with comp Rs

Brad

 

Dave,

he has plenty of spring for that cam.

Brad

 

Thanx guy's.

 

I am under the impression that it does not matter on the ls1 for you to set pre load that is why the engine hydralic stuff.....But I am not possitive. I was also under that you had to use rockers with the comp r's to make them work