Those with roller motors...

[mountainexplorer]

So, those of you that have or have run roller motors... any comments on how you liked them?

I've never had one before, but am considering getting one. It's a 454 with a Comp roller cam, roller rockers, 781 casting heads that are ported, domed pistons (was about 10.5:1 or so compression ratio), and Pete Jackson gear drive. It ran hard, but is currently apart to just re-ring and bearing and fix a valve guide that started wearing. The cam that was run in it was Comp Magnum hydraulic roller 260/260 adv duration, 206/206 @ 50, .510/.510 lift.

I was thinking if I got the motor, about possibly going with the 280 cam with .566 lift... depending on how big of a cam I can go.

 

[BadBob]

There's a lot of area under the curve with a roller, but if you like to wind the crap out of the engine you need to buy the valvesprings that match, and the lightest retainers you can afford.

 

[mike n]

For a Big Block a .510" roller cam is a waste, imo. Roller's are nice when your net lift gets above the .620" range, or you want to go drag racing with a 12 to 1 compression engine. For the street or the trail, a nice hydraulic or solid flat tappet cam should work nicely.

If I had that engine I'd scrap the roller and the PJ gear drive and run something like a Comp 280 Hydraulic and a Cloyes double roller timing chain setup.

 

[mountainexplorer]

I've never run a roller motor before and always have been content with regular hydraulic cams. But the way this motor ran and how it seemed to have good power and response is what made me consider getting it and running a roller cam in it since it's all set up.

This is it in my friend's Blazer (the brown '84 k5)
http://video.google.com/videoplay?docid=3907031540337741516

Supposedly they are more responsive and can handle higher reving than normal hydraulic cam motors. Is that true? It ran hard with that smaller cam in it... and I'd want to put a bigger one in it, at least the .566 lift or bigger... as long as I don't hit the pistons.

The gear drive in it was a Pete Jackson noisy gear drive, which was quieter than my small block Cloyes gear drive which wasn't too loud. He called Pete Jackson and they said that with a roller cam a gear drive isn't as noisy because there's less vibration or something? Thats what he was told.

 

[Ryan B.]

I had a hydraulic roller in my big block before i went to a solid roller.
Even with my hydraulic roller i could buzz it to 7,000 without floating the valves. I probably floated the valves once or twice in the 3 years of romping on that hydraulic roller cam..

If you get it and want to go bigger with the cam, take a head off it, put some clay on the top of a piston. retorque the head on with the gasket, and spin the engine over once.
Then you can cut the clay in half and measure your piston to valve clearance. Then you can calculate just how much more lift you can get away with before your getting tighter than about .100" PTV clearance.