Are roller rockers a simple "bolt on" job, and is going to a 1.6 ratio any better on a stock internally engine? Was thinking of going with some stamped steel rollers, with new pushrods.

 

Yes they just bolt on. I would go with a complete roller not just a roller tip(waste of money). The ratio will also help you out. Comp cams makes a nice set of aluminum or chrome moly, stay away from the stainless rockers they hold heat.

 

I think they would be especially helpful to raising top end breathing on a base engine, where the cam is pretty small. I have 1.6 ratio full rollers under stock valve covers. Had to use very thick gaskets, but they fit. Tried a couple of other 1.6 rockers before settling on the GM self-aligning 1.6s. Others hit the covers.

No doubt very soon someone is going to chime in that you won't gain anything in power. That may be true, depending on your combination. I've seen dyno tests with gains ranging from 5HP to 20HP. No doubt you gain a lot more if your cam is too small to start with. It's certainly easier than changing cams.

OEM stamped rockers are generally not 1.5:1, even though that is what they are nominally spec'd at.

 

Roller tip rockers will fit under most stock valve covers if you use stock adjusting nuts. Full roller rockers usually won't fit under stock covers, especially if you use poly-lock nuts.

Upping the rocker ratio to 1.6 increases the lift at the valve slightly. It also increases the effective duration very slightly. Whether or not this is any benefit to you will depend on the cam you have, the rear end ratio in your car, and the way you normally drive.

The term "stamped steel rollers" sounds like roller tip rockers to me. They have the benefit of reduced tip friction, but I doubt that is an improvement you could feel.

If you're going to the trouble to install new push rods, I suggest you use those made in one piece of high strength steel. The cheap ones with separate ball tips will bend easily and the ***** can come off. I know.

 

The only real benefits to the roller tip rockers are:

1. Reduced Valve stem and guide wear.
2. Very slight increase in rocker ratio (stock rockers are actually less than 1.5 - some say 1.44, some 1.47, etc., and the Comp. Cams rockers are 1.52.

I have used them for many years (in several different vehicles, all under the stock valve covers), mainly for the reduced wear aspect. If I need to replace the rockers, a slight upgrade does not hurt (and since I do my own valve jobs, including guide replacement, I have seen a reduction in guide/stem wear - of course, better oils don't hurt either).

I have also used full roller rockers, but only on race vehicles. The older full rollers did not have a very good reliability record, and they do cause "fit" problems under stock covers. But the full rollers are the best bet for max power.

As for the Crane stamped steel / roller tip versions, I have not used them, and probably never will (very pleased with the Comp. Cams units).

Going to the 1.6 ratio, I agree with what has been stated previously. If you have the cam specs, give a call to Comp. Cams, and ask their opinion. They are very honest as to what changes you will see. Last time I asked them that same question, I was talked out of going to the 1.6 ratio rockers (for the cam / engine combo I was usiing).

Plasticman

 

One of the magazines (Super Chevy, Car Craft, or one of those) did a back-to-back live dyno comparison of stock vs. 1.6:1 rockers on the same engine ("Mighty Mouse"?) with four or five different camshafts about a year ago to answer that age-old question, and the data (zero to 5hp increase) indicated the change wasn't worth the effort, regardless of the hype in the catalogs, especially if you have to modify the pushrod slots in the heads to get the required clearance. I wouldn't bother.

 

Right on John,

 

Not sure what my cam specs are, sooooo? I really just wanted to freshen up valvetrain, so sounds like 1.5 would fit the bill just fine. My buddies truck recently lost a rocker, which in turn wiped out two pistons, so it kinda got me thinking. Maybe i'll just pull the heads and have em done up. I'm not sure how many miles are on this engine, so in my opinion it will give me some piece of mind knowing heads are "new". Thanks again for the well taken advice everyone.

 

While others have mentioned that this is a simple bolt on operation, not one has told you that to use 1.6:1 ratio rockers, you may have to (will probably have to) elongate the slot in the heads that the push rods poke through or the push rods will rub. This will require that the heads be removed for this grinding, unless you want shavings in your oil.

(I guess that even with advise, you get what you pay for.)

 

Why not just go with the 1.5's would you still have the same clearance trouble? If not that would hat save some trouble. I have read in Chevy Hi Performance magazine that some of the advantage to these Full Roller Rockers and Roller Tip Rockers is the accuracy of the ratio's. That even the 1.5's can make a difference in Hp (maybe not a big difference) because your essentially making the valve lifts consistent across all eight cylinders,in theory balancing power made by each cylinder by getting rid of the supposed 1.42 to 1.5 variance in the rocker ratios across the intake and exhaust valves. You will still get the benefit of reduced friction or wear.

 

The easiest and best bang for the buck would be to use the 1.52:1 roller-tip rockers. No clearancing is necessary and the stock valve covers work fine. A true roller may get you a couple more hp, but depending on your set-up, it may not.

I use the Comp Cams roller-tip rockers and the Crane Cams Vintage Muscle 327/350 hp cam and my 331 CI (9.5:1 CR) makes about 300 hp at the wheels (293 ft-lb/293 hp measured on the chassis dyno before some carb mods and a Lars tune-up). The roller-tip rockers should work fine for you too.