crane roller rocker's?
 

I recently rebuilt my twin 330 h.p 454's I went with .100 dome pistons to get the compression up a bit, stock cam, performer intake and stock carb and ignition. w.o.t is about 4500 r,p,m would the addition of roller rocker's make any noticeable difference? Thank's for any help.

These are 1990 non roller's also will they clear stock late model valve cover's

Re: crane roller rocker's?
 

My 509 engines have Crane gold rockers and stock covers, with Merlin rectangle-port heads. I've seen several GM rectangle-port head/Crane gold/stock cover setups without any issues, but I've also had to use double-thick cover gaskets on a couple of engines I've done.
The addition of roller rockers will eliminate the weak link that's inherent with the stamped rocker/ball setup.

Re: crane roller rocker's?
 

2 of the rockers will need to have the corners ground down for clearance for the V/C hold down bolt bosses. Even Merc does that from the factory.

Re: crane roller rocker's?
 

If you mean noticeable difference in power, that would be NO. Might give you 5hp.

Re: crane roller rocker's?
 

US1 Fountain is correct about the Roller rockers having to be trimed to clear the rocker cover. It is on the #1 & #8 intake valves. The left corner has to be radiused about 3/16" to clear.

Re: crane roller rocker's?
 

at 4500 wot with fairly small cams the rockers would only be insurance against stock rocker failure (which probably won't be a issue). Grind off oil drippers inside valve covers and use double gskts,Smitty

Re: crane roller rocker's?
 

Stock cam and springs won't overtax the stock rockers.
Rollers will give you a more rigid rocker (which you don't need with a stock cam), needle bearings and roller tips that can wear out over time and fail suddenly (whereas the stock rockers pretty much wear gradually not all at once), but they look cool.

High lift cams require either special stamped rockers or roller rockers. High spring pressures will kill stamped rockers.

Any ad that makes ridiculous hp claims for their rockers is just marketing jibberish.

Re: crane roller rocker's?
 

Just changed to Jesel and the bolts were higher. Instead of grinding we simply ordered new V covers.

Re: crane roller rocker's?
 

I agree with mcollinstn. You will not see any performance gain. You will most likely have to change rocker arm studs also to accomadate a roller rocker. And yes you will have clearance problems with roller rockers in a stock valve cover if you don't grind or shim up with gaskets. And if you are changing to rollers, I would want to go with a 3/8 pushrod instead of the 5/16 that you have in there now. I would also look at twisting that engine up some from 4500RPM. 4800-5000 RPM is fine for that engine. They are better than most people think.

Re: crane roller rocker's?
 

Does triming the rockers change the weight distribution? If so, does the balance of a rocker play a role in the performance of the valves opening and closing? Just curious. I had Crane golds installed and chose to buy some new (used) covers that I did not really like because the ones I had did not clear. If I don't trim, what tall covers will fit?

Re: crane roller rocker's?
 

Ding Ding!!! I know this is a Correct Answer!!!

Re: crane roller rocker's?
 

Thank's for the input! That is my goal getting them up around 4800-5000rpm I was looking for some easy bolt on power. I dont want to go back inside the engines.

Re: crane roller rocker's?
 

Another option to avoid the valve cover hassles. I had a set of Comp Cams steel roller rockers I wasn't using so I put them on the intakes and had to do no grinding.

Re: crane roller rocker's?
 

stock rocker usually aren't the 1.7 to 1 ratio they should be. when you go to a set of good a'mkt roller rockers you get better valve timing accuracy, durabilty and a lot of reliabilty over the stock suff. it gets even more important when you run a lot of spring pressure for hi po cams. a lot of the valves covers have oil drippers over the pivot point to try to lube the the stamped steel ones. roller rockers live long happy lives with minimal oil. you can also get a set of 1.75 to 1 ratios for intake and run 1.7's for exhaust or vice versa if your running a blower with heads that don't have good flowing exhaust ports. i say step up for the reliabilty alone and get all the other benifits for free,,, ratman

Re: crane roller rocker's?
 

Ratman,
The question is, if he were to put the rollers on an otherwise stock engine. We all know the benefits if you are running a modified engine with differnent cam and other modifications.

Re: crane roller rocker's?
 

correct valve timing will help any engine. his stocker would im sure benifit from an addl .05 rocker ratio for a better cylinder fill. wouldn't you agree? also any engine will benifit from less friction in the rocker fulcrum area, as well as much improved reliabilty.

Re: crane roller rocker's?
 

I think the key word here in his original post was "noticeable". How much HP at best would rockers alone make and how much does it take to be noticeable when you already have 700 HP?

Re: crane roller rocker's?
 

I guarantee that if you take a stock 330 HP 454 and change from the stock stamped rockers to roller rocker arms you will not notice a difference in performance. What I am saying is, it is not effective cost wise. If the engine is only turning 4500 RPM he needs to either tune it up if its in good shape, or make the changes in prop necessary to get it spinning to at least 4800 RPM. That would be cost effective. Do some head modifications, camshaft changes then you can worry about rocker arms.

Re: crane roller rocker's?
 

Yup, and on a stock engine, I quarantee the stock rockers are more reliable than the rollers.