Wes Burmark

I read in an automotive magazine (some time ago) that roller rockers showed little h.p. gains on a dyno but lowered oil temperature up to 20º. Does anyone have any personal experience with this? I had roller tip Magnums on my last twin small-block boat but did not have oil temp gauges on that boat to make any kind of back-to-back comparisons. Do roller rockers fit under stock 6.2MPI valve covers?

Trash

I can't comment on whether they lower oil temps or not. Seems logical they might, but like you, I don't have an oil temp gauge.

I can comment on what will fit under the stock small block valve covers. I have a late model 1 pc rear main seal block with the center bolt valve covers on Dart heads with ARP 7/16" rocker studs. I went from the stock rockers to aluminum Crower full roller and they indeed take up a bit more real estate, BUT, the stock covers will fit with some careful tweaking and one little trick.

The inner valve cover support braces "may" need to be trimmed away to fit between the rollers. The tightest spot is between the trunions, but once the bracing is past/below the fulcrum point there's plenty of room. You can usually just squeeze the inner brace to fit between the rocker trunions and you'll be good to go.

The oil breather baffle needs to be pinched a little (with your bare hands) to fit down between the rockers too.

The second issue is height. The lock on the castle nut would just "BARELY" touch the top of the valve cover when torqued down. The rocker itself clears with no problems. To solve this use a double thick valve cover gasket (got mine from Summit) and it lifts the cover enough to clear the lock nut without causing the valve cover to intrude into exhaust manifold space or any other item around.

Hope this helps.

low_psi

It would make sense that they would reduce temps somewhat, as they do reduce friction. Don't know about 20 degrees... That seems like a lot. 20 hp sounds believable with roller rockers....

dereknkathy

roller rockers won't give noticable power gains by themselves. they WILL allow you to run a cam that a flat-tappet lifter can't keep up with. that's where the power increase comes from. i would also doubt 20 degrees temp drop from less friction...

Raylar

The amount of actual friction eliminated by roller rockers is minimal based though on the camshaft profile, lift and the valve spring pressures. They are more important for valve train stability at higher rpms than the friction elimination and on higher horsepower engines with higher operating rpms they are more necessary and effective.
As long as your 6.2L is basically stock and mild-save this money and spend it towards other upgrades.
As for lowering oil temperatures by 20 degrees or 20 percent- Nope,Don't believe everything you read in magazines.

Best Regards,
Ray @ Raylar

articfriends

iTrader: (1)

I'll reiterate what Raylar said too: A roller rocker on a stock application is not going to show a measurable gain over a stock one , make the lift .150 higher though and add another 150 psi of spring pressure and those stock rokers will turn blue and fall apart in short order wheras a quality true roller will keep on chugging along , Smitty

BadDog

Do they help preserve valve guides due to lower side loading?

Raylar

Yes, I think they probably eliminate a little side loading on valves and guides if they are working properly and valve train geometery is ok. If the particular heads being used have high valve wear issues or weak valve guide material the rollers may help but they won't correct issues in the head from these areas. In higher rpms and higher spring pressures this becomes more of a factor also. Many performance boaters with mild performance engines are obviously always looking for a little extra power at fairly low costs but things like roller rockers are not the panacea that many hope they will be when it comes to just making more power.

Best Regards,
Ray @ Raylar

Still Crazy

iTrader: (1)

They will only increase guide life if the geometry is correct. I personally would never install a set of rollers without checking the geometry first with an adjustable pushrod and a marker.