84cfi3.73

On a 1984 corvette is it worth it to go to the effort to install roller tip rockers on the crossfire engine? If it is worth it which ones fit under the stock valve covers? How much hp gain is it if any?

Cliff Harris

If you don't change the rocker arm ratio there will be no horsepower gain. I have heard that the oil temperature will be lower because of less friction between the rocker arm and the valve stem.

I have the Comp Cams steel roller tip rocker arms on my car.

Jay7199

nope. full roller or don't waste your time.

corvettenorway

I have the Comp Cams roller tip 1,6 , gain - yes ! they are bolt on under stock valve covers

John A. Marker

I would suggest that you go with the full rocker, not just the roller tip.The heat is generated between the pressed rocker and the half ball that goes under the stud nut. Yes there are groves in the ball to oil this area. When I installed the full rocker my oil temperature dropped 8-9 degrees. The pressed rockers you have on there now are supposed to be a 1:5 ratio but when measured usually run 1:45 +/_. The 84 might be like my 85 and idle better with a split ratio of 1:5 and 1:6. The 1:6 on the exhaust valves. You will see a 5-7 gain in HP. You can find several manufactures that make the split ratio.

You will have to cut off the drip tabs under the VC and might need to go to a taller VC gasket.

mike100

The roller tips gain performance over the stamped steel units. As mentioned previously, the oem ones are more like 1.45 or 1.47 ratio and the roller tips (at least Comp Cams brand) are 1.52 to 1 ratio.

I put a set on a 305 L98 on a 5 speed camaro and I could totally feel the extra pop. That said, a stamped steel, non-roller 1.6 could make more power than a 1.5 full roller just due to the cam function. I do not trust fancy rocker arms on a street engine. If you aren't endurance racing, why spend the money? A 5500 rpm smallblock? I don't think so. Roller tip units are proven to be reliable and not too expensive. Look how much trouble GM had with the LT4 roller rocker recall... if I had to do it, I'd probably buy Crower shaft mounted ones, but I think you might need the tall valve covers.

mtwoolford

if you're on a budget...or even if you aren't...roller tip rockers have a definite advantage. The roller ROLLS across the valve stem tip and doesn't impart a side load on the valve stem = (much) less wear on the valve guides. Do it

84cfi3.73

Do you recall the part number or does comp cams only make one roller tip rocker?

corvettenorway

http://www.ebay.com/itm/Chevy-265-283-302-305-327-350-400-Comp-Cams-Magnum-Roller-Rockers-Arms-3-8-1-6-/150782152924?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item231b5110dc pics in my crossfire album https://www.corvetteforum.com/g/picture/1347320

84cfi3.73

I see some sets of roller tip rockers have 7/16 and some have 3/8? Which to get for the C4 84 350 small block?

corvettenorway

3/8

84cfi3.73

Do they fit under the stock valve covers without hitting? What valve cover seals did you get? I see in ebay you can get a whole kit with pushrods for a bit more money?

corvettenorway

Do they fit under the stock valve covers without hitting = yes ! valve cover seals =stock ! go get the set / with pushrods !

84cfi3.73

Thanks for your help. I better get a professional to install them. Not sure in how tight to set them.

corvettenorway

tigten to you can feel it turning the pushrods , then 1/2 turn

WW7

Tightening roller rockers, or roller tip rockers down is the easy part, you have to check to make sure the rockers aren't making contact with the spring cap or spring, or they can self destruct in minites after startup, there should be a minimum of 0.040 between the rocker and spring cap....You also have to make sure the roller is dead center on the valve tip so you get a straight line drive from the rocker,If it's not in the center the push rods may need to be changed,, if it's off one way or the other you will get excessive premature valve guide wear because the push rod isn't being pushed straight down.....There's a lot more to installing aftermarket rockers then just pulling the old ones off , and bolting the new ones on..For the top end to last, the geometry has to be perfect.....WW

84cfi3.73

I have seen some that say self aligning that should take care of the being dead center problem.

Jay7199

you know on the subject.. the 84 heads (assuming you still have a 84 with stock heads) don't have open pushrod area, it has just small guides that i believe would act the same as having guide plates.

mike100

The self aligning ones are for oem GM roller cam engines from 1987 onward. The non self aligning (OG type of rocker arm) is for older heads with the cast in push rod slots that acted like guide plates. If you have aftermarket heads or reworked GM heads for use with a big cam, you may already have guide plates in which case you could run either style. I think full roller rockers may need guide plates no matter what.

You can run non-self aligning rockers on a roller cam engine for about 2-3 years (with a stock cam), but eventually the valve stem scrub will wear down to the retainer and all hell will break loose when the valve drops down into the cylinder. (ask me how I know).

rocco16

That ^ is the bottom line.
Here are some of my thoughts:

The power that is gained from going to 1.45 to a 1.52 rocker arm ratio will barely be measurable. It certainly cannot be felt by the driver. I had a set of Comp Cams roller tip rockers installed in my built 400 cu. in. smallblock years ago. Two of the roller tips seized at about 8500 miles. Replaced all the roller tips with stock rockers; engine ran the same.

95% of the friction in a stock (stamped steel) rocker comes from the fulcrum. The tip contributes almost nothing. Go full rollers...steel or aluminum...for any benefit. Stamped steel with roller tips are a waste of money.

I now have nearly 100K miles on my LT4. The aluminum roller rockers have given no problems. If a component is acceptable for endurance racing, it will have no problem giving good service on a street engine. Endurance racing is the ultimate test of engines.