Installing roller rockers
Thread Starter
Safety Car
Joined: Jan 2004
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From: Macedonia Ohio
Installing roller rockers
I am going to install a set of Harland Sharp roller rockers in my 65 L-79. Can anyone tell me the correct procedure. I have a feeling it is not just a matter of bolting them in. Also, I have a stock engine rebuilt with flat top pistons. Can anyone tell me if I have 3/8" or 7/16" studs? Are there any other parts that I should purchase? I am assuming I should go with 1.5 ratio as apposed to 1.6.
Thanks,
Larry
Thanks,
Larry
Thread Starter
Safety Car
Joined: Jan 2004
Posts: 4,270
Likes: 561
From: Macedonia Ohio
GCD1962,
I appreciate your feedback. I was just talking to a buddy who said the same thing. I am looking for ways to improve the car. It has been done for about 3 years and I am dying to wrench on it again.
I appreciate your feedback. I was just talking to a buddy who said the same thing. I am looking for ways to improve the car. It has been done for about 3 years and I am dying to wrench on it again.
Race Director
Joined: Mar 2009
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From: Canada's capital
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You'd be better off with a steel roller rocker like comp cams ones. They fit under the stock covers, the Harland ones don't. You won't notice any performance gain, none.
Last edited by Kerrmudgeon; Sep 25, 2010 at 06:17 PM. Reason: sp
Burning Brakes
Joined: Feb 2003
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From: Upland Ca
It's unfortunate that a person can't ask for advise and receive it. Seems now days lot's of people just want to rain on someones parade. Hopes it's just a few grouches and not corvette snobbery.
Le Mans Master
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From: Puget Sound
The comments above were made to help out the O.P. and were right on the money.
Jim
Race Director
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From: Canada's capital
2020 Corvette of the Year Finalist (appearance mods)
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If you want some fairly easy noticeable improvements, look to increasing the air and exhaust flow with headers and less restrictive mufflers, and low restriction air filter. That and re-curving your distributor with an advance kit are fairly easy, and even if you don't go a lot faster, you'll sound good....! Better than your first choice IMHO.
Le Mans Master
Joined: Nov 2008
Posts: 5,691
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From: columbus oh
I am going to install a set of Harland Sharp roller rockers in my 65 L-79. Can anyone tell me the correct procedure. I have a feeling it is not just a matter of bolting them in. Also, I have a stock engine rebuilt with flat top pistons. Can anyone tell me if I have 3/8" or 7/16" studs? Are there any other parts that I should purchase? I am assuming I should go with 1.5 ratio as apposed to 1.6.
Thanks,
Larry
Thanks,
Larry
harland sharp is the originator of the roller rockers and for many years they made them for crane cams and others
you more than likely have the 3/8" studs
if you install them and do notice a performance gain, then your old ones were faulty or were not up to the 1.5 ratio specs
follow the sticky on how to adjust them depending on which cam you are running
however you are more than likely wasting time and moolah here
jmho...good luck....
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Team Owner
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From: cookeville tennessee
I am going to install a set of Harland Sharp roller rockers in my 65 L-79. Can anyone tell me the correct procedure. I have a feeling it is not just a matter of bolting them in. Also, I have a stock engine rebuilt with flat top pistons. Can anyone tell me if I have 3/8" or 7/16" studs? Are there any other parts that I should purchase? I am assuming I should go with 1.5 ratio as apposed to 1.6.
Thanks,
Larry
Thanks,
Larry
Race Director
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Larry you have the smaller one in the studs. Plus this upgrade will help the car as far as less wear on the vavle train. And will help in freeing up some HP but like the other guys have said may not be able to tell any diff in the perforance of the roller on the car.. But will put alot less wear on the top end.. Go for it man.... And stay with the 1.5 All the 1.6 will do is give the car a little more lift in the cam...
Le Mans Master
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From: Rocklin California
Harlan Sharp roller rockers will add maybe 1% HP due to less friction with the fulcrum rocker. Check and make sure you have the correct pushrod length and I would recommend hardened tip pushrods since you are replacing the rockers anyway. Have fun 
Team Owner
Joined: Oct 2000
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From: Washington Michigan
Reduced wear on the valve stems is marketing hype; the only benefit is a miniscule friction reduction at the fulcrum that you'd need NASA-level instrumentation to quantify.
The "LS" engines (including the 638hp LS-9) and the Viper use cast-steel roller-fulcrum rockers with plain tips (see photo below) - that tells you something about the worth of rollers at the valve stem end.
The only production full-roller rocker arm application I recall offhand was the short-lived C4 Corvette LT-4 that used Crane roller rockers, and that didn't last long.
Spend the money somewhere else where you'll actually derive some benefit.
The "LS" engines (including the 638hp LS-9) and the Viper use cast-steel roller-fulcrum rockers with plain tips (see photo below) - that tells you something about the worth of rollers at the valve stem end.
The only production full-roller rocker arm application I recall offhand was the short-lived C4 Corvette LT-4 that used Crane roller rockers, and that didn't last long.
Spend the money somewhere else where you'll actually derive some benefit.
Team Owner
Joined: Oct 2000
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From: Washington Michigan
The best seat-of-the-pants performance improvement while still keeping it stock is to clean up the cast transition between the valve seats and the ports; all those sharp edges in the bowl area under the valves are hiding a LOT of mid-range power, but the heads have to come off to do that.
Thread Starter
Safety Car
Joined: Jan 2004
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From: Macedonia Ohio
Thanks John,
I should have mentioned that I have a MSD distributor. The shop I deal with plugged the vacuum advance. I am not totally convinced that was the right thing to do. This distributor has provisions to adjust the curve via different stops.(different colors)
As to the heads. Are you talking about polish and porting?
Larry
I should have mentioned that I have a MSD distributor. The shop I deal with plugged the vacuum advance. I am not totally convinced that was the right thing to do. This distributor has provisions to adjust the curve via different stops.(different colors)
As to the heads. Are you talking about polish and porting?
Larry
Team Owner
Joined: Oct 2000
Posts: 38,897
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From: Washington Michigan
Thanks John,
I should have mentioned that I have a MSD distributor. The shop I deal with plugged the vacuum advance. I am not totally convinced that was the right thing to do. This distributor has provisions to adjust the curve via different stops.(different colors)
As to the heads. Are you talking about polish and porting?
Larry
I should have mentioned that I have a MSD distributor. The shop I deal with plugged the vacuum advance. I am not totally convinced that was the right thing to do. This distributor has provisions to adjust the curve via different stops.(different colors)
As to the heads. Are you talking about polish and porting?
Larry
No, I'm not talking about porting and polishing; just cleaning up the transitions in the bowl area immediately below the valve seats.
Pro
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Le Mans Master
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