roller rockers
12-18-2010, 07:39 PM
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roller rockers
Hey everyone,
I have an L98 from a 91 vett with aluminum heads. My question is if I up grade to 1.6 roller rockers to get a little more lift can I keep the stock valve covers or do you need deeper ones?
I have an L98 from a 91 vett with aluminum heads. My question is if I up grade to 1.6 roller rockers to get a little more lift can I keep the stock valve covers or do you need deeper ones?
12-18-2010, 08:50 PM
#2
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Car: 87 IROC L98
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Re: roller rockers
The ratio change is done by moving the pushrod location slightly closer to the rocker stud. It doesn't change any other aspect of the rocker so wherever a 1.5 rocker will fit, so will a 1.6 rocker.
Rocker design however may cause problems. The aluminum roller rockers have a larger body than the stock stamped steel ones. This "might" cause interference with some rocker covers but normally doesn't. If you use a high end rocker like the Comp Cams Pro Magnum (old name, they've upgraded), they'll fit even better but will cost you a lot more.
Going from a stock stamped steel rocker to even a 1.5 roller rocker will be an improvement. The rocker ratio with stamped steel rockers is nowhere close to being exact.
If you went from a 1.5 roller rocker to a 1.6 roller rocker, you might see a 5ph gain from the increased lift.
As long as you're using a stock cam, there's never a problem from using 1.6 rockers. If you use an aftermarket cam with more lift, there are a lot of clearances to check to make sure using a 1.6 rocker won't cause any problems.
Rocker design however may cause problems. The aluminum roller rockers have a larger body than the stock stamped steel ones. This "might" cause interference with some rocker covers but normally doesn't. If you use a high end rocker like the Comp Cams Pro Magnum (old name, they've upgraded), they'll fit even better but will cost you a lot more.
Going from a stock stamped steel rocker to even a 1.5 roller rocker will be an improvement. The rocker ratio with stamped steel rockers is nowhere close to being exact.
If you went from a 1.5 roller rocker to a 1.6 roller rocker, you might see a 5ph gain from the increased lift.
As long as you're using a stock cam, there's never a problem from using 1.6 rockers. If you use an aftermarket cam with more lift, there are a lot of clearances to check to make sure using a 1.6 rocker won't cause any problems.
12-18-2010, 09:16 PM
#3
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Car: 1983 Z28
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Re: roller rockers
I am assuming I have "blue" Summit roller rockers that are 1.5rr. Would I know or see any improvement going with 1.6?
(I'm assuming this, because they were blue and the summit rockers that are blue are 1.5, but idk if they are summit brand either)
(I'm assuming this, because they were blue and the summit rockers that are blue are 1.5, but idk if they are summit brand either)
Last edited by TheMonster; 12-18-2010 at 09:23 PM.
12-19-2010, 09:20 AM
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Re: roller rockers
The ratio change is done by moving the pushrod location slightly closer to the rocker stud. It doesn't change any other aspect of the rocker so wherever a 1.5 rocker will fit, so will a 1.6 rocker.
Rocker design however may cause problems. The aluminum roller rockers have a larger body than the stock stamped steel ones. This "might" cause interference with some rocker covers but normally doesn't. If you use a high end rocker like the Comp Cams Pro Magnum (old name, they've upgraded), they'll fit even better but will cost you a lot more.
Going from a stock stamped steel rocker to even a 1.5 roller rocker will be an improvement. The rocker ratio with stamped steel rockers is nowhere close to being exact.
If you went from a 1.5 roller rocker to a 1.6 roller rocker, you might see a 5ph gain from the increased lift.
As long as you're using a stock cam, there's never a problem from using 1.6 rockers. If you use an aftermarket cam with more lift, there are a lot of clearances to check to make sure using a 1.6 rocker won't cause any problems.
Rocker design however may cause problems. The aluminum roller rockers have a larger body than the stock stamped steel ones. This "might" cause interference with some rocker covers but normally doesn't. If you use a high end rocker like the Comp Cams Pro Magnum (old name, they've upgraded), they'll fit even better but will cost you a lot more.
Going from a stock stamped steel rocker to even a 1.5 roller rocker will be an improvement. The rocker ratio with stamped steel rockers is nowhere close to being exact.
If you went from a 1.5 roller rocker to a 1.6 roller rocker, you might see a 5ph gain from the increased lift.
As long as you're using a stock cam, there's never a problem from using 1.6 rockers. If you use an aftermarket cam with more lift, there are a lot of clearances to check to make sure using a 1.6 rocker won't cause any problems.
12-19-2010, 06:35 PM
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Re: roller rockers
Sweet that cleared a lot up.. ALKYIROC u should make that first post from u a sticky for others that are interested in upgrading there valve train..
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12-20-2010, 09:21 AM
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Re: roller rockers
Has anyone used the ProForm roller rockers? I was looking at the Comp ones but notice I could save a lot with the ProForm ones. They are listed to work with the center mount valve covers as well.
12-25-2010, 01:01 AM
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Car: 1986 Vett, 2001 Expedition
Engine: 383SBC 435 H/P, 500 TQ
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Re: roller rockers
To run rolller rockers under the stock L98 Valve cover you need to grind down the drip tabs under the valve covers you see them when you flip them over.
A lot of us Vett guys end up doing this are self so we can use roller rocker arms under the stock Valve covers.
On the C-4 Vett we can't run tall Valve covers on mine Tall Valve coves willn't clear the windsheild wipper motor and some of the later years they hit the A/C compresser un less you cut and reweld the covers to fit.
A lot of us Vett guys end up doing this are self so we can use roller rocker arms under the stock Valve covers.
On the C-4 Vett we can't run tall Valve covers on mine Tall Valve coves willn't clear the windsheild wipper motor and some of the later years they hit the A/C compresser un less you cut and reweld the covers to fit.
12-25-2010, 07:34 AM
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Car: 1978 Chevrolet impala
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Re: roller rockers
ProForm have a pretty shady reputation. A lot of their stuff comes poorly machined and doesn't always fit right. I had a set of roller tip rockers from them and busted two tips in like 1500 miles.
This is not to say their products WONT work, just that they have been known inthe past to be less than stellar. You get what you pay for.
This is not to say their products WONT work, just that they have been known inthe past to be less than stellar. You get what you pay for.
12-25-2010, 11:49 AM
#12
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Car: 88' IROCZ
Engine: 388 TPI Motown 350 Race block
Transmission: 700R4
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Re: roller rockers
Mine are ProForm 7/16 RRs. No problems to date, but I don't race, and haven't been to the track so they've only been through normal wear & tear.
12-25-2010, 01:00 PM
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Car: 1986 Vett, 2001 Expedition
Engine: 383SBC 435 H/P, 500 TQ
Transmission: 700R4
Axle/Gears: 307
Re: roller rockers
I have a set of cheep China brands in my motor now I going to swap them out for a set of Comp Cam Magnum Ultra SS.
Yes they are over kill for what I need them for but I dont have to worry about them failing on me 100 miles away from home.
I read lot engine failure due to the cheeper China brand RRA Like other have said pay now or be walking sooner or latter.
Yes they are over kill for what I need them for but I dont have to worry about them failing on me 100 miles away from home.
I read lot engine failure due to the cheeper China brand RRA Like other have said pay now or be walking sooner or latter.
01-05-2011, 09:44 PM
#14
Re: roller rockers
To run rolller rockers under the stock L98 Valve cover you need to grind down the drip tabs under the valve covers you see them when you flip them over.
A lot of us Vett guys end up doing this are self so we can use roller rocker arms under the stock Valve covers.
On the C-4 Vett we can't run tall Valve covers on mine Tall Valve coves willn't clear the windsheild wipper motor and some of the later years they hit the A/C compresser un less you cut and reweld the covers to fit.
A lot of us Vett guys end up doing this are self so we can use roller rocker arms under the stock Valve covers.
On the C-4 Vett we can't run tall Valve covers on mine Tall Valve coves willn't clear the windsheild wipper motor and some of the later years they hit the A/C compresser un less you cut and reweld the covers to fit.
(Here is my thread covering my issue with pictures, https://www.thirdgen.org/forums/tech...-wont-fit.html )
Clearanceissue-valvecover4.jpg?t=1294284280
01-05-2011, 10:22 PM
#15
Re: roller rockers
Run the comp magnums... roller tip design and a lower profile than the promags. THey will clear the valvecovers. The promags are significantly taller due to the nut that fits on top. I dont know if they clear the covers. I run a tall cover for these now.
I found about a tenth in the 1/4 with the rocker arms. Should be more tho, as it was running pretty lean. Before the rockers, i put down 246whp with a 12.5 or so air fuel ratio. After new injectors and 1.6 mag rockers, it put down 254whp at 14.4 air fuel ratio...so it was very lean. I expect another 5-10 hp hopefully with richer tune but never happened. So they should give good gains for the 170 bucks you would pay for them.
I found about a tenth in the 1/4 with the rocker arms. Should be more tho, as it was running pretty lean. Before the rockers, i put down 246whp with a 12.5 or so air fuel ratio. After new injectors and 1.6 mag rockers, it put down 254whp at 14.4 air fuel ratio...so it was very lean. I expect another 5-10 hp hopefully with richer tune but never happened. So they should give good gains for the 170 bucks you would pay for them.
01-05-2011, 10:38 PM
#16
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Car: 1986 Vett, 2001 Expedition
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Re: roller rockers
The drip taps are on the perimeter type Valve cover.
What I know about Center bolt type you need to get the narrow body Roller rocker arms.
I have Aluminum RRA on my motor now I going to swap them out for Steels they say they last longer.
Aluminum ones what I read they work harden after time and they mite crack on you, If you take the Valve cover off and check them every now and then I gusse it will work but I want to beable to close things up and forget about them.
What I know about Center bolt type you need to get the narrow body Roller rocker arms.
I have Aluminum RRA on my motor now I going to swap them out for Steels they say they last longer.
Aluminum ones what I read they work harden after time and they mite crack on you, If you take the Valve cover off and check them every now and then I gusse it will work but I want to beable to close things up and forget about them.
01-06-2011, 07:54 AM
#17
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Re: roller rockers
To run rolller rockers under the stock L98 Valve cover you need to grind down the drip tabs under the valve covers you see them when you flip them over.
A lot of us Vett guys end up doing this are self so we can use roller rocker arms under the stock Valve covers.
On the C-4 Vett we can't run tall Valve covers on mine Tall Valve coves willn't clear the windsheild wipper motor and some of the later years they hit the A/C compresser un less you cut and reweld the covers to fit.
A lot of us Vett guys end up doing this are self so we can use roller rocker arms under the stock Valve covers.
On the C-4 Vett we can't run tall Valve covers on mine Tall Valve coves willn't clear the windsheild wipper motor and some of the later years they hit the A/C compresser un less you cut and reweld the covers to fit.
01-06-2011, 01:37 PM
#18
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Car: 92 1LE B4C
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Re: roller rockers
The GMPP 1.6's will work with our stock centerbolt valve covers. I just did a bunch of research on this.
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