Adding guide plates to use non self aligning rockers on a 91 TPI???
#1
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Adding guide plates to use non self aligning rockers on a 91 TPI???
Hey all, first post in probably 10 years on here, LOL!
So back when I was in high school I bought some really nice roller rockers, comp cams pro magnum full roller chromo 1.6 ratio rockers. I got push rods at the same time. I had grand plans for the car, such as new heads so I specifically bought the non self aligning rockers for them, but the new heads never happened. Question is, can I just add guide plates to the factory L98 heads to use the non self aligning rockers, or would I be best off trying to sell the rockers here or on ebay and just buy the correct self aligning ones for my heads? If I were to get the guide plates would I also have to get new studs? Would there be any downsides to doing this? Benefits? This is no longer my daily driver, I basically drive it about 50 miles once or twice a week in the summer to and from work and around town. I don't need crazy power but 10 or 15 hp would be way nicer to have than a box of parts taking up space in my garage! Hopefully my sig still has all my engine info, if you need anything else to accurately answer, just ask.
Thanks!
Eli
So back when I was in high school I bought some really nice roller rockers, comp cams pro magnum full roller chromo 1.6 ratio rockers. I got push rods at the same time. I had grand plans for the car, such as new heads so I specifically bought the non self aligning rockers for them, but the new heads never happened. Question is, can I just add guide plates to the factory L98 heads to use the non self aligning rockers, or would I be best off trying to sell the rockers here or on ebay and just buy the correct self aligning ones for my heads? If I were to get the guide plates would I also have to get new studs? Would there be any downsides to doing this? Benefits? This is no longer my daily driver, I basically drive it about 50 miles once or twice a week in the summer to and from work and around town. I don't need crazy power but 10 or 15 hp would be way nicer to have than a box of parts taking up space in my garage! Hopefully my sig still has all my engine info, if you need anything else to accurately answer, just ask.
Thanks!
Eli
#2
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Car: 91 G92 Z28
Engine: 305 TPI
Transmission: T5
Axle/Gears: 342
Re: Adding guide plates to use non self aligning rockers on a 91 TPI???
I'd sell them and use that money for something else....like better flowing heads. Roller rockers, even going from 1.5 to 1.6 are probably not going to translate into anything near 10-15 hp to your rear wheels.
#3
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Car: 92 Trans Am Conv
Engine: LB9
Transmission: T5
Axle/Gears: 3.08
Re: Adding guide plates to use non self aligning rockers on a 91 TPI???
NSA rockers are too much "trouble" for a TPI. You'll have to invest in guide plates and ideally hardened pushrods. NSA are better for higher RPM which TPI doesn't see.
I say sell them and get some SA rockers, and there is more they do for you than just 10-15whp at peak. They add power across the entire powerband and increase mpg.
I say sell them and get some SA rockers, and there is more they do for you than just 10-15whp at peak. They add power across the entire powerband and increase mpg.
Last edited by Vanilla Ice; 09-07-2016 at 02:40 PM.
#4
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Re: Adding guide plates to use non self aligning rockers on a 91 TPI???
For guide plates you have to mill the old rocker towers down, have them tapped for screw in studs in order to hold the guide plates on. Also, with 1.6 ratio, if you don't have your pushrod geometry correct you end up with "Z" shaped pushrods at some point, ask me how I know...I agree with the others, sell them and put the money to a better performance use unless you are willing to tear the heads off for all of the work needed. MTC
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Car: 87 Iroc
Engine: modified 350
Transmission: high performance built 700R4
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Re: Adding guide plates to use non self aligning rockers on a 91 TPI???
Look up Professional products They sell a set made by Jomar.They are they are thin and very adaptable.They are not like any other guide plates out there.You will have to use hardened push rods with them.
#6
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Car: '90 Trans Am-12.45@110.71
Engine: 355 w/AFR 195's Elem. 400/430 HP/TQ
Transmission: Tremec T-56
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Re: Adding guide plates to use non self aligning rockers on a 91 TPI???
First, take off a valve cover and look at the push rod holes.
Some heads came with round holes, some came with oval holes.
If you have oval holes you can use non-SA rockers.
Some heads came with round holes, some came with oval holes.
If you have oval holes you can use non-SA rockers.
#7
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Re: Adding guide plates to use non self aligning rockers on a 91 TPI???
So getting new heads to accomodate the rockerss would not be an ideal solution any more financially. Even though that was my intention back when I got them.
So am I understanding it right that the factory heads have pressed in studs instead of threaded ones that are generally required for guide plates? I found those jomar guide plates. Are you saying I could use those with my existing heads and studs? I do have hardened rods I ordered at the same time as the rockers, sitting in the same box as the rockers.
I can pull a valve cover and look at my heads. Are you saying heads intended for self aligning rockers had the round holes, or that even though there are no guide plates I could still use the non self alligning rockers with a head with oval holes, even it it was originally installed with self aligning rockers?
So am I understanding it right that the factory heads have pressed in studs instead of threaded ones that are generally required for guide plates? I found those jomar guide plates. Are you saying I could use those with my existing heads and studs? I do have hardened rods I ordered at the same time as the rockers, sitting in the same box as the rockers.
I can pull a valve cover and look at my heads. Are you saying heads intended for self aligning rockers had the round holes, or that even though there are no guide plates I could still use the non self alligning rockers with a head with oval holes, even it it was originally installed with self aligning rockers?
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#8
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Thread Starter
Re: Adding guide plates to use non self aligning rockers on a 91 TPI???
Well, some time has gone by and I've decided to just sell off these rockers and buy some replacement S/A ones.
If anyone is interested there posted here on TGO: https://www.thirdgen.org/forums/engi...-cams-pro.html
If anyone is interested there posted here on TGO: https://www.thirdgen.org/forums/engi...-cams-pro.html
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