Roller rocker questions
Thread Starter
Melting Slicks
Joined: Feb 2004
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From: Sarcasm. Just one of the many services I offer.
Roller rocker questions
I'm sure this has been asked before....how hard are roller rockers to install? what will they cost, and how much HP can be gained on an L98?
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
On an early L98 you can install 1.5:1 RRs pretty easily but 1.6:1 requires removing the heads to machine the head slots that serve to guide the stock push rods.
On a late L98 ('88 and later and maybe on '87) you can directly install 1.5:1 RRs but to install 1.6:1 RRs you need to remove the stock guide plates for self aligning RRs or install hardened guide plates & push rods for non self aligning RRs.
Cost of Pro Magnum RRs is about $300 for self aligning or for non self aligning and other parts. The installation is quite simple to do.
However, when installing 1.6:1 RRs it's wise to install new springs and keepers this drives up cost a little and degree of difficutly more than a bit.
With a stock cam you can expect to gain about 10chp with 1.5:1 RRs and maybe 15chp peak with 1.6:1 RRs.
My installation cost about $600 since I not only did 1.6:1 ProMagnums but also, valve seals, springs, Ti retainers, 10deg locks, hardened guide plates & push rods along with some shims and light assembly lube.
On a late L98 ('88 and later and maybe on '87) you can directly install 1.5:1 RRs but to install 1.6:1 RRs you need to remove the stock guide plates for self aligning RRs or install hardened guide plates & push rods for non self aligning RRs.
Cost of Pro Magnum RRs is about $300 for self aligning or for non self aligning and other parts. The installation is quite simple to do.
However, when installing 1.6:1 RRs it's wise to install new springs and keepers this drives up cost a little and degree of difficutly more than a bit.
With a stock cam you can expect to gain about 10chp with 1.5:1 RRs and maybe 15chp peak with 1.6:1 RRs.
My installation cost about $600 since I not only did 1.6:1 ProMagnums but also, valve seals, springs, Ti retainers, 10deg locks, hardened guide plates & push rods along with some shims and light assembly lube.
Burning Brakes
Joined: Jan 2002
Posts: 993
Likes: 4
From: Glen Burnie MD
Originally Posted by 65Z01
On an early L98 you can install 1.5:1 RRs pretty easily but 1.6:1 requires removing the heads to machine the head slots that serve to guide the stock push rods.
[RICHR]
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Originally Posted by rrubel
I did 1.6's on my early 86 (CI heads) and there was no interference with the guide slots. I did need to grind down the drip tabs on the valve covers (not all the way, just about 1/4" or so).
[RICHR]
[RICHR]
Pulled the heads, had the slots elongated and it was good to go.
Jake
Burning Brakes
Joined: Jan 2002
Posts: 993
Likes: 4
From: Glen Burnie MD
Originally Posted by JAKE
Yep, and I bent at least half a dozen exhaust pushrods on the same engine.
Pulled the heads, had the slots elongated and it was good to go.
Jake
Pulled the heads, had the slots elongated and it was good to go.
Jake
Perhaps it was the brand I was using. Different design?
[RICHR]
Drifting
Joined: Aug 2001
Posts: 1,550
Likes: 27
From: Minneapolis MN
Originally Posted by rrubel
Dunno what to say... put 8k miles on the setup including long trips, track days, and dragstrip runs and didn't bend a thing. Only reason they're not still there is because I've got a roller block now.
Perhaps it was the brand I was using. Different design?
[RICHR]
Perhaps it was the brand I was using. Different design?
[RICHR]
What brand were you using?
Burning Brakes
Joined: Jan 2002
Posts: 993
Likes: 4
From: Glen Burnie MD
Originally Posted by FlyboyZR1
Some people say 1.6's will work on the iron heads, and some people say they won't.
What brand were you using?
What brand were you using?
[RICHR]
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Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by FlyboyZR1
Some people say 1.6's will work on the iron heads, and some people say they won't.
What brand were you using?
What brand were you using?
RACE ON!!!
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Originally Posted by FlyboyZR1
Some people say 1.6's will work on the iron heads, and some people say they won't.
What brand were you using?
What brand were you using?
Camshaft valve lift may have a bearing on the problem too. I was running a CompCams Xtreme Energy flat-tappet hydraulic cam at the time. Valve lift was somewhere in the .480 range.
I had read about the possibility of pushrod interference problems in TPIS' Insider Hints book and another mag, so when I took the heads to the machine shop for freshening, I told them to elongate the slots.
Well, they only did the intakes and I didn't check when I got the heads back. From years of experience, I KNOW to check behind the work of others, but for some reason in this case I didn't - AND I PAID THE PRICE TOO.
In addition to being bent, I could see the well-worn areas on the pushrod where it was riding against the head in the slot. Nice and shiny with lots of metal gone.
I've read, too, that some haven't had a problem; wish I had been one of them. Pulling heads isn't my idea of a nice way to spend the day.
Jake
Burning Brakes
Joined: Jan 2002
Posts: 993
Likes: 4
From: Glen Burnie MD
Originally Posted by JAKE
Camshaft valve lift may have a bearing on the problem too. I was running a CompCams Xtreme Energy flat-tappet hydraulic cam at the time. Valve lift was somewhere in the .480 range.
...
I've read, too, that some haven't had a problem; wish I had been one of them. Pulling heads isn't my idea of a nice way to spend the day.
...
I've read, too, that some haven't had a problem; wish I had been one of them. Pulling heads isn't my idea of a nice way to spend the day.
I don't think pulling heads is *anybody's* idea of a nice way to spend the day
.[RICHR]