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I think with roller rockers then ya need taller valve covers. Then ya have problems with things like the AC not fitting right because of the taller valve covers. If you want the rollers better ask if they'll clear your stock valve covers before buying. The little bit of HP gained doesn't justify the money spent and the work.
From: One day you're a Comet...the next day you're dust... Arkansas
Why would roller rockers require taller valve covers unless the ratio was raised? Yes full RR's will help. Higher ratio full RR's will help more. Long tube headers will probably help more.
Will good roller rockers alone boost horsepower on a bone stock 1986 vette with a one owner 60,000 motor.
Yes, though depending on the rocker you buy you may have to trim the inside of the valve covers. The drip tabs won't be needed with the rollers. It's not that hard to do and if you have stock valve cover gaskets change them out. Mine leaked terribly!
Why would roller rockers require taller valve covers unless the ratio was raised? Yes full RR's will help. Higher ratio full RR's will help more. Long tube headers will probably help more.
Should be no trouble if your going with same ratio as stock 1.5, if you go to 1.6 removing drip tabs is needed from what I understand.
I have a question is there a bigger benefit on a stock motor from using a full roller 1.6 to a roller tip 1.6?
Last edited by floridamale; Apr 14, 2009 at 09:49 AM.
Should be no trouble if your going with same ratio as stock 1.5, if you go to 1.6 removing drip tabs is needed from what I understand.
I have a question is there a bigger benefit on a stock motor from using a full roller 1.6 to a roller tip 1.6?
I think most benefit is from the roller trunnion so I wouldn't just use a roller tip. A roller trunnion with a slider tip would be better but just use the full roller. Of course the ratio makes the most difference for power.
According to TPIS Insider Hints Full Roller Rockers (1.5) on a stock 1985 Corvette added 13.7 Lb Ft @ 4250 RPM and 12 HP @ 4750 RPM. 1.6 Intake and 1.5 Exhaust improved performance to 16.5 Lb FT @ 4250 RPM and 13.3 HP @ 4250. I am installing 1.5 full roller rockers as my next project on my 1985.
Man am I glad I joined this site!! You guys are a great help. I have already purchased the taller valve covers just incase I need the room and to make things look better under the hood. I was going to go 1.6 all the way around but it sounds like I should go 1.5 and 1.6 according to some of you.
I also called Summit about some headers and exhaust. Can you believe that they had nothing I could use without fabrication? Any help in this area would be appreciated. I live in Kansas and I will NOT put a Cat. Converter back on.
Why would roller rockers require taller valve covers unless the ratio was raised? Yes full RR's will help. Higher ratio full RR's will help more. Long tube headers will probably help more.
Thanks for the feed back. I'll be doing the headers as well when you guys tell me which ones to get lol. Thank God for tax refund money lol.
From: One day you're a Comet...the next day you're dust... Arkansas
If you need to pass SMOG you will want headers with EGR. A lot of people like Hedman Elite. Some like Hookers. Look at Summit Auto web site. Do some research. I would just do the 1.6 RR's all around.
If you need to pass SMOG you will want headers with EGR. A lot of people like Hedman Elite. Some like Hookers. Look at Summit Auto web site. Do some research. I would just do the 1.6 RR's all around.
I don't need anything SMOG related in Kansas and I called Summit and they were no help with headers and exhaust combo.
I only know of two companies that offer headers that are bolt on for my 1985. Stainless Works and TPIS. They both offer the front "Y" pipe you need. Stainless works says some fabrication may be required. This is my project for next year.
From: One day you're a Comet...the next day you're dust... Arkansas
Originally Posted by David O'Hara
Yes they do, but the guy I called at Summit said that they had nothing that would be a total bolt on from header to exhaust without the cat.
He is right. You will need to modify your pipes or install duals after the headers are on. It's cheaper doing that anyway. Any decent muffler shop can do it.
Im also thinking some 1.6 rockers are a good idea for me. i like what i hear about pro magnums.
I also have an 86, mine with iron heads and just want someone to clarify that ill need the set for 3/8" studs right??
Has anyone ever heard of problems with staying with 3/8" rather than making the upgrade to 7/16"??
The reason i ask is because i plan to upgrade heads when its time to rebuild and i would rather not have to buy the same part over again in a different size. or do aftermarket heads typically have 7/16" studs?
Stud size 3/8 vs 7/16 should not be a problem with a stock cam and either 1.5 or 1.6 RR. The 1985 showed better idle with the combination 1.5 & 1.6. I would be tempted to go 1.6 for the 1986 all the way around. You will need to trim the drip tabs and perhaps use a taller gasket.