Dyno after adding 1.6 CC RR's
Thread Starter
Racer
Joined: Jun 2002
Posts: 401
Likes: 41
From: Parrish FL
Dyno after adding 1.6 CC RR's
For all those that are asking what you get by adding these. Got my car dyno'd today after adding the 1.6 Comp Cam Roller Rockers. I got 12.2 more peak RWHP, and about 15 more RWHP at about 5800 RPM. The HP now climbed continuously until 5800 RPM where they shut it down, while before it tappered off to 275 RWHP at 5700 RPM where they shut it down. The numbers are:
w/o RR 278.4 RWHP, 302.2 RWTQ
w/ RR 290.6 RWHP, 305.8 RWTQ
I noticed after that the AC was on, but the guy doing it said it shuts off at WOT. Is he right? This weekend I'm adding SLP shorty headers. I'll post results in the next week or so.
Jim
w/o RR 278.4 RWHP, 302.2 RWTQ
w/ RR 290.6 RWHP, 305.8 RWTQ
I noticed after that the AC was on, but the guy doing it said it shuts off at WOT. Is he right? This weekend I'm adding SLP shorty headers. I'll post results in the next week or so.
Jim
Melting Slicks
Joined: Oct 2000
Posts: 2,019
Likes: 2
From: Na
Re: Dyno after adding 1.6 CC RR's (jstkrsn)
I noticed after that the AC was on, but the guy doing it said it shuts off at WOT. Is he right?
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Thread Starter
Racer
Joined: Jun 2002
Posts: 401
Likes: 41
From: Parrish FL
Re: Dyno after adding 1.6 CC RR's (fixit)
Are you using the ProMagnum or Magnum arms? Did you change the valve springs also?
Instructor
Joined: Aug 2003
Posts: 113
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From: los angeles ca
Re: Dyno after adding 1.6 CC RR's (jstkrsn)
What year is your Corvette? I was going to do this on my '94 but heard (rumor) that the polylocks on the Promagnums will hit the drip tabs on the inside of the valve covers. Did you have any clearance problems with the valve covers?
Incidently, I would venture that over 1/3 of your HP increase is due to the reduced friction availed by the roller rocker arms based on CompCams own advertisement for the 1.52 (stock ratio) arms.
[Modified by fixit, 7:09 AM 8/31/2003]
Incidently, I would venture that over 1/3 of your HP increase is due to the reduced friction availed by the roller rocker arms based on CompCams own advertisement for the 1.52 (stock ratio) arms.
[Modified by fixit, 7:09 AM 8/31/2003]
Thread Starter
Racer
Joined: Jun 2002
Posts: 401
Likes: 41
From: Parrish FL
Re: Dyno after adding 1.6 CC RR's (fixit)
What year is your Corvette? I was going to do this on my '94 but heard (rumor) that the polylocks on the Promagnums will hit the drip tabs on the inside of the valve covers. Did you have any clearance problems with the valve covers?
Incidently, I would venture that over 1/3 of your HP increase is due to the reduced friction availed by the roller rocker arms based on CompCams own advertisement for the 1.52 (stock ratio) arms.
Incidently, I would venture that over 1/3 of your HP increase is due to the reduced friction availed by the roller rocker arms based on CompCams own advertisement for the 1.52 (stock ratio) arms.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: Dyno after adding 1.6 CC RR's (jstkrsn)
What year is your Corvette? I was going to do this on my '94 but heard (rumor) that the polylocks on the Promagnums will hit the drip tabs on the inside of the valve covers. Did you have any clearance problems with the valve covers?
Incidently, I would venture that over 1/3 of your HP increase is due to the reduced friction availed by the roller rocker arms based on CompCams own advertisement for the 1.52 (stock ratio) arms.
I cut the drip tabs down to about 3/8". And your right I probably would have gotten 3-4 HP with just the 1.5 ratio.
Incidently, I would venture that over 1/3 of your HP increase is due to the reduced friction availed by the roller rocker arms based on CompCams own advertisement for the 1.52 (stock ratio) arms.
I cut the drip tabs down to about 3/8". And your right I probably would have gotten 3-4 HP with just the 1.5 ratio.
Somethiing like 2/3. It really doesn't give you much extra lift at all. I have the 85 motor with iron heads, so that doesn't matter anyways... since I can't fit 1.6's on my heads. :(
Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
Re: Dyno after adding 1.6 CC RR's (fixit)
What year is your Corvette? I was going to do this on my '94 but heard (rumor) that the polylocks on the Promagnums will hit the drip tabs on the inside of the valve covers.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Dyno after adding 1.6 CC RR's (CentralCoaster)
I disagree. I've heard that the majorty of the horsepower comes from the reduced friction of the roller fulcrum, and the more precise ratio on all valves.
Somethiing like 2/3. It really doesn't give you much extra lift at all. I have the 85 motor with iron heads, so that doesn't matter anyways... since I can't fit 1.6's on my heads. :(
Somethiing like 2/3. It really doesn't give you much extra lift at all. I have the 85 motor with iron heads, so that doesn't matter anyways... since I can't fit 1.6's on my heads. :(
Going from 1.6 to 1.7 rockers took my lift from .525 to .558. As far as cam specs go that's a lot of lift. Consider the same cam with 1.5's would only be .492 lift!
Melting Slicks
Joined: Sep 2000
Posts: 3,099
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From: PITTSBURGH PA
Cruise-In IV Veteran
Cruise-In V Veteran
Re: Dyno after adding 1.6 CC RR's (Nathan Plemons)
nathan on your test did you do it back to back at the dyno like do a couple of runs then change the rockers while its still on the dyno then run dyno again :cheers:
Le Mans Master
Joined: Feb 2002
Posts: 7,858
Likes: 2
Re: Dyno after adding 1.6 CC RR's (STL94LT1)
Any aftermarket roller rocker will hit the drip tabs on you valve covers. Simple solution, just cut the drip tabs off.