What rocker ratio would you run?
Thread Starter
Le Mans Master
Joined: Mar 2001
Posts: 6,240
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From: Watkinsville, GA and Glen Cove, NY
What rocker ratio would you run?
I am doing the motor over and have a solid flat tappet from Clay Smith. The cam is 258 @ .050 304 advertised with .615 lift on a 108 LSA. The cam card uses a 1.75 rocker ratio. Being greedy, I don't want to give up the .005 thousandth's lift (are you laughing at me yet) so Should I just run a 1.7 or the 1.75 or maybe even a 1.8. Any experiences with different ratios out there. Thanks, Bill. I will run a full roller rocker.
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Joined: Aug 2001
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From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Re: What rocker ratio would you run? (69ttop502)
It will be nearly .018 actual valve lift, so use the 1.75 if you can find one.
1.7 = .597 lift
1.8 = .632 lift
Just out of curiosity, what is your compression ratio, type of heads used.
1.7 = .597 lift
1.8 = .632 lift
Just out of curiosity, what is your compression ratio, type of heads used.
Team Owner
Joined: Feb 1999
Posts: 34,455
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From: Republic of Texas
Re: What rocker ratio would you run? (69 N.O.X. RATT)
You have to decide if spending $300 is worth the increase in lift from 1.75 to 1.8. I'd spend the moeny elsewhere, but that's me. Now if you HAVE to buy new rocker arm then I'd opt for the 1.8.
my .02
my .02
Thread Starter
Le Mans Master
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
Re: What rocker ratio would you run? (Corey 68)
No I don't have the rockers yet. I have actually been toying with the idea of running the Jesel SS shaft system. Crower is the only 1.75 ratio rocker I have seen. With the Jesel system I wouldn't need studs or guideplates and they may fit under stock valve covers.
N.O.X, I am running a 502 with Brodix BB+2 heads angle machined down to 100cc so with that I am going to have 10.5 to 1 compression. I just sold my old GM intake so I will run a Holley strip dominator and an 850 or 950HP carb. A friend of mine is going to try a World intake and if it fits under the L88 hood I may try one too as I have an L88 hood also. MY goal with this motor is similar to yours, I am looking for 500 horses at the wheels. My 502 in its previous 440hp crate motor form dynoed at 353 at the wheels. Bill.
N.O.X, I am running a 502 with Brodix BB+2 heads angle machined down to 100cc so with that I am going to have 10.5 to 1 compression. I just sold my old GM intake so I will run a Holley strip dominator and an 850 or 950HP carb. A friend of mine is going to try a World intake and if it fits under the L88 hood I may try one too as I have an L88 hood also. MY goal with this motor is similar to yours, I am looking for 500 horses at the wheels. My 502 in its previous 440hp crate motor form dynoed at 353 at the wheels. Bill.
Safety Car
Joined: Aug 2001
Posts: 3,892
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From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Re: What rocker ratio would you run? (69ttop502)
It will be interesting how the motors compare on the dyno, it should be pretty close. Good luck.
