Roller cam infor needed
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 27
Likes: 0
Roller cam infor needed
Hi,
I have a 1975 Corvette L82 ( no emissions) 1:3/4 headers true duels (2:5) I am installing a TKO600 trans ( 2.87 first .64 fifth) with a 4:11 differential. I cruise the car at around 2500 with a 5500 redline, basically a street car.
What I presume I need is a cam which wont lug the engine hence needs torque from 1000 to 5000 due to the 4:11 rear gear. I have been looking at howards roller cams ( & am still waiting on feedback from their tech dept) I am also installing AFR cylinder heads 180cc runners 64cc chambers. So who can tell me what the best cam set up is (also 1.5 or 1.6 pushrods) to take advantage of the heads & the gearing I am obviously looking for torque. I doubt I will ever take the car over 100mph as the speed limit here is 75 mph ( I am English living Spain)
I am lost when it comes to cams aside from ( I think from research) I need a hi lift short duration set up. Any information greatly appreciated as this is costing me a lot of $$$ & I want to get it right first time around. Thanks in advance
I have a 1975 Corvette L82 ( no emissions) 1:3/4 headers true duels (2:5) I am installing a TKO600 trans ( 2.87 first .64 fifth) with a 4:11 differential. I cruise the car at around 2500 with a 5500 redline, basically a street car.
What I presume I need is a cam which wont lug the engine hence needs torque from 1000 to 5000 due to the 4:11 rear gear. I have been looking at howards roller cams ( & am still waiting on feedback from their tech dept) I am also installing AFR cylinder heads 180cc runners 64cc chambers. So who can tell me what the best cam set up is (also 1.5 or 1.6 pushrods) to take advantage of the heads & the gearing I am obviously looking for torque. I doubt I will ever take the car over 100mph as the speed limit here is 75 mph ( I am English living Spain)
I am lost when it comes to cams aside from ( I think from research) I need a hi lift short duration set up. Any information greatly appreciated as this is costing me a lot of $$$ & I want to get it right first time around. Thanks in advance
Melting Slicks
Joined: May 2012
Posts: 2,192
Likes: 343
From: Allenton Wisconsin
To answer your ? regarding the best cam choice; the cam grinders them self. With what your building with 4.11 screws that engine is going to be at your red line really quick. SBCs like 1.5 rockers. Also contact Chris @ STRAUB TECH. He's an engine builder / cam grinder with a good rep. T
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 27
Likes: 0
Hi,
At present my CR is 9.0 to 1 ( regular CR for the L82) I presume my CR will be raised to 10.5 to 1 using the AFR heads 64cc chambers versus 76cc as I have now. I am no engine builder so am using a mechanic BUT I want to get as much information for the best combination for "seat of the pants" acceleration hence the 4:11 rear gears.
I know my first gear is steep (11.79) but going on the calculators changing at 3000rpm 1st=20mph 2=31 3=43 4=59 5=92 at present with my 4 speed I am at 3300rpm @75mph with the extra gear & a 4:11 I will be at 2500rpm @ 75mph so I gain at both ends although Ist gear may be a bit of an issue.
What I am looking for is 0 to 60 stoplight to stoplight, this is only a weekend car & my dilemma at present is finding a roller cam with correct ratio lifters & pushrods to take advantage of the AFR heads & the gearing I have hence asking you guys for any advice. many thanks.
I forgot to mention my tyre size is 27 inch ( 255/60x15)
At present my CR is 9.0 to 1 ( regular CR for the L82) I presume my CR will be raised to 10.5 to 1 using the AFR heads 64cc chambers versus 76cc as I have now. I am no engine builder so am using a mechanic BUT I want to get as much information for the best combination for "seat of the pants" acceleration hence the 4:11 rear gears.
I know my first gear is steep (11.79) but going on the calculators changing at 3000rpm 1st=20mph 2=31 3=43 4=59 5=92 at present with my 4 speed I am at 3300rpm @75mph with the extra gear & a 4:11 I will be at 2500rpm @ 75mph so I gain at both ends although Ist gear may be a bit of an issue.
What I am looking for is 0 to 60 stoplight to stoplight, this is only a weekend car & my dilemma at present is finding a roller cam with correct ratio lifters & pushrods to take advantage of the AFR heads & the gearing I have hence asking you guys for any advice. many thanks.
I forgot to mention my tyre size is 27 inch ( 255/60x15)
Le Mans Master
Joined: Feb 1999
Posts: 8,351
Likes: 75
From: Tampa Bay FL
Howards' makes a really good line of retro roller cam kits. I personally went with a Comp Xtreme Energy Retro roller K-Kit as it was very complete and met my performance goals. With 1.52 ratio rockers (see signature), I have relatively high lift of .502/.509 with the duration and LSA of my prior Crane Energizer 272-H10 cam. With your 4.11's and 5-speed with .64 OD, this cam would be in the ballpark of your performance goals; you could probably go 1-2 cams 'down the page'. I would keep max lift safely under .550 to play nice with your stock dimension pistons/valves.
If I were running 'gears' and/or higher stall converter, I would probably opt for the equivalent of the Comp XE K12-432-8. You give up torque for increased horsepower and it all comes later in the power band. This cam is two steps down the page from my K-Kit.
If I were running 'gears' and/or higher stall converter, I would probably opt for the equivalent of the Comp XE K12-432-8. You give up torque for increased horsepower and it all comes later in the power band. This cam is two steps down the page from my K-Kit.
Last edited by TedH; Dec 21, 2014 at 11:03 AM.
Race Director
Joined: May 2005
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From: Millington Illinois
St. Jude Donor '08-'09
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Race Director
Joined: May 2005
Posts: 10,674
Likes: 121
From: Millington Illinois
St. Jude Donor '08-'09
Hi,
I cruise the car at around 2500 with a 5500 redline, basically a street car.
What I presume I need is a cam which wont lug the engine hence needs torque from 1000 to 5000 due to the 4:11 rear gear. Any information greatly appreciated as this is costing me a lot of $$$ & I want to get it right first time around. Thanks in advance
I cruise the car at around 2500 with a 5500 redline, basically a street car.
What I presume I need is a cam which wont lug the engine hence needs torque from 1000 to 5000 due to the 4:11 rear gear. Any information greatly appreciated as this is costing me a lot of $$$ & I want to get it right first time around. Thanks in advance
Last edited by 63mako; Dec 22, 2014 at 11:37 AM.