Road Race Cam Specs? Warning - Some AMC Content!
#956951
03/23/11 01:42 PM
03/23/11 01:42 PM
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Joined: Aug 2008
Posts: 773 San Antonio, Tx
bulletpruf
OP
super stock
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OP
super stock
Joined: Aug 2008
Posts: 773
San Antonio, Tx
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Fellas - I'm building a road race engine and it's time to pick the camshaft. I'm new to road racing, so could use a bit of advice here. Car is a 1971 Javelin AMX. Yes, I know it's not a Mopar, but AMC used Mopar parts, so I think it's kind of a stepbrother to a Mopar. Anyway, the plan is to keep the car street legal (barely) and race it in the NASA American Iron series. Should weigh about 3,200 pounds with driver. Trans is a T-10 close ratio (2.23 first), 9" rear with a 3.50 gear. Engine is a .030 401 that's been balanced. Forged crank, rods, and pistons. Aluminum flywheel. 9.8:1 compression (a little lower than I would like, but can live with it). Stock Edelbrock aluminum heads. Single plane intake (Torker) with a Holley (have a few to choose from; thinking 750 DP or something like that). Max rpm is going to be 6,500 or so. Headers and 3" exhaust. Plan to run a solid flat tappet cam. Edelbrock says no higher than .580 lift with their springs. Manual brakes, so no need to worry about vacuum. Not worried about idle quality, either. Guess my first question is what do folks look for in a road race cam? I'm thinking that a nice flat torque curve would be nice, with hp up to 6,500 or so. Problem I see is that a wide LC (112?) will give me a flat torque curve and a tight LC (106?) will give me more max torque and increase my cylinder pressure, which I think will help with my somewhat low compression. Think a larger cam with a wide LC will be lazy with 9.8:1. Figure I will be making around 450 hp with the right cam. Here are a few grinds that I think are in the ballpark: Comp has a solid flat tappet cam that may be a bit too big - it's the 290B6 or 10-601-5 Hi Tech. 255/266 @ .050, .576/.570, 106 LC. RPM range of 3800-6800 sounds about right. I'm right at the limit with the stock springs here, too. Crane has a solid that's a bit smaller - #861201, 238/248 @ .050, .512/.533, 112 LC. Crane PowerMax #861241 sounds good except for the wide LC - 248/258 @ .050, .533/.555, 112 LC. I like the Comp Hi Tech with the 106 LC, but it may be a bit too big. I can also get something custom ground for not too much $. Your thoughts? Thanks, Scott
Please Check Out My YouTube Channel for Vintage Musclecar and Truck Rescues and Builds -- https://www.youtube.com/@THEBULLETPROOFGARAGE/videos
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Re: Road Race Cam Specs? Warning - Some AMC Content!
[Re: Cuda367]
#956954
03/23/11 06:57 PM
03/23/11 06:57 PM
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Joined: Feb 2005
Posts: 320 PA
w7smallblock
enthusiast
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enthusiast
Joined: Feb 2005
Posts: 320
PA
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Do away with the torker and get an air gap or performer RPM it will give you a wider torque curve without much loss in top end power if any. Plus a custom cam.
Last edited by w7smallblock; 03/23/11 06:58 PM.
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Re: Road Race Cam Specs? Warning - Some AMC Content!
[Re: bulletpruf]
#956957
03/23/11 11:00 PM
03/23/11 11:00 PM
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Joined: Dec 2003
Posts: 22,696 Bitopia
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,696
Bitopia
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Quote:
Fellas -
I'm building a road race engine and it's time to pick the camshaft. I'm new to road racing, so could use a bit of advice here.
............
Your thoughts?
Not sure what you are trying to achieve other then "road racing'. From my experience, if you are on the track by yourself, low end grunt is fun, but with street adapted cars/chassis's, putting the torque down is rather difficult on corner exits, but if you are trying to pass the car in front of you, its almost always done at the top end (ie HP), with overtaking combined with out braking.
I would just build a well tuned, balanced, reliable, able to be flogged motor, and get the driver some seat time first, the motor is not that important until the driver, tires/suspension and brakes are sorted out first.
Just reread your question, forget the motor, if you are going NASA, you need seat time before anything
Last edited by jcc; 03/23/11 11:05 PM.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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Re: Road Race Cam Specs? Warning - Some AMC Content!
[Re: jcc]
#956958
03/24/11 12:09 AM
03/24/11 12:09 AM
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Joined: Sep 2004
Posts: 1,828 houston texas
gremlinsteve
top fuel
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top fuel
Joined: Sep 2004
Posts: 1,828
houston texas
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start reading up on oiling mods for the amc v8 also. your going to need it done in that application to keep from losing the bottom end. similar mods that are done to a cleveland series ford btw. once thats done it should be fine.
steve
if You Like Gremlinsteve. Gremlinsteve Likes You.
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Re: Road Race Cam Specs? Warning - Some AMC Content!
[Re: jcc]
#956962
03/24/11 11:35 AM
03/24/11 11:35 AM
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Joined: Aug 2008
Posts: 773 San Antonio, Tx
bulletpruf
OP
super stock
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OP
super stock
Joined: Aug 2008
Posts: 773
San Antonio, Tx
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Quote:
Quote:
Fellas -
I'm building a road race engine and it's time to pick the camshaft. I'm new to road racing, so could use a bit of advice here.
............
Your thoughts?
Not sure what you are trying to achieve other then "road racing'. From my experience, if you are on the track by yourself, low end grunt is fun, but with street adapted cars/chassis's, putting the torque down is rather difficult on corner exits, but if you are trying to pass the car in front of you, its almost always done at the top end (ie HP), with overtaking combined with out braking.
I would just build a well tuned, balanced, reliable, able to be flogged motor, and get the driver some seat time first, the motor is not that important until the driver, tires/suspension and brakes are sorted out first.
Just reread your question, forget the motor, if you are going NASA, you need seat time before anything
Well, I don't know if I can "forget the motor" but I understand your point. I'm not going to go crazy at this point, but if I'm spending $ on a cam, I might as well try to find something that is in the ballpark.
Thanks,
Scott
Please Check Out My YouTube Channel for Vintage Musclecar and Truck Rescues and Builds -- https://www.youtube.com/@THEBULLETPROOFGARAGE/videos
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Re: Road Race Cam Specs? Warning - Some AMC Content!
[Re: bulletpruf]
#956966
03/24/11 12:32 PM
03/24/11 12:32 PM
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Joined: Dec 2006
Posts: 235 Tucson AZ.
RADAMX
enthusiast
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enthusiast
Joined: Dec 2006
Posts: 235
Tucson AZ.
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Quote:
No Air Gap for AMC. Will see if I can find a dyno comparison between the Torker and RPM.
Will check on a custom cam as well.
Thanks
Scott
yes there are air gaps for amc
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