Doing a custom grind cam, need help designing cam!
Doing a custom grind cam, need help designing cam! I have a 383 LT1 with a CC306 cam in it now. The car comes out of the hole pretty strong, but doesn't pull as hard as I would like it to up top. Here are the details of the motor. 383 as I said, eagle rotating assembly. Edelbrock castings for the heads with extensive porting/combustion chamber/flowbench work by Livernois Motorsports(dont have the flow sheets), SRP 9.8 pistons with 22cc dish(I plan on spraying a large shot, but want the car very strong without nitrous), 1.5 rr's, long tubes to TSP true duals, 58mm TB with port matched LT1 intake, cold air intake w/ 1le, blah blah, that should be about it that matters without the flow sheets. I am going to run a 3500-3800 stall, with 3.73 gears. I would not mind sacrificing out of the hole power, but I want as much up top as possible while still drivable. I know I'm going up quite a bit in the lift(CC306 is .525 .540), but as far as the other specs, I definitely need help with this. Thank you. Nick.
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If all you want is more top end and are willing to sacrifice some bottom end, then a pretty simple change would be to close the intake valve later. That would reduce DCR, which reduces bottom end, but gets it back up top. IVC is the single most influencial aspect of a cam to determine hp and rpm range.
The cc306 cam closes the intake valve at 43 ABDC. Adding 6 to that would put it at 49. I haven't seen many cams, including full race cams, that go much past 50. Just this change alone makes the new spec's 236/244-113.5, +2.5. Coincidentally, that's not too far from the off-the-shelf Comp Cams 236/242-112 Extreme cam that's offered.
Now, if you take it a bit further, you can close the exhaust valve later and open the intake valve sooner. Essentially, you're adding overlap. This helps out the entire power range, but will roughen up the idle a bit. Let's just add 6 deg on both. The new spec's are (retaining the change from earlier) 242/250-111, +2. Now that one's pretty dang close to the new Comp XFI LT1 cam that's 242/248-113.
My point is that we don't all need custom grind camshafts. Comp cams alone offers 13 different LT1 cams for naturally aspirated. I'm sure something out there fits the bill.
Mike
The cc306 cam closes the intake valve at 43 ABDC. Adding 6 to that would put it at 49. I haven't seen many cams, including full race cams, that go much past 50. Just this change alone makes the new spec's 236/244-113.5, +2.5. Coincidentally, that's not too far from the off-the-shelf Comp Cams 236/242-112 Extreme cam that's offered.
Now, if you take it a bit further, you can close the exhaust valve later and open the intake valve sooner. Essentially, you're adding overlap. This helps out the entire power range, but will roughen up the idle a bit. Let's just add 6 deg on both. The new spec's are (retaining the change from earlier) 242/250-111, +2. Now that one's pretty dang close to the new Comp XFI LT1 cam that's 242/248-113.
My point is that we don't all need custom grind camshafts. Comp cams alone offers 13 different LT1 cams for naturally aspirated. I'm sure something out there fits the bill.
Mike
Put down roughly 370 horse and roughly 375-380 torque on a mustang dyno(if I remember correctly), not sure of the rpm's that it did it. This is on 3.23's with a unlocking 2200 stall and a miss up top from a bad opti. Any recommendations in the lift catagory? Whats the lift on the comp XFI? Thanks for the info.
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Originally Posted by 94strokedz
Any recommendations in the lift catagory? Whats the lift on the comp XFI? Thanks for the info.
The XFI 242/248 cam has .584/.579 lift with 1.6 rockers.
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Well whats is killing me on my setup is my lift
I am going to choose one of these cams from Comp
TN-236XH 236/244 duration, .608"/.613", 112lsa
or
TN-233XL 233/239 duration, .569"/.577", 112lsa
or
TN-230HL 230/236 duration, .598"/.608", 112lsa
mybe you should try a custom grind by Joe O or Bret Bauer
I am going to choose one of these cams from Comp
TN-236XH 236/244 duration, .608"/.613", 112lsa
or
TN-233XL 233/239 duration, .569"/.577", 112lsa
or
TN-230HL 230/236 duration, .598"/.608", 112lsa
mybe you should try a custom grind by Joe O or Bret Bauer
Last edited by streetwarrior96; Jul 9, 2006 at 10:12 PM.
One of the problems here is the low compression, just reducing DCR is going to kill the low end and response of this motor. It's not the best idea, that also means just throwing cam duration at it haphazardly is not a good idea either. Which right now is all that has been suggested to you.
How much N2O you want to throw at that motor?
What's the rest of the valvetrain parts? Springs, Rockers, lifters, pushrods?
Did you dyno the motor and do you have a sheet? Where does the power start to drop off?
You could have issues of valvetrain float, but most likely the lakc of lift is killing you here the most.
Bret
How much N2O you want to throw at that motor?
What's the rest of the valvetrain parts? Springs, Rockers, lifters, pushrods?
Did you dyno the motor and do you have a sheet? Where does the power start to drop off?
You could have issues of valvetrain float, but most likely the lakc of lift is killing you here the most.
Bret
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Originally Posted by SStrokerAce
One of the problems here is the low compression, just reducing DCR is going to kill the low end and response of this motor. It's not the best idea, that also means just throwing cam duration at it haphazardly is not a good idea either. Which right now is all that has been suggested to you.
Originally Posted by 94strokedz
I would not mind sacrificing out of the hole power, but I want as much up top as possible while still drivable.
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Verdad Gallardo I know it will handle up to 600/610 ish on the lift. 1.5 gold race RR's and plenty of spring, so floating is not an issue. Lifters and pushrods are Comp I believe, I have all of the part numbers on the build sheet if needed. The valvetrain is about as strong as it gets, didn't cut any corners there, other than the low ratio rockers.
I'd just add 1.6's to your 306cam...since you still have 1.5's. that will give you more lift within your limits.....and be cheaper to do than another cam install. just save up your money for later on down the road for a new cam swap..to something bigger than that.
) is .510 .540 lift with 1.5's. 1.6 RR's increase it to .544 .576 lift.
Originally Posted by 94strokedz
I know it will handle up to 600/610 ish on the lift. 1.5 gold race RR's and plenty of spring, so floating is not an issue. Lifters and pushrods are Comp I believe, I have all of the part numbers on the build sheet if needed. The valvetrain is about as strong as it gets, didn't cut any corners there, other than the low ratio rockers.
You sure about that? Cause I do this everyday and I'm not.
Bret
