I am using a Clevite cam p/n 229-1786
Duration@.050 204 INT 214 EXH
Lobe spread 110 degree
Valve lift .449 INT .296 EXH
SAE Duration 280/289
What RPM range is this cam making the most power on a mild 304 with a 600cfm carb with stock heads/valves/ and compression ratio?
Looks like a 3000rpm camshaft
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meaning that it peaks at 3000RPM or doesn't start making decent power till 3000RPM. I'm pretty happy with it it seems to pull well from 1500 on up but I'm thinking of building another motor and want to know what would be better for an all around trail rig.
You could look for a cam with a 112LSA to widen the torque curve. This along with a shorter SAE duration would give you better off idle response and better bottom end torque.
SAE duration is measured from .006 tappet lift.
A little more lift should help overall power figures as well. Is that 296exh valve lift correct?
Bare Tub Restoring 69 BBB Javelin SST 390 Go/Mod Pak
Frame Off Restoring 82 Wagoneer with 401 MPEFI transplant
"First rule of government funding; Why build one when you can build two at twice the price!"
Here's a cam that should offer an improvement in all aspects over the cam you are currently using.
Camshaft ,Engle 35018-H
Rocker Ratio,1.6
ILCL,109
LSA,112
Int. Duration @ .006,248
Exh. Duration @ .006,260
Int. Duration @ .050,207
Exh. Duration @ .050,216
Intake Valve Lift,466
Exhaust Valve Lift,496
Overlap,30
Hydraulic Intensity,41
Recommended RPM's,Off Idle - 4000
Hydraulic Intensity:
The ideal cam profile would raise the valves to full lift instantly, hold them open for a specified duration and then close them instantly. The laws of physics make it impossible to achieve instantaneous valve opening and closing, but recent advancements in design technology have made it possible to open and close the valves with more area under the lift curve. By so doing, engine efficiency is improved because the valves spend less time at very low lift.
Hydraulic Intensity may be computed by subtracting duration at .050" tappet lift from duration at .006" tappet lift. A lower number translates to more low end power, without any loss of top end power, and solves many complaints of poor idle quality. It also means it may be practical to install a cam with slightly longer duration at .050" cam lift than might otherwise be practical.
In practical terms, if two cams have the same duration at .050" lift, maximum torque and horsepower will be almost identical. However, the cam with the smaller Hydraulic Intensity figure will have a smoother idle, better off-idle response, superior low speed drive-ability, and a broader power curve.
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If I have done the math right, your Clevite cam has an overlap of 61 degrees and a Hydraulic Intensity figure of 76, which is very high for a stock CR motor. It also has a very late intake closing point that is losing cylinder pressure and torque.
Bare Tub Restoring 69 BBB Javelin SST 390 Go/Mod Pak
Frame Off Restoring 82 Wagoneer with 401 MPEFI transplant
"First rule of government funding; Why build one when you can build two at twice the price!"
^^ Now that's some informative stuff right there. =D>
WOW!!! makes me wish I'd done more homework before I picked my cam. That 296 was Exh cam lift. valve lift is .473. where do I find this cam and how much is it?Thanks for the info.
www.englecams.com
$134.00
Bare Tub Restoring 69 BBB Javelin SST 390 Go/Mod Pak
Frame Off Restoring 82 Wagoneer with 401 MPEFI transplant
"First rule of government funding; Why build one when you can build two at twice the price!"
I think I just found my next cam..!!
thanks Waggy
"A man's got to know his limitation's"
Dirty Harry.
Is that the Clevite CAM 1980_CJ7 used in his 401 build
that hosed the pistons because the builder incorrectly installed
the cam gear on the oil passage instead of the keyway ?
The intake closing angle is early and increases dynamic CR ?
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