383 Cam Question
02-21-2009, 12:33 PM
#1
383 Cam Question Just wondering if anyone has used this cam:
Comp XE 236 / 242, .520 / .540 112 LSA
or one similar to it in a 383. if so what are your impressions of it? power/e.t. numbers? where do you shift it at? I understand most people will say "go custom" but I was just using this cam as a base since I'm looking at it along with AI and LE grinds in a similar size
Comp XE 236 / 242, .520 / .540 112 LSA
or one similar to it in a 383. if so what are your impressions of it? power/e.t. numbers? where do you shift it at? I understand most people will say "go custom" but I was just using this cam as a base since I'm looking at it along with AI and LE grinds in a similar size
02-21-2009, 12:51 PM
#2
Just wondering if anyone has used this cam:
Comp XE 236 / 242, .520 / .540 112 LSA
or one similar to it in a 383. if so what are your impressions of it? power/e.t. numbers? where do you shift it at? I understand most people will say "go custom" but I was just using this cam as a base since I'm looking at it along with AI and LE grinds in a similar size
Comp XE 236 / 242, .520 / .540 112 LSA
or one similar to it in a 383. if so what are your impressions of it? power/e.t. numbers? where do you shift it at? I understand most people will say "go custom" but I was just using this cam as a base since I'm looking at it along with AI and LE grinds in a similar size
If you examine the difference between most off the shelf cams and the custom spec'd (or "semi-custom" ones like LE and AIs listed cams), you will notice that the custom cams all have 108-110 LSA and a lot more lift then the off the shelf ones. There is a reason for that, letting you get away with less duration while making the same peak power as an off the shelf cam but having more useable power under the curve.
Most off the shelf cams throw in lots of duration because too many uninformed motorists base their cams just on duration @ 50 numbers, then they compensate by using less then desirable LSA like 112 or more, and lowering the lift. You then end up with a cam that sounds mean as hell, and may make great peak numbers - but can usually get a custom with the same peak, better low end, easier to tune, and better drivability.
I'm willing to bet something like the LE 232/240 or AI 230/238 will both come within a few hp peak of that comp XE, but be easier to tune and have more low end. After spending all that money on a rebuild, and carefully choosing the parts for a car, for the extra couple of bucks I don't see the reason to go off the shelf with something as important as the cam.
02-21-2009, 01:20 PM
#4
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I'm not sure on LT1's, but on 383 thirdgens, with good exhaust, gearing, ect most thirdgen's are in the 11.7-11.9 range
It's a good streep strip cam and I was going to use that to replace my xr276 cam but i went custom instead
It's a good streep strip cam and I was going to use that to replace my xr276 cam but i went custom instead
02-21-2009, 01:42 PM
#5
8 Second Club
Excuse the long post, and sorry if its not 100% on topic
If you examine the difference between most off the shelf cams and the custom spec'd (or "semi-custom" ones like LE and AIs listed cams), you will notice that the custom cams all have 108-110 LSA and a lot more lift then the off the shelf ones. There is a reason for that, letting you get away with less duration while making the same peak power as an off the shelf cam but having more useable power under the curve.
Most off the shelf cams throw in lots of duration because too many uninformed motorists base their cams just on duration @ 50 numbers, then they compensate by using less then desirable LSA like 112 or more, and lowering the lift. You then end up with a cam that sounds mean as hell, and may make great peak numbers - but can usually get a custom with the same peak, better low end, easier to tune, and better drivability.
I'm willing to bet something like the LE 232/240 or AI 230/238 will both come within a few hp peak of that comp XE, but be easier to tune and have more low end. After spending all that money on a rebuild, and carefully choosing the parts for a car, for the extra couple of bucks I don't see the reason to go off the shelf with something as important as the cam.
If you examine the difference between most off the shelf cams and the custom spec'd (or "semi-custom" ones like LE and AIs listed cams), you will notice that the custom cams all have 108-110 LSA and a lot more lift then the off the shelf ones. There is a reason for that, letting you get away with less duration while making the same peak power as an off the shelf cam but having more useable power under the curve.
Most off the shelf cams throw in lots of duration because too many uninformed motorists base their cams just on duration @ 50 numbers, then they compensate by using less then desirable LSA like 112 or more, and lowering the lift. You then end up with a cam that sounds mean as hell, and may make great peak numbers - but can usually get a custom with the same peak, better low end, easier to tune, and better drivability.
I'm willing to bet something like the LE 232/240 or AI 230/238 will both come within a few hp peak of that comp XE, but be easier to tune and have more low end. After spending all that money on a rebuild, and carefully choosing the parts for a car, for the extra couple of bucks I don't see the reason to go off the shelf with something as important as the cam.
02-21-2009, 02:12 PM
#6
Good points and all are true but the reson that cam companys use more duration and less lift has to do with . larger duration with les lift means less acceleration of the seat . which means less valve spring pressure and less wear and lifter problems it takes pressure to controle the valve when you start opening the valve fast . so many builders want to skimp on valve springs and other valve train parts. And the first thing they say it was the cams falt when they beat the rollers off a set of stock lifters. If you want to make good power and be reliable listen to Puck but do not skimp on springs any other parts in the valve train. get a Custom i have not used a off the shelf in 15 years.
.They know that people will skimp on parts, and also that what someone THINKS they want and what they really want are not always the same thing...so a lot of off the shelf grinds are made to compensate.
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02-21-2009, 09:16 PM
#8
Excuse the long post, and sorry if its not 100% on topic
If you examine the difference between most off the shelf cams and the custom spec'd (or "semi-custom" ones like LE and AIs listed cams), you will notice that the custom cams all have 108-110 LSA and a lot more lift then the off the shelf ones. There is a reason for that, letting you get away with less duration while making the same peak power as an off the shelf cam but having more useable power under the curve.
Most off the shelf cams throw in lots of duration because too many uninformed motorists base their cams just on duration @ 50 numbers, then they compensate by using less then desirable LSA like 112 or more, and lowering the lift. You then end up with a cam that sounds mean as hell, and may make great peak numbers - but can usually get a custom with the same peak, better low end, easier to tune, and better drivability.
I'm willing to bet something like the LE 232/240 or AI 230/238 will both come within a few hp peak of that comp XE, but be easier to tune and have more low end. After spending all that money on a rebuild, and carefully choosing the parts for a car, for the extra couple of bucks I don't see the reason to go off the shelf with something as important as the cam.
If you examine the difference between most off the shelf cams and the custom spec'd (or "semi-custom" ones like LE and AIs listed cams), you will notice that the custom cams all have 108-110 LSA and a lot more lift then the off the shelf ones. There is a reason for that, letting you get away with less duration while making the same peak power as an off the shelf cam but having more useable power under the curve.
Most off the shelf cams throw in lots of duration because too many uninformed motorists base their cams just on duration @ 50 numbers, then they compensate by using less then desirable LSA like 112 or more, and lowering the lift. You then end up with a cam that sounds mean as hell, and may make great peak numbers - but can usually get a custom with the same peak, better low end, easier to tune, and better drivability.
I'm willing to bet something like the LE 232/240 or AI 230/238 will both come within a few hp peak of that comp XE, but be easier to tune and have more low end. After spending all that money on a rebuild, and carefully choosing the parts for a car, for the extra couple of bucks I don't see the reason to go off the shelf with something as important as the cam.
I wondering how a cam of around that size (like the LE/AI with similar duration but with a bit more lift and on a 108~LSA) reacts in 383 and just wondering if anyone had a real world experience of a similar ground whether it be the LE/AI variants or an off the shelf cam
btw I am running the Crane Dual Coils (10308 I believe) would you see the bigger off the shelf LE/AI cams (.58x Lift) being a problem running too close to the max lift since they're rated for .600"?
Last edited by myltwon; 02-22-2009 at 04:11 AM.
02-22-2009, 09:57 AM
#10
The .58x lift will be fine, but it still depends on the cam lobes ramp rates and how high the cam you choose will peak since beehives will help you more then duals in high rpm engines with aggressive cam lobes.
