CAM LIFT > Comparing .527 lift vs .561 lift > Any real HP gain?
04-13-2002, 05:38 PM
#1
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CAM LIFT > Comparing .527 lift vs .561 lift > Any real HP gain? Please help me a little. I am still over here in Korea, so I can only put togather a list of parts for my 98 TA/A4. Soon I will be back in the US and then will begin mods.
Using CompCams (Custom Xtreme RPM) #3752 lobes, I will get a 218/218 .527/.527 114 LSA shaft
Using the MMS 218 cam, I will get a 218/218 .561/.561 114 LSA shaft
Obviously, the .527" lift cam will be easier on valvetrain components.
1. Do you think there will be very much of an increase in overall power and throttle resonse using the bigger lift cam in a Stage 1 heads/LT header car to justify the tall .561 lobes?
2. Since both of these cams have the same duration and LSA, will the .561 lift cam reduce idle quality vs the .527 cam? (A4 car)
Any input would be very much appreciated
Ron,
Using CompCams (Custom Xtreme RPM) #3752 lobes, I will get a 218/218 .527/.527 114 LSA shaft
Using the MMS 218 cam, I will get a 218/218 .561/.561 114 LSA shaft
Obviously, the .527" lift cam will be easier on valvetrain components.
1. Do you think there will be very much of an increase in overall power and throttle resonse using the bigger lift cam in a Stage 1 heads/LT header car to justify the tall .561 lobes?
2. Since both of these cams have the same duration and LSA, will the .561 lift cam reduce idle quality vs the .527 cam? (A4 car)
Any input would be very much appreciated
Ron,
04-13-2002, 06:01 PM
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Re: CAM LIFT > Comparing .527 lift vs .561 lift > Any real HP gain? The larger lift cam has more duration at higher lifts.
At .050" of cam lift, your valve is only .085" off the valve seat.
The difference in these larger lift cams come in at higher valve lifts.
For example, you might have 130@.200" on the smaller lift cam and 138@.200" on the larger lift cam, this does make a difference.
Sometimes two 218@.05" cams will have different "advertised durations" which usually means @ .006" cam lift.
For example the shorter lift one might have 288 advertised and the taller lift one only 265 advertised.
The 265 advertised is going to make more cyllinder pressure.
It could be the other way too, the 218 short lift COULD have more @.200" but not lift out as high.
Get the whole picture, also get information about other combos with this cam.
At .050" of cam lift, your valve is only .085" off the valve seat.
The difference in these larger lift cams come in at higher valve lifts.
For example, you might have 130@.200" on the smaller lift cam and 138@.200" on the larger lift cam, this does make a difference.
Sometimes two 218@.05" cams will have different "advertised durations" which usually means @ .006" cam lift.
For example the shorter lift one might have 288 advertised and the taller lift one only 265 advertised.
The 265 advertised is going to make more cyllinder pressure.
It could be the other way too, the 218 short lift COULD have more @.200" but not lift out as high.
Get the whole picture, also get information about other combos with this cam.
04-13-2002, 06:47 PM
#3
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Re: CAM LIFT > Comparing .527 lift vs .561 lift > Any real HP gain? HP-GURU
Great info!
I got this info out of Comp Cams web page on the 218 .527 cam I mentioned above:
Rated duration: 272
Duration @ .050 lift: 218
Duration @ .200 lift: .132
Lobe lift: .310
Tappet Lift @ 106 degrees: .059
Tappet Lift @ 110 degrees: .048
Lift @ 1.7 Rocker Ratio: .527
Any ideas relating to these numbers?
Great info!
I got this info out of Comp Cams web page on the 218 .527 cam I mentioned above:
Rated duration: 272
Duration @ .050 lift: 218
Duration @ .200 lift: .132
Lobe lift: .310
Tappet Lift @ 106 degrees: .059
Tappet Lift @ 110 degrees: .048
Lift @ 1.7 Rocker Ratio: .527
Any ideas relating to these numbers?
04-14-2002, 06:23 PM
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Re: CAM LIFT > Comparing .527 lift vs .561 lift > Any real HP gain? Get the numbers for the .560" lift cam and lets compare.
If you have shorter advertised, and more @.200"
then this is a more agressive lobe, you'll have more cyllinder fill which will show up as a higher peak TQ number.
If you have shorter advertised, and more @.200"
then this is a more agressive lobe, you'll have more cyllinder fill which will show up as a higher peak TQ number.
04-14-2002, 06:43 PM
#5
Re: CAM LIFT > Comparing .527 lift vs .561 lift > Any real HP gain? Awe hell Ron! Just get a built 422 and don't sweat the small stuff <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
Glad to see you WILL be returning the the USA <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />
Glad to see you WILL be returning the the USA <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />
04-14-2002, 09:03 PM
#6
TECH Addict
Re: CAM LIFT > Comparing .527 lift vs .561 lift > Any real HP gain? Kimche and rice, with stock heads smaller lift cam would make similar power to MMS if seat durations are close, but i think it would be a mistake not to use bigger lift cam with ported heads, lobes and valvetrain on Ls1 can take advantage of large cam journals, and large base circles, the LS1 has great advantages to other motors in this area, it seems a shame to not take advantage of this with more aggressive and larger lift profiles. Stock heads loose flow over .470" lift so big lift cams dont shine with them, BTW.
