MadMarv
Apr 11th, 04, 8:06 PM
Ok-- Did anyone else have problems with this article?
Step 1) dyno engine as is (on how liberal a dyno we don't know).
Step 2) add a dual plane. Grabbed some free ft-lbs and didn't lose anything up top. Sounds great.
Step 3) Change the cam to get a lower, torquier, motor. To me this made no sense. They gained 100ft-lbs at 2000 rpm-- but lost over 100hp at like 5700 (the article isn't right in front of me). They claimed, somethign to the tune of, while we lost hp, its torque that gets things moving.
This is true.
But: How much time at the strip does your motor spend at 2k ? Wouldn't a torque converter that went right over that rpm make it pointless? Would an engine with 100 more ft lbs at 2000rpm be faster than an engine with 100 more hp at 5700 (or so) rpm?
The other problem I had was with the cam they picked-- I think they could have struck a somewhat decent balance between low end and top end.. but instead they went out and picked probably the smallest hydraulic roller I realized GM would put in a BB crate motor!
Was this just to show the effects of cam size? I mean?
The only thing it showed me was that my cam is probably *waaaay* to big as has been suggested, as its 256/260 @ .050 while the GM stock 572 can is 256/264 @ .050. But-- Did this test in the magazine make any sense to anyone out there? or did I read it totally wrong and I am complete bonehead?
happy easter-
If my engine doesn't nuke on the dyno (or not supply enough fuel) I will be posting some chassis dyno sheets with an ultra-tight converter tomorrow night.
matt
Step 1) dyno engine as is (on how liberal a dyno we don't know).
Step 2) add a dual plane. Grabbed some free ft-lbs and didn't lose anything up top. Sounds great.
Step 3) Change the cam to get a lower, torquier, motor. To me this made no sense. They gained 100ft-lbs at 2000 rpm-- but lost over 100hp at like 5700 (the article isn't right in front of me). They claimed, somethign to the tune of, while we lost hp, its torque that gets things moving.
This is true.
But: How much time at the strip does your motor spend at 2k ? Wouldn't a torque converter that went right over that rpm make it pointless? Would an engine with 100 more ft lbs at 2000rpm be faster than an engine with 100 more hp at 5700 (or so) rpm?
The other problem I had was with the cam they picked-- I think they could have struck a somewhat decent balance between low end and top end.. but instead they went out and picked probably the smallest hydraulic roller I realized GM would put in a BB crate motor!
Was this just to show the effects of cam size? I mean?
The only thing it showed me was that my cam is probably *waaaay* to big as has been suggested, as its 256/260 @ .050 while the GM stock 572 can is 256/264 @ .050. But-- Did this test in the magazine make any sense to anyone out there? or did I read it totally wrong and I am complete bonehead?
happy easter-
If my engine doesn't nuke on the dyno (or not supply enough fuel) I will be posting some chassis dyno sheets with an ultra-tight converter tomorrow night.
matt