desk top dyno
#21
MarineKinetics
Platinum Member
Re: desk top dyno
Sutphen30
They aren't especially forthcoming with that info (especially design information like lobe area). The end user doesn't ask for them and they aren't as "glamorous" as the head companies flow numbers.
Bob
They aren't especially forthcoming with that info (especially design information like lobe area). The end user doesn't ask for them and they aren't as "glamorous" as the head companies flow numbers.
Bob
#22
Registered
Join Date: Jan 2001
Location: Holland MI
Posts: 3,140
Likes: 0
Received 0 Likes
on
0 Posts
Re: desk top dyno
Ok, here are some DD results.
Isky at 0 cam advance
rpm hp tq
3000 362 633
3500 422 633
4000 475 623
4500 519 606
5000 539 566
5500 531 507
Crane 731, installed at 0
3000 371 649
3500 430 644
4000 478 627
4500 510 595
5000 512 538
5500 494 472
I entered the cam timing event data as published by rmbuilder. Thanks, Bob.
If the cams are timed similarly (the 0 vs. 5 degree difference that rmbuilder pointed out) the numbers become virtually the same. Hope this helps you. Dave
Isky at 0 cam advance
rpm hp tq
3000 362 633
3500 422 633
4000 475 623
4500 519 606
5000 539 566
5500 531 507
Crane 731, installed at 0
3000 371 649
3500 430 644
4000 478 627
4500 510 595
5000 512 538
5500 494 472
I entered the cam timing event data as published by rmbuilder. Thanks, Bob.
If the cams are timed similarly (the 0 vs. 5 degree difference that rmbuilder pointed out) the numbers become virtually the same. Hope this helps you. Dave
Last edited by Crazyhorse; 01-11-2005 at 05:31 PM.
#24
MarineKinetics
Platinum Member
Re: desk top dyno
Dave,
Thanks for the good work you did on this! Post #9 has some accurate flow #s on those(390) heads if you want to enter them into your data base.
Bob
Thanks for the good work you did on this! Post #9 has some accurate flow #s on those(390) heads if you want to enter them into your data base.
Bob
#25
Registered
Thread Starter
Join Date: Oct 2004
Posts: 51
Likes: 0
Received 0 Likes
on
0 Posts
Re: desk top dyno
thank's guys, realy appreciate your inputs and work.
Dave what do you mean by numbers become virtualy the same ? outcome on DD the same ?
Bob, post #14,if you retard the crane of 5*,will it do the same,bring the crane #'s close to the isky #'s ?
Dave what do you mean by numbers become virtualy the same ? outcome on DD the same ?
Bob, post #14,if you retard the crane of 5*,will it do the same,bring the crane #'s close to the isky #'s ?
#27
Registered
Join Date: Feb 2004
Location: Murray,KY
Posts: 487
Likes: 0
Received 0 Likes
on
0 Posts
Re: desk top dyno
I think what's confusing you is "the same"
What they mean is the HP/TQ curve are more down in the rpm range when a cam is advanced and up when it's retarded(backed off).One mfg quotes the "straight up"
figures one quotes the advanced. Since you can adjust these when installing it doesn't really matter which they use,just that you know and compare them with the same advance.Look at how the Crane makes more power down low on rpm. If you installed the Isky advanced like the crane its power would move down the rpm scale. It's ALL a compromise, like everything.
What they mean is the HP/TQ curve are more down in the rpm range when a cam is advanced and up when it's retarded(backed off).One mfg quotes the "straight up"
figures one quotes the advanced. Since you can adjust these when installing it doesn't really matter which they use,just that you know and compare them with the same advance.Look at how the Crane makes more power down low on rpm. If you installed the Isky advanced like the crane its power would move down the rpm scale. It's ALL a compromise, like everything.