What SS Prop for 383 stroker on 21' 3,000 lb Senza
07-16-2002, 10:30 PM
#1
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What SS Prop for 383 stroker on 21' 3,000 lb Senza
OK, time to re-prop again.
I've got a 383 ci. stroker motor putting out 380 HP @ 5200 RPM and 450 ft-lbs torque at 3,700.
What prop would you guys recommend for a 3000 lb. total wt boat? I was running 60 mph (GPS) with a stock 5.7L 260 hp/ 21" SS Laser prop last year. Same prop shows ~ 70 mph at 5300 RPM now.
Engine is rollerized (lifters, rockers). Where should I shoot for in RPMs for this combo?
I've got a 383 ci. stroker motor putting out 380 HP @ 5200 RPM and 450 ft-lbs torque at 3,700.
What prop would you guys recommend for a 3000 lb. total wt boat? I was running 60 mph (GPS) with a stock 5.7L 260 hp/ 21" SS Laser prop last year. Same prop shows ~ 70 mph at 5300 RPM now.
Engine is rollerized (lifters, rockers). Where should I shoot for in RPMs for this combo?
Last edited by 21_senza_383_2; 07-16-2002 at 10:33 PM.
07-17-2002, 12:36 PM
#4
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Id say you are prety close now... have you tried the vatios other types of props out there.. Like bravo 1s? In all my testing Ive always found the 3 blade to be fastest. If you should be maxing out at 5200 and you are currently hitting 5300 Id say try 1 size up. You will cruise faster and be in the fat part of the torque band .
07-18-2002, 11:51 PM
#6
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Thanks for the help guys. Right now, I am leaning toward trying a 23" Mirage Plus, as I've heard great things about them, and a 200 RPM drop (maybe more?) would likely do me some good.
Torque of this cam in a 3,000# package is pretty fat for a small block. On the Dyno, 400 ft-lbs from ~ 2,400 - 5,000 RPM, maxing at 450 ft-lbs at 3700. Max HP is 378 w/ the Q-jet rejetted (didn't care for the Holley steady-state mid-range & idle properties while on the dyno). Holley pulled the dyno a little faster, but owner of shop steered my away from the Holley, as the Q-jet is less "High Maintenance".
Misc. question maybe someone out there can answer. Wierd thing I noticed last year when testing some Revolution 4 demo props last year. Spinning a 23" 4 -blade (all they had in stock at first), my old engine would not pull that sucker up past ~3400 RPM. Aftre getting ahold of a 19", I could spin it to ~5,000. Was I just not getting up on the curve enough to get it to within 400 RPM of the 19" Revolution 4??? Seems pretty drastic. I'm thinking I could likely spin at least a 21" Rev 4, but I need to keep the Alpha in decent shape (at least until late in the season when "Whoops...Dear, I think we blew the outdrive...Have to change to a Bravo...boy, that was good timing...just in time for winter!"
Torque of this cam in a 3,000# package is pretty fat for a small block. On the Dyno, 400 ft-lbs from ~ 2,400 - 5,000 RPM, maxing at 450 ft-lbs at 3700. Max HP is 378 w/ the Q-jet rejetted (didn't care for the Holley steady-state mid-range & idle properties while on the dyno). Holley pulled the dyno a little faster, but owner of shop steered my away from the Holley, as the Q-jet is less "High Maintenance".
Misc. question maybe someone out there can answer. Wierd thing I noticed last year when testing some Revolution 4 demo props last year. Spinning a 23" 4 -blade (all they had in stock at first), my old engine would not pull that sucker up past ~3400 RPM. Aftre getting ahold of a 19", I could spin it to ~5,000. Was I just not getting up on the curve enough to get it to within 400 RPM of the 19" Revolution 4??? Seems pretty drastic. I'm thinking I could likely spin at least a 21" Rev 4, but I need to keep the Alpha in decent shape (at least until late in the season when "Whoops...Dear, I think we blew the outdrive...Have to change to a Bravo...boy, that was good timing...just in time for winter!"
