GM crate motor HP and torque - The 1947 - Present Chevrolet & GMC Truck Message Board Network

okiefab · 05-04-2009, 01:09 AM

how accurate are the HP and Torque on GM crate motors, such as the ZZ383
425 HP at 5400 rpm and 449 lbs torque, 9.7 to one,roller cam 509/528 lift 222/230 @ .050,. fast burn aluminum d port heads 62cc 2.00 intake/155 exhaust valves. has one been put on a Dyno , are just taking GM's word on this.

6600DURAMAX · 05-04-2009, 09:17 PM

I have always wondered this too. I believe I heard on the Show TRUCKS that the 572 in copperhead actually made more but I cant remember the details. would be interesting to see a true dyno of the 572. I know there are others out there using high quality parts making more than the GM advertised HP with less than 572''.

Would be interesting

BossHogg69 · 05-05-2009, 10:32 AM

Chevy High Performance and Custom Classic Trucks have both dynoed these engines and they were right on their claims. From what I've seen in many different magazine tests over the years, GM is good about hitting or even over delivering on their power claims for the GMPP crate motors. You can probably search the websites www.chevyhiperformance.com and www.customclassictrucks.com and find the articles in their archives.

okiefab · 05-05-2009, 01:09 PM

thanks for the information, using these crate engines for a blueprint
with an upgrade on parts, should give me a starting point to build on.

05-04-2009, 01:09 AM	#1
okiefab Registered User Join Date: Mar 2009 Location: Covington, Oklahoma Posts: 27	GM crate motor HP and torque how accurate are the HP and Torque on GM crate motors, such as the ZZ383 425 HP at 5400 rpm and 449 lbs torque, 9.7 to one,roller cam 509/528 lift 222/230 @ .050,. fast burn aluminum d port heads 62cc 2.00 intake/155 exhaust valves. has one been put on a Dyno , are just taking GM's word on this.

05-04-2009, 09:17 PM	#2
6600DURAMAX Registered User Join Date: Nov 2000 Location: Wheatfield IN, USA Posts: 1,119	Re: GM crate motor HP and torque I have always wondered this too. I believe I heard on the Show TRUCKS that the 572 in copperhead actually made more but I cant remember the details. would be interesting to see a true dyno of the 572. I know there are others out there using high quality parts making more than the GM advertised HP with less than 572''. Would be interesting __________________ 1972 K5 Build - plans - LS3-6L80e-One Tons..... 1971 CREWMAX Build.....at body shop for couple more years

05-05-2009, 10:32 AM	#3
BossHogg69 motor exploder Join Date: Mar 2009 Location: Pittsburgh, PA Posts: 2,346	Re: GM crate motor HP and torque Chevy High Performance and Custom Classic Trucks have both dynoed these engines and they were right on their claims. From what I've seen in many different magazine tests over the years, GM is good about hitting or even over delivering on their power claims for the GMPP crate motors. You can probably search the websites www.chevyhiperformance.com and www.customclassictrucks.com and find the articles in their archives. __________________ Adam 1969 Chevy CST/10 stepside, DART Big M/TREMEC Magnum Extreme/3.73's w/Detroit Truetrac 1965 Chevy Bel Air Wagon (daily driver), 327/TH350,10 bolt w/3.08's 1961 Chevy Bel Air Sport Coupe, ZZ454/M21/9" rear w/3.50's & Detroit Truetrac 2005 GMC 1500 ccsb 2wd, 6.0L/4L65e/3.73 G80 2006 GMC 2500HD ccsb 4x4, DMax LBZ/Allison 6spd/4.56's w/Detroit TrueTrac Use the SEARCH function on this forum - it is your friend!!

05-05-2009, 01:09 PM	#4
okiefab Registered User Join Date: Mar 2009 Location: Covington, Oklahoma Posts: 27	Re: GM crate motor HP and torque thanks for the information, using these crate engines for a blueprint with an upgrade on parts, should give me a starting point to build on.



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