Help Figuring Horsepower? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

lash · 01-31-2003, 12:04 AM

Hey everyone, I just put my new motor in my 72 4x4. Was curious if anyone could give me a idea of HP and torque?

383 stroker .30 over
6" rods
forged pistons@10.6/1
vortec heads trued up and milled for 1.5 roller rockers 194/150
roller cam w/510 lift adv. 272/276 .50 220/224 lobe center 109.5
edelbrock performer intake
streetdemon 650 carb w/k&n filter
heddman comp headers

Any help will be appreciated
Thanks Lash

oldsub86 · 01-31-2003, 12:10 AM

Figure out what you think it is and divide by 2 or 3 and you should be close. Most people including the factories tend to exagerate quite a bit.

Does it really matter anyway? The seat of the pants feel is much more relevant than whether your motor has more horsepower or torque than what the next guy claims he has.

lash · 01-31-2003, 12:15 AM

Just wanted to know. I could care less what the next guy has! I built it for me.

mikep · 01-31-2003, 12:24 AM

Without more cam info its hard to tell but its a fairly close approximation to the hot LT4 cam. Give us the cam grind number so we can get the cam specs . I cam up with around 365 HP and 430 ft lbs on the DD 2000 but without more exact cam specs its a crap shoot.

bigjimzlll · 01-31-2003, 12:52 AM

do you have any problem with detonation?..It should be vary torquey..run out of rpms around 5500 rpm..do you have new (big) valve springs on it?...sounds like a good combo...the DCR is a little high, but the vortecs can handle a little more than older heads.
Jim

lash · 01-31-2003, 09:25 AM

grind # is 10085 and valve springs as well as all head components were beefed up. backed this all up w/ turbo 350 w/shift kit 2300 stall and 4.10 posi rear. I hope she is strong.

mikep · 01-31-2003, 01:07 PM

grind # is 10085

Who is the maker ?

lash · 01-31-2003, 06:35 PM

PBM roller cam Sorry

mikep · 01-31-2003, 06:45 PM

I'm not familiar with PBM . Do you have a cam card. sorry to ask so many questions but we need the intake and exhaust valve opening and closing points.

lash · 02-01-2003, 01:43 AM

Sorry on this end.

Int. open 30 close 62

exh. open 72 close 24

lobe lift .340

int centerline 106
exh centerline 114

mikep · 02-01-2003, 02:11 AM

Pretty good numbers. I'm not too happy with some of the desktop dyno features such as their intake manifold selection and theres always a few things you can do to finesse a few more HP out ( or lose some ) . It looks like your engine would be doing approximately the following give or take.

2000 RPM 122 HP and 321 Ft Lbs

2500 RPM 166 HP and 348 FT Lbs

3000 RPM 205 HP and 359 Ft Lbs

3500 RPM 258 HP and 387 FT Lbs

4000 RPM 311 HP and 409 Ft Lbs

4500 RPM 359 HP and 419 Ft Lbs

5000 RPM 393 HP and 413 Ft Lbs

5500 RPM 408 HP and 390 Ft Lbs

6000 RPM 405 HP and 354 Ft Lbs

6500 RPM 386 HP and 311 Ft Lbs

One thing that became pretty obvious with this combination is that you are going to be running out of carburetion fairly early on with that 383 trying to huff through a fairly small manifold and a 650 carb. By changing to a 800 cfm carb you picked up 10 HP and 6 ft lbs although with a larger manifold and the bigger carb you'd be looking at around 450 HP and 440 Ft Lbs with approximately the same curve.

FYI that same setup with the 800 carb and small single plane intake on a set of $750 pro action 200 cc heads would get you around 505 HP at 6000 rpm with 455 ft lbs at 5000...Food for thought.

lash · 02-01-2003, 10:04 AM

Thanks Mike pretty much what i expected Interesting food for thought. Will run this combo this summer and may entertain those thoughts this summer. Thanks again
Lash

01-31-2003, 12:04 AM	#1
lash Registered User Join Date: Feb 2002 Location: Central Illinois Posts: 163	Help Figuring Horsepower? Hey everyone, I just put my new motor in my 72 4x4. Was curious if anyone could give me a idea of HP and torque? 383 stroker .30 over 6" rods forged pistons@10.6/1 vortec heads trued up and milled for 1.5 roller rockers 194/150 roller cam w/510 lift adv. 272/276 .50 220/224 lobe center 109.5 edelbrock performer intake streetdemon 650 carb w/k&n filter heddman comp headers Any help will be appreciated Thanks Lash

01-31-2003, 12:10 AM	#2
oldsub86 Registered User Join Date: Dec 2002 Location: Canada Posts: 695	Figure out what you think it is and divide by 2 or 3 and you should be close. Most people including the factories tend to exagerate quite a bit. Does it really matter anyway? The seat of the pants feel is much more relevant than whether your motor has more horsepower or torque than what the next guy claims he has. __________________ 1968 Chevy - 292 with a powerglide

01-31-2003, 12:24 AM	#4
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	Without more cam info its hard to tell but its a fairly close approximation to the hot LT4 cam. Give us the cam grind number so we can get the cam specs . I cam up with around 365 HP and 430 ft lbs on the DD 2000 but without more exact cam specs its a crap shoot. __________________ No truck :-(

01-31-2003, 12:52 AM	#5
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	do you have any problem with detonation?..It should be vary torquey..run out of rpms around 5500 rpm..do you have new (big) valve springs on it?...sounds like a good combo...the DCR is a little high, but the vortecs can handle a little more than older heads. Jim __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

01-31-2003, 01:07 PM	#7
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	grind # is 10085 Who is the maker ? __________________ No truck :-(

01-31-2003, 12:15 AM	#3
lash Registered User Join Date: Feb 2002 Location: Central Illinois Posts: 163	Just wanted to know. I could care less what the next guy has! I built it for me.

01-31-2003, 09:25 AM	#6
lash Registered User Join Date: Feb 2002 Location: Central Illinois Posts: 163	grind # is 10085 and valve springs as well as all head components were beefed up. backed this all up w/ turbo 350 w/shift kit 2300 stall and 4.10 posi rear. I hope she is strong.

01-31-2003, 06:35 PM	#8
lash Registered User Join Date: Feb 2002 Location: Central Illinois Posts: 163	PBM roller cam Sorry

01-31-2003, 06:45 PM	#9
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	I'm not familiar with PBM . Do you have a cam card. sorry to ask so many questions but we need the intake and exhaust valve opening and closing points. __________________ No truck :-(

02-01-2003, 01:43 AM	#10
lash Registered User Join Date: Feb 2002 Location: Central Illinois Posts: 163	Sorry on this end. Int. open 30 close 62 exh. open 72 close 24 lobe lift .340 int centerline 106 exh centerline 114

02-01-2003, 02:11 AM	#11
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	Pretty good numbers. I'm not too happy with some of the desktop dyno features such as their intake manifold selection and theres always a few things you can do to finesse a few more HP out ( or lose some ) . It looks like your engine would be doing approximately the following give or take. 2000 RPM 122 HP and 321 Ft Lbs 2500 RPM 166 HP and 348 FT Lbs 3000 RPM 205 HP and 359 Ft Lbs 3500 RPM 258 HP and 387 FT Lbs 4000 RPM 311 HP and 409 Ft Lbs 4500 RPM 359 HP and 419 Ft Lbs 5000 RPM 393 HP and 413 Ft Lbs 5500 RPM 408 HP and 390 Ft Lbs 6000 RPM 405 HP and 354 Ft Lbs 6500 RPM 386 HP and 311 Ft Lbs One thing that became pretty obvious with this combination is that you are going to be running out of carburetion fairly early on with that 383 trying to huff through a fairly small manifold and a 650 carb. By changing to a 800 cfm carb you picked up 10 HP and 6 ft lbs although with a larger manifold and the bigger carb you'd be looking at around 450 HP and 440 Ft Lbs with approximately the same curve. FYI that same setup with the 800 carb and small single plane intake on a set of $750 pro action 200 cc heads would get you around 505 HP at 6000 rpm with 455 ft lbs at 5000...Food for thought. __________________ No truck :-( Last edited by mikep; 02-01-2003 at 02:16 AM.

02-01-2003, 10:04 AM	#12
lash Registered User Join Date: Feb 2002 Location: Central Illinois Posts: 163	Thanks Mike pretty much what i expected Interesting food for thought. Will run this combo this summer and may entertain those thoughts this summer. Thanks again Lash



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