dynoed my engine...what do you think?

[devildog1313]

HI, I just found this board, looks good to go.  I look forward to learning from you all and sharing what I know with al of you.  I just built a motor for my rig and took it to the dyno.  I was suprised by the readings and would like some feedback.  

Here is the info on the vehicle

vehicel type:  1986 GMC crew cab dually 4x4
vehicle weight: 7200 lbs
Tranny:  NV4500 5 speed
gears and tires:  4.10, 33" tires
Engine:  454 .060 over.  edelbrock ProFlo MPFI, 9.5 compression, steel crank, forged rods, balanced, etc.
Isky hydrualic roller cam
Cam info:   intake timing            exhaust timing
duration    265 degrees             275 degrees
open        20.5 BTDC                69.5 BTDC
close        64.5 ABDC               25.5 ABDC
cam lift     .312                       .325
valve lift   .500                       .520
overlap:  46 degrees
lobe center:  112 degrees

I was surprised with what I got on the dyno.   I thought is would be more.  Regardless of what the numbers say, I couldnt be happier with how it performs.  When I am idleing along in first gear and stomp the peddle to the floor, it just obliterates the rear four tires!  It pulls hard in every gear, runs on 87 octain, and idles nicely...even when cold.

So...the numbers at the rear wheels:  Max HP 282  Max TQ 371

The really nice thing is the large flat torque curve and linear HP curve.  From 1600 rpm I am making over 325 lb/ft  of TQ and that carries all the way to 4700 rpm before falling off.  HP doesnt start falling off until 4800 rpm.  The pulls were on a Superflow chassis dyno and the
numbers all all uncorrected for barometric pressure, temp, altitude, etc.

I am really curious to hear what you all have to say and to hear about any dyno pulls you all have done. Other than the machine work, I built the entire motor myself (first one) to include porting and polishing the heads.

Have a good one.  Robby

[Lt.Del]

Hey Robby,

I think you found the correct website.  Chris (roundedline) does an excellent job keeping this site up and running and is full of info.

I agree with you.  The numbers seem a little low for what you have.  I guess it is because the motor was dynoed installed in your truck and variations in the driveline perhaps lower the number.  Below is a link to my 383 stroker.  I am sure this motor was tested prior to installation (well, it had to be, i installed it myself and it aint never seen no dyno--how's that for english).  

I watch those shows on sunday mornings on speed and spike tv and it does make a difference when the hp goes thru the drivetrain.  


383 stroker specs

I can pull my 30' camper over the blue ridge mountains of shenandoah without a problem, and I have a 3:08 rear.

SgtDel
www.delbridge.net/chevy

Edited by: SgtDel at: 4/19/06 8:51 am

[roundedline]

That is pretty good power to the rear wheels in my opinion.  Welcome to the site!

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[devildog1313]

Thanks fellas.  

I just added a flow master 70 series big block muffler and a KN airfilter and flow through top.  It seems to be a bit crisper throttle response in the low RPM range.  Probably all psychological!

The next projects are:

-rewiring power door locks
-suspention upgrades
-figuring out how to lighten the truck with various bits of alluminum and fiberglass!

Robby

[SUX2BU99]

I was suprised to see a sub-300 HP number too but you do get a fair bit of loss through that heavier-duty driveline that you have. Still though if it feels strong to you, that's what matters. After reading the list for the motor, first thing I thought of was "what about the heads?" but I see your ported and polished them.

Del, how much did that 383 set you back? That sounds exactly like what I want for my truck. Right now the very mild 350 it has won't light up the tires when I punch it (but it will do a brakestand with some effort) and can only wheeze to 4500 rpm   Runs like a top though.

[Lt.Del]

I paid a total of about $2,800 if i remember correctly (4 blt main) (no core charge).    This didn't include the qjet ($470) or waterpump ($85-hi volume).  Put on a 4 core radiator also ($196).  I ordered the engine as EGR compatible with the edelbrockk performer intake 2901 i think.  Ordered it with an RV type cam--I love the idle!!.   Kept all the smog stuff on it.  

I bought it from ...

D&J Machine & Performance Engines
(602) 395-0800 Mon-Fri 8:00AM to 5:00PM MST
or email us at enginebuilder1@yahoo.com

They are in Arizona.  I am pleased with it.

383 stroker install

SgtDel

Edited by: SgtDel at: 5/5/06 10:02 pm

[SUX2BU99]

Right on, thanks for the info.

[devildog1313]

Thanks for the "welcome aboard" and all the replies.

Forgive me skepticism, but I have to doubt the 335/415 figures that the 383 with an RV cam is making, especially at 3500 rpm!  

Peoples claims to HP/TQ is like claims to wieght lifting.  I cant tell you how many say they bench 400lbs, but ask them to do it and it doesnt happen.  I think if you got the motor on the dyno, especially a chassis dyno, the motor would be struggling to hit 200/250 at the rear wheels.  

Obviously the numbers dont matter, it is what you feel in the seat of the pants that counts.

I just today took a ride with one of my Marines that just put a new 454 with an RV cab in his 85 1 ton 4x4 chev, and though it pulled relatively hard, it sure as heck wont break the tires loose.  It is a lot harder than most people think to make massive power and torque with out special fuel, or power adders of some sort, etc.

Heck, at the dyno shop, Marco had a pull from a brand new vortec 454 in a 3/4 ton 4x4.  (The pulls were done a few years ago and saved on the machine).  Advertized HP from the factory was 290 (or was it 310, I dont remember?) and 345 lb/ft tq.  It barely made 200 hp and 275 lb/ft tq!

What do you all think?

[Lt.Del]

devildog, the engine builder claims 335 hp.  I do not doubt that one second.  The pleasure I get out of driving that truck w/ the 383 is indescribable.  I can bury the speedo w/ no problem.  I can pass and pull away from sports cars at a green light.  So much fun.

It's awesome to push down the accelerator and just feel the torque.  Did I mention I can pull a 7k lb 30' camper over a 3500' mountain range with pedal left?   I don't care what the numbers are on it, I just know it is so much fun to step down on it.  My original 350 had stock 179 hp, i think.  Heck, this 383 with the performer intake and new edelbrock quadrajet puts it to shame, I'd say at least double the power.  

The only drawback is I have to put high octane in it or she knocks and diesels--even after adjusting timing and throwing cold plugs in it.

SgtDel
www.delbridge

[roundedline]

The rating on the 335/415 is pretty normal and I don't disagree with it at all.  Keep in mind it was probably dynoed with absolutely NO accessories on it at the crank.

Once you stick it in a vehicle you add a alternator, power steering and A/C.  This will easily suck 15hp off
Then you bolt a transmission to it and you drop off about 50 for a manual and 75 for an auto.  Now you are down to about 280hp as you get to the tires.

We dyno'd my 2000 FRC Corvette (6 speed) that is completely STOCK.  It is advertised at 345hp (at the crank with accessories).  It put down a MAX of 314hp at a peak (spike), but across the top it put down average of 308hp.

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[SUX2BU99]

^ That's only about a 15% loss which isn't that bad at all. 15-20% for manuals is common and 20-25% for autos. I know too that not all dynos read the same numbers. User-input can make a difference as well, altitude, temperature, humdity, etc. Bigger trucks though like 3/4 and 1-tons use heavier duty trannies and rear ends and probably larger accessories on the engine like the alternator and possibly stronger power steering pump.  All the thicker, heavier parts inside those heavy-duty items suck up more power. A Dana 60 diff is going to have more parasitic loss through it than say a 10 bolt. I don't doubt those 383 numbers either. Most any 383 engine out there has numbers like that, but would be bare engines like Chris said. No smog equipment, accessories, etc. Very similar to what the old 'gross' ratings were on muscle cars compared to todays 'net' ratings.