Tonys96

For those of you that don't know, I bought a '79 L-82 in December, just finished the engine rebuild.

WOW !!!

Had it on the engine dyno at MAS Performance in Ellsworth, WI all morning and half the afternoon, getting the Demon carburetor dialed in.

John, hmmm...another wrench named John, rejetted the carb about 7-8 times, till he got the A/F ratio dialed in perfectly.

Mike, the owner, showed me all the internals, he was building another "Crate Motor" using the same internals, I used Dart Pro1 heads, his crate motors use Edelbrock heads.

Enough blabering.

New Information





490.8 Ft/lb Torque @ 4400 RPM, more than 425 ft/lb from 2700 rpm up.
479.4 HP @ 5800 RPM, more than my '96 LT-1 made from 3700 rpm up.

All this with a Dart Kool Kan intake, hope it fits under the hood, if not the recommended manifold should bring it up over 500 HP. Along with a new hood.

73C34me

what's the specs?

Tonys96

Made a 383 using the stock block.

1035037507I Eagle Cast steel Crankshaft
SIR5700BPLW Eagle ESP 5140 Steel SIR I-Beam rods
H860CP Speed Pro coated pistons
2M139 Hastings rings
12-432-8 Comp Cams XR282HR-10 retro roller cam
CB663P Clevite Rod Bearings
MS909P Clevite Main Bearings
SH290S Clevite Cam Bearings
M55HV Melling High Volume Oil Pump
Dart "Kool Kan" Intake Manifold (Air Gap clone)
11121112 Dart Pro 1 Aluminum heads Dual Spring
1301-13 Comp Cams "Pro-Magmum" Roller Rockers
12-327-13 Holley High Volume Mechanical Fuel Pump
68308 Hedman Headers Coated Elite Headers
1412020 Barry Grant Speed Deamon Carburetor 88P/95S Jets

35 Degree @ 3800 Full Advance, vacuum advance disabled
10.25:1 Compression ratio
92 Octane Fuel requirement

Eddie 70

Pretty darn good numbers. Should be a lot more fun to drive now.

Tonys96

Thanks, I hope so.

b71vette

I believe the 750DP Demon Jets out of the box is like 74Primary and 76Secondary. Looks like yours were uped to 88P and 95S, that's a pretty large increase, must be the cam needed more fuel.

I see you have the Pro Magnum Roller Rockers, I want to upgrade to those some day. I hear they are great rockers for the money.

Tonys96

That sounds about right for the out of the box jets, the dyno tuner rejetted 9 times, with a pull between each rejet to check the numbers, going up between 2-5 jet sizes each time to get the A/F ratio and primary to secondary balance he was looking for. He could hardly believe how big he went.

The motor shop I used, builds a crate motor using the same bottom end and cam, but uses Edelbrock E-Tec heads and Edelbrock Air Gap manifold that makes about the same HP, but with a lot less jet than the DART stuff required. I think if I were to do it over, I just should have bought their crate motor, but I'm excited about the build I had them do and can't wait to get it on the road, dragstrip and racetrack.

Full roller fulcrum and tips, stainless steel, should be very durable. Also upgraded to a full roller valve train, engine builder said that'd give me about 35 HP for the same lift and duration flat tappet cam.

panchop

nice numbers

LFZ

nice numbers...hows the idle on that cam? I considered it for my 383, but took a chance on the XR288 instead.

nastee383

I'm jealous! Those are good #'s. Actually I'm confused and a little PO'd. My 383 with 11:1 comp., XR294HR, Canfield heads, C&A ZGS rings, RPM air gap did 445hp@ 5600 and 460tq@ 4400. I was hoping for 500 & 500 minimum with a 6100 or better power peak. But anyway, congrats on what is obviously a well built motor.

Hitch

How choppy does that XR282HR sound? The numbers you put up look about where I would think that setup should be. I'm doing almost the same setup though without going to 383... I think that cam is the heat.. I just can't wait to fire mine up and dyno it.. Thankx.. Dave

Tonys96

Idles fairly well at 850-900, wish it had more lope.

Tonys96

Do you have the 195cc Canfield heads ?

My engine guy talked with me for a while about engine RPM, heads, cams and intakes.

Here's my condensed version.

On Small Block Chevy's running up to 6500 RPM,

Valves over 1.94" will actually make less HP, around 10 HP less than a 1.94", I chose to ignore him and went with 2.02", right, I'm down about 10 HP from where I wanted to be.

Intake runners over 170-180 cc will make less torque and consequently less HP, same engine and revs. I went with 180CC.

The intakes we need to fit under the hoods, Air Gap, etc, will drop about 20 HP off the motor as well.

Roller valve train, (Retro roller cam in my case) and full roller rockers (not just roller tip, they do nothing) will give you about 40 HP, same engine and RPM.

So if I'd listened to my builder, I'd have had about another 10 HP and if I would get another hood, add another 20 HP on top of that.

Oh...like I said, they found an additional 45 HP in the carb, on the dyno, well worth the money there.

Tonys96

Cam sounds to smooth, although I've only heard it run on the dyno.

The crankshaft is helping with the power too. It is a cast steel unit with hollow journals.

Comp has a good "Techincal Section" on their website, lists about 405 HP on a 350 with Dart Sportsman heads and a Holley 750 DP. They compare quite a few cams there, good reading.

GDaina

you will break the tires loose without a sweat....

Tonys96

Those numbers look like mine before dyno tuning the carb.

The cam should be good for about 10 more HP than mine, you're right were you need to be on compression ratio.

What are the head specs and what carb did you use.

Did you get A/F ratio and F/R Fuel flow info off the dyno ???

My guys worked their butts off getting the A/F Ratios below 13 and F/R balance within 1 lb/hr.

nastee383

The heads are Canfield 195's, 65 chambers, minimal porting on the intake/exhaust ports, 2.055/1.60 valves. The carb was a DEMON750 vacuum secondary.

A/F ratio was 12.8 to 13.8 from 3500 to 5200. Then it started richening up 13.3 to 12.7 from 5300 thru 6000. Don't have F/R fuel consumption. I assume that's front/rear VE was 94.6 @ 4900rpm. BSFC was in the low .400 range from 3500 to 5200 then it started rising slightly to .500 @ 6000. The carb was jetted 80/86.

Tonys96

My dyno/builders extolled upon me the virtue of smaller intake runners for engines running less than 6500 RPM. Looks like you have the runners and valves to run a lot more cam.

Jetting still looks off, again, my guys kept putting in bigger jets to get the A/F ratios below 12:1, the highest is 12.74 @ 5200, but it looks like a flyer, most are 11.0 - 11.5. My BSCF numbers were .592 @ 2700 dropping to .470 @ 4000 and then holding .500 to 5600, climbing after that to .560 @ 6000

I'm running a little smaller cam and 15cc smaller runners, same combustion chamber size and a little less CR. Demon 750 Mech secondary. Jets are 88 primary and 95 secondary.

Does your dyno guy have individual pyrometers for each cylinder exhaust gas temperature ??? Very important when trying to balance the carb.

SanDiegoPaul

YOWZAA!!

bickel

Fantastic numbers should grab you by the seat of the pants and give you one hell of a ride!!
You were at the mas performace shop working with john? I am in Germany I have been talking to john on the phone about the 420hp 350 he makes and I have been heavly conserding the purchase trying to hold closer to spring but it is looking like sooner is going to come than later so would you recomend them? John seems real nice and knowldgeable?