Ran my car on a Dyno this weekend

[eagleone1983]

I hooked my car up to a dyno this weekend. I thought by HP numbers were going to be a bit higher but maybe this is where she should be. These numbers are not corrected for anything they are as exact as they can be to the rear wheels. I definitely have a little more tuning to do as at idle my eyes burn and you can smell fuel. My spark plugs don't look overly black or coated with soot. Engine is a 383 automatic, the last two pulls the transmission kicked down and fudged the torque numbers.

 

[dieseldazzle]

Cant get a real good look at it.

 

[mopar12372]

just looks like numbers from a slightly modified engine , not bad if you ask me for a street car.

 

[dieseldazzle]

I cant see it real good but if it says max power at the wheels was 360hp like I THINK it says then that is way more than just a warmed up 383 is gonna put out at the wheels i can promise you that.

 

[lewtot184]

I cant see it real good but if it says max power at the wheels was 360hp like I THINK it says then that is way more than just a warmed up 383 is gonna put out at the wheels i can promise you that.

i agree. thats a lot of power for a 383 auto, even with modifications.

 

[eagleone1983]

Sorry I forgot that some are older than others The first run was 359HP @ 4600 and 439.5 ft lbs of torque @ 3500. The 383 is bored .030 over with KB400 pistons, CR is at 9.7:1. Cam is a comp XE275-HL, roller rockers, stealth heads, eddie Performer RPM intake, Holley 770 Street Avenger carb, Schumaker Tri-Y headers. Engine was balanced and blueprinted. I'm not sure what other specs to give, I just have fun with my car. I learned all this from books, here, and you tube.

When the RPMs went much over 5k I think the valves started floating at it sounded like crap and white smoke started coming out the pipes. I've never experienced that on the street although I may have never gone that high in RPMs since I don't get that crazy in my car and I don't have a tach.

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Lewtot, do you think the guys dyno is off? I'm not sure what it all takes to set a dyno up I'm just going off what he told me. He did ask me what my stall coverter was but I couldn't remember, I think it's somewhere in the 3000 area but I believe he set it at 2500 since I wasn't sure.

 

[dieseldazzle]

If the heads are stock out of the box stealths you may need better springs for that cam. How did your air fuel ratio look? Cant see the graph real good on here but you can tell when the float occurs typically looking at the power graph

 

[eagleone1983]

Thanks for the suggestion Diesel. Yeah they are out of the box stealths, the only thing I changed were the locks as recommended by 440source for the lift of the cam.

They didn't hook an air fuel ratio gauge up to my pipes but I don't have bungs in my exhaust, would I need that?

I know the picture isn't the best but it was all I could do. He didn't have his printer working when I ran the car. I only noticed the issue on the first run with the floating valves. After it happened he didn't take it past 5k rpm to avoid the valves floating.

 

[dieseldazzle]

Thanks for the suggestion Diesel. Yeah they are out of the box stealths, the only thing I changed were the locks as recommended by 440source for the lift of the cam.

They didn't hook an air fuel ratio gauge up to my pipes but I don't have bungs in my exhaust, would I need that?

I know the picture isn't the best but it was all I could do. He didn't have his printer working when I ran the car. I only noticed the issue on the first run with the floating valves. After it happened he didn't take it past 5k rpm to avoid the valves floating.

Your car is making great power if you are asking me Id leave it alone if you are happy with it and it runs well and performs as you want it to.


Personally I would look at the valve train after hearing your statements. Especially if you used the OTB springs on the stealths and DEFINITELY if you used the 440 source rockers both of which I have used on 3 motors now.

Also they can stick an A/F monitor in your tail pipe.

I have a little wideband I use that is lm1 and Iused to take it from car to car after having a bung welded in and plug it after tuning but I just have a stock 67 charger now, sold everything else.

Again, 360 rearwheel horsepower and that torque is great for any naturally aspirated v-8 on pump gas under 400 cubes if you ask me.

 

[lewtot184]

Sorry I forgot that some are older than others The first run was 359HP @ 4600 and 439.5 ft lbs of torque @ 3500. The 383 is bored .030 over with KB400 pistons, CR is at 9.7:1. Cam is a comp XE275-HL, roller rockers, stealth heads, eddie Performer RPM intake, Holley 770 Street Avenger carb, Schumaker Tri-Y headers. Engine was balanced and blueprinted. I'm not sure what other specs to give, I just have fun with my car. I learned all this from books, here, and you tube.

When the RPMs went much over 5k I think the valves started floating at it sounded like crap and white smoke started coming out the pipes. I've never experienced that on the street although I may have never gone that high in RPMs since I don't get that crazy in my car and I don't have a tach.

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Lewtot, do you think the guys dyno is off? I'm not sure what it all takes to set a dyno up I'm just going off what he told me. He did ask me what my stall coverter was but I couldn't remember, I think it's somewhere in the 3000 area but I believe he set it at 2500 since I wasn't sure.

i think the dyno might be a little on the happy side. with that converter and figuring at least a 20% loss, and it's probably a little more, thats 450hp or more at the crank. those real wheel torque numbers are very high for a 383. way over 500lbsft at the crank. 383's don't make torque. nevertheless, thats probably a sound street package for a 383. get some track mph numbers and do some calculating off that.

 

[Dennis H]

Think I have the same cam in the 440. It has a nasty thump at 750 ;). 415 rwhp chassi dyno and stops pulling at 4850. Rev limiter now set at about 4900. No need to go higher. Remember when bumping the limiter it sounds like a machine gun or like you blew up the engine.

 

[eagleone1983]

Your car is making great power if you are asking me Id leave it alone if you are happy with it and it runs well and performs as you want it to.


Personally I would look at the valve train after hearing your statements. Especially if you used the OTB springs on the stealths and DEFINITELY if you used the 440 source rockers both of which I have used on 3 motors now.

Also they can stick an A/F monitor in your tail pipe.

I have a little wideband I use that is lm1 and Iused to take it from car to car after having a bung welded in and plug it after tuning but I just have a stock 67 charger now, sold everything else.

Again, 360 rearwheel horsepower and that torque is great for any naturally aspirated v-8 on pump gas under 400 cubes if you ask me.

Yeah I'm happy with it, my only issue is the burning eyes at idle. Especially when it is in the garage, I did lean out the mixture screws a little bit this weekend and I also advanced the timing until when starting the engine it tried to bog down the motor (like a dead battery) then I backed it off a few degrees. It runs great and just purrs down the highway.

My rockers are not 440source, heard too many bad things about them. I have the Comp Cam Magnums on mine build.

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Dennis,
YEP same cam although I set my idle speed at 950 but that's in park so I'm probably somewhere around 750 or so.

 

[dieseldazzle]

I put the same cam in my buddies 451 and its a nice cam if you ask me. Power fell off before I would have expected it to tho. Makes some nice torque.

As far as your timing and idle mixture etc I like to do it all with a vacuum gauge. I feel it is the best way on the planet.

Ride around in your car with a WIDEBAND A/F and a Vacuum gauge hooked up and you will understand the motor 100X more.

Then you can tune it the right way. Thats just whats worked for me and I dont know everything **** I have TONS to learn still.

Either way those are GREAT numbers for a naturally aspirated pump gas engine under 400 cubes man.

 

[HT413]

You don't have enough spring for that cam. I'm no guru by any stretch, but both 440 source and comp suggest dual springs for that cam. 440source says those springs are maxed out at 0.510 lift. There are guys running behive springs with that cam and their engines pull hard right to 5800.

 

[dieseldazzle]

I don't have my buddies dyno info but maybe he will chime in here we used comp springs I don't remember which ones but they are 440 source heads on his 451 with a weiand intake that was ported anyway it made peak power at 5600 if I remember right

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I don't have my buddies dyno info but maybe he will chime in here we used comp springs I don't remember which ones but they are 440 source heads on his 451 with a weiand intake that was ported anyway it made peak power at 5600 if I remember right

and the head porting and block machine work was also done at mopar engines west where yours was Dennis but I'm the one that assembled it all Dave and Angie are like family to me

 

[Dennis H]

Not intending to hijack - Rich Nedbal and crew @ MEW came up with the formula/combo. No input from me. I told him I wanted a warmed-up 440 for the street. I could not be happier with the performance and reliability. Thousands of miles of brutal desert heat, drag racing, you name it. Car Show arrivals uncapped bring thumbs up and questions what cam? Just romped it to Monterey yesterday - 13.7 mpg with the Tremec 5 and no vacuum advance. Pump 91.

 

[SlinktRR]

You need a tach with that 383. It's making great power for the mods you have, very impressive.

 

[383man]

If thats accurate then I agree thats good #'s for your eng. Your looking at about 450 hp at the crank. Thats a nice running 383. Ron

 

[SublimeSixpack]

Those are good power numbers! But Comp's site states that cam's range is 2000 to 5800 RPM. If the valves are indeed floating beyond 5000 RPM I'd be changing to different springs. You might just as well get all the performance you can from that camshaft.

 

[lewtot184]

comp recommends a 924 dual spring. the 924 isn't very stout but will allow for some extra lift. the edelbrock spring would probably work with that cam. the bad thing about those short comp cams hydraulics is the 4 degrees of advance ground into them. this takes several hundred rpm out of the engine. if it were me i'd install the cam straight up.