Need Engine Help

[pjmopar]

Hi guys,
71 Charger SE 383 Magnum, 3.23 Detroit Locker, 750 Speed Demon on an Edlebrock Performer, Hughes cam 228 intake/232 exhaust, lift=.523 intake/5.400 exhaust, iron heads, roller rockers 1.5, 2600 stall.
The problem: I don't have a really good launch she comes out of the hole good but not great. Around 25-30 mph is when you feel yourself being pushed back into the seat. I've installed a bigger squirter because it use to nose dive when taking off. Put a 3/4 spacer under the carb which helped. Had it chassis dynoed and calibrated the fuel/air ratio. H.P. = 278, Torque = 372 ft lbs.
I was told to start advancing my timing in 2° incriments until its where I want it or till it becomes hard to start. Initial timing was at 17° I'm up to 26° there may be a little improvement, but I'm not for sure. Can a person go too far advancing the timing? When it was dynoed the total time was around 37°.
Put your thinking caps on and tell me what I need to do.

[Jer]

PJ,
It doesn't sound like you need "engine help" as much as you need or want "hi-performance" help.

Being "pushed back into the seat" at 25 to 30, is just about right for these 2 Ton Behemoths, in my
experience.

Asking any more than that, or trying to push the envelope tighter sounds to me like this thread
needs to be in the Hi-Performance Shop section,
which is why that board was created...

So that's where it's going!!

Good luck to you in your pursuit of satisfying Launches !!
#DriveBurnout#
#2Thumbs#

[71greengo]

You say you have 3:23 gears....which are not the best for launching....If you want to improve this 3:73 gears may be a much better choice....also you haven't mentioned tire size....If you had 275/60/15 tires it would greatly reduce low end launch......
Lower gears/small diameter tires....that should help allot!

[DynoDave]

May 14, 2010 22:59:26 GMT -5 pjmopar said:

383 Magnum, 3.23 Detroit Locker, 750 Speed Demon on an Edlebrock Performer, Hughes cam 228 intake/232 exhaust, lift=.523 intake/5.400 exhaust, iron heads, roller rockers 1.5, 2600 stall.

Had it chassis dynoed and calibrated the fuel/air ratio. H.P. = 278, Torque = 372 ft lbs.

Something strikes me as odd here. I know you lose some H.P. on a chassis dyno Vs. an engine dyno. But a factory stock 383 Magnum is good for 335 H.P. (net, without accessory drag), and that was an engine number, no driveline drag. Still, with the work that has been done to your engine, I would expect to see more rear wheel horsepower. Not an expert here....might expect to see 50-75 horse loss from driveline drag. You're current 55 horse shy of stock. Just doesn't seem right.

Along with those dyno numbers, did they give you a graph showing engine rpm in relation to your H.P. and torque peaks?

Is that really an Eddy Performer intake, or a Performer RPM?

Is this your cam? www.hughesengines.com/Index/products.php?browse=category&level0=QmlnIEJsb2NrIDM4My0zNjEtNDAwIChMb3cgRGVjayk=&level1=Q2Ftc2hhZnQ=&partid=21850

[pjmopar]

Yeah I may be expecting more than I should. But when I was running stock it had a pretty good launch and it would melt the tires. I know I'm running a locker now but with the same ratio as stock and don't expect or want to melt the tires. But it just seems when I come out of the hole it takes a few seconds for the engine to reach its potential.
I hear what you're saying Green, a lower gear is on my wish list. When I put the car in reverse I can smoke the tires easily. If you have some gears (preferably 8.75 the whole third member) lying around your garage in the way I'll take them off your hands. I'm running the stock 14" wheels T/As 245/60s.
Dave: I was also concerned with the low HP readings, but after asking a few people that are suppose to know, those are good numbers. I have asked 2-3 different people at different times and they all come up with 400 - 425 H.P. I know the engine is a lot stronger than before, on top end it just keeps making power. That is the cam I have, except mine does not have the 3 at the end. HEH2832BL. The intake is a Performer RPM.
What do y'all think about advancing the timing I do not have any trouble with the engine cranking back up. I have always thought you keep advancing the timing till the engine becomes hard to crank and then back off a few degrees. I'm a little nervous advancing the timing that high and I can still go further.

[texaswolffs]

Got a questin on con rods. My 74 has a 440 mag. When I got the car in March on '92, I paid $100, then drove to Sacramento, CA to get the original engine so I would have a numbers matching car. I tried to press to rod pins with a 20 ton press, but they wouldn't budge. Took them to a company just outside of NAS MIramar (now MCAS Miramar) CA and had them done. When he asked me what engine they were out of I told him a 440 mag and he said that they couldn't be. He said mag rods were "J" coded and the ones I have are "L" coded. Could they be from a 440 "six pack"? Would appreciate all the help I can get. Thanks.

[shermantank]

hey guys im running a 383 out of a 69 newort cop car, i have documentation to prove its a true 383 interceptor engine. it is currently in my 1974 dodge charger 3 speed auto. i was thinking about droping a blower on it, never delt with blowers before what should i do anyideas would be appreciated, Motor is stock with a Holly 650cfm 4barrel carb on top

[hotrodder]

sherman, U might as well start a whole new thread on that subject....

[superduperbee]

pjmopar
You should switch to a 4;10 gear, and I'd go to a 3500-4500 stall converter. With your engine combination, you're probably not even in the engines powerband before 3000 rpm. The higher gear & stall speed will get you off the line right away.