She's A Slug..help!!!

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The timing is probably retarded. Symptoms of that are poor off-idle/part-throttle performance and greater heat. Check the initial and total timing and the carb pump shot and possibly jetting. If worse comes to worst, "the guy" may have not degreed your cam properly and your cam timing may be off.
 
sounds like its starvin for gas until the secondaries open to me.Swap out to a 750....or try changing the power valve at least.
 
Wilnutt said:
BTW..With these parts..does 425 at the crank sound about right?
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Yes if you have good flowing exhaust on it although the carb is a little small IMHO. Theoretically a 600 should make 425 hp but...

I respectfully disagree with toolmanmike's statement that the cam isn't big enough to need a high stall converter. That cam has to have a ton of overlap with 308 degrees intake and 318 degrees exhaust duration so it probably won't have a bunch of low end torque and it's gotta be pretty rough idling. A high stall is definitely needed. Not only to improve performance but to allow it to idle in gear at a decent rpm and not tear the u-joints out shifting it into gear. If this were a 416 stroker I'd say you don't need a high stall but it's a 340. A good 2800-3000 stall would not only make it more pleasant to drive but make it come on like a bear.

The Lunati cam I have in my 360 has the same duration at .050 but much less total duration so the overlap is much less and it only pulls 8" of vacuum at 800 rpm in neutral. If I didn't have a loose converter in it I'd have to have the rpm at 900 or higher to keep if from killing the engine when I drop it in gear. And this is in an engine with 20 more cubes than wilnuts.
 
It sounds like it will have good topend just nothin on the lowend side...So I would try to make it up with gears and a little more stall.
 
Where does it backfire, through the carb or the exhaust? Be sure you have clean/new spark plugs and get that timing light out to find out where the timing is set. What ignition do you have?
 
One thing you need to look at for sure is that carb. if it is a 600 cfm then it is probably a 1406 edelbrock right? that carb is set for fuel economy and is going to be way lean for a motor like that without changing rods, jets, and springs. even still i would run a 700 or 750 cfm carb. check your total timing as it should probably sit around 36 degrees or so with that setup. as far as the coverter go with what fishy said and look for something in the 2800 stall.
 
what carb is it? 1406 eddy? holley? which hole is the acc pump arm in if an eddy? If its and eddy, the carb need to be taken off and have the floats set. if its a holley, a power valve/acc pump fine tuning needs to be done. what is the timing at. find another place to take it to to get initial/total timing numbers, and more precise diagnosis.
 
Too many unknown variables. However, at first flush, IMO, that's a lot of duration, for a streeter, and from how the car reacts, I'd say you need more gear to compensate. I'd also be looking at the timing...............
 
it's a 1406 eddy.
i have just spent $1500 on rebuilding the 8 4/3 with 3.21 non posi gears, there's no way in hell i'm spending another $500 to change gears... and the stall..well...maybe there... i was told that this cam wouldn't be too aggressive?

if anyone knows a good tuner on the west coast of FL..let me know
 
sorry to tell you ....but not e nuf carb ...750 ......not e nuf stall... 3500+......not e nuf gear ..3.55 min....timing should be at least 36...all in by 2500.....that cam is bigger then youve been told..prob dosnt make hp intell 3200....she well run, dont give up .....theres good info here ....try dynamic convertors....1877 846 5876 or 302 454 9203.............good luck
 
Wilnutt said:
i was told that this cam wouldn't be too aggressive?
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Sorry but you were told wrong. It's never going to be a 1/4 mile stormer with a stock converter and 3.21 gears. Should have awesome top end with all that duration and tall gear but running 150 mph will get you a ticket to jail in a heartbeat.
 
Wilnutt, it does sound like there`s a lack of continuity in your build. Your cam is like a stock eliminator cam or for a much wilder engine. Depending on what you want to do with your car will determine where you should go with it. If you want to spend a lot of time at WOT you will assuredly need more gear, more stall in your converter, and more carburetor for everything to sync up and get the most out of your engines combo. If you want to street ride mostly then just a slightly larger carb (say 650 cfm) and a smaller cam, like the Comp 268 would put the car in a lower power band and match your gear and converter better. Your engine sounds like it has great potential, just don`t take it back to that mechanic. 20K for what he hasn`t done is way too much. See if you can find a reputable mechanic who has had experience with older Mopars. When you find someone who is competent and conscientious ,stick with him.
 
Longgone said:
Wilnutt, it does sound like there`s a lack of continuity in your build. Your cam is like a stock eliminator cam or for a much wilder engine. Depending on what you want to do with your car will determine where you should go with it. If you want to spend a lot of time at WOT you will assuredly need more gear, more stall in your converter, and more carburetor for everything to sync up and get the most out of your engines combo. If you want to street ride mostly then just a slightly larger carb (say 650 cfm) and a smaller cam, like the Comp 268 would put the car in a lower power band and match your gear and converter better. Your engine sounds like it has great potential, just don`t take it back to that mechanic. 20K for what he hasn`t done is way too much. See if you can find a reputable mechanic who has had experience with older Mopars. When you find someone who is competent and conscientious ,stick with him.
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I agree with Longgone, to get the most out of any combo it must match across the board. your compression, cam, heads, carb and torque convertor should have been matched for what your goal was. Then the suspension and rear should have been matched to the power. This should all have been mapped out by your mechanic before hand and discussed with and approved by you before anything got started.

I have 450hp also and when I take someone for a ride I warn them first and they still let out a yelp and only see the headliner. Perfectly matched from fan to exhaust!
 
Cams a little big,need bigger carb,and some gear in that car.I can,t believe $1500 for non-posi rear.You need to find a local Mopar guy(At shows or the track)for some assistance.With spending that much it sounds like he,s an out of the box mechanic.
 
this is F'N ridiculous...i mean..gahhh..i mean, what and f'n a-hole to go and rip me off like this...i told him i wanted a nice streetable car with est 400hp, but more importantly was planning on being a daily driver...and this thing feels like it was about 225hp and just doesn't wanna run right...i don't know what to do..i can't dump another 5k into this thing to fix it...i don't have the $$$...
i paid like $400 for the 8 3/4 disassembled, and paid like $800 for a guy to do a total rebuild..so $1200..my bad...
 
did more in depth research, found my stuff..he said he got a total rpm kit...he did not..he got teh performer plus cam..ok here's the specs.....

ENGINE: CHRYSLER 318-340-360 V8
RPM RANGE: 1500-5500

Duration at 0.006" Lift: Intake: 270° Exhaust: 270°
Duration at 0.050" Lift: Intake: 204° Exhaust: 204°
Lift at Cam: Intake: 0.280" Exhaust: 0.280"
Lift at Valve: Intake: 0.420" Exhaust: 0.420"
Timing at 0.050" lift: Open Close
Intake: 4° ATDC 28° ABDC
Exhaust: 36° BBDC 12° BTDC
Centerlines: Lobe Separation - 110° Intake Centerline - 106
 
Wilnutt said:
did more in depth research, found my stuff..he said he got a total rpm kit...he did not..he got teh performer plus cam..ok here's the specs.....

ENGINE: CHRYSLER 318-340-360 V8
RPM RANGE: 1500-5500

Duration at 0.006" Lift: Intake: 270° Exhaust: 270°
Duration at 0.050" Lift: Intake: 204° Exhaust: 204°
Lift at Cam: Intake: 0.280" Exhaust: 0.280"
Lift at Valve: Intake: 0.420" Exhaust: 0.420"
Timing at 0.050" lift: Open Close
Intake: 4° ATDC 28° ABDC
Exhaust: 36° BBDC 12° BTDC
Centerlines: Lobe Separation - 110° Intake Centerline - 106
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That sounds more like an RV cam but definitely has it`s power in a lower rpm range. A cam closer to a 68 340 4spd or hemi grind cam would`ve been a better pick. Your cam specs like a rockhopper cam, a lot of power down low. Something in the 284/484 range would raise the power band some and still serve you well for driving the street. I agree with the other guys here, a slighty larger carb or rejetting is in order and no less than a 2700 stall converter. Give us more info on your converter stall. First thing though is to get that timing checked and find out what it`s set at. Even if you have 425 hp , if the timing`s not right the car won`t get out of it`s own way.
 
Wilnutt said:
did more in depth research, found my stuff..he said he got a total rpm kit...he did not..he got teh performer plus cam..ok here's the specs.....

ENGINE: CHRYSLER 318-340-360 V8
RPM RANGE: 1500-5500

Duration at 0.006" Lift: Intake: 270° Exhaust: 270°
Duration at 0.050" Lift: Intake: 204° Exhaust: 204°
Lift at Cam: Intake: 0.280" Exhaust: 0.280"
Lift at Valve: Intake: 0.420" Exhaust: 0.420"
Timing at 0.050" lift: Open Close
Intake: 4° ATDC 28° ABDC
Exhaust: 36° BBDC 12° BTDC
Centerlines: Lobe Separation - 110° Intake Centerline - 106
Click to expand...

Thats a pretty small cam...not much more than stock grind...204* @ .050 w/ .420 lift???? RV-style cams would be 204-214* w/ high .400 - low.500 lift, 112*/114* CL. This cam shouldn't have much, if any, lope at idle. Stock convertor should be fine. I think we should be looking at dizzy initial/advance. Like what has been suggested, get a dial-back timing light on the engine and see how much advance you're getting, if any. Do that, and then get back to us.
 
ok gonna work on it...but i should still look into a stall converter hmm..sigh..allrighty if ya'll insist..i'm gonna try to find a guy local who's a good tune...
 
wil, what do you have for tools? I need to know what the cranking compression is on it. That's easy, and you need a $15 gage. My guess is you are way out of tune, this fellow used ok parts, but has no experience with mopars. Live and learn... In no way would a cam with 204°@.050 get you even 350hp, never mind 425. He may not have known that. Ignorance on both sides really. Get the cylinder pressure readings, and get back to us. we can fix it.
 
ok so with the set-up i have..what am i looking at with a set-up like this? i'm sure compression plays a big deal.. but this is all i can give you with what i have... and i already made the statement idk about cams so...i was suprised when he said it would cut it too..

i have all teh edelbrock for teh top end, including a performer-plus double plane intake...bottom end is stock crank, .40 over keith black flat tops (forged)
i'm gonna try to hit the local car show in a few weeks....if anyone sees SGBARRACUDA, ask him if he knows a good local guy..THANKS!!!
 
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