74Charger73Dart

Okay first of all I love this site. Just signed up and this is my first post.
I have a 1974 Dodge Charger SE with a 318. I am the second owner and have all of the original documents including original window sticker. This is an unmolested car and everything is there and works including the seat belt safety switch.
I recently tore down the motor after checking the compression. I took the heads into a machine shop and them completely redone. After that I installed new...the following parts : Cam, Lifters 280/420 290/440 ( from Summit), Double roller timing chain and gears, Weind aluminum intake and a Edelbrock 600cfm Carb, Headers and a complete 2.5 inch exhaust sytem that goes from the Headers back. Plugs, wires, and distributer. You would think that all of this would definately improve performance however ... This thing doesnt run any better than it did with the single stock exhaust, Cast iron intake and 2bbl carb. It is a sluggish dog!!!!!! No power!!! Ive check and rechecked the timing Tried settings from 0-10 deg BTDC Dont know what else to do. Also it seems that there is also a slight hesitation when you step on it while idling.While driving its the same thing, if you step on it, it seems like the secondaris dont even kick in...Any suggestions would be greatly appreciate!! Thanks!!

PS..Cant even get the tires to spin during a brake torque.

TVLynn

Bad choice in cam !!!!

Coronet 500

Welcome. Not my first choice for a camshaft, but if it is as bad as you say I would wonder if crank to cam timing is off first. Some timing chain sets have markings or dimples that can easily be mistaken for alignment marks.

Kern Dog

You will find the performance that you are looking for, you just need to match all the components.
Heres the thing. STOCK engines do well with low stall torque converters, tall (Freeway type) gearing and single exhaust systems. You changed the engine, but now the engine isn't matched to the rest of the car. There are a few things you can do. The 318 can be made to run strong, but the heads that came on them are terrible for power. The camshafts that came in the LA 318 had .373 of lift so the heads didn't need to flow very much air. Your new cam is much larger and the heads are too restrictive. Some guys go with 340 or 360 heads that have larger ports. They DO flow better, but swapping them into a 318 is a trade-off. The 340 and 360 heads also have a larger combustion chamber that will reduce your compression ratio by at least a point. What you may gain in flow you lose in compression/power. You can have the 318 heads ported, but they are limited and the cost of porting can really be expensive.
Some guys have had great luck with the 1992-2002 318/5.2 and 360/5.9 Magnum heads. These flow a ton more than the old heads and have a small combustion chamber to keep your compression ratio where it is. Check out www.enginequest.com. they sell NEW magnum heads that cost less than any aluminum head out there.
Besides the cam and head mismatch, I suppose that you have the original stock torque converter in place. The more aggressive cam means that you lose a bit of power on the bottom end in exchange for more power at a higher RPM. When the stock torque converter is used, it will engage before your engine is starting to make useable power. Think of it like starting a manual trans car in 3rd gear. A cam larger than stock needs a higher stall rated torque converter. I'd recommend a 2500-2800 10" unit.
Finally, the rear axle ratio is probably the same as before, right? Once again, a more aggressive camshaft makes the engine less powerful at low rpms, and a freeway friendly rear gear is slow to get any car moving. It makes things worse with a bigger cam. My guess is that the car has an 8 1/4" axle with a 2.76 ratio. Your car probably weighs 3600 lbs or more. You would need at least a 3.55 ratio to make this combo work.
If you look back at any STOCK performance Mopar, they were always more than just the engine. They were a total package. The 340, 440 and 426 HEM cars always had higher stall torque converters and lower gearing. The 3.23 ratio was standard for 340 and 440 cars. The 3.54/3.55 was standard for HEMIs.
Good luck with the car.


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I looked at your post again. Your ignition timing with a more aggressive cam will need to be MORE than it is with a stock engine. 10 degrees may not be enough. I run 17 degrees initial in the Charger and it could actually run better with a bit more. You should try 12 degrees and see how it feels. I don't know about the Edelbrock carburetors, but a hesitation on acceleration may be due to a weak accelerator pump stream. Maybe you could Google "Tuning Edelbrock carburetors" and have some luck.

74Charger73Dart

How so?...Size or manufacturer?

Thanks

74Charger73Dart

Thanks a lot Kern Dog..A lot uf very useful information. I will have to re-think my direction here. Will post mt progress!!

440roadrunner

Actually, this might be fairly easy to fix ---get rid of that cam.

My Dart has a used 318 which is surprisingly snotty. Its a stock compression mid 70's engine with stock 318 pistons and heads.

The changes were a "340 look alike cam" that is a cam that is a similar grind to the 340 factory cam in rough comparison

Intake is Ed performer which is a "torque" manifold similar to the 340/ 360 cast iron intake.

Ed 600--625 carb, headers

low stall stock converter

The only concession is lower gears, but with the tall tires I run, it still turns about 3200 at 70.

For a REAL low budget hop up, this thing runs GREAT.

TIMING. You need more timing with modern alcohol fuel and low compression. BUT on the top end, the distributor will OVER advance. This is because the "smog" factory distributors had a long slow advance curve.

You need to do one of several things:

Buy a performance distributor with adjustable advance

Buy the advance "limiter" plate kit from FBO:

(go way down the page, bottom left) J685K, 40 bucks

Have someone who knows how weld and resize your advance slots, and install lighter advance springs.

My 318 runs about 15-17* initial advance, is mostly all in by 2-2200RPM and runs 35* total, not counting vacuum advance.

Coronet 500

Do you have a cam part number? I just now found one that was close and the odd thing is durations at .050" are 204 and 214 with 112' LSA. The description says it is quite mild. If it is a cam like this then I'd say not too bad and there is something else going on.

74Charger73Dart

Thanks for the reply.Yes I do...The cam is from Summit and the number is SUM-6900.
It was a Cam and Lifter set.I thought that it was quite mild as well. I dont know if this helps but the double roller timing chain gears that I purchased new also from Summit, had three different markings for Advance,Retard and normal. I'm 99% sure that I installed it at the normal mark. any way to verify without tearing it all apart again ?

Again... Thank You for the replies, I appreciate it!!!

Coronet 500

TDC stop that screws in the sparkplug, not hard.

Degree wheel mounted to harmonic balancer, not hard.

Dial indicator at rocker arm, not hard but innacurate.

Solid lifter changed for hydraulic with manifold on, not impossible but not easy.

It can be done and there are special tools like extensions for dial indicator stem or lifter to be accurate but a careful reading at rocker or valve can be accurate enough.

A commpression test and other tests first are easier to do first and may give answers. That is the cam I found.

Kern Dog

Ever get a part from the local parts store and find out it doesn't fit?
SOMETIMES the companies screw up and put the wrong part in the wrong box.
A local Mopar buddy had this happen with a cam in his Charger. He wanted a 284/484 for his 440. He installed the cam and it idles rougher than he expected and was a dud off the line. He pulled the cam to check the part # and found that it was for the 292/509 cam. He called the MP tech line and learned that he wasn't the only customer to complain about the problem. Apparantly this happens more than people know.
There are several methods to determine the actual specs of the cam, but the only way for sure is to remove it and check the # that is often stamped on the far end.
The timing marks on the cam sprocket can be a little tricky. 20 some odd years ago i did a timing chain swap in a dimly lit one car garage. After completion, the car was slower than before. It turns out I was one tooth off. On a Chevy 305, that equals 8.18 degrees! It was retarded over 8 degrees but still ran.
Another story....In 2008 I did a quickie resto on a 74 Duster. Body and paint, interior and some other small stuff. The 318 ran smoothe but was an absolute slug. I tried different carbs, distributors...It still wouldn't even peel out in dirt! I decided to pull the timing cover. It had a seriously stretched timing chain and the chain was off by 3 teeth on the cam sprocket! I was absolutely shocked that it ran and did no damage. I installed a new chain and gears and it ran great. Afterwards it did great burnouts... on asphalt!

74Charger73Dart

Just wanted to say thanks to everyone for you posts, Have to paint my sons Dart sport this week and then go out of town on buisness until the 12th.
Will dig back into the Charger when I get back. Will update then.

Thanks again!!

ozzie8336

I have a 73 roadrunner with the 340 auto headers aluminum intake cam holley 650 carb. Nothing really special but, it has started backfiring and running very badly. It has new tank and sending unit wires plugs and just rebuilt carb. It ran very rich and was backfiring before I started the tune up with plugs wire cap rotor carb rebuild. now it's worse. Any suggestions?
At full throttle it will smooth out around 60 or 70 mph but it sounds like it's gonna blow up with all the popping and such when you hit the gas.

Coronet 500

To ozzie, best if you start your own thread and you'll get more responses.

Zoomer59

280 and 290 duration,I would tone it down a bit to around 255-260 with about 440 to 450 lift.make shure you get the timing gears lined up correctly also. 600 cfm Edelbrock carb should work fine. easy to tune with the metering rods.

74Charger73Dart

Hello all, I'm back. Ended up in the hospital for a while from a botched hand surgery. Had to have a second emergency surgery due to infection. Re-coupling at home with daily IV's twice a day. This weekend is the infamous Woodward dream cruise...yes I live in Michigan and am about 20 min. From Woodward.... Maybe next year. Anyway... Got rid of the Pos Edelbrock carb....turns out the secondaries were not opening. Switched to a QFT 600 with vacuum secondaries. We'll see how that works. Thanks again for all of the helpful posts.

74Charger73Dart

Hi all, back after a long endeavor.


Latest findings:


Found that the distributer being used was from a 1987 318. I found the original 74 Dizzy that was initially on the motor and replaced.


New Cap,Rotor,Plugs, Wires, Oil and Filter have been changed.


#1 Piston at TDC on Compression stroke with Intake/Exhaust valves (#1) closed. Balancer mark is dead on 0. Rotor is pointed at the #1 cylinder.


Carb has been changed to a Quick Fuel Tech, 650 with Vac. secondary's.


It hit 51 degrees here yesterday and all of the snow has melted off the roads so I took it out yesterday.


Synopsis:


Idled great (In the beginning)
Nice top End
Absolutely no Torque, cant even spin the tires on wet pavement.
Try to do a brake torque and it bogs down.
Drove around for about a half hour...The longer I drove, the worse It got.
By the time I got back to the garage It had a dead spot in the acceleration to the point that it stalled out every time I started to accelerate unless I feathered the pedal past that point.
I'm ready to give up and sell the thing or maybe I shouldn't be working on cars!


Any thoughts? I would greatly appreciate it.

440roadrunner

Any factory distributor built in the smog days is not going to work unless it's recurved

You need a LOT of initial advance.

There's not much info on that cam. "Throwing" a cam in an engine with stock timing drive is not necessarily the "right" place to install it. This is why people preach "degree your cam." But without more info ON the cam, you won't know "where" that is.

moe7404

TO: 440roadrunner i am lost as to the cam size. i am still old school i under stand advertised degree, not .050. like i had a 65 300 L 413 with a .430 lift at valve and 268 degree advertised. that i under stand. it sure is nice to have people that do know these things. thanks.

Coronet 500

Don't give up, together we'll get this thing snapping.

#1- you'll need to give us your initial and total ignition timing without vacuum, hose plugged. (12 initial and 34 total would be a good start).

#2- listen to 440, he's got some good step by step stuff on those distributors.

#3- you might be asked to do a fuel delivery test, what pump and fuel line size do you have now? Do you know float height?

#4- You said the timing set had multiple set points and thought you had it at normal. If the timing and fuel don't do it you might be asked to pull the water pump and front cover.
What you described sounds like retarded cam, but 1,2 + 3 first.

pro-tech

OK hold the phone here...All this is good advice BUT..Is the timing chain from Mopar performance?????Your car is doing the same thing that mine was doing....Out of desperation I tore it apart again and found that the timing markes were not stamped in the right place....Your going to have to take the timing cover off..(sorry) Take or old timing chain and compare the marks for verification...Another give away to this problem will be that it will run on the hot side....Mine was 3 teeth off and still ran and wasn't as bad as you would think...After the timing chain sprockets were installed correctly it now has a nice cam lope and will spin the tire through 2nd gear of the 904 no stall with 2:76 gears...Mine is a 360 in a Duster (see avitar) Good luck and I am 99% sure this is your problem...Bill

RacerHog

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74Charger73Dart

Thanks for the great info!!!!Here are some of the cam specs- Sum-6900 ( summit racing)


Cam timing Opens. Closes. Lobe cntr. Duration
@0.50. Intake (5) atdc. 29 abdc. 107. 204
Tappet lift Exh. 44 bbdc. (10) btdc 117. 214


Adv. Duration. Lift
260. 420
272. 442


Thanks again for the help, you guys are the best!!!!

moparted

exactly why you degree the cam