Hello Everyone,

i have a 1971 Scamp with a 440 and 727 tranny. Its nothing special has a mild cam and headers but nothing fancy. My probelm is everything runs fine but from a stop you floor it and its like no power but once it gets up into rpms it starts pulling and climbs in rpm. I found some problems prior to, like the transmission main line pressure lever (not sure of actual name lol) wasnt hooked up at all, and the column shifter transmission braket was broken so it wouldnt go into 1st. so i put on a lokar transmission cable and fixed the shift linkage thinking ok sweet now thats all squared away and dropped into 1st to do a celebratory burnout and it goes to like 1200 rpm and holds there like a dog... i let off the brake and then it starts to climb in rpm and begin to pull alittle. i feel like a 440 should be able to spin over some tires, so im not sure if its a transmission issue or engine issue. Let me know what you guys think.

 

How big is the cam and do you have a stock torque converter?
Also what carb do you have and rear axle gears?

 

Man i wish i new the spec on the cam, i just recently got the car. the best i can describe is a mild choppy idle but still has 15in. vaccum at idle. i looked up the convertor and it has a 1500 stall , i have a holley 750 on it and the gear ratio is unknown to, but at highway speeds around 60-70mph its cruising around 2000rpm so i would guess 2.??

 

Carb vacuum secondary?

 

mechanical secondaries

 

So to much carb and cam for to little stall and gear = dog off the line. How does it run once its moving say 30 mph in first?

 

once its starts going it pulls decent and climbs rpm, so you thinking the stall and gear are holding it back from getting in the power band off the line?

 

Yep, not having any idea about the cam other than the vacuum it would be nice to have 2400 rpm to work with and a 3.55 gear. The mechanical secondarys dont help off the line with no rpm, a vacuum secondary carb would help there.

 

James -

What do we know:
60/70 mph @ 2000 is probably a 2.73 rear.
15" vac = a very mild cam, bad timing or vac leak.
(How much does the vac drop from neutral to gear?)

A decent 440 on a car that light should fry the tires, even with a 2.73.
A 750 carb is appropriate for that motor, and either vac or mech secondaries is fine, but with that later you have to know how to work the throttle.

Sorry, still too much we don't know.

Do a compression check on all cylinders, check for vacuum leaks and set the timing to 10 initial/34 total for starters.
Report back.

Archer

 

Archer,

I will be checking all that this weekend to see if we can narrow it down a little. Ill let yall know as soon as I do! thanks for all the help!

 

ok fellers,

so here is what I got , sorry if it seems a little confusing. So I let the car warm up and get to operating temperature and checked the base timing with vacuum advanced disconnected and it was a at 20 degrees. so I backed if off to 10 degrees and checked total timing and it was all in around 3000rpm at 35 total timing. I bring it back down to idle and it wants to die, so I adjust the carb for the new timing and it feels a little rough but its running , I drop it into gear and it dies. I adjust the carb some more to get it to stay alive in gear and it has hesitation, slow response, hard starting ( you have to crank for longer than you should) and it has 8in of vacuum. So I spray carb clean all around the carb, intake and anywhere where there could possibly be a vacuum leak and nothing. so out of curiosity I fired it back up and adjusted the timing to base off of how it sounds and it smoothed out nicely and I looked and that was around 20 degrees again. it had good throttle response , ran in gear, and fired up in .5 seconds of cranking it so now I'm thinking, why when its set where the timing should be it runs like crap and you set it just by ear and where it seems to want it and it smooth's out and runs decent?

initial timing: 10 degrees
total timing: 35 degrees
vacuum: 8in
( runs rough, slow response, dies in gear, long cranking)

initial timing: 20 degrees
total timing: 45 degrees
vacuum: 8 in
(smooth through all rpms, quick throttle response, fires up in .5 seconds)

 

James -

So you set the timing back to it's original settings, that didn't work initially, and now works fine???
Assuming you didn't miss a vacuum leak... ah, what happened to the 15" on the vac???

Sounds like either the cam is a lot bigger than you thought or some one messed up the cam installation (didn't degree it properly).
Or... the timing chain slipped a tooth.
Or...could your timing light be off? Sorry, have to ask.

Next move is yours.
If you're happy with it, and you don't get a run-on after shutdown, you can either leave it or re-install/replace the cam with a known item.

Archer

 

lol yes, so the vacuum gauge I had before may or may not have been dropped / thrown around a few times! so after getting a new one I got the actually reading that I can trust. So my original complaint was low power, and with it at 20 degrees it runs smooth, quick throttle response, and yes no run-on or anything. I tried putting it at normal 10 degrees initial timing and it ran rough. so for now yes ill keep it at 20 degrees for just driving purposes but I'm beginning to question the cam as well. Unfortunately I just don't know anything about this engine as I just got it. No idea what has been done before me.. if anyone is in vegas and could use some beer come over and help me doink around with this thing to try and get it dialed in!

 

You might want to check the damper for TDC against the #1 piston, the outer ring on the damper will spin causing the timing marks to be off. Replacement is needed at that time.

 

this can make all the difference in the world. just a few degrees on mine made a big difference in its idle and low end.

a good idea would be to see how much a shop would want to toss it on a dyno and get you a proper tune and baseline. theyd likely be able to ballpark your cam sizing based on running and known parts on the engine.

 

thanks for all the help fellas, unfortunately this is where the thread stops because the ex-wife wants to keep ruining my life I had to pay more lawyers fees which means I have sold the car. I wish I could of tracked down the issue just for gee wiz but she's gone. thanks again for all the help!!.

 

I head this once,,,, the reason a divorce is so expensive is because its worth it!
In my case it was so true.....
Sorry you had to give up your Mopar.

 

The first thing I would do is check the gear ratio. You can do that easily by jacking the car up putting a paint mark on a drive shaft and on one rear Tire. Count the number of times the paint mark goes by as you're turning the tire one full rotation. You can estimate roughly what the gear ratio is but simply estimate the number of degrees if goals after the full rotations. For example: four rotations and a little more would be 4.10 gears. A little less than four full rotations would be
3 90's

 

Cars gone he sold it.

 

thanks Davew I appreciate the help, but she gone. I definitely appreciate the time and thinking power.