Power Loss

[JMF]

The 68 i've just bought seems to be down on power, it seems to be running and idling fine but compared to Mopars i've had in the past it doesn't seem that quick at all, if flooring it from standstill for exampe it won't even spin the rear wheels and at full throttle with the pedal to the carpet it doesn't exactly do much in terms of performance, just feels really sluggish

When I first got the car it was backfiring anything above 3/4 throttle but that seems to have sorted itself out now after a long drive as I don't think the previous owner had used it much, plus we adjusted the timing a little, don't really know the ins and outs of the spec of the engine at the moment but it's a 440 with a 4 Barrel Edelbrock carb, haven't changed plugs or anything yet, I wanted to get a better idea of the problem before replacing things, any ideas ? Can old dirty plugs cause these kind of problems ? Thanks

[RECHRGD]

I doubt that dirty plugs is the problem.  The engine gurus here will want more info.  What year is the 440?  If from the mid and later 70's, they are low compression dogs if not rebuilt for performance.  How much do you know about it?

[Dino]

First things first.  Is your carb/kick down linkage adjusted properly? 

[myk]

Low 'comp 440 with an 'eddy 'carb; I thought I was the only one with that killer street combo, lol. 

First thing you do when you inheirit a used motor is to give it a tune-up; before you start digging into it and passing judgement/drawing conclusions you want to make sure it's in the best possible shape and tune possible.  Then, if you're still not satisfied or feel there's still something lacking then have a compression check performed; the most trick engine parts in the world won't matter if you're not making good compression.  Actually, you may want to perform a compression check first-no point in tuning it up if your motor is hurt and needs repairs. 

Ultimately, you may wind up in the same spot as I; my car has a '78 coded 440 and I have no idea what's inside of it, so when funds permit I wil have it torn down and built to my specifications-it's the only way to be sure...

[cudaken]

Boy JMF, you sure did not give us much to go on! Here where I would start trying to figure out what was going on.

1 Set the timing by vacuum not a timing light. Outer ring damper may have slipped on the hub. It might show 14 degrees BTDC but could be retarded. Set the timing so you have the highest vacuum, take it for a test drive. If it knocks, back it off a little and drive again. 

2 Is the distributor vacuum advanced or mechanical? If it is vacuum, did you have the advances unplugged when you sat the timing?

3 See what the total advances is and at what RPM. We will assume right now the outer ring as not slipped and timing readings are correct.

4 What gears, tire sizes and transmission are you running? If the car has 2:76 Sure Grip gears, stock 727 converter and say 265 /60 / 15 it may not light the hides when nailed. My old engine in my 69 Charger R/T (Stands for Rusted / Trash when I got it) had the above and would not light them when nailed. But, it accelerated well, I could melt the tires when I powered braked her a little. Added a 73 400 Police converter that had a 2400 RPM stall and I could make the tires protest on a roll but still not light them up.

5 Next I would pull the plugs and read what going on.

There are many other things I could list but with out details?  Heck you did not say what kind of 68 it was! Now if it is a C body well I bet it rides well!

More than likely you will find the problem in timing. That would be where I would start.

When I was young and dumb and in the Army I was timing my 68 Road Runner (which I still own 40 years later) at the Army Auto Craft Shop the manager came over and said the idle sound rough. Would I like him to make it run smoother? I said sure and he got her to sound real smooth. Took her for a quick drive and got my ass kicked by a 289 2 barrel Mustang.

Went back and set the timing to 15 degrees BTDC and went back and kicked that Stangs ass.

Cuda Ken

[JMF]

Thanks for the reply, unfortunately the previous owner didn't have much info on the engine, I will try some of the things you suggested and go from there, thanks again

[cudaken]

You are more than welcome.

Cuda Ken