Technical This 283 just won't run right

283 in my roadster, New Speedway three 2 setup, Totally new points type distributer. Dwell and Timing right on, new Morosco plug wires, new plugs, clean gas, fuel pressure regulator.
Engine has a very slight miss and popping sound as it accelerates. It has headers and noisy mufflers. When you kick in the three 2's it accelarates a little better but still pretty bad. When you kick in the three 2's it just mostly seems to make more exhaust noise and seems to feel like it's being held back. Takes forever to get up to 4000 RPM on the tach. Driving me nuts.
Any ideas??

 

You say the timing is right on but it still sounds to me like a timing issue. Maybe worth taking another look at that.

 

Is the TDC mark accurate on the balancer?

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i know you said the dizzy is new but it sounds like it isnt advancing quite right.

 

I'd be curious to see what crank pulley you have and what the marks look like....

 

I agree

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my first thoughts are also related to timing. How does it sounds/act at idle?

 

283, 3x2 here also. Had a similar issue. Are you running idle circuits on all three carbs with progressive linkage? Mine hated that. Blocked the end carb idle circuits and shut them at idle, things got better. What size fuel lines are you using? I had 1/4" and it wasn't enough for my 97's. Went to 3/8" and got more improvement. Maybe not the cause of your problem but some things to look at anyway.

 

Unrelated engine, but my Hemi manual said to dead time with an initial advance of 6 degrees. The car never ran right, so I took the dizzy and bench tested it and it required 12 degrees of advance. I couldn't believe it, but I tried it and that Chrysler ran like a sewing machine after.

 

im with the others....how is dizzy set up, timing marks etc...set up on tdc correctly?

 

You might want to go to any auto store and get a lead additive for the fuel system. All 283's need lead gas in order for them to run right and not pop like you say. Try it. Also check the springs in the distributor, they might not have the tension they require. Small things like that can help your engine run better. Good Luck.

 

Check that distributor and timing marks carefully. New these days doesn't mean it's good. I've had lots of 283s and I've never added lead to the fuel and they run just fine. I have one now that is was an original 45k mile car when I bought it and it's run fine on unleaded gas for the past 30k miles.

 

Most people are telling you to check your timing and that is a good answer, but you might look for a vacuum leak. With engine idling, spray a bit of starting fluid around the intake and base of carb. Just a thought......

 

Check your firing order for crossed wires. If thats OK, crank in some advance. Ignore the marks, just wing it and see how it runs. I always look at timing marks as a place to start.......Engine's needs change just like people.

 

A vacuum leak was my first thought too. The starting fluid trick should make one show up if it's the problem.
Second, was the distributor originally a vacuum advance model? If it was and you don't have the distributor connected to a vacuum source or the one you're using is non-ported (direct manifold) vacuum, your advance curve is probably incorrect.
Last, it could possibly be the gas you're using, especially if it contains ethanol. The carbs we use weren't designed for today's fuels. Ethanol blends require 'richer' jetting to run properly... my riding lawnmower was backfiring until a friend (and fellow HAMBer) who's small-engine-savvy suggested that I try non-ethanol gas. The problem went away with the first tank of 'real' regular gas. It's not easy to find non-ethanol gas, but it's usually available near marinas.

 

Install a fuel pressure gauge. I've had those fuel regulators swell and restrict the fuel. A lean condition will cause backfire.

 

Thanks guys, I'll try messing with the timing. The carbs are the brand new Speedway 97 clones. They are the correct set up with 1 primary carb and 2 secondary carbs. It idles fine. The brand new distributer is from Auto Zone, it's Chinese. Fuel lines are 3/8. I'll check for vacuum leaks too, there are 2 vacuum connections on the manifold, 1 to the distributer and a larger hose to the rear top of the engine for ?? Hoses are new. I'll put a vacuum gauge on it.

 

The old distributer which quit working and I never could figure out why was connected to vacuum at a carb port. (Rochester carb) These new speedway carbs don't have a vacuum connection on them. The new distributer is connected to a vacuum connection in the manifold

 

And I've got a fuel pressure gauge on it too, I failed to mention that.

 

distributor connected at the manifold is not correct, its pulling vacuum (advance) always like that

 

You don't want the dizzy connected to manifold vacuum. It works differently than carb "ported" vacuum. Just for a test, try setting initial to 8 to 10 degrees and total no greater than 40. disconnect that dizzy vacuum line and plug the manifold. Be sure you have no other vacuum leaks as mentioned (carb to manifold, manifold to head).

 

I hate to tell you this but there is no place to get ported vac on a Rochester carb. A vacuum advance dist is always hooked up to manifold vacuum with a few exceptions that are made to work together The vacuum hook up on the side of a Rochester 2bbl carb is open to manifold vacuum below the throttle plates. Ported vacuum is a modern thing for emissions and was not available when they were new. No such thing!!!

 

I have 2 small block Chevrolet engines (327's) in O/T Corvettes I have owned for almost 30 years. Over this time, I have had problems with both of them that ended up being "slipped" dampers on BOTH of them. I had the dampers rebuilt with the timing marks set correctly. and it solved the problems. It seems that given enough years, these things WILL fail. In the interim, I was able to get them running satisfactorily by using a vacuum gauge to set the timing. Put on the vacuum gauge, disconnect and plug the vacuum advance, turn the distributor to obtain the highest vacuum reading, and retard just a teeny bit. Done.

 

New timing covers and dampers are not correct for the pre 1968 engines. Off by 10 degrees. Should find TDC and correctly mark the damper or move the mark to be sure where you are. Lazy way, just keep advancing till it pings and then back it off a little.

 

As Tommy said in post #22 pre smogger vacuum advance units were connected to manifold vacuum rather than ported vacuum. That is the reason you always had to disconnect the line and plug the fitting on the intake or carb. Set the timing on that setup with the vacuum hooked up and the timing will be late.

One other thing to consider, New from the store does not mean "adjusted correctly" I'd make sure the points were set right and the advance was working right both mechanical and vacuum.

 

If I was living at No.2, that chinese unit would be on the roof at No.8

 

You want constant not ported vacuum to the vacuum advance. That will allow the dist. to pull in more advance at idle, and high vacuum situations like cruise. Ported vacuum was added as an emissions control measure and is not performance related.
As for the disconnect and plug the vacuum advance, I just pinch it off with needle nose vice-grips. Much easier.
The easy thing to do is just advance the timing and see what happens. If it wants to kick back when you try to start it, you have too much. If it detonates (pings) under load, you have too much or, need higher octane.
There is no really magic timing number, the best amount is what your particular engine "wants". So, just play with it and see what makes it run best. You can then see what the number is.

 

It matters greatly where the dizzy gets hooked up based on its original application, what modifications are done from there, and what specs the china man used to reman it.

 

my 51 plymouth flat 6 is set up for ported vacuum from the factory, zero emissions concerns back then.
and yup, i know its not a chevy, just tossing some relevant factual data out there.

 

My '50 Buick the same. I do not know when Buick started using ported vac, maybe always. I do understand some makes only started in "modern" times.

Agree sounds like timing.

Ben