Ping Ping Ping - Timing Issues, What are you running?

[Great68]

Hey classic people! It has been a while since the last time I've posted here, and I need some help.

A few years back, I did AFR heads (165's with 61cc chambers), Air Gap RPM intake, Demon 650 vac., Comp XE262 cam, and MSD pro billet distributor. Since then I could never seem to get the timing right. It just pings and pings and pings, even on 94 octane.

I think I am ready to throw this MSD billet distributor into the trash.

Problem #1: When the motor warms up (IE running for more than 10 minutes) I can't turn the distributor AT ALL. It's like the aluminum is expanding enough to push against the distributor collar, locking it in place. HAS ANYONE ELSE WITH AN MSD PRO BILLET EXPERIENCED THIS??? I have tried to clearance it with emery cloth to no avail, I don't feel like I should HAVE to do this with a $500 part. I have to do my timing adjustments within 10 minutes of first starting up the car. If I have to make any additional adjustments I have to wait for the motor to cool down.

Problem #2: I just can't seem to get the car to not ping. Right now I am running 8 degrees initial, with the blue bushing (according to the manual that's 21 degrees mech. advance), and 2 heavy silver springs, and I get pinging above 4000 RPM.

I checked my TDC with a positive stop, so I know that's good
I checked my total timing, which is almost 35 degrees (According to the MSD manual, I should only get 29 degrees total).

8 degrees initial seems WAY low, the car idles like crap and has terrible and boggy throttle response compared to when I have the initial at 12-14 degrees. Of course, at 12 degrees initial the car pings like mad at all RPMS.

Oh yeah I forgot to mention, I am running 94 octane.

Am I doing something terribly wrong here?

 

[Rapid]

I have an MSD Pro Billet as well but have not experienced the sticking you are. If the pinging has always been there, make sure you are at top dead center and re-time. If it is new take steps to clean the carbon out of the cylinder heads.

What gear / situation are you in when it pings? Engine temp?

 

[Rapid]

Sorry, you did check TDC. I had a similar problem and found that carbon build up was the problem. Several companies make a cleaner for removing the carbon. I am at 10 degrees BTDC, medium springs, I think the blue bushing as well, 60 cc heads with flattops so about 9:1 compression. Have you made sure you are not overheating? The swelling and pinging at the same time could be due to excess heat...

 

[rbohm]

it sounds like first your advance curve is coming too fast. i would set things up where you have 10 degrees initial timing, with 26 degrees mechanical advance. i would have it set up where everything comes in between 4000 and 4500 rpm. second i think you have a lean condition above 3500 rpm as well.

 

[Great68]

Thanks for the replies guys,

Overheating: I don't think I am, I am running a Griffin 2x1.25" tube rad which should be overkill for my motor. I have a 180deg RobertShaw T-Stat.
When I drive on the highway, the temp gauge barely gets above the "C".

Rapid: I hear the pinging when I'm in third gear, pushing it on the highway. I don't hear pinging when blasting through 1st or 2nd, but who knows maybe I just can't hear it... Have you ever changed your advance stop bushing? Can you do it without pulling and disassembling the whole distributor? I can't figure out how to do it otherwise...

rbohm: My timing curve is at the slowest it possibly can be with the two heavy silver springs... I'm running #68 jets in the primaries and #76 jets in the secondaries of my Speed Demon, I wouldn't think that should be a huge problem.

What's the name of this carbon cleaner? When I did the heads carbon buildup on the pistons was minimal, but since then who knows it could have built up.

 

[mrmustangman357]

see is there is any burrs or nicks on the hole in the block and the collar. try putting oil on the collar shaft, which really helped mine move freely. Check TDC and time for 36 degrees total advance with the vac advance pulled. That should start you out

 

[SoCalCruising]

When the engine is cold and the cap off the dizzy, you shoudl be able to move the rotor up and down, freely, for maybe .020 -.030" (that's a bit of a guess). If it's tight, you must clearance it at the bottom. I'd take it to a good machine shop and have them do it, if it's tight. Don't blame MSD, it might be your block.

Are you running vacuum advance? You didn't say.

I had my new MSD small diameter billet dizzy curved at Dougans here in Riverside. The guy does this for race motors (SCORE trucks, mostly). He said these give about 18-20 degrees mechanical (there is some variation). That's about right. I run 14-15 degrees initial and have about 34 total. AFR heads don't need too much advance. You can run 32-34 total and be good, once the pinging is solved.

I have a feeling your dizzy shaft needs clearancing and the advance mechanism isn't working right.

 

[Rapid]

It is not hard to change the bushing. You do have to take the body off of the dizzy but there are only two screws and no need to remove it . Look at the MSD website for directions before you try it just to get a picture in your head.

If you are pinging when you lug the engine only I still think you should run some Lucas or Seafoam through the gas tank. I used Lucas but only after physically cleaning the cylinder heads and pistons. I don't have but around 4k on a re-build and am running a fairly similar set up and got the build up. It seems to be happy now...

 

[rbohm]

Rapid: I hear the pinging when I'm in third gear, pushing it on the highway. I don't hear pinging when blasting through 1st or 2nd, but who knows maybe I just can't hear it... Have you ever changed your advance stop bushing? Can you do it without pulling and disassembling the whole distributor? I can't figure out how to do it otherwise...

rbohm: I'm running #68 jets in the primaries and #76 jets in the secondaries of my Speed Demon, I wouldn't think that should be a huge problem.

you definitely have a lean condition probably due to a weak fuel pump, or low fuel pressure. if you are running a stock mechanical fuel pump the step up to a carter super street pump Federal-Mogul - Carter Super Street Racing Fuel Pumps as you need more fuel when running hard. remember to run a good pressure regulator and a return line to prevent running too much fuel at low speeds. or oyu could step up to an electric pump.

 

[SoCalCruising]

Do yo have endplay for your rotor?
(see my post above)

 

[10secgoal]

If you have them, I would see waht jetting the thing up 5 in the front and rear does. It looks like a healthy motor, and Demons are notoriously lean. I would check the pump pressure when your on it. 3rd gear is really going to need fuel.

 

[Great68]

you definitely have a lean condition probably due to a weak fuel pump, or low fuel pressure. if you are running a stock mechanical fuel pump the step up to a carter super street pump Federal-Mogul - Carter Super Street Racing Fuel Pumps as you need more fuel when running hard. remember to run a good pressure regulator and a return line to prevent running too much fuel at low speeds. or oyu could step up to an electric pump.

I'm running an Edelbrock RPM pump, and I just upgraded my lines to -6 AN last year. I have a Autometer gauge on the inlet to the carb, it's a good 6.5psi at idle.

I'm going to try upping the jet sizes this weekend, I'll let you know how that goes.

It's hard to believe that it would be lean. At idle the car STINKS, my clothes literally reek when I get out of the car... And I'm only 1 turn out on the idle mixture on all 4 corners.

Maybe I have a bad power valve?...

I'm going to check the rotor play this weekend too.

 

[rbohm]

I'm running an Edelbrock RPM pump, and I just upgraded my lines to -6 AN last year. I have a Autometer gauge on the inlet to the carb, it's a good 6.5psi at idle.

I'm going to try upping the jet sizes this weekend, I'll let you know how that goes.

It's hard to believe that it would be lean. At idle the car STINKS, my clothes literally reek when I get out of the car... And I'm only 1 turn out on the idle mixture on all 4 corners.

Maybe I have a bad power valve?...

I'm going to check the rotor play this weekend too.

fuel pressure and a/f ratios at idle mean nothing when you are turning 5500 rpm. tape a fuel pressure gauge to your windshield next time you make a banzai blast, and see what the fuel pressure is in the upper rpm range. 6psi at idle is good, but if you have less than say 3psi at 5000 or so, then you are going to run lean, especially in third gear as the float bowls start to get empty. it might also be that you have a low float level, that happened to me once. i had the float levels in a holley set too low and i would run out of gas running hard in third gear.