602 timing issue

[DV8]

Please forgive the lengthy post but I want the situation to be understood, my memory is vague on a few things as it happened a while ago. We run the car on E85 with a new stealth carburetor.

I bought a used 602 it was still running, just smoking a bit through the turns. Took it to a certified engine builder, he is squared away and have no issue with the work he does. Builder put a new MSD distributor in and a serpentine pulley system on the front. I think everything else was a standard rebuild.

I got the engine in the car, it has a MSD box with 3 races on it (I don’t have the designation right now, we sent it to MSD to be tested but it is the box where you set the RPM on the box not with a chip), I ran it with a 358 with no issues coil was old but again I ran it with the 358.

Took it to the track, ran hot laps and part of a heat race and it ran great turned it around 54/5600 for maybe 10 laps and on a restart the engine laid down on me. I finished the heat race but as I was coming off the track the oil light was flickering (I dented the bottom of the pan because I didn’t raise the engine up enough, it was replaced later in the story). Oil light was not on during race.

Got it in the pits and checked the timing and it had jumped either 6 or 9 degrees. Took the car home, checked the wiring which was okay. I put a new coil on it, since it was the only electrical part not new, then we reset the time and I changed the oil. We also replaced the ignition switch in the car since the start button had become a bit finicky. Took it back to the track, no oil light flicker but when I tried to hot lap the engine laid down again, checked the time and it was off again 6 to 9 degrees. Took the car home and I pulled the engine out and took it to the builder, it was at the point the Builder saw that the pan was dented. He replaced the pan and though unneeded the crank, he said it was close on the tolerances and he knows I like to run legal, the block was checked and it was a standard rebuild again.

Engine back in the car and raised up to clear the pan I also added a racing alternator, took it to the track and we were able to hot lap and ran about 5 laps in the feature (no heat race) until I crashed. Car ran great, the only issue was that I have a reverse mount power steering pump and I had the belt too tight, it broke and I had no PS. Fixed the body and came back the next week and the engine laid down again during hot laps, it felt different this time so I just turned the engine off on the track and they pushed me back to the trailer. Since the feel was different this time we didn’t start it back in the pits to check the time.

Pulled the engine and took it to the builder, he said it was a detonation issue and it hurt the rod bearings. I pulled all of the MSD stuff and sent it to MSD to be tested, it all passed. All of the issues seem related to timing, but I’m not sure. The engine builder hasn’t experienced this before and has offered to put it together and take it to the dyno on his dime to test it there, but I’m not comfortable with pinning this on someone if it isn’t their fault. Honestly I’m ready to punt on the engine, I have less than 30 laps and a lot of cash tied up in it.

Have any of you guys experienced this type of thing before?

[50j]

It'd be smart to dyno it carb to pan with your fuel and ignition. Have you put a reference mark on the distributor and intake to make sure the distributor isn't moving? Is the timing advancing or retarding?

[JustAddDirt]

typically if it distributor loosens it retards timing.
so if it is a detonation issue, as indicated..... that sounds as if it is advancing.
You aren't by any chance timing the motor with an adjustable timing light are you?
when MSD dist. is plugged into the lead wire to the box, you don't have purple striped wire to purple striped wire do you?

[50j]

Yes, but it's always better to ask than to make assumptions.

[DV8]

Thanks for the advice, dyno may be the best way to go. We did check the distributor and it was tight, we didn’t have a mark to see if it was slipping on the cam. That would be a good check. As far as the wires the plug is pokiokie, in that it can only plug in one way. That is good advice so I’ll check to make sure it is correct, the plug could be wrong. I was just hoping someone had a “hey that happened to me back in 63” story.

[50j]

It's helpful sometimes to put a small mark (line) where the distributor meets the intake manifold after the timing is set so that if you see that the line is no longer continuous you can quickly see that the distributor has moved. Timing chain stretch or distributor gear wear will make timing change too. You may have more than one problem going on so it'd be good to see why the timing is changing, check rotor phasing, check the fuel for water and for ethanol percentage, and make sure the carb or delivery isn't causing a lean condition.

[Lizardracing]

To add another idea. The damper outer hub can spin on the inner hub and make the timing look all wrong. I paint on all mine as a quick reference and check it ever so often during usual lash checks. This only makes the timing look wrong but not loose power like your describing unless you actually have two problems. The damper and a fuel delivery problem.

I've also seen the dizzy bottom out on the oil pump shaft. The clamp feels tight but the dizzy body can still turn under vibration.

[JustAddDirt]

Also when timing is checked, is the motor brought up in rpm to see how stable the timing is?
Might need to check the lash/endplay on distributor shaft. Too much will retard timing.
Also check to see how much endplay is in the camshaft. Too much will retard timing.
I have seen a plug in wired backwards right out of the package on wire harness. Just something to check.

[50j]

Did you find the problem?

[brad hibbard]

I read a lot of good replies here but what I am focused on is the fact that you said the timing is 6 to 9 degrees off after a run and then you had a detonation problem signifying that the timing is advanced-----

one thing I didn't see you mention (and I might have missed it)
Is the centrifugal advance mechanism securely locked or are you running the weights and springs?
advance mechanisms can hang in either direction ---when setting timing with advance in the distributor we never recommend an RPM for it to be checked but we do recommend to increase RPM 6 to 700 RPM past where it stops advancing and then hit the throttle once hard to see if it jumps

one other poster mentioned this as well but I want to review your answer---What kind of timing light are you using?
If it has buttons or dials on it, I can safely say that was your problem

one thing I didn't see mentioned directly was the distributor gear material.
this would only apply to a retarded timing but since this is a 602 I have to mention
NEVER should a bronze gear be used on a 602---it will deteriorate very quickly

hope you find your problem
Brad
www.race-1.com

[DV8]

Sorry I don’t log in often but I appreciate your interest. We haven’t put the engine back together yet. The distributor gear was not bronze, it was factory and new. The distributor was locked as well. The builder used a quality timing light, he set the time ran it in on an engine stand then checked the time again. I believe he is OCD like most engine builders.

The cam isn’t new so it may be a wear issue there, since the timing issue only happened under load. If we put it back together we will take it to the dyno and try to break it there. I’m not an engine guy but my understanding is that a timing chain slip would cause it to not run at all, so it must be in the cam distributor area like the poster above mentioned. Again all the MSD stuff checked okay.

[DV8]

One more thing, the builder was at the track when the timing jumped and he used the same timing light to check it. So that was consistent.

[7uptruckracer]

Brad What Timing Light would you recommend?

[fastford]

I read a lot of good replies here but what I am focused on is the fact that you said the timing is 6 to 9 degrees off after a run and then you had a detonation problem signifying that the timing is advanced-----

one thing I didn't see you mention (and I might have missed it)
Is the centrifugal advance mechanism securely locked or are you running the weights and springs?
advance mechanisms can hang in either direction ---when setting timing with advance in the distributor we never recommend an RPM for it to be checked but we do recommend to increase RPM 6 to 700 RPM past where it stops advancing and then hit the throttle once hard to see if it jumps

one other poster mentioned this as well but I want to review your answer---What kind of timing light are you using?
If it has buttons or dials on it, I can safely say that was your problem

one thing I didn't see mentioned directly was the distributor gear material.
this would only apply to a retarded timing but since this is a 602 I have to mention
NEVER should a bronze gear be used on a 602---it will deteriorate very quickly

hope you find your problem
Brad
www.race-1.com

you are 100% correct about that timing light , I destroyed an engine one time with one of those , all i use now is a cheap ole strobe type and mark my balancer.....

[brad hibbard]

I personally like the flaming river battery operated light---they are about $50
the MSD light is a bit brighter but but the cost is quite a bit higher as well
however, in any case we never like to see anything with a button or dial that alters the timing read
even when those lights are used correctly they have had errors in calibration

we are working a deal with Flaming River and hope to include a new timing light with every new engine sale and rebuild
we have had so many terminal failures due to the fancy timing lights that we would rather give you a timing light and have you visit us every 3 or 4 years rather than become someone that I have their shipping address memorized.

Brad
www.race-1.com

[fastford]

I have been aiming to get one of those , I,m using a old craftsman that you hook to the car battery , I sit in the stands a lot of nights and hear engines popping at high rpm,s and wander what kind of light there using..........

[JustAddDirt]

I personally like the flaming river battery operated light---they are about $50
the MSD light is a bit brighter but but the cost is quite a bit higher as well
however, in any case we never like to see anything with a button or dial that alters the timing read
even when those lights are used correctly they have had errors in calibration

we are working a deal with Flaming River and hope to include a new timing light with every new engine sale and rebuild
we have had so many terminal failures due to the fancy timing lights that we would rather give you a timing light and have you visit us every 3 or 4 years rather than become someone that I have their shipping address memorized.

Brad
www.race-1.com

I use one of those Flaming River lights. they work very well, but you are correct, the light is a bit dim. I set timing, and if I am in shop I double check it with the lights off just to be sure.