fresh rebuilt 401 Nailhead is over heating during break in. New aluminum radiator with dual fans, coolant was flowing good then put cap on. It came out the overflow tube at about 220. i turned it off. With the number one cylinder at top dead center compression stroke, the rotor pointed to the number one plug terminal. When i tried to start it, it was back firing through the carb. I had to turn distributor cap counter clockwise way over,about one plug. The wires are on right, triple checked. Then it ran smooth,(2200 rpm) but got too hot. Its a new MSD distributor. Valve timing seems to be off. I put back on top dead center #1 , the timing mark is about 4 inches to the left of the tab. At this point i pulled off the timing chain cover expecting to see sprocket off one tooth. Nope, all lined up.The pic of balancer is at TDC At my wits end ! any ideas whats happening?
Probably have number one off by one terminal location. Mine is - still runs fine but I need to move timing light pickup to the next sparkplug to get a read. I haven't rectified because I was tired of the job at the time and it doesn't matter. Here I am two years later driving it most every weekend with the distributor off by a plug. And it whoops ass.
Retarded timing will make for excess heat , especially on a under 9 to 1 motor if that's the case. You know your Distributor timing is in the ball park when you can advance the Distributor and the motor gets hard to Crank over. If you need to rotate the Distributor more then 20 degrees to get this to take place then something is up! This should be one of the first things confirmed on a new build once the firing order is checked out twice! What does your cranking compression check in at?
Are you sure you have the wiring correct? The number one cylinder is on the passenger side. Positive wires correct. if the piston is on top dead center and your not at o* on damper the your damper is off. Agree, Picture shows that. That proves that the the ring has slipped on the rubber. I marked a white paint line at 0,(not shown in above pic) #1 is at TDC, Distributor put in so rotor is aiming at # 1 plug terminal. I need a new harmonic balancer right? Retarded timing will make for excess heat , especially on a under 9 to 1 motor if that's the case. You know your Distributor timing is in the ball park when you can advance the Distributor and the motor gets hard to Crank over. If you need to rotate the Distributor more then 20 degrees to get this to take place then something is up! This should be one of the first things confirmed on a new build once the firing order is checked out twice! What does your cranking compression check in at? Is counter clockwise Retarded on a Nailhead ? it was not hard to crank. Did not check cranking compression. If those timing chain marks look correct ?, i am going to put it back together. (Ordered gasket kit, one week del.) Sure the distributor is not off by one tooth? at #1 TDC compression, rotor pointing at # 1 Thank for the help everyone.
You said you had to twist the dist nearly to the next plug tower to get it to start which makes me think the dist is a tooth off. I've done the same thing.
Unless I missed it, I have not seen what the timing was as the engine was breaking in. It should be at least 30*, 40* would be better. This is a brand new MSD distributor which has adjustable mechanical advance. Should be very easy. Retarded timing will heat an engine up.
you can send the damper out to rebuilt it. counter clockwise is advance NOT retard. timing marks look good on the chain you have it right. i would put a new mark on the damper to zero it in then timing from there just to see how it runs, put it about 5 degrees advance just to get close.
Did you swap the springs in the dist and set up the total advance before you put it in? The MSD's are not "drop in ready" like many think. What is your total timing? Too many people time off initial and think that's it. Total timing is way more important, although hard to do at break in. To check the balancer, at least at a glance, take the bolt out and see if the timing mark lines up with keyway, it should. It can be off a couple degrees either way, but not a big deal as long as it's on the keyway. At break in, you need to have a hose and water ready to spray on the radiator and/or big fan to blow on it. Remember, lots of friction and no air movement is bad. I have broken in a lot of Nailheads and have never seen one overheat.
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You said you had to twist the dist nearly to the next plug tower to get it to start which makes me think the dist is a tooth off. I've done the same thing. True, but I thought #1 at TDC rotor should be pointing at #1 plug. I don’t know, maybe I was off. Unless I missed it, I have not seen what the timing was as the engine was breaking in. It should be at least 30*, 40* would be better. This is a brand new MSD distributor which has adjustable mechanical advance. Should be very easy. Retarded timing will heat an engine up. Im not sure what timing was exactly ,set at TDC, backed off to 10deg. On tab, checked rotor to see if near #1 post. you can send the damper out to rebuilt it. counter clockwise is advance NOT retard. timing marks look good on the chain you have it right. i would put a new mark on the damper to zero it in then timing from there just to see how it runs, put it about 5 degrees advance just to get close. Looking straight at engine, it spins clockwise. As the timing mark is coming up to the tab, (tab says 12,5 and 0 deg.) If I stop at 5 wouldn’t that be BTDC? Retarded? Did you swap the springs in the dist and set up the total advance before you put it in? The MSD's are not "drop in ready" like many think. What is your total timing? Too many people time off initial and think that's it. Total timing is way more important, although hard to do at break in. To check the balancer, at least at a glance, take the bolt out and see if the timing mark lines up with keyway, it should. It can be off a couple degrees either way, but not a big deal as long as it's on the keyway. At break in, you need to have a hose and water ready to spray on the radiator and/or big fan to blow on it. Remember, lots of friction and no air movement is bad. I have broken in a lot of Nailheads and have never seen one overheat. I did swap the springs and bushing according to Russ at Centerville auto. Not sure what total timing was Timing mark is approx. 4” off keyway(must be spun) I will re-assemble and try to set total timing with dial back. Taking a vacation for a week Friday. Going to start over when I get back. Thanks for the help. Here's a pic of my car
With #1 at TDC, (verify that valves are closed), then rotate distributor until points open or using a test light, and that is the zero TDC of the distributor and the #1, then verify the balancer is at zero.
am talking about the distr. facing it turn it counter clock wise and that is advancing the timing. btdc is advance not retard. think about it spark is coming in before piston hits the top so its firing before and advanced
I haven't seen this question, is the electric fans wired properly? If they aren't they will spin in reverse of what you want them to. Where at in SE Michigan are you, I'm in the slums of Rochester Hills.
Do you have a timing light? Yea, by the time I got ready to use, it got to hot. With #1 at TDC, (verify that valves are closed), then rotate distributor until points open or using a test light, and that is the zero TDC of the distributor and the #1, then verify the balancer is at zero. I will try that am talking about the distr. facing it turn it counter clock wise and that is advancing the timing. btdc is advance not retard. think about it spark is coming in before piston hits the top so its firing before and advanced Got it, that makes sense. I haven't seen this question, is the electric fans wired properly? If they aren't they will spin in reverse of what you want them to. Where at in SE Michigan are you, I'm in the slums of Rochester Hills. Fans are good, they came on around 195-200 moving a lot of air ! I am in Garden City, 40 minutes from Rochester Hills. Food, Beer, Cash, if you can come figure it out!
Good morning, As I was reading thru all of these post and reply’s to your problems I just kindof started wondering how you were figuring that you had number 1 at TDC. Then in one of your reply’s you said that maybe you were off... And since no one else has mentioned it I guess it falls to me, have you read Larry’s timing thread?
