Ignition Problem

MrMagoo · #1 (**permalink**) 07-24-2004, 02:49 PM

Hello cobra fans.

I am trying to diagnose an ignition problem. My 351w was running well. At around 3500 rpm it died out on the highway. The engine just cut out. Now it's in my garage. Fuel delivery looks good. The coil IS getting voltage. I tried a new coil (I keep a spare). No luck. I popped the distributor cap and cranked the engine. I would have expected the rotor to rotate, right? It doesn't. It appears to be seated correctly, etc. Any ideas???

Thanks!

Dist: Mallory Unilite 47
Coil: Mallory Promaster E-coil
Eng: 351W
Intake: Edelbrock Performer 351
Carb: Edelbrock Performer 1406

Dennis Kelley · #2 (**permalink**) 07-24-2004, 03:07 PM

Sounds like the distributor shaft that connects to the oil pump has broken. Take the distributor out and look down the where the shaft goes and see if you can see the shaft. Good luck

MrMagoo · #3 (**permalink**) 07-24-2004, 03:21 PM

You know, I was hoping you wouldn't say that

But, I think that sounds right to me.

I haven't removed a distributor before.

Should I just be able to pull up the distributor after removing the clamp?

G.R. · #4 (**permalink**) 07-24-2004, 03:33 PM

Yes it should come right out you may have to "wiggle" it a little at first---be sure and mark the dizzy and a corresponding mark on the manifold and the rotor location as it now sits--could help when reinstalling. That is what I did when I replaced my stock dual-point with an MSD billet dizzy. didn't take much tweaking on restart---but since I'm not a mechanic I may have been lucky. FWIW

MrMagoo · #5 (**permalink**) 07-24-2004, 03:44 PM

Thanks. I got the Distrib out.

The little pins that hold the gear on to the distributor shaft are broken.

I think that solves the problem. Now, to get it fixed! I guess a machine shop should be able to fix this???

Rick Parker · #6 (**permalink**) 07-24-2004, 06:08 PM

Before you reinstall the distributor be sure the oil pump is not locked up, check the condition of the gear. Some thing with resistance (oil pump) caused the pin to shear. Look for that reason.

Rick

MrMagoo · #7 (**permalink**) 07-24-2004, 07:36 PM

Yeah, I suppose that the pin is engineered to sheer at a certain level of resistance. Hmmmmm....

The distributor shaft gear looks fine, no apparent damage.

BTW I have a melling hi-volume oil pump, I wonder if the hi-vol version of the pump creates more resistance? Also, I am running Castrol 20w50 synth oil.

One peculiarity of my engine build is that the oil temp has always been on the high side, especially when in the higher RPM range. like 250 F to 275 F. Water temp is very cool, around 150 F to 180 F.

Dennis Kelley · #8 (**permalink**) 07-24-2004, 08:01 PM

I have a high volume pump and my engine builder told me not to run any oil except 10W30 due to heavy oil causing heavy shaft load. due what you want but I would lower the oil weight thats just my opinion. I just know what I was told by the guy that built my engine. Good luck

MrMagoo · #9 (**permalink**) 07-24-2004, 08:37 PM

I can turn the rotor by hand, and spin the oil pump. It's certainly not effortless but it doesnt appear to be stuck either. That, and the fact that the gears do not appear to be damaged would support your theory that the heavier weight oil and hi volume pump combination may have something to do with the pin shearing. Thanks for the info!

Rick Parker · #10 (**permalink**) 07-24-2004, 09:18 PM

Mr Magoo:

Dennis's idea of the 10-30 is valid. Yes the HV pump takes more "effort/torque" to turn and therefore loads the gear more heavily, especially if you are using 20-50 oil. Unless you are running bearing clearances that are looser than standard or a remote filter/cooler the pump will be in "bypass" constantly and will beat the oil and put more heat into it. That may explain your oil temps.

Rick