Resuming Cam Break-in

craigblock · 03-18-2010, 10:24:08 AM

Last fall, I started the camshaft break-in. It was going well, until a plug wire caught on fire after about 5 minutes of running. We had to shut it down and put it out with an extinguisher.

I didn't have a solution for the plug wire heat issue until it was too late. There was no more time before winter and I had to wrap it up.

I want to finish the break-in soon, so that I can finish the car. If the cam fails, I don't want to put any more time or money into the car until next year, so it's a priority.

What do I need to do to finish? Should I be pulling the intake and re-lubing the cam and lifters, or will a simple pump priming and restart be all that I need to do?

BondoSpecial · 03-18-2010, 10:51:12 AM

Yes I would re lube everything. That is way too long to have sat for me.

craigblock · 03-18-2010, 06:40:58 PM

What about the poor oil filter, should I replace it?

I'm concerned about how much assembly grease could actually end up in it once I re-lube everything.

POS71RS · 03-18-2010, 06:44:58 PM

5 minutes... enough time to wipe off the lube, but not enough to breakin anything.
Re-lube. And change the oil/filter.

ahale2772 · 03-18-2010, 08:38:52 PM

no to steal this thread but whats the rule of thumb on break in of a cam? 30 minutes? ive heard take off inter valve spring as well but im lazy do i really have to?

cmonson · 03-18-2010, 08:59:48 PM

Quote:

no to steal this thread but whats the rule of thumb on break in of a cam? 30 minutes? ive heard take off inter valve spring as well but im lazy do i really have to?

search for proper break in.

20-30 mins is good practive.

what are you spring pressures?

Quote:

but im lazy do i really have to?[/

go and pick a new hobby.

POS71RS · 03-18-2010, 11:53:10 PM

Quote:

Originally Posted by ahale2772

no to steal this thread but whats the rule of thumb on break in of a cam? 30 minutes? ive heard take off inter valve spring as well but im lazy do i really have to?

If you're running double valvesprings, then sure, you can take out the inner for break-in.
BUT... don't confuse the 'damper' of a standard valve spring with a dual valve spring. That flat-sheetmetal coil inside your valvesprings is NOT a spring. That is to dampen valvetrain harmonics.
And I'm lazy too.. but after having wiped out an entire engine with a bad camshaft... I can't afford to be that lazy or cheap again.

DoTheDew · 03-19-2010, 10:50:03 AM

If it was running before you shut it down, that means the timing is all setup and ready to go then right? Mark the distrubutor, add a new plug wire. How high dollar of an engine is it? If its a simple cam swap on an old engine (and this is just me), i'd run a 1/2 bottle of lucas into it. Prime the oil system really well, stab the distributor back into it and hopefully fire on the first or second revolution, and resume break-in. I personally wouldn't worry about relubing, but I've never had a problem chewing up any lobes, so I could be wrong to.

craigblock · 03-19-2010, 03:10:37 PM

It's a fully machined and rebuilt 355 with new AFR Eliminator heads and almost all new parts.

cmonson · 03-19-2010, 10:40:05 PM

before you do anything, what are your spring pressures? If they are dual springs, they are probably very stong and you may need to remove the inner. If it is single with a damper, then you are probably OK.

Either way, prime the oiling system an use a break in type oil.

Air_Adam · 03-20-2010, 03:16:55 AM

I'd say pull the intake off, back off the rockers, then tame out the pushrods/lifters one at a time and with a small brush 'paint' as much of the cam lobes with break-in lube as you can...

ahale2772 · 03-23-2010, 10:30:47 PM

looks like the damper is what i was thinking about sorry again to jack the thread, im not quite lazy just didnt wana take the heads off before and after the break in (i dont have one of those funny spring compressors that can be used with the head s on) guess i should invest thanks anyways

Rick WI · 03-24-2010, 01:04:12 AM

If you want to be super anal pull the distributor and reprime the engine turning crank by hand 90 degrees every minute or so. Reinstall distributor and fire it up. Tearing the engine down is a waste of time. Just basing this on 15 to 20 years of dyno work for what its worth.

jakeshoe · 03-24-2010, 01:10:30 AM

Quote:

Originally Posted by Rick WI

If you want to be super anal pull the distributor and reprime the engine turning crank by hand 90 degrees every minute or so. Reinstall distributor and fire it up. Tearing the engine down is a waste of time. Just basing this on 15 to 20 years of dyno work for what its worth.

Agreed.
I personally would definitely pull the distributor and reprime the oiling system.
I would probably add an extra qt of Joe Gibbs break-in oil or other ZDDP additive.
Drop the dizzy in, fire it up and finish break-in.

I assure you that GM didn't spend 20 minutes breaking in every flat tappet cam they ever installed.

5 minutes of run-in time has probably taken care of any break-in anyway IMO.

ZS10 · 03-24-2010, 03:20:36 AM

Another vote for making sure spring pressure is minimal.