Camshaft Break In

1658 Views 8 Replies 7 Participants Last post by SideCarGT, Jun 15, 2020

poisonguy

Discussion Starter · May 20, 2020

Trying to do the cam break in on my rebuilt 289. It has a Edlebrock Performer Intake and a rebuilt 600 Holley carb and Pertronix Distributor otherwise stock. Cam/crank marks lined up with #1 up, Air mix is at 1 1/2 turns, total timing is at 34, intake re torqued after 10 minutes break in time, no vacuum leaks that I can find (all vacuum lines are plugged except the line from carb base to pvc), starts easily and sounds normal when running (which is why I don't see how I could be 180 off). The problem is that after a few minutes the headers are glowing red hot and temp starts to rise. I've shut it down when it goes over 195. Yesterday when I tried it, I did let it get up to 200 before I shut it off so it looks like it wants to keep getting higher. It does puke out fluid but I do know that that's not that unusual. Never had this problem breaking in a cam before so I don't know how high I can let it get to without causing serious problems. I've read that it's caused by timing being retarded, running too lean or rich or valves being too tight and exhaust valves not closing. (I checked with the engine builder and he assured me they were adjusted correctly). What am I missing? Thanks in advance for your help!

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Driveway

· #2 · May 20, 2020

Start with the simple stuff.

Coolant

Water pump, pulley, belt

Thermostat

Good exhaust coming out the tail pipes

And that is a big carb for a 289, rich, what jets?

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Grimbrand

· #3 · May 21, 2020

Your total timing may be at 34, but your initial timing is a bit off, sounds like. Hot exhaust headers indicates retarded timing most likely; combustion still happening in the exhaust system.

If I were you, I would first check to make sure the damper hasn't slipped its inertia ring, and verify timing marks by finding TDC mechanically again. You can't be 180 out or it wouldn't start at all.

Are you setting timing with a light? Be sure to disconnect vacuum when you're setting timing.

Hope this stuff isn't too basic - sounds like you probably understood most everything I'm mentioning already. But if there's anything you missed, maybe this will help.

Best wishes!

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JustAnotherRuki

· #4 · May 21, 2020

When the sucker is puking out coolant is getting hot. My old 289 will start doing that through my reservoir tank line once temp reached 230. I never, ever got to dial the right timing on the engine therefore it was always getting hotter and hotter.

J

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chasmalo

· #5 · May 21, 2020 (Edited)

The red-hot headers sound like retarded timing. When the timing is late fuel is still burning in the exhaust manifolds.

CJM

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poisonguy

Discussion Starter · #6 · May 21, 2020

Thanks for your reply. The vacuum advance is plugged and I'm using a timing light to set the timing. I had already decided that I need to start all over by checking that TDC is correct. Will also check to see what jets Holley put it there.

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Grimbrand

· #7 · May 21, 2020

And BTW - welcome to AFM!!

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Gt350HR

· #8 · May 21, 2020

Easy enough to advance it 6*s . If you have a slow ( stock) advance curve , you could be retarded like Grimbrand suggested.

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SideCarGT

· #9 · Jun 15, 2020

Doing the right thing checking basics again and clearing the timing. Probably timing, but I did know a guy with a brand new thermostat that wouldn’t open so make sure you’re getting circulation.

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