Thread: Motor Rebuilding Issues

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I have a concern about the break-in procedure. I do have time to break in most motors proporly but I also build race motors. These motors a basically stock parts but the motors don't even get to 1000 miles in there lifetime. 300-400 miles is average. What should a guy do to speed up the break in time?

The heads I,m going to use are off a 350. They were rebuilt about 4 yeras ago. Have about 20.000 miles on them. I would like to get a vale compresser and take out vales and glean heads. Also get some of that vale grinding compound for the vales and seats. Any advice on that? Thanks John.

Originally posted by toad mountain
I have a concern about the break-in procedure. I do have time to break in most motors proporly but I also build race motors. These motors a basically stock parts but the motors don't even get to 1000 miles in there lifetime. 300-400 miles is average. What should a guy do to speed up the break in time?

a simple word of advice for break in on a race engine is... do the 20 minute and you're good to go.... if its gonna break its gonna break.... thats what most racers go by... they also build their motors with tougher than stock parts.... the other way if you want a garaunteed break in... pay for it to have a dynod break in.... its expensive... but its the best way you can do it

Originally posted by Johnwalkeasy
The heads I,m going to use are off a 350. They were rebuilt about 4 yeras ago. Have about 20.000 miles on them. I would like to get a vale compresser and take out vales and glean heads. Also get some of that vale grinding compound for the vales and seats. Any advice on that? Thanks John.

Here, a fellow explains the procedure on a "F" head Willys (intake valve in head, exhaust valve in block).
http://www.public.asu.edu/~grover/willys/valves.html

Here's another guy saying "don't do it".
http://yarchive.net/metal/valve_grinding.html

Originally posted by techinspector1
Here, a fellow explains the procedure on a "F" head Willys (intake valve in head, exhaust valve in block).
http://www.public.asu.edu/~grover/willys/valves.html

Here's another guy saying "don't do it".
http://yarchive.net/metal/valve_grinding.html

My take on it? I've lapped the valves on every motor I've ever put together 'til I saw a "witness ring" and I'll do it the same way 'til they drop me in a box.

If you have coated valves, usually stelite, you cannot lap them. You wont see stelite coated valves in any autmotive application.

Somthing tells me the proff is in the lapper. On 2nd thought, I,ll leave it alone. I,m not very handy with stuff like that. My feeling is, my heads are okay. But I,ll have them checked out. Thanks for the advice.

Tech, What do you mean by set spark advance and valves so motor will crank right up. Should they be set any differnt than nomal? If so how I should I set the timeimg, spark plugs and valves? Thanks, John.

John, no, no different than what you'd normally run. It's just that I'm suggesting that you MAKE ABSOLUTELY CERTAIN that everything is ready to go so that you won't be grinding on the starter and putting pressure on the cam lobes without any splash lube.

Thanks Tech, Understood.

One thing I've learned when I built my motor.. look for ALL holes that can be plugged that you will absolutely not need. I once found an oil galley hole halfway covered by a cylinder head that I put on.

Boy was I mad when I had to take off the cylinder head and rockers just to plug a little 3/8" hole.