Camshaft break-in

[ITSANSS]

I think I'm finally gonna' get around to swapping my sister's old 350 c.i. engine for the rebuilt 355c.i. in the next week or so.

Got a question about the camshaft break-in.

I know fire it up and rev the engine back and forth 1,500 - 2,200 RPM for about 20 minutes, but what does one do if the vehicle doesn't have a tachometer?  Go get a cheap one from the parts store and hook it into the distributor and to the battery?  Or is there a better way?

Thanks

[VileZambonie]

Make sure you prime the system with a good oil that contains high levels of phosporous and zinc. Start the engine and get the RPM to 2-3K RPM. You don't really need a tach to know where this is if you have a good ear but a good timing light will have a built in tach and you need to set the timing anyway. Some multimeters have a tach as well. Just hook it to the negative side of the coil. If you are using freshly coated headers I would advise against it or it may ruin the coating. Make sure you fill the engine with your coolant 50/50 mix through the intake until it's full. Then put the thermostat in and finish filling the radiator with a spill free funnel. After you get the engine running to about 2500RPM set the timing at 36° degrees and tighten the distributor hold down clamp. Make sure there is good air flow around the engine compartment ( an extra shop fan in front of the truck is a good idea if you have one ). Vary the RPM slightly between 2,00 and 3,000 RPM over the course of about 20 minutes, lower the engine rpm, set your idle speed, recheck your timing and you should have the cam broken in. It's a good idea to continue to use a good oil or suppliment with those higher levels assuming it's a flat tappet cam.

[ITSANSS]

I kinda' figured I could just judge the RPM by sound.  I guess I'll just plan on doing that.  I've got a timing light, but it's oooooolldd.  Still works fine, but it doesn't have a tach. built in, which would be really cool if it did, though.

I do have some brand new Flowtech metallic ceramic long tube headers, but I have an old/non-coated set that I'm gonna' use for the break in (hope they fit!).  That's another question I have.  When it says (in big letters) not to use coated headers to break in an engine, is that just for the initial start-up or is that until you get 500 miles or so on it?  Also, how does the coating get damaged?  What's the difference between a new engine and old when it comes to header coating?  'Cause of the oil and fuel going out the exhaust until rings are seated, etc.?

One problem filling the intake manifold and then the radiator....I already have the thermostat and housing installed with RTV silicone and everything.     Is doing that for the good of the water pump....to not run it dry?  The hole on top of the water pump where a cap or heater hose outlet goes is still uncovered, could I put some in there before start-up?

Also, I really don't know what kinda' cam. is in it.  I assume it's a flat tappet.  Whatever the company Advance Auto Parts uses put in it.  Haha

Thanks!

[VileZambonie]

The heat from running the engine at higher RPM will ruin the coating without the air flow you would have during normal driving. So just during the initial break in. Once you have everything set up put your nice headers on.

You do not want to overheat the engine so take the thermostat back out and fill it that way. You shouldn't have to use silicone if you are using a gasket.

If it's a reman from advance then it's a stock cam essentially so yes it's a flat tappet.