willem wallace

Looking for some facts on ceramic headers being screwed up by heat during initial engine break-in. Have a GM ZZ383 never run and was going to install a set of ceramic headers, but read that the heat during break-in process will get them so hot as to possibly ruin the ceramic finish. If that is the case, could I put a set of cast-iron exhaust manifolds I might scrounge up somewhere on for the initial break-in, then just take them off and put the new ceramic headers on? My heads are D-port, so would the exhaust manifolds I use have to be D-port also? Last thing I want to do is to screw up the break-in process. Where would be the best place to try to find a set of the correct type exhaust manifolds for the break-in? Any info is appreciated!

OMF

I just did a breakin on my 406 two weeks ago, with ceramic hedmans. I didn't want to screw around with cast iron manifolds, so I set up everything as good as possible, and made sure the timing was about 15 degrees advanced (definitly do not want retarded timing here) and left the hood off for the inital start. No problems at all with the headers getting overly hot....no discoloration at all. Ran it for a few minutes....then had to shut it down because of a minor fuel leak. After repairs ran again for 15 minutes with no problems at all with the headers. Just make sure there is no oil drips on the pipes....that will stain.

baxsom

did it come broke in from the factory? i thought they ran those before they were shipped out?

Vince'82

ZZ383 uses a roller cam.
does it really need a cam breakin ?

baxsom

other than seating the piston rings i have read that roller cam engines do not need break in.

gerry72

Excessively high EGTs are a result of late ignition timing and/or a very lean fuel mixture. Has nothing to to with the break in. Just a bad initial set up. Also, you can not seat rings in an unloaded engine running at idle or high idle. Rings need high cylinder pressure to create the pressure they exert against the cylinder wall to allow them to seat. Moly rings tend to seat on start up, though. And if this engine has a roller cam, as others have stated, you don't need to do a break in to run in the cam.

TopGunn

Your engine has a roller cam and doesn't require the high rpm break in at startup that a flat tappet cam does that could harm the ceramic. I screwed around installing cast iron headers on mine for the startup before I realized I wasted alot of time and energy doing it. Just start it normally and go thru the ring seating procedure after you get it on the road, the headers will be fine.

69vettester

I used that GMPP shortblock and full roller top end. When I did initial startup my Hooker headers Glowed red Both sides all cylinders. After a few seconds they cooled down. During the Build I used every bonified Break in product and procedure Known to Man! I do think the above comments are correct and alot of the severe heat was the mixture and timing. It took me awhile to get it Right on, including another Carb.

If your sure your not too lean and your advance is in the ballpark, You might not need to change out for the Breakin? Im not sure of that though.

TopGunn

Vettster.......You mean your headers glowed red hot with the engine at idle??

AWilson

I had a different situation. I just did my break in with traditional chrome headers. My engine is hydraulic flat, no rollers. I asked the manufacturer this question too. He said they will definitely discolor. He said if I don't care for the discoloration that just do the break in 5 minutes at a time. Letting it completely cool down inbetween. This sounded reasonable and I was planning to do that. But once I started I just did the whole 20+ minutes. Discolored definitely but I don't mind.

Anyway, maybe this is an option for you so you can play it safe.

69vettester

It started up with a Roar wasnt a nice Idle But was supposed to be. Yes My hookers were glowing for 2-3 seconds then cooled and stopped glowing I shut it off as fast as I could and did a distrubuter adjustment. Im pretty sure it the problem was the Carb. It was a Brand new holley street avenger 670 that Had been sitting on my shelf for 4 yrs. Eventually, when it wouldnt tune I took it apart and saw the rubber Vac. advance was ruined. I Replaced the whole Carb , it was a Little small for My build anyway. I got it all dialed in with a new BG speed demon 750. The engines Runs Perfectly , Idles and comes Off the Line smoking rubber or on the Interstate at 80MPH under 3K rpms purring like a Kitten. Gas mileage around 15MPG and never a stutter in any range. A real Joy to drive. Anyway My initial over the glowing pipes turned out to no Damage.

PS I have a .62 overdrive gear.

TopGunn

Must have been too much fuel combined with maybe timing issues or something. Nice to hear a sucess story with BG, sounds like a real bear of an engine!