Ok, here's my question. I have a 69 COPO clone that is just about completed. It has all the correct 512 427ci block, 840 head, 163 intake and exhaust manifolds. I had the motor built with the L88 solid cam and I will need to run the engine for at least 15 minutes to properly break the came in. I have a local guy who does exhaust unbelievable and want to have him install the exhaust. I want to have the car running before taking it to him. One of my buddies told me that 15 minutes at 1800 rpm was too long to run on stock exhaust manifolds and could possibly damage the engine.

Is this true? I don't want to do anything that is going to cause problems. Anyone ever had this problem?

Kevin

Not sure why he would think running the car with stock manifolds would hurt the motor. I'm assuming you don't have an exhaust on it now, but it would be no worse than running with open headers. Personally, I'd never break in a new motor without some sort of exhaust on it, even cheap header mufflers. I say this because the motor will be so loud, you won't be able to tell if anything is wrong. BTW, I always vary the RPM above 2000 for 20 minutes on a new cam break-in. Fifteen minutes at 1800 rpm is not enough in my book. It's probably personal preferance, but I've never had a cam go flat on me. My .02 worth.

I want to have the car running before taking it to him. Kevin
Why? You can't drive it without exhaust, running open manifolds risk buring up the firewall paint. Tow it to the exhaust shop and tow it home. What's a $100 in tow fee's on a COPO Resto budget, 1/10 of 1%?

I guess your right, but the exhaust guy said that he doesn't want to have to push around on the car. Also he would like to have it running to see if there is any problems with leaks. I guess that there is also the curiosity of whether or not the statement that my buddy made is true.

you need exhaust to break in the cam!

find another exhaust guy or tell him he's doing it without it running!

and it takes 20-40 mins to break in a cam! not 15!

buy exhaust from gardner.......put it all on yourself......

Agreed, find another exhaust installer. If he wants to leak check, build him an adapter.

Go the home repair store and buy PVC piping/adapters and vinyl hose to fit over the tailpipes, smear petro jelly to lube. Fit the vinyl hose over the tailpipe with hose clamps, join the other end of the hose to a PVC tee/PVC tubing and hose clamp it. At the third outlet of the tee, reduce it down to fit you air compressor quick disconnect. Pressurize the system with 4-6 PSI of shop air and spray the bejesus on the joints with soapy water. Look for bubbles.

I agree completely with those who said not to first start a new engine without an exhaust system and mufflers. It's fun for sure, but I'd never do it. Lotsa things can go wrong and I'd much rather hear em before I see em!

Usually you break in a motor with some stock exhaust manifolds or beater headers, just because of all the extra heat generated by the motor during break in.

You must have an exhaust system on your engine before you run it! If you run the engine with no manifolds or manifolds with no pipes, you run the risk of warping many of your valves, usually exhaust, due to the rush of cold air back into the heads when you shut the engine down. You would not need a complete system, just manifolds and a few feet of pipe off the manifolds. Please listen to the more knowledgeable people on this forum and not your buddy that says the stock exhaust will mess something up.

Keith

how much was the exhaust guy going to charge? with labor and materials?

go here and do it yourself..

this is top notch!!

http://www.gardnerexhaust.com/soundclips.html

I called Gardner today and they wanted $750 for exhaust :eek:. That was way higher than the exhaust guy said. I believe that I may just order a kit from Ricks. It's about half that price. Any way, I have been conviced to install the exhaust first. Thanks for all the help!!!

I called Gardner today and they wanted $750 for exhaust :eek:. That was way higher than the exhaust guy said. I believe that I may just order a kit from Ricks. It's about half that price. Any way, I have been conviced to install the exhaust first. Thanks for all the help!!!

you will be pleased with the rick's set.......i have installed it on my friends 1969......