The Stovebolt Site Forums The Shop Area Engine Shop Cam Survival Hints?

Well, I'm down to the last couple of items on my short list before firing up the SBC in my 56. I went through the engine a while back and installed a new cam, valve seals, lifters, springs, pushrods, etc. Everything looks to be a go, but this is the first time I have ever started an engine with a fresh cam. I sure don't want to ruin it right out of the box. I read that I should not crank it more than 30 seconds without starting, that the timing should be set already, and to run it above 2000 rpm for 20 minutes with an occasional blip to 3000. That all sounds good, but how do I "already have the timing set?" I'm close I know, but without it running, how do I know. I've installed several engines over the years and I have always had some unexpected issues that prevented a quick start. Will cranking for more than 30 seconds really destroy my cam? I used plenty of assembly lube and have primed the oil pump with a drill. Oil filter is full.

Cam is a Summit 1102. Any hints from you experts out there. I'm anxious to get this puppy running. Just got it titled, insured and registered (thanks Broadway!). I'm ready to put it on the road. Just don't want to screw it up now! Thanks!

You might want to think very hard about your choice of oil. There was a flurry of posts several weeks ago about the lack of zinc and other stuff in modern high quality oils. I and my hot rod buddies has changed to a high quality diesel oil with still has the zinc to protect the cam/lifter interface.

if you set the distr. at #1 at TDC ...ya should not have crank that ol gal very much for her to breath fire , double check your fuel delivery an GO FOR IT.
It all part a the fun ! ...if you lubed the top end like ya said you wont have any probs ...heck i had a HD ..OLD HD engine run for over a minute after a fresh rebuild that wasnt gettin oil due to a chunk a crap in the return ....it ran figured out prob an it stil runs just fine

Use Shell Rotella for break in. If you want peace of mind ad some EON (from General Motors).

Frank

CD2 Street Legal High Performance Oil Booster has the same active ingredients (ZDDP) as the EON and is a lot less expensive. Check a Big Lots store.

OK, the oil gurus have spoken, and I agree. I've used 15W40 diesel-rated oil in everything I run, including the lawn mower, for several years. No problems yet!

Now, for the "why" of breaking in a cam above idle speed. Virtually everything inside the engine except the cam runs with at least some clearance between the parts. The cam/lifter relationship is a scuffing motion that requires a high film strength oil, and lots of it, especially during the critical break-in period when the cam lobes and lifters are establishing a running fit. The idea behind breaking in at high speed is so the oil slinging off the connecting rods and crankshaft will keep the cam flooded with lots of oil. As soon as you see the oil pressure come up, pick up the speed and hold it, no idling at all if possible. Run the engine at a constant speed of 2,000 RPM for 20 minutes or so, and don't worry about blipping the throttle. Make sure the cooling system is FULL, no trapped air. I've had a couple of cooling system gushers during a break-in run due to not gertting the cooling system full enough before startup. Once the wear pattern is established, idling won't damage the cam lobes.

I like to static time the engine by bringing the timing marks into alignment with the distributor rotor pointed toward the #1 plug tower, then turning the distributor housing in the direction of distributor rotation until the points close, then turning the housing opposite rotation until the points just break. That will get the ignition timing set within a couple of degrees of the correct setting. If you have a 12 volt test light, connect the light from the distributor side of the coil to ground. With the ignition switch turned on, the light will go out as the points close, and light up as soon as you turn the distributor far enough in the advance direction to open the points. That's a litle more accurate than just eyeballing the point opening.
Jerry

Clint;
Just did this on my 261 rebuild. Used GM's EOS supplement (not EON) during the rebuild and then poured the rest into the crankcase. I used straight 30wt Valvoline during the start-up after checking it's zinc properties on the web. Also put in some LucasOil as an additive. Like SW and Hotrod said, don't be scared and don't second guess yourself. If the static timing is good, valves adjusted close, all fluids good and plugs wires correct, get it and let it fly! I cranked mine about three times for 15 to 20 secs each time until the carbs were full and she started right up! Kinda of scary listening to that thing running at that RPM right out of the gate but it does work. Make sure you have some cold Coronas to celebrate when you shut her down. Good luck!

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