Technical Here We Go Again - Cam Break-In

I just fired up a 305 SBC today that I just rebuilt. The cooling system of my "run stand" leaves a lot to be desired and I could only run the engine at 2500+ for about 5 to 7 minutes before the temp went over 200 and I shut it down. I did another 5 minute run after a cool down, again keeping the RPM up around 2500.

For break in I used RedLine assembly lube on all bearings, cam (new Elgin cam), lifters and rockers. Oil for break-in is Rotella 15W40 with a 16 Oz. bottle of RedLine break-in additive. I really hated to shut the engine down before running about 20 minutes without stopping, but thought overheating was an even bigger risk.

I plan to do another couple runs again tomorrow, as abbreviated as they might be, to get a total of about 20 minutes in, but just wondered if some well-experienced engine guys think I might be past the critical point at least on cam break-in? I guess only additional run time will tell, but the oil is still clean as a whistle and the engine sounded great.

Thanks, in advance, for your input.

Lynn

 

Every time you start it it will take a certain amount of time to establish a hydrodynamic lubrication film, while that film is developing wear will occur. When you start it once and run for 20 minutes it only has to go through that period one time. The way you're doing it, it has to go through it every time you start it up. I can't say it won't work this way, but it's obviously not ideal. I would get a radiator and fan on that run stand.

 

Check this out.....and for the love of God....they make break in oil...use it...not a rotella concoction...I don’t get that...every Cam mfg. recommends a break in oil...and people wanna use diesel oil...

Also Try running it at 2000 RPM...might keep it cooler..

 

My cam man. actually recommended Rotella as an option

 

Was it a Diesel haha…I get “people do it” but a good break in oil takes all the guess work out of it and it’s one less thing to worry about during the whole process..

 

Since I posted my questions I found a Comp Cam video (don't know how old it is) that suggests 3 - 10 minute intervals at 2500-ish RPM with time to cool down between them. Based on that procedure I almost followed directions. I guess in the end I'll either have caused a problem or not.

Lynn

 

Can you spay down the radiator to help keep them under control.
I always have the garden hose with a spay nozzle at ready when I break in a cam.

 

Yeah, exactly this is what I´m usually doing when breaking in a new engine.

 

I use a crap load of Moly Lube on the cam and lifters, and cheap oil from Walmart. Still works for me, last time was in November. had a similar thing happen to me breaking in another cam. After I replaced the thermostat I ran it for 30 minutes and didn't have a problem

 

Moly lube ( isky rev,-lube) + Lucas break in oil

 

You’ll be fine Lynn,,,,,don’t give it another thought .
There are no hard and fast rules on this subject,,,,,,,many different ways to come to the same result .

Tommy

 

I coat the cam liberally in Moly grease, to the point you can not see the cam itself.
After priming the oil system I run at about 2500rpm for a total of 20-25 minutes, 2, 3, 4 periods as long as it is about 20-25 minutes, I am sure it could be less. Once run in you can play with timing and carb tuning and see how it responds.
As long as the cam is burnished you will get many years out of it.

The Moly grease ends up diluting with the engine oil over time adding extra protection.
On the mains, rod and cam bearings I use a 50/50 mixture of STP friction modifier and dino oil, this helps with initial start up and again some protection over time.

 

Yep, Desoto speaks the truth. I have been doing cams since 1962, and have never had one go flat during break-in.
I started when there was no "gospel" to follow. Lube it up well, get it started, set the carb and timing and
run it. Many times I had to shut it down due to water, gas or oil leaks, with no problems with the cam.

Just installed my last cam last year. Used a high zinc oil, plus ZDDP zinc additive and no issues. We all
worry about the same thing you do. It's normal and I'm sure you'll be fine. Bob

 

It will probably be fine. But you should strive to make sure the car can keep running and be cool for the break in. My engine builder said Valvoline VR1 10w-30, so I did. Added a bottle of Comp Cams additive. I've used large box fans in front of the radiator and that really keeps the engine happy.

I have done probably 40 or 50 FT cams in the past, more than a few on stock cars. Break it in... last minute on race day sometimes... and head for the track. Never lost a cam. Back in the day, a smart parts counter guy threw you a tube of cam lube when you bought a cam. Lots of guys used STP or some moly grease.

 

If you read the directions that comes from Hughes cams, they tell you to do it in 10 min intervals, with varying rpm. I believe you will be fine. I agree on the break in oil.

Tony

 

I heard a story of one of our old local racers putting a motor together the night before a race..pushed the car on the trailer, fired it up, set the accelerator cable, and drove the 30 minutes to the track, shut the car off, changed the oil, checked timing, adjusted the carb, and ran at the track

And this was when we still had good oil…

I can’t verify the story…but it sure sounds cool haha

 

I'd be willing to bet that Isky Rev Lube is nothing more than a good quality EP Moly grease, and they use it 'till this day. Nothing fancy, but it works.

 

I used to know an old Super Stock racer,,,,,,had a 283,,,, in a wagon .
I asked about his break in procedure,,,,,he laughed .
Said,,,,,,,when I get it to the track,,,,,,I fire it,,,,,do my burnout ,,,,and run,,,,,,then it’s broken in !
This was one of those screaming small block Chevy engines .
Won several races too,,,,,had the front wheels in the air in several photos on the wall .

Tommy

 

Nope not a diesel, a y block. The cam manufacturer gave 3 recommendations for oil to run with their cam, the Rotella 10-30 is the only one readily available to me locally, so that’s what I m using. For the break in I used moly grease and added a quart of zddp

 

So tell us, what is it about this "Break In Oil" that makes it special for running in a cam? Can you say, or are you just repeating what the marketing people tell you?

 

I just like to make things simple…if a cam manufacturer tells me it’s what they recommend to break in their product, I’ll take their advice..all the good stuffs in it…



So I would think second best option would be use a high quality motor oil and get some ZDDP and add it in prior to break in…

And if Rotella floats your boat with some break in lube added to it…have at it

Last motor a friend built used some off the shelf oil, fired it up, ran it for 20 minutes and called it good…

lots of ways to skin a cat I guess…

 

I also agree that you are fine with your procedure. The main thing about the 2500-ish rpm is to get some good oil splash around inside the engine for extra lube on the cam and lifter face. The extra rpm is also good to facilitate lifter rotation, as that is important for break in and also long term reliability. If a flat tappet stops rotating, it will kill a cam lobe and lifter face. The 20 minutes was probably plenty good for the break in, although some extra time won't hurt at all. When you do finally get it idling, just increase the throttle occasionally to help spread some of that oil splash. But realistically the prior 2500 rpm break in has done it's thing by then.

Using the moly cam lube during installation on the lobes and lifter face is to help with intial wear-in. It is gone quickly and then the ZDDP and other wear additives do their work.

 

OK, not trying to pick on you, but really you just posted marketing copy from somebody that is partially correct. If I was a social media fact checker I would slather some kind of "Missing Context" or "Partially True" banner on it. It's a simplified explanation intended for a non-technical consumer, but it's also marketing copy intended to sell a product.

 

Like I said…many ways to skin a cat…I’ll keep it simple and use a break in oil..

 

I think the OP thought he was keeping it simple too by using a diesel engine oil....

 

You should be just fine with what you are doing for the little chevy.

 

And right there is what I believe this whole shebang is about. Oil splash and lifter rotation. I'm nobody, but I have smart friends, and they have said this many times. Use a good product, good lubrication, make sure assembly is clean, and your lifters should drop in and spin on assembly.

 

Reminds me: one of my first times at the track, went with a group of guys, only knew one if them. Guy pulls up with the group has a nasty Falcon. He and a friend start tearing the engine apart. Slide In a New cam, get it on jack stands and run it - Screaming RPM - in Gear - for a few min to get everything up to temp, hit the staging lanes. Pulled the front wheels on first pass, adjusted suspension, quick tune, and clicked off passes all day.
Made me rethink a few things. But I still use plenty of lube and follow break in procedure

 

I like to pre-oil a new build or even will do that on engines that have sat for a while. That helps a new FT cam stay alive. Making sure lifters turn in their bores (before the cam goes in) is wise. Good machine shops will check this and clean up bores that are gummy or tight.

 

If the machine shop is doing the engine assembly , the machine shop can do the engine break in ( or be responsible for the first 1000 miles) Too many fingers spoil the pot !