oil for camshaft break in

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something went wrong with the engine in my plow truck so I found a low mileage replacement in the form of a 1990 305 from a c1500.

not being sure that the little 305 is up to the task of pushing snow and counter balance weight in a 3/4 ton truck, I've decided to put a bigger cam in the engine in hopes of bolstering performance all around. the nice thing about this is that the factory cam is SOOOO small, that it doesn't take much of a cam at all to increase performance through out the entire range.

FWIW, the cam I've chosen is a single pattern 204°/204° @ 0.050" lift (260°/260° advertised) and has 0.427" lift on intake and exhaust. this is a flat tappet engine. new lifters and appropriate springs are also part of the upgrade. this is still a small cam by just about anyone standards.

so, what do I use to break in the new camshaft at start up?

I've seen several break in oils available, but most of them are being advertised as containing no friction modifiers to aide in break-in. this makes sense for a full rebuild (not sure that I agree, but I it makes some sense), but for an engine that is all ready broken in except for the cam, I'm not sure that a oil without friction modifiers is really that good of an idea.

I'd prefer to buy the right oil, vs putting in an additive if at all possible.

the long term plan is to run it on a ZDDP rich oil for the remainder of my ownership.

any suggestions on specific oils to use?
 
You didn't mention any cam break in lube. You should certainly use that on the cam and lifters.
Also, make sure to get the engine fired and running quickly. If you end up with lots of cranking, you'll wipe all the lube off before the splash oiling starts.

I haven't done any flat tappet engines since they changed the oil but anything with zinc added should serve you well.
 
Try a google search for break in for flat tappet cam .

I looked this up once , but can not remember the result . Forgot about it when it was pointed out to me that my 1991 305 Chevy engine had roller lifters .

Best of luck , :)
 
88862586 - GM Engine Oil Supplement, Lucas #10063, Comp Cams #159 etc. Race only, or older high zinc/ZDDP oils work best, but a high zinc additive will suffice. Many flat tappet cams come with assembly lube (like a moly/zinc paste) that you rub into the lobes/coat lifter bases with. Keep your RPM around 2K for the first 10-15 minutes of break in.

Breaking in a cam with those specs is a relatively low risk affair.
 
Just did the cam break in on my Toyota pickup along with a new cylinder head. I lubed it up real good with Permatex Ultra Slick engine assembly lube. Cam looked really good after 150 miles when I went in to adjust the valves hot.

I used Ford Motorcraft 10W-30 diesel oil available at Walmart in five quart jugs. Would have used the Rotella 10W-30, but they don't stock it. I needed almost five quarts, so buying a gallon jug plus one quart would have been about the same price. PQIA just tested the Motorcraft oil too.

http://pqiadata.org/Ford_Motorcraft__SDF_10W30.html
 
I did a simple cam swap in my Suburban's 350 2 1/2 years and about 4,000? miles ago, and used VWB with Lucas' high-zinc break-in additive. So far the engine purrs like a kitten. Just make sure to get the RPM's up and keep them there (I've heard 2,000 for 20 mins.) ASAP. Probably change the oil after about 500 mi., I'd say stick with a high zinc oil or additive the first time around, then assume your regular OCI and don't be too worried about any extra zinc additive thereafter. I've seen plenty of evidence that with a calm cam it isn't necessary after break-in.
 
Also, the cam you're using doesn't require a ton of spring pressure. It shouldn't be too much of a break in.
 
Originally Posted By: meborder
the cam I've chosen


You should let the cam manufacturer choose the cam. Speaking from experience.

To answer your question: Slather up the cam and lifters with assembly lube and break in with SAE 30.
 
Originally Posted By: NYEngineer
Also, the cam you're using doesn't require a ton of spring pressure. It shouldn't be too much of a break in.


This.

We aren't talking about a Lunatti Voodoo here.
 
Originally Posted By: Merkava_4
Originally Posted By: meborder
the cam I've chosen


You should let the cam manufacturer choose the cam. Speaking from experience.

To answer your question: Slather up the cam and lifters with assembly lube and break in with SAE 30.


I will generously use the cam lube provided. I also bought some from CRC, so I can use either.

As to cam choice, it is a summit branded cam and I did get their input. They couldn't offer a better choice and said that this the one they would have recommended. I didn't go in blind.

I called Howard's and Lunati as well. Howard's recommended one with 204/214 split which I really wanted but it was a lot more money and several more weeks to get it. Lunati recommended a 284/284 from their bracket master line, which sounded like WAY too much cam for a 305 in a truck.


Originally Posted By: OVERKILL
Originally Posted By: NYEngineer
Also, the cam you're using doesn't require a ton of spring pressure. It shouldn't be too much of a break in.


This.

We aren't talking about a Lunatti Voodoo here.


Not quite as aggressive as the voodoo, but probably more aggressive than Lunati's bracket master line. About in line with comp's high energy line of cam, but not as much as their extreme energy. The ramp profiles on this cam are some of the more aggressive ones that summit offers, which is why I chose this one over others. It has more lift than most cams in the low 200's and the single pattern so work well with the 165/140 I/E the heads flow, or at least that was my reasoning.
 
The last 4 engines that I've built or done camshaft swaps on all had really mild cams just like yours. All of them I broke in on Wal-Mart Super Tech 15w40 diesel oil. All of those engines are alive and well with one even being used in an air boat (454). It's reasonably priced and has a nice dose of zinc for break in on a flat tappet camshaft. Good luck with your car swap. Report back how it goes.
 
Originally Posted By: bioburner
I may be wrong but most breakins are for the piston and rings not the cam and valve train


Not on a flat tappet engine.

You want a high zinc oil, a light coating of moly paste on the cam lobes, and you want to run it at 2000 minimum with variance rpm for 20 minutes, no idle. There was a article posted that described 2 10 minute breakin periods with a cool down in between, again no idling.

Lower spring pressure should have less risk, but i'd still not take the chance, break it in right.
 
Last edited:
Originally Posted By: spasm3
Originally Posted By: bioburner
I may be wrong but most breakins are for the piston and rings not the cam and valve train


Not on a flat tappet engine.

You want a high zinc oil, a light coating of moly paste on the cam lobes, and you want to run it at 2000 minimum with variance rpm for 20 minutes, no idle. There was a article posted that described 2 10 minute breakin periods with a cool down in between, again no idling.

Lower spring pressure should have less risk, but i'd still not take the chance, break it in right.


Yes, it would be great if you could break in the pistons and rings, and cam separately, as they have vastly different leeds...what the cam needs isn't that great for rings and pistons.
 
The cam you described is just slightly hotter than the 305 H.O. cam (L69). I doubt Chevrolet did anything different with that engine compared to the "stock" engines concerning break in. That said, your plan of moly paste on the lobes and using a 'diesel' oil sounds solid.
 
MY 2c worth... make sure when you fire it up and your'e doing the bed in on the cam and lifters that the pushrods are "spinning" slowly, or you will wipe out that lobe and lifter pretty quick.. Sometimes it just takes a turn on the pushrod tube with your fingers to get it going...and always use a moly paste cam lube on a new cam & lifters..
 
Originally Posted By: bioburner
I may be wrong but most breakins are for the piston and rings not the cam and valve train


Fudge the cam break-in, and you'll lose it for sure
 
With respect to the mention of racing lubes, there's one problem with that. They are highly friction modified. One might be best to stick with a dedicated break in oil, particularly if you're going to spend the money on something other than an ordinary oil.
 
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