camshaft break-in

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abqphilbert

abqphilbert

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Does anybody out there have any experience to share regarding breaking-in new Comp Cams - or other brands? I've rebuilt a lot of engines, but almost all in European cars. Many of the European engines have had double valve springs. I've built a few American V-8s, but this is the first I've built with double valve springs. The car has been more that three years in progress, and I'm just about ready to fire it up, so-to-speak.
Comp Cams says I need to assemble the valve train with only the outer springs installed until I run-in the new parts per their instructions, and then install the inner springs. Seriously?
I have lots of time, love, and money in it, and if I really need to take this extra step, I'll do it, but this is something I've never heard of before. I've never had a camshaft fail out of (literally) hundreds of engine builds, but like I said, American V-8s are kind of foreign to me. Ha Ha!
For the record, this is a solid-lifter .468 lift, 318 LA motor. If anyone out there has used this kit from Comp Cams, I'd love to hear about it. Did you follow their instructions, or did you just build it and run it (like I'm tempted to do with this motor, and like I have with LOTS of European engines)? And what kind of results did you have?
Hope to hear from anyone on this.
Thanks.
Darts are cool!
 
We put a new comp cams 268h cam lifters and springs in dads 273, we THOUGHT it had dbl springs, but it turns out that it was just dampers on the inside of the springs. We were kinda lost with it...we called Compcams and told us they were not dbl springed, just dampers. I have heard/read that with dbl springs, the inners have to come out....
 
The biggest thing is not to let it idle. AT ALL for the first 15-20 minutes. You need to keep RPM up from 2500-4500 and vary it.
 
What springs with that cam? 901's are single with a damper....If 995's? i believe your best bet is to remove the inners. A lot of us old school guys have done break-in's with both, but these day's, while I may do it with a lot of additive, I couldn't recommend it with good conscience.
 
I asked a lot of the same question you did. And over and over people and Comp cam told me to take the springs out. So I did. Made sure everything was straight before start up because you don't want to have to shut it down half way though. I used a high zink oil plus comp cams break in additive. Fired it up, once it running ramped it to 3000rpms until it comes to operation temp 180+. I let it run for nearly 20-25 minutes like that. Than I shut it down. And put it away. Next day changed the oil and filter. Next I installed the inner springs. I purchased the right tool to use with shaft mount rockers. Cost me like $50, worth every penny. Swaping out the springs went so smoothly. Then it was ready to rock.
 
RustyRatRod said:
The biggest thing is not to let it idle. AT ALL for the first 15-20 minutes. You need to keep RPM up from 2500-4500 and vary it.
Click to expand...

^ This.

The idea is to get the high metal cam lube on the faces of those lifters and lobes to start spinning the lifters. When you decelerate for longer duration, like going from 4500 down to 2000 it unloads the engine and allows the cylinder tension to drop from being under load, back down to just spring and cyl. pressure. This allows the lifters to unload and allows them to spin.

All you are accomplishing is pattern and Rob's suggestion there is what makes this happen.
 
You can break in the camshaft with double springs, but it depends on the spring or seat pressure. I can't recall which one it was.
 
Comp has a solid lifter with a laser-drilled hole to oil the face of the lifter, you might ask them about it. As was said, make sure it starts up right away, and have the engine primed. Make sure it has at the distributor initial timing at least 10 btdc and run it for 20 minutes at 2500 rpm. I have never broken an engine in with the inner springs removed, haven't had cam issues at all. Been lucky, I guess. Comp can nitride a cam for around $120, just a little more insurance.
 
Coat the camshaft and the bottom of the lifter with the cam lube that came with the cam.

Make sure the engine oiling system has been primed and ready to pump oil...

make sure the distributor is installed correctly and is close enough to fire with in a few cranks..have timing light ready to set the timing ...

make sure you have a GOOD carb that is not going to dump raw gas down the intake manifold and foul the oil....make sure the carb has gas in the bowls and is ready to go..

have the cooling system full of water and does not leak....also have a hose with a sprayer ready to spray radiator if the engine begins to run hot.

as far as springs are concern...I have never removed the inner spring on dual springs....

and yes..get it fired and get the rpm up...dont let it idle...if you have problems..shut it off...

I use 10w-30 Mobil oil with Hughes Extreme Pressure Lube additive...

in the last 4 or 5 yrs I have done at least 6 flat tappet camshafts this way...have not had a problem.
 
I would listen to Comp. If they say remove the spring,remove the spring. If you wipe a lobe,you have nobody but yourself to blame.You certanily wont be the first person to do this,its pretty common practice.I would also use their break in oil.
Good luck !
 
Yes remove the inner springs if equipped. Do not let it idle for the first 20 minuets, keep the RPM above 2000. Use a break in oil such as http://www.summitracing.com/parts/cca-1590
Or as 70AARCuda mentioned an additive at the least. Make sure it fires right up, fuel primed, timing set, good charged up battery. Have your timing light ready to go, and set the total timing to 35* around 2500 RPM once fired up.
http://www.summitracing.com/parts/cca-1590
 
I had an engine biulder tell me to retard the timing once running to keep heat down . It seemed to make sense.. I was concerned about bluing my new dougs headers.
What do you guy think?
 
Retarding the timing does just the opposite. It puts heat into the exhaust.
 
mbaird said:
I had an engine biulder tell me to retard the timing once running to keep heat down . It seemed to make sense.. I was concerned about bluing my new dougs headers.
What do you guy think?
Click to expand...

No!!! Rusty is absolutely right.

I had a guy bring me a single axle dump to tune with a 366" BBC that he had put shorty headers on for a little more power.......It was a stone, and when I got back from the test drive, 4 inches of pipe off the heads were glowing red. He had set the initial timing at 8* ATDC instead of BTDC. It actually liked a little more then 8 BTDC, but I was cautious considering the load it may encounter.
 
Johnny Dart said:
I would listen to Comp. If they say remove the spring,remove the spring. If you wipe a lobe,you have nobody but yourself to blame.You certanily wont be the first person to do this,its pretty common practice.I would also use their break in oil.
Good luck !
Click to expand...
i agree with johnny on this remember if you wipe a lobe the whole engine has to come appart to clean that metalic **** out it would be easier to just follow comp cams instructions.
 
The only way oil gets to the lifter faces is being tossed off the rotating assembly. That's why i's imperative that the new engine fire immediately, and that you preoil, and that it not be allowed to idle. At idle there's not enough oil volume to"fling" off and get the cam suitably covered. Also in terms of lifter rotation - this should be checked as part of the assembly process. As long as the cam is turning, the lifters should rotate. If they dont you will eat the cam in short order so it's not an rpm based thing. Turning the engine by hand the lifters rotate.
If you have true dual springs - meaning an inner round-wire spring plus an outer round wre spring with a flat wound dampener between them, you have to pull the inners for cam break in. If they are just single round wire spring with the flat wound dampener you break in the cam with the springs "as-is".
 
moper, just throwin this out there......what do you think of the EMD lifters and how do you think they impact break in?
 
Thanks to everyone for your input. Well, I learned a ton. Most important I think, is that it seems I do not have double springs after all, but outers, with dampers. The inner part is coiled like a spring, but flat - not a round coiled wire spring. I did get the special cam lube from Comp and I have the break-in oil from Comp as well. I'm thinking I'll fire it up in the next couple of weeks and run it. I'll post the results on this thread when I get it going.
After I got the car out of the body & paint shop (Maurer's Collision, Albuquerque, New Mexico), I moved it to a storage unit to reassemble it. The chassis is all built, engine & tranny are in, cooling system and fuel system are done. I have to buy an alternator & a battery, then move the car out of the storage unit to a friend's shop, so I have access to running water, compressed air, etc.
Thanks again to All.
 
Well - I haven't used them and i've never had a cam failure that wasn't due to my own stupidity or an overlooked step. I stay away from high spring pressures because I build street engines. That's what will kill the cam. If I need to run a large cam, and it needs a big spring, I'd use the EDMs.
As far as do I believe they help? Yes - I'm sure they do in those special cases where extreme fast rates of lift mandate heavy springs with a flat tappet. Examples of these would be the SQ, -12 & -13, or XX Comp lobes. We're talking pretty ragged before I'd worry about using them. Imports have been using EDM holes in the valvetrains for years because they work. But that being said I'd bet the farm that the vast, vast majority of mopar cam failures has everything to do with assembly/builder/first start/oil issues rather than the camshaft design or lifters.
 
Correct - you have single springs. That's why I figured I'd describe them to you... :)
 
Right. I was just wonderin what you thought. Thanks. I have them for my 383 build. I didn't intentionally plan on them. A friend found them on clearance about a year ago. They are the Howards brand. I got them for 89 bucks. lol


moper said:
Well - I haven't used them and i've never had a cam failure that wasn't due to my own stupidity or an overlooked step. I stay away from high spring pressures because I build street engines. That's what will kill the cam. If I need to run a large cam, and it needs a big spring, I'd use the EDMs.
As far as do I believe they help? Yes - I'm sure they do in those special cases where extreme fast rates of lift mandate heavy springs with a flat tappet. Examples of these would be the SQ, -12 & -13, or XX Comp lobes. We're talking pretty ragged before I'd worry about using them. Imports have been using EDM holes in the valvetrains for years because they work. But that being said I'd bet the farm that the vast, vast majority of mopar cam failures has everything to do with assembly/builder/first start/oil issues rather than the camshaft design or lifters.
Click to expand...
 
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