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Camshaft running in

Posted: Mon Feb 16, 2015 1:06 pm
by PDB
With all the excitement of getting my car up and running I've totally forgotten about running the cams in.

They are Poncam's which I bought new from the states and get them shipped over.

Advise please, hope I've not buggered them ? They still look fine. Had engine running for varying periods in my garage, and have driven the car about 10miles.

Re: Camshaft running in

Posted: Mon Feb 16, 2015 2:23 pm
by jondee86
General procedure with new cams is to apply a generous coating of
assembly lube to the shims, cam lobes and journals. Make sure the
engine is ready to start and run on the first crank, and fire it up.
Immediately raise the engine speed and keep it spinning in the
2000-3000rpm range for ten minutes by varying the throttle. Do
not let the engine idle... you want to get a good oil supply up to the
cams ASAP and ensure that the buckets rotate during the initial
break-in period.

After ten minutes, your engine is fully warmed up and you have
checked for leaks or unusual noises. Job done... go for a drive :)

Cheers... jondee86

PS: If tips of the lobes are clear of any scoring, scratching or other
wear marks, you don't have a problem.

Re: Camshaft running in

Posted: Mon Feb 16, 2015 2:45 pm
by oldeskewltoy
jondee86 wrote:General procedure with new cams is to apply a generous coating of
assembly lube to the shims, cam lobes and journals. Make sure the
engine is ready to start and run on the first crank, and fire it up.
Immediately raise the engine speed and keep it spinning in the
2000-3000rpm range for ten minutes by varying the throttle. Do
not let the engine idle... you want to get a good oil supply up to the
cams ASAP and ensure that the buckets rotate during the initial
break-in period.

After ten minutes, your engine is fully warmed up and you have
checked for leaks or unusual noises. Job done... go for a drive :)

Cheers... jondee86

PS: If tips of the lobes are clear of any scoring, scratching or other
wear marks, you don't have a problem.



this.... ;)

Re: Camshaft running in

Posted: Mon Feb 16, 2015 8:24 pm
by allencr
Are the shims finished on both sides? I so, then use the unused side for the new lobes.
NFG SORRY... They all NEED lube but since the 4ag has a direct source for it drilled into the lobe, it should get all the lube it needs at any RPM, unlike a non-OHC engine that only gets lubed by the stuff flung from the crank..
They all NEED lube, the 4ag keeps a little puddle around each one so it's sorta immersed if pre-filled during assembly and gets what it needs, unlike a yada yada...
The cam assembly lube/moly grease is great stuff, use it, and break-in is just driving it, nothing else. There is always the same load on the cams whether driving or not, only difference is the RPM. They are going to live a long life or die soon depending on their first minute or less of running, so since you are absolutely going to check the lash pretty soon, you'll know that they're OK.
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THANKS jondee!

Re: Camshaft running in

Posted: Mon Feb 16, 2015 9:53 pm
by jondee86
allencr wrote:They all NEED lube but since the 4ag has a direct source for it drilled into
the lobe, it should get all the lube it needs at any RPM,

I assume that you meant to say "cam" instead of "lobe" ? As the
rifle-drilled camshafts only deliver oil directly to the cam journals,
not to the lobes. The lobes are lubricated by whatever oil gets
flung around by the spinning camshafts.

Cheers... jondee86

Re: Camshaft running in

Posted: Tue Feb 17, 2015 8:39 am
by oldeskewltoy
jondee86 wrote:
allencr wrote:They all NEED lube but since the 4ag has a direct source for it drilled into
the lobe, it should get all the lube it needs at any RPM,

I assume that you meant to say "cam" instead of "lobe" ? As the
rifle-drilled camshafts only deliver oil directly to the cam journals,
not to the lobes. The lobes are lubricated by whatever oil gets
flung around by the spinning camshafts.

Cheers... jondee86


this is correct except for BIG cams(READ RACE ONLY)....

Image

Re: Camshaft running in

Posted: Tue Feb 17, 2015 12:53 pm
by jondee86
That ^^^^ would be a good reason for having a restrictor in the
oil flow to the head. And possibly fitting shells in the cam caps,
although I can't make that out in the pic.

Cheers... jondee86

Re: Camshaft running in

Posted: Tue Feb 17, 2015 2:33 pm
by yoshimitsuspeed
I'm sure this will be an ongoing source for debate.
The most important thing is to stick to the manufacturers break in procedure.
Tomei doesn't have a strict procedure though. They suggest not bouncing off the rev limiter on the first run down the driveway. That's about it.
I would definitely stress making sure they are well lubricated on installation and that you don't let it idle on first start up. I would at least get it reving a bit then take it out for your test drive. If you have new pistons IMO their break in will be much more important.

Toda recommends using the break in that is in the FSM.
I have never seen a new cam break in procedure for stock cams but traditionally out of the factory motors do not get any significant break in. They might be started long enough to get oil flowing and prove everything works. After that they are put on the showroom floor where they will go through any number of break ins from people test driving them. Anywhere from grandmas idling around the parking lot to people bouncing off the rev limiter more often than not.

Kelford is one that recommends the more traditional break in procedure. I am trying to get more information on exactly why. I'm not sure I exactly agree with it or believe in it but if I was breaking in a Kelford cam I would use it just so that if anything happened I could say that I used their procedure.
http://www.kelford.co.nz/flat-tappet-cam-break-in

Their article stresses new lifters must be installed with the new cams but they told me that this isn't vital and as long as the cam follower surface appears okay it can be used again with a light polishing. It is however vital that all clearances are checked and reshimmed as needed.