new camshaft installation question

when installing a new flat tappet cam, all the emphasis is put on the lube on the cam lobes, to the point that some say if the engine doesn't fire immediately and come up to the correct rpm you'll waste the cam.

so if it has to crank over too many times before it starts, all the lube is wiped off of the lobes and it's done.

but what about assembly? so lube is put liberally on the lobes, but even as you initially adjust the valves it is going to to turned over multiple times. even if you only put the lifters in as you do that particular valve, the ones put in first are going to have made a number of revolutions.

then still you want to turn it over as you are pre-oiling it, so there are a few more revolutions.

it just doesn't make much sense that so much emphasis is put on that lube being there, when it seems that a good deal of it will be wiped off most of the lobes by the time it finally fires.

Its important, but don't drive yourself insane. Its not automatic failure. What I do is lube the lifters and cam, assemble, set everything up, and put the intake on last. Before it goes on I dump more on the cam/lifters. That stuff comp sells now is weird, amazing it works I call it BBQ sauce. Its runny/low viscocity which doesnt help.

Anyway, prefil your carb bowls, ballpark your timing. When you assemble make sure the liftters spin free in their bores, and once assembled make sure they spin as you turn the engine over (they spin slowly). The goal is to hit the key, get it running, and up over 2k rpm. Ut I've had friends do goofy stuff and not wipe lobes. One turned his engine over probably 200 times with the starter trying to build oil pressure, one let it idle at like 600 rpm for what seemed like an eternity, was probably only about a minute. Then he wanted to stop after 20 minutes instead of 30... Their stuff has been fine. My last one I started up, got the revs up, had to shut down, restarted, revs up, had to shut down AGAIN, this is the first 2 minutes on a fresh engine. But just kill it, restart, revs back up right away, no problems. Use the break in oil and don't do anything dumb and you'll be ok!

Put the intake on last, after the valves are adjusted and hopefully the motor doesn't need to be turned anymore. Add more lube to the lobes, then install the intake. I don't think it's THAT critical, but I figure every bit of precaution is worth the effort. Of course I try not to use a flat tappet cam in anything anymore.

why don't you use a drill to prime the engine instead of the starter?



Joe

It is one of those "in a perfect world" scenario's ?
Invariably, yes... the lube wipes off with just residual left behind, which is hopefully enough until it gets running and splash lube, etc., can take over.
just me,
but IMO, V/Spring pressure is what kills Flat tappet Cam run-ins more than the EP additives.
And keeping it well below 300#,(260-280# if you can) over the nose for run-in goes a long way to insuring a patent lobe establishment.... then AFTER break-in.... re-install inners ? whatever ? back to running V/Spring pressure.
If no inners to remove.... low ratio rockers for run-in ? +.060" retainers and leave the Spring shims out ? ANYTHING to get it DOWN !

Which type of cam lube are you using? The greasy moly black paste or the liquid red stuff? Bottom line is make sure and add a can of ZDDP zinc additive and make the motor start up quickly, no grinding on the starter for 2 or more mintues and rev the motor up right away above 1500 RPM

I always put the intake on last when the eng is in the car ready to fire. You can see in this pic when I put my last eng in that I leave the intake off and then lube the cam lobes up and then put the intake on and fire the eng as I already have all the valves adjusted and the timing set before I do the last lubing of the cam lobes and install the intake. It gives me peace of mind and I have never had a lobe wipe on me. Ron

thanks for the thoughts everyone. that is pretty much what i assumed, although i've heard some pretty extreme ideas on this, like if it doesn't fire immediately you're screwed.

off she goes!

The cam I am installing this week will be my last flat tappet. The 512 I build next will be roller off the top.

I adj the valves then remove the rocker arm assys & lube the cam then reinstall em as they will not change adj just from a R&R. preoil with the drill with #8 piston at TDC (BB I'm assuming) then hand turn the dampener CW 3/4 of a turn till dampener marks line up at TDC & preoil #6. backup the dampener slightly to ~15 BTDC & line up dist magnet with the tooth that places the rotor under the #6 cap terminal. Do all of the std caveats; bowls filled/batt charged/inner spring out/thermostat out/fan in front of rad/several helpers, one on top to man the light to power time the dist when it fires (to 40 or so deg). one to spot leaks. you in dr seat to watch gauges/shout orders/gun the eng. any issue dont think about it just shut it down IMMEDIATELY then fix the issue then restart. read "breakin secrets" at www.mototuneusa.com As said good breakin oil. You have ONE shot to get an excellent cam and ring seal on breakin day that will produce good power for years as opposed to one that has an earlier demise (& less power) & all the time you thinking you did a good job. You have thousands of dollars invested plus your time. EDIT on mockup do the Hughes "thunk" test with the lifters (they must be free to rotate)