time to fire big block.

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derek fletcher

derek fletcher

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I purchased this big block from a good ol boy from Fort Mojave NV while buying my 67 dart.


After I.D. ing cam I discovered that the cam bearing oiling orientation is far from concentric.
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my big concern is the 4# journal that oils the valvetrain seems to be the worse of the bunch. (second photo).

This engine is a freshened 383 915 heads isky rockers with crane F-284 mechanical (solid) lifter camshaft heads installed the bottom end is unknown but spins freely.

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this will be my first engine build/ break-in and any input would be appreciated.

Thank you.
derek
 
If those are the worst you've ever seen, you ain't seen a lot of um. I've seen worse than that right from the factory. They're fine. Run it.
 
thanks will button up valvetrain.
what is a good initial lash for start up?
Factory says .028/.032 at operating temp.

Was thinking about robbing a proven thremoquad/distributor/ecu out of my 73 winne brave 440 ci to do the break-in.
any foreseen problems?

Plugs?

break-in oil? vr1, rottela, plus and additive?

thanks, and will be back shortly
 
If that cam is very big it won't have much vacuum and a Carter needs vacuum to keep the metering rod pistons pulled down. It will be rich, or what you want on a breakin.

The Cam bearing is normal. There are 3 oil holes in #4 bearing. The bearing holes don't all line up,with the block holes so it's a compromise installing #4. Get a mirror and look at the upper part of that one, the other 2 oil holes are perpendicular to the deck surface.
 
O.K.

Is this what they would call a moderate cam?

F-284 mechanical (solid) lifter Crane camshaft from the late 1960's. It's a single pattern camshaft with 284 degrees advertised duration, and 241 degrees duration at .050" tappet lift. Lobe lift is .302", gross valve lift with 1.5:1 rocker arms is .453". Lobe separation is 112.5 degrees. Recommended valve lash at operating temperature is .028" intake, .032" exhaust. This should have a fair idle, with a basic rated RPM range from 2600 to 6000 RPM.
 
I have a 4150 holley 750 with electric choke and mechanical seconds. but am not familiar with them.

It will have to be gone thru.
 
A 440 distributor will not directly bolt into a 383 unless you have a spacer, it’s longer.
 
ALL carbs need vacuum to operate [ post #5 ].

Because of the large lash & wide LSA, that cam in a 440 should idle reasonably well with some lope. Crane normally ground 5* of advance into their cams, so if the machining is correct, the ICL would be 107*. If you want to do a rough check on the cam timing, get either #1 or #6 cyls on overlap at TDC [ exh closing/int opening ]. The intake lifter should be 0.005-0.020" higher than the exh.
Set the lash cold. I never found a worthwhile difference between hot & cold lash on all iron big blocks.
 
derek fletcher said:
O.K.

Is this what they would call a moderate cam?

F-284 mechanical (solid) lifter Crane camshaft from the late 1960's. It's a single pattern camshaft with 284 degrees advertised duration, and 241 degrees duration at .050" tappet lift. Lobe lift is .302", gross valve lift with 1.5:1 rocker arms is .453". Lobe separation is 112.5 degrees. Recommended valve lash at operating temperature is .028" intake, .032" exhaust. This should have a fair idle, with a basic rated RPM range from 2600 to 6000 RPM.
Click to expand...
I'd set the valves at .026 and .30 cold and let it rip. Degree the cam.
 
I would defiantly degree your cam. Remember what you have said that this camshaft was made back in the late 1960's. Now this cam is probably perfect but you might as well be sure it is where you want it to be. There was no CNC machines yet back then.
 
Don't cheap out on oil, buy Brad Penn (or whatever their new name is) or even Comp Cam break in oil (mineral), I was led to believe it has a higher amount of ZDDP than say VR1 and the like. Ignore any posts that say you should breakin with Synthetic ;)

I used 10w30 Comp break in oil and my cam made it through
 
Pull the heater hose/ fitting below the T stat to be sure you fill it without airlock.

Be sure to get the timing right, do you know how to do that and sure to get the dist on the firing stroke for no.1?

With a flat tappet cam, you want to be able to get right up to cam break in RPM without screwing around with other engine problems

Remember that the dist rotates CCW in a B/RB. If you prime the oiling system, I always start with the filter removed, and a can below the filter mount. Pump should prime in 1-2 or maybe 3 seconds on a drill. Be sure to rotate the engine so the cam oiling holes to the rockers line up
 
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