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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20241204_115554.jpg
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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.
 
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