If you built a 2056 Options

[Geezer914]

I just built a 2056 and had a number of no start issues, I finally got the engine to start. but it looks like I wiped out the cam. So I have to start over with a complete tear down and cleaning of the block and the internals. (IMG:style_emoticons/default/headbang.gif)

My question is with determining push rod length: Are you measuring the length of each push rod, or measuring the #1 intake and exhaust and cutting all the intake and all the exhaust push rods the same length? With turning the engine over and over by hand to get the correct push rod lengths you would assume it has wiped all the assembly lube off the cam lobes before you start the engine. (IMG:style_emoticons/default/WTF.gif) I sure as hell don't want this to happen again.

[jcd914]

Cam break-in does not have any real effect on the performance of the engine in the first few hundred miles.
If you wiped out your cam during break-in you would not likely know it. Poor performance from a fresh engine is not going to be caused by your cam break-in process.

Many years ago I destroyed a cam during break-in and I did not discover it until the engine had 150 miles and a valve spring broke.

This was a 78 Bus engine I was building for my self but I used complete assembled aftermarket heads, too long ago to know who's. I did not disassemble and inspect the heads as I should have (and would today), I just looked them over and they appeared OK.
Young dealership mechanic expects part to be right and work right, what a fool!

This was a hydraulic lifter motor and on start up the lifters rattled until oil press built up and everything else seemed normal.

I had just gone past 150 mile, which was my planned oil change but I had not gotten there yet.
One morning I started it up and there was a valve clatter, I thought a lifter bled off and would pump up but it didn't.

So when I drained the oil I found a bunch of silver metal flake in the oil and when I popped the valve covers off I found the broken valve spring on the driver side head.

After complete tear down I found that the cam and lifters were worn severely, all lifters cupped and cam lobes visibly worn and rough.
Ultimately I trace this to the passenger side cylinder head had thicker valve spring wire diameter and the height the spring keeper sat at on the valve. Together this meant the springs would coil bind and the valve could open no more before the cam and lifters had reached full lift. During assemble I did not have issue because the hydraulic lifters stay collapsed until oil pressure fills them up. So as soon as the lifters pumped up and tried to reach full lift, the extreme pressure on the cam nose destroyed the cam and lifters as well as the rockers and rocker shafts on the passenger head.

During the 150 miles I drove the bus it ran well, I only tore it down because the valve spring on the drivers head broke, not because I had a running issue or my cam did not survive break-in. If the cam wear caused any performance lose it was not noticeable.

My point I guess is, that my cam and lifter were worn well beyond what a poor break-in would cause and the engine still ran well.
It was not going to last, the metal was everywhere.
I never found a cause for the valve spring on the driver side head to break but it probably save the rest of the engine.

The supplier of the cylinder heads provided a new set of heads, lifters, rings, bearings and Elgin's provided another cam, ground to the same profile and at a discount even though they had no part in the failure. I disassembled and inspected the new heads and reassembled with new OE springs.

Jim