Ate a cam, time to switch to roller, I guess, but which one?

[V_TastyTacos_V]

Depending on which "stock" pistons are in the engine, the larger cam might have piston to valve clearance issues.
My 383 was rebuilt with the forged flat tops, but also the engine deck was milled so the pistons were just slightly below the block deck, and my heads were also milled 0.040" for compression, all of which moved the valves closer to the piston at TDC limiting cam duration because of P-V clearance.
I would put checking springs on the valves of one cylinder, set cylinder at TDC, and measure how far the valves can drop before contacting the piston.

I would call Bullet / Ultradyne cam and have them custom grind you a cam to match your engine combination and application.

I was afraid of getting a cam that wouldn't clear the pistons going into this blind. That's why I got one close to .500" lift. I made some checking springs and degreed the new cam in while checking for clearance every couple degrees as the piston came up on TDC by pressing down on the valve till it touched the piston.

 

[451Mopar]

I was afraid of getting a cam that wouldn't clear the pistons going into this blind. That's why I got one close to .500" lift. I made some checking springs and degreed the new cam in while checking for clearance every couple degrees as the piston came up on TDC by pressing down on the valve till it touched the piston.

Max lift don't matter in piston to valve clearance. Max lift is at the intake centerline, usually around 110 degrees crank rotation, so the piston is way down the bore at max lift.
The closest points are around overlap when the piston in nearing TDC the exhaust is closing, and when the intake is opening as the piston is just starting to go down the bore.

 

[V_TastyTacos_V]

Here's the lifter

 

[V_TastyTacos_V]

Here's the cam

 

[V_TastyTacos_V]

Here's another lifter. It's starting to concave, but still looks like the others visually. Smooth with similar wear pattern, but the others are still convex.

 

[V_TastyTacos_V]

The Parkerizing is worn all the way across on the flanks, and most of the base circle on that cylinder, far left. The flat lobe is third from the left.

 

[Don selleck]

wow, munched

 

[PRHeads]

In light of the extra low CR of that engine, what are the plans now?
Shove a cam in it and hope for the best and keep driving it while building a “better” short block?
Or ??

Any idea how many miles that cam has on it?

 

[V_TastyTacos_V]

In light of the extra low CR of that engine, what are the plans now?
Shove a cam in it and hope for the best and keep driving it while building a “better” short block?
Or ??

Any idea how many miles that cam has on it?

I was estimating about 15,000 miles on the cam. I have a stroker motor for the car, but wanted to put this motor in my Dart. I found the original cam and I numbered lifters, so for the price of a couple gaskets, I'm going to take a shot at putting it back in. I tell you, although I'd rather not have a flat cam, it's amazing how easy and fast everything comes apart when it doesn't have 50 years of rust and crud on it.

 

[Geoff 2]

See your other thread.