Warming up "Forged" pistons

[Gremlin4ever]

Had a small discussion over in "401 pistons" about a combo I would like to run. Was asked to read "Collapsed pistons" as a result and found this noteworthy fact.

I have come up with a question concerning "Cam break-in" with forged pistons:

If you need to warm up the engine before revving so the pistons don't score themselves from expansion before the block can catch up, how can you break a cam in using the cam's instructions of bringing the RPMs to 2500 and then revving between 2500 and 3000?

Will the cam be ok at idle till the engine hits that operation temp before the break-in period is to begin?

Just a thought I had from reading the other threads

[dwg86]

Forged pistons use a little bigger bore to piston clearance. So i don't see a problem with reving an eng to 2500 rpm to break the cam in. Running an engine at 2000 t0 2500 rpm to break a cam in causes the lifters to spin in thier bores. If the lifters don't spin you WILL wipe out a cam lobe. I built a .040 over bore 401 with 10.5 forged pistons and had no trouble when breaking in the cam. But like I said there is more bore clearance than with a cast piston. Hope this helps.

[1980_Cj7]

Had a small discussion over in "401 pistons" about a combo I would like to run. Was asked to read "Collapsed pistons" as a result and foud this noteworthy fact.

I have come up with a question concerning "Cam break-in" with forged pistons:

If you need to warm up the engine before revving so the pistons don't score themselves from expansion before the block can catch up, how can you break a cam in using the cam's instructions of bringing the RPMs to 2500 and then revving between 2500 and 3000?

Will the cam be ok at idle till the engine hits that operation temp before the break-in period is to begin?

Just a thought I had from reading the other threads

I had the same question.

[jeep_man_401]

I drilled some small holes in the lifter valley just above the cam lobes to drop some more oil on them. Not to help with break in...but to help oil the cam while sitting in traffic at idle.

I know this dumps more oil into the spinning crank an rods...but if you're driving it on the street you can afford the few HP loss for the extra life you will recieve in return.

A all out race motor would be different...block the lifter valley holes.