bubbaf100

Got a 412 Ford FE With Lunati Hydraulic flat tappet lifters with Bracket Master II cam. Have a total of 34K street miles on it. Lifter makes tapping noise like its collapsed. Only makes noise at a constant speed or deaccleration.
When you give it throttle or flat foot it the noise disappeares.
It has the non adjustable 1.73 ratio rocker shafts.
Makes idle cold start 35lbs. Idle when operating temp. 30lbs.

I think the plunger is partially collapsed. Any suggestions?

TheYellaBrick

Any metal in the oil when you drain it ? Might be a flat lobe.

bubbaf100

No shavings at all. I have the magnetic drain plug.

bubbaf100

Case closed easy fix bent Pushrod. Done a few times in the past, just slightly
but enough to make a different tap than previous.
It's happened to me once every 8000-13000 miles when driven hard.
That's why I have a spare set of Manton Pushrods lying in the
tool box.

bixblk

I do not know alot about fords, but sorta surprised that it bends push rods, is that normal or is it a spring pressure or "geometry" issue, Just curious. good job finding it.
Jeff

bubbaf100

It a little bit of geometry issue with the FE's but no problems till you flat foot the hell out of it but leave your foot out of it it won't bend pushrods till the end of its life. When driven hard they occasionally bend them typical problem on the FE Ford and the high perfromance 460's do it too.
It's hot rodding.

bixblk

OK, if your gonna hurt any part of the valve train on an engine the push rod is the "best" thing to hurt ;)
Easy to change and usually no "collateral" damage.
Jeff