head scratcher- pushrod problem

[robertf03]

This has been kicking my ass all day.... valves stay open on my new engine.

heres the specs:
86 ford 5.0 roller block, 87 e7te heads. Looks like all ford roller blocks use the same length pushrod from the factory.

When I tighten down the rocker arms (pedestal mount, torqued down, no adjusted valve lash like a gm) the valves open .145" according to my dial indicator. The pushrod length is 6.25", and after doing some research it looks like the shortest production 5/16" pushrod.

Is there preload on the hydraulic lifters when the valves are closed? This engine was probably sitting a while, is there a chance that the extra length is due to stuck lifters? People claim to do this swap all the time with stock pushrods.

I really don't want to get custom length ones, seems like something is wrong here.

[Fredo]

I know on st.john's mustang, they had shims under the rockers on it...that might be your problem

[robertf03]

I was thinking that too, but I went and played with it some more. I think I'm over looking the obvious, but the heads are decked, valve seats ground, and mismatched parts overall.

swapped all 3 sets of heads I have on it and they all do the same, even the stock to that engine heads. Went and tried the same thing on my old engine and same thing happened. I figure its got to be the lifters (?)

the gap opens enough that if i pour red tracer fluid (ATF :D ) down the intake it goes through.

now to see if I can free up the hydraulic portion of the lifters.
I can't remember, is soaking lifters in oil ok to do? I think I read somewhere that it was bad for them.

[Graystroke]

A guy at a machine shop said that's not a good idea anymore. I would just use some Marvel Mystery Oil and poor it down the push-rod while it's running. and the covers off.

[agjohn02]

A guy at a machine shop said that's not a good idea anymore. I would just use some Marvel Mystery Oil and poor it down the push-rod while it's running. and the covers off.


you think it'll run with all the valves open?

[jerryg79]

cracked heads

[Graystroke]

you can go buy a set of lifters. call local machine shops and see what they charge. they're rollers right? I paid 230 for a set of roller lifters for a big block chevy. I would definitely inspect them. if they have rust in them then they are probably scrap.

[mudtoy67]

I put a cam in an Impala with a LT1 in it not too long ago. The factory valve lash was set lash to zero and then tighten one turn. When I did this the valves would open slightly, and when I was turning the motor over by hand it felt like it had no compression. But I double checked the specs and it was exactly like the computer said. It fired up just fine and ran just fine. I think the lifters have a certain amount of preload in them and when the engine starts and runs the compression will close the valves.

[agjohn02]

I put a cam in an Impala with a LT1 in it not too long ago. The factory valve lash was set lash to zero and then tighten one turn. When I did this the valves would open slightly, and when I was turning the motor over by hand it felt like it had no compression. But I double checked the specs and it was exactly like the computer said. It fired up just fine and ran just fine. I think the lifters have a certain amount of preload in them and when the engine starts and runs the compression will close the valves.


yes, there is preload on any hydraulic lifter, but not enough to hold the valves open. when you turn it by hand your just turning it so slowly that the compression leaks by the rings. the valves should be seated completely. i didnt look at the specs when i put my top end back together i just did the ol' twist the pushrod till ya get it tight enough that it donesnt spin then add a half to it.

[agjohn02]

now to see if I can free up the hydraulic portion of the lifters.
I can't remember, is soaking lifters in oil ok to do? I think I read somewhere that it was bad for them.


not arguing, but how can this possibly be bad for them?

[mudtoy67]

when you turn it by hand your just turning it so slowly that the compression leaks by the rings.

This thing was more like when you have all the spark plugs out. It had no compression. But it started up just fine.

[Graystroke]

it may have to do with the load you would put on the lobe surfaces on the cam on start up-although not really the case on a roller-before oil pressure builds and lubes the cam properly. I know pack in the day people use to submerge them in oil and pump the lifter to fill it up. Maybe this makes them too hard and can damage, bend push rods.

[robertf03]

had them soaking in oil for the past day, installed them and it didnt change anything. went out for a while and came back to a lifter valley full of oil and no exta valve lift :D Looks like the oil loosened it up and the load from the springs finally broke it loose.

[uglyota]

so your big "head scratcher" was frozen lifters?
guess it could've been worse...like crossed spark plug wires or something :D

[robertf03]

yeah those extra 4 cylinders are a *****

[BMFScout]

so your big "head scratcher" was frozen lifters?
guess it could've been worse...like crossed spark plug wires or something :D
or a burnt fuse, or fouled plugs, $%&@$ JAP TRUCK!