This guy struck gold

[Icetech]

Well I`ll be the first dummy to ask, how does that even work?
I assume the mushroom part is bigger than the body and would have to be installed from the bottom?

I don't think it was mentioned other than installing from the bottom but that larger platform for the cam to ride on allows for some pretty radical lobe profiles for a flat tappet cam, coming close to roller.... You never used to hear bout mushroom lifters cept from really serious guys...

 

[Dale Davies]

Well I`ll be the first dummy to ask, how does that even work?
I assume the mushroom part is bigger than the body and would have to be installed from the bottom?

Correct. In some applications at close to max lift the mushroom could hit the bottom of the lifter bore. In those cases a bit of relief had to be machined.
There was some engines built that had small diameter lifters of about 1/2" and required the mushroom.
The mushroom allows a more aggressive cam profile without the edge of the lifter "digging" into the cam ramp.

 

[Jim wellesley]

I've been reading your comments. I have a racer brown ground mushroom cam and lifters. Was ground for a guy i know. Ground back in 1997. I'll post pictures. No block facing required.

 

[Jim wellesley]

I test fit it in a 440 I have, looked to be more than a 1/8 of clearance between block and lifter. It's a backup engine for my gasser palara. I'll let you know how it works out. The cam card is in the photos. It's a .590 lift with 276 @ 50.

 

[Kern Dog]

I'm guessing that these lifters still need to spin in the bores like all other flat tappet lifters?

 

[mygasser]

I test fit it in a 440 I have, looked to be more than a 1/8 of clearance between block and lifter. It's a backup engine for my gasser palara. I'll let you know how it works out. The cam card is in the photos. It's a .590 lift with 276 @ 50.

ooh! gasser polara? i need to see that

 

[Newbomb Turk]

I'm guessing that these lifters still need to spin in the bores like all other flat tappet lifters?

Yes. The benefit is the bigger face allows faster lobes.

 

[CRUZE 418]

Aircraft engines used mushroom hydraulic tappets, much larger base than the ones shown here. Roller tappets are offered now, engine cases are different for the roller tappets to keep the tappets from turning.

 

[33IMP]

That racer brown mushroom is relatively mild (compared to a mini express, anyway).
Should have good metal in it and be very durable. Unlike some new flat tappet cams. You should have good luck with that.

 

[burks440]

i know a local guy that has a mushroom tappet cam he has had for decades.

 

[Kern Dog]

Those cam and lifters sets look like they'd be impossible to install with the crank in place.

 

[Jim wellesley]

I'm guessing that these lifters still need to spin in the bores like all other flat tappet lifters?

Yes sir. And they do.

 

[Jim wellesley]

Those cam and lifters sets look like they'd be impossible to install with the crank in place.

I used a magnet and worked ok. No problem.

 

[Jim wellesley]

ooh! gasser polara? i need to see that

ooh! gasser polara? i need to see that

 

[Jim wellesley]