standard or mushroom lifters

[moparsquid]

I have a chance to get a new Racer Brown 590 cam that the sell has mushroom lifters ,both are new . I really know little about these lifters its a STX-22 grind 590-590 what are the pros and cons its going into a 64 dodge 330 with a 426 max wedge with hilborne injection any thoughts

 

[PurpleBeeper]

I have a chance to get a new Racer Brown 590 cam that the sell has mushroom lifters ,both are new . I really know little about these lifters its a STX-22 grind 590-590 what are the pros and cons its going into a 64 dodge 330 with a 426 max wedge with hilborne injection any thoughts

The "mushroom lifter" cams aren't really used anymore. They required permanent modification to the engine block. People figured out that roller cams work much better roughly 30 yrs. ago.
My 2-cents --> If you have enough cash to build a hilborned injected 426 max wedge ($50,000'ish engine), then I would avoid "deals" on parts or you'll end up with a hodge podge that won't run well. Maybe consider a crate motor?

 

[R/T Boy 67]

Mushroom lifters have been around forever. Some classes of racing didn't allow roller lifters, so mushroom lifters were used as a work around. The bigger base diameter allowed more radical cam profiles. Block machining was required on the underside of the lifter bores for clearance, and the lifters went in from the bottom. If it was me I wouldn't use them.

 

[66Satellite47]

IIRC the STX -22 was a very good SFT design. It is not a mushroom grind though. Many of the mushroom design grinds produced power/torque equal or better than roller cams of the day. I still have my General Kinetics mushroom cam/lifters from the mid/late '80's. It was equal to my 660/284 Comp roller and only about .003 slower than my 690/284 Lunati in my 400/451 iron head motor(10.50/127 in my '65 Coronet). The common theory was you needed to machine the block for the mushroom lifters. I never did, they fit fine with a three of my standard 440 blocks and two of my 400 blocks, I measured the installed clearance on all of them.
Edit: The Comp roller was 660/280. Good power, but same as the GK mushroom cam.

 

[Geoff 2]

There is NO advantage at all from using MLs on a non -ML lobe. Only disadvantages.
Block may need machining & MLs are heavier.

 

[padam]

There is NO advantage at all from using MLs on a non -ML lobe. Only disadvantages.
Block may need machining & MLs are heavier.

I would think that the mushroom lifter would pick up the ramp a little sooner and hold it longer, providing more duration on the same cam.

 

[moparsquid]

Thanks for all that responded I've given it thought and decided not to get it I'll just go with my local cam guys at Schneider I've had good cams from them in the past thanks

 

[Photon440]

Back in the day, it was more common for the Chevy guys to use mushroom lifters. With their .842 lifters, they needed to catch up to the .904 Chrysler size.

 

[33 IMP]

I would think that the mushroom lifter would pick up the ramp a little sooner and hold it longer, providing more duration on the same cam.

I doubt it. The lobe profile has to be matched to the lifter diameter. That's why a profile for a Chevy lifter diameter had to be milder than a similar lobe ground for the bigger Mopar lifter.
So, if it's safe, and ground for a .904 lifter, putting a 1 1/2" lifter would mean nothing, it's still going to work only in the central area of the .904 lifter.

 

[Ghostrider 67]

Are there any other flavors?

 

[Geoff 2]

Post #9 nailed it. Using a smaller diam lifter on a ML cam would see the edge of the lifter dig into the lobe & quickly destroy the lobes.

 

[66Satellite47]

The point is that a mushroom lifter is designed to match the mushroom cam profile. Mix & match is not a good plan.

 

[33 IMP]

The point is that a mushroom lifter is designed to match the mushroom cam profile. Mix & match is not a good plan.

Exactly. A mushroom lifter on a normal cam is no benefit, and a normal lifter on a mushroom cam is a disaster.

 

[33 IMP]

Are there any other flavors?

You don't like Cream of Mushroom? (I prefer Cream of Celery myself, lol).

 

[Ghostrider 67]

You don't like Cream of Mushroom? (I prefer Cream of Celery myself, lol).

Cream of Chicken Noodle.

 

[66Satellite47]

IIRC Mopar started using the mushroom cams because NASCAR Grand National rules did not allow roller cams. So the mushroom cam did the job. But I never did put the 1.6 rockers in to get extra lift.

 

[Gunner1]

Mushrooms have to be installed. From the crank side of the block. So some means of holding them in place is needed in order to install the cam. Either hold the block upside down or magnets to hold them up for a in chassis cam swap. Small neodymium’s work on small chevys.

 

[Rusty34]

They were originally invented for NASCAR because roller cams weren't permitted at the time, If memory serves the foot diameter was 1.100." I have installed them in 357 Chevrolet engines very early in my career as a NASCAR team engine builder in the late seventies. The cam lobes were also much narrower to provide clearance from interfering with adjacent lifters. It was very critical when installing those cams to mock up a first check of clearance on all adjacent lobes. You would first install all the tappets and then the cam dry, no oil and using a depth mic on the nose of the cam you would measure the depth of the cam thrust surface on the front of the block to the cam gear surface on the front of the cam while rotating the cam by hand to 8 positions on the left side which were critical and 4 on the right which were the only critical lobes (on a SBC). You would rotate to position each lobe against the tappet foot it could contact, press the cam against the tappet foot and take a measurement with the depth mic. You would record all your different readings and they all varied due to production tolerances, pick the closest number and add .010 to get your cam gear depth and machine the thrust surface on the cam gear to get the required depth dimension down to the cam nose mounting surface. We ha1d thrust washers made in several different thicknesses as well as shims for between the cam nose and the boss inside the cam gear. A little bit of math was involved but it was absolutely critical that you got it right.

 

[66Satellite47]

One other silly advantage of the mushrooms is that if a pushrod failure occurs you still have oil pressure, not like a standard lifter. My 426W died from that problem, adjuster backed off, pushrod & lifter cam out, no oil pressure. Seized up twice on the return road. Towed it home, had to chisel the rod bearings off the crank. One more advantage of the mushroom.

Edit: Still my favorite cam. Big power, unless you take it to 8400 RPM with wedge valve train. OOPs

Second Edit: My 8400 RPM experience was broken valve spring, pushrod. Replaced those. Next weekend discovered the edge of the mushroom lifter had broken off, flattened the cam lobe. Called GK asked for a replacement mushroom cam. The guy on the phone sounded like an old timer. When I told him my mushroom cam made as power as my best roller cams, he said ya, the mushroom grinds accelerate the valve like a roller. That's why I still have it on the shelf. I bet my 512 would like it, especially with a 1.6 rocker.

 

[Bobzilla]

I have a chance to get a new Racer Brown 590 cam that the sell has mushroom lifters ,both are new . I really know little about these lifters its a STX-22 grind 590-590 what are the pros and cons its going into a 64 dodge 330 with a 426 max wedge with hilborne injection any thoughts

If you buy this stuff and find out it really is mushroom lifters and are not compatible with the cam as post #4 suggested, maybe you can contact @Bighead440 because he had a wanted add for mushroom lifters.
[WANTED] - P3690137 mechanical tappet, MUSHROOM