The mushroom deal was actually developed for the NASCAR program....Chrysler wanted the big numbers, and they were not feasable with a flat tappet. Rollers were illegal in NASCAR....hence the develpment of the mushroom tappet. Those old "mini express" worked real good, too.

Thanks, that makes more sense.
BTW: there are really big radius flat tappets for other engines: 3".

Anyone have a mushroom tappet Mini Express cam that they would like to sell ?

Help a brother out Please

Set your ebay preferences to email you when a mushroom cam/lifters come up...

Last week one seller had a non dc but mopar cam like the mini ex for $250

He had a set of dc lifters and one other brand at $200 a set.

I cant find the listing so they must have sold, but they do pop up there every few months.

The cam was like .640 lift, as cool as it was ive got near the same cam specs in a hughes so I passed.

Thank you EV2Bird

I don't think some understand the purpose of the mushroom tappet. First, it is not mushroom shaped at all. It just looks like a regular lifter with a 1" diameter base welded on it. So it's flat on the bottom and is STILL a flat tappet lifter and as such is limited on spring pressure just like any other flat tappet. It provides no more lift. The ONLY things it does is move the valve events. Meaning the lifter starts up the ramp and comes down the ramp at different times because the diameter is larger. The larger diameter means it contacts the ramp earlier. That's ALL, nothing else. Why was this needed? Because at the time, cam cores were very limited as to the valve events that could be ground into them. So you fixed that with a larger lifter. With cores available today, the mushroom lifter is NOT needed. You can get cores to get about any events you want within reason

If you look at the drawing linked to above, it shows exactly what I am explaining. But you can also accomplish the same thing with a cam with more of a roller profile on the lobe.......or just put 1" lifters in the motor.

With the roller profiles available today and everything we have to choose from, it baffles me though why guys even WANT a flat tappet though. Just as David Reher addressed in that article, there are so many potential issues with a flat tappet

At a given maximum lifter acceleration, you can get more lift out of a 1.00" tappet than you can with a .904". My refaced Mini-Express is .652 gross lift (.018 lash), 272@.050. I feel safer running it on a 1" lifter than an Ultradyne .640 on a .904, which is 277@.050. The mushroom has more lift with less duration. Sounds kind of like a roller...

There are also potential issues with roller lifters on the street... depends on who you talk to. Like everything else here, there are multiple opinions.

Perhaps more importantly, not all of us have John Force's budget for engines and components. A good set of roller lifters alone costs more than I have in my mushroom cam & lifters, pushrods, used Isky rockers, and Comp springs

I would think if they were the end all of camshaft/lifter designs they would still be made today.

Its easy to fully understand the budget! At times we do, only what we can do which is better then nothing.

The shubeck puck solids at 69 grams and $700 might seem like alot of money upfront, I just sold a set I used on six cams over a five year period with zero issues for $350.

In those six different cams at $150X6 a set of regular lifters Im far ahead of the lifter game.

As well Ive resold the cams, cheap but they would still rotate a new set of lifters.

I really wanted the cam/lifters I mentioned off ebay but I just didnt have a reason.

As far a solid roller lifters, for the street if you can find a old reed cast core roller and matched lifters you can run a gentle roller cam for a long time.

Or if like some on here that god blesses you everyday, you can run a normal roller cam and lifters.

One of the issues I have is that the valve gear on OE heads just isn't rigid enough for the spring pressures a roller needs. If all you are doing is beat the hell out of the valve gear you aren't doing much.

That's why I used a SFT in my last build. When I do the W-2 heads I may use a roller. Or, I may say piss on it and use a mushroom lifter.

Like I said, I have the lift I wanted with a .904 lifter or I'd have used a mushroom this this time. But much over .600 lift and it's hard to get all the valve train correct.

Back to back is there really any positive benefit of running the old cam and lifters? Other then just the want?

My last hughes solid I was at .680 lift at the valve and with there vast selection of cams going up the ladder in duration I could stay near .700 lift with a 260@50 or what is it the 276@50 or in between.

Reed used to be able to grind them up till maybe ten years ago or so, but I just looked and if they moved out of GA, there done, history.