Mickey Thompson pistons

-
33IMP said:
Who knows? I'm sure that's why the op is looking for info.
Full skirt. How much ovality? How much barrel? More measurements are required to make an educated guess.
I took out an ancient set of full skirt pistons like those from a maxwedge that was running OVER .010 p to w. (.060 over)
I honed it a little, and put standard 440 pistons in it (.070).
I would not run those M/T pistons any less than .005.
Click to expand...
I asked my boss, he agreed .007, were going to dig out some of those old type heat em up and measure them.
 
Rat Bastid said:
.007 isn’t much for that piston. I think MT had those pistons made by Jahns. Or however they spelled it. I’d use them. I’d just make damn sure the cylinder finish has enough oil to lube those skirts with that finish on them. Even with .007 cold you won’t have that much at temp. You’ve got to have some oil on the skirts or they will grab the bore.
Click to expand...
What would you do for finish surface, hone with 100 stones close to 2 or 3 tenths finish and finish off with 300s the final 2 or 3 tenths ? (depending on rings)
 
Get the ROSS pin-eye bushings and then have them honed to .984 instead of .990", these fit a 1.094" bore in a stock or any pressed-pin 440 rod. I even had a set of Hemi (1.031") rods bored to 1.094 and used the Ross bushings to get .990" for an odd wedge build. These M/T pistons would make a great street piston, IF you have VP clearance for your valves/camshaft choice, or can machine reliefs in safely.
 
Bighead440 said:
Get the ROSS pin-eye bushings and then have them honed to .984 instead of .990", these fit a 1.094" bore in a stock or any pressed-pin 440 rod. I even had a set of Hemi (1.031") rods bored to 1.094 and used the Ross bushings to get .990" for an odd wedge build. These M/T pistons would make a great street piston, IF you have VP clearance for your valves/camshaft choice, or can machine reliefs in safely.
Click to expand...

what length rods would you run with these with a 440 crank? 6.700?
 
CrustyCuda said:
what length rods would you run with these with a 440 crank? 6.700?
Click to expand...
With a 440 crank cut down to 383 main size, and 440 rods bushed to sbm pin size, those would be .004 out of the hole at a blueprint 9.98 deck. Could easily be ten or fifteen thousand either way, depending upon the deck height of YOUR block.
If you give us an idea of what heads you are gonna use, we can give an educated guess as to the compression ratio.
You WILL need to cut valve reliefs in them (or use a 6.700 rat rod and KILL the compression and quench), and I will bet you will want to cut the reverse dome off too.
 
Well, here I can really see what type of clearance those pistons could need as a 2816 or 2618 needs a minimum of .005 thousands & if it is a race application would need another .003, that's alot but I guess it is necessary. I bored my first big block Mopar yesterday for 4.375 icon pistons.
 
33IMP said:
With a 440 crank cut down to 383 main size, and 440 rods bushed to sbm pin size, those would be .004 out of the hole at a blueprint 9.98 deck. Could easily be ten or fifteen thousand either way, depending upon the deck height of YOUR block.
If you give us an idea of what heads you are gonna use, we can give an educated guess as to the compression ratio.
You WILL need to cut valve reliefs in them (or use a 6.700 rat rod and KILL the compression and quench), and I will bet you will want to cut the reverse dome off too.
Click to expand...


Wasn’t planning on running anything special. Home ported 906’s
 
Okay, ALL of this is assumption/Wild assed guess, as any actual measurements can throw off any of these calculations.
If that .085 step was full size, it would be 20cc. It looks like about a quarter of the piston top, so I'm gonna figure 5cc (actual measurements would be required for accuracy)
So, these assumptions:
4.28 bore
3.75 stroke
90 cc combustion chamber, 906 head.
5 cc dome volume
.038 head gasket compressed thickness
4.375 head gasket bore diameter
.000 deck height (yours will be a few thousandths either way)
1cc for "other" (Wallace calculator)

I get 431.6 Cid, and 10.17cr

Now ALL of those numbers are very changeable (dome removal, valve relief install, deck height actual, milled cylinder head, actual cylinder head volume, etc. etc).
Just an educated w.a.g.
Edit: you won't have to remove the reverse dome with 906s, you would with 915s, closed chamber Eddie's, or trick flows.
 
I think Kim is right about being a Chevy piston primarily from the pin bore diameter. However you could use these the give a 438 inch stroked 383, will require pin bore work to use a 990 pin and aftermarket 6.76 rods on whatever 3.75 stroke crank you want to use (stock 440 or aftermarket), the compression height of these is 22 thou difference between what is commonly used now (1.32 vs the 1.342 which you have) so you will have to do some figuring on your final compression ratio requirements and pick the right heads and gaskets. Also probably need to cut reliefs cut in them…..

all this may not be worth your effort and expense at the machine shop.
 
For what it's worth....
I read somewhere recently where a forged piston manufacturer around the mid seventies (maybe Arias?) was bragging their SMALLBLOCK Mopar pistons could be "fitted as tight as .008 piston to wall"..... WTF?
I wish I knew where I read it, was either here or FBBO. I should have bookmarked it.
WAIT! It was a discussion of the Mopar version of Trw pop-ups for a 340. The Mopar catalog description said 'as close as .008".
And the Mopar part# version of $250 (at the time) TRW's was $640!!
 
I have a set of 1992 year, Venolia’s that were run at .007 clearance, in a .030 overbore 440. They make a little rattle at cold start but, within a minute the noise abated. No boy racer free revving!
 
You must log in or register to reply here.
-

Back
Top