Does anyone have or Know where to purchase higher compression pistons for a 291 DeSoto? i know hotheads list some but i didnt know if any others were available?
I'd definitely try Egge Machine. Usually if they don't have it on the shelf they can cut some for you.
Not to knock Egge but isn't most their stuff made to OEM specs ? I went though a deal like this on a 325 Dodge Hemi that was being prepped as a street blower motor and ended up having a set made by Arias . Pricey ? yeah, but they are forged and are designed to do the job. Another longshot is to take your bore size , compression height and pin diameter and do a search in a replacement piston catalog that lists by sizes . I found a Ford 6 cyl. , I believe a 240 that would work with some mods in the 325, but opted for Arias .
Jahns used to make pop-ups for the 291. Now all you can get is a ross piston (basically a custom piston) which hot heads sells. JE or any other higher-end piston manufacturer could make a set also, but they are all at least $100 each. A 330 has a little more compression stock than a 291 and the pistons are dimensionally the same. Still it only has 8.5:1 (I think, off the top of my head).
ok ok i know every one hopes this thread will die but has anyone tried to put desoto 341 pistons in a bored out 291? compression is up to 9.25 and the bore size is 3.78, 0.060 over 291. i just have a hard time paying as much for a ross piston as tony shumacher does for his
If the block will bore that much I'm pretty sure you can use those pistons. The stroke is the same in a 330 as a 341, and they are both tall decks. I'm almost 100% sure that the pin height stayed the same from a 291 to a 330, the deck height/rod length changed. I might be wrong though, I can't remember where I saw that. I have both 291 and 330 pistons at home, I'll measure the pin height when I get there.
These might not be accurate because I used a vernier caliper to measure them. It looks like the 291 and 330 have the same pin height @ 1.610", they also have the same pin diameter @ .921". The 330 piston has a .050" dome for more compression. So I think a 341 piston would also work, although I don't have one to measure. Hope this helps.
Go with Venolia. They have lots of experience with the Desotos and are less expensive than most. I got my 341 pistons for about $150.00 less than Ross. Bill
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