forged pistons for 291

Discussion of the Early Dodge / DeSoto HEMIs.

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Gullwing
Posts: 35
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Location: aLBANY

forged pistons for 291

Post by Gullwing » Thu Dec 14, 2006 10:33 pm

At $800 forged Ross pistons are a little pricey. Has anyone tried using pistons from another make motor that are about 40% cheaper. The 265 Chevy motor had about the same bore as did an AMC motor. Anyone ever tried that. Oh yeah I am shooting for a flat top 8:1 compression ration.

392heminut
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Post by 392heminut » Fri Dec 15, 2006 7:13 am

I think where you will run into problems is with the valve relief cuts in the piston tops. Chevys are wedge heads, the valve reliefs are nowhere near where they would need to be for a hemi head.
Owner of the Poor Man's Hemi Cuda

desotoman
Posts: 54
Joined: Sun Jul 17, 2005 1:02 pm

Post by desotoman » Fri Dec 15, 2006 10:50 am

I know of one guy that did it. He was a machinist by trade and took a set of 265 chevy pistons and put them in his 291 desoto. It has been a long time since I have talked to him but as I recall he used some kind of ford rod also. This was many many years ago when 265 pistons were dirt cheap.

Question? Is this a race motor? Do you really need Forged pistons? Cast piston will work fine for the street. Just a suggestion.

Good luck on what ever you decide.

johnny5
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Location: St Charles, MO

Post by johnny5 » Fri Dec 15, 2006 11:43 am

Have you tried Venolia? They're better quality and probably a couple hundred buck less than Ross.

41hemi
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Post by 41hemi » Sun Dec 17, 2006 2:00 am

I used Silvolite pistons made for the 292 Ford Y block in my 330 Desoto which I think has the same bore as the 291. The stock bore 292 piston was actually .030 over for my 330. All that was needed was to cut the reliefs in the pistons.
41 Chevy with blown 330 Desoto / 32 Ford coupe with blown 392 Chrysler

TrWaters
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Post by TrWaters » Sun Dec 17, 2006 8:47 am

I have a set of NOS L2091F TRW .030 forged pistons sitting on the shelve for this very reason. :D These are for a HD truck application, and are a higher compression than the car pistons. :o They have a thick top, and cutting a bevel on the outside edge and valve notches are no problem.
When you have the rods refurbished, just bush to the correct pin size.
Keep in mind, that unless you can do some of these operations yourself, you probably wont save much money in the end over buying pistons.
Early hemi to late sb Mopar trans adapters. Precision billet parts for early hemis.

desotohemibill
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Post by desotohemibill » Thu Apr 05, 2007 1:57 pm

I recently sold a 291 and a 341 to 2 different buddies. Each of them bought Venolia forgings at 9-1. They ran about $525.00 a set. The 291s have quite a dome. I will send a photo of them on request.
I am always looking for early hemi info and willing to give some to those not yet schooled in these old engines. I have a small machine shop and am currently gathering material for a small foundry. Hope to make custom parts for the old hemis.

jimstandefer
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Joined: Wed Dec 12, 2007 5:36 pm

Cheap 291 pistons

Post by jimstandefer » Wed Jan 16, 2008 1:23 pm

I'm using chevy 305 flat top (no valve notches) hypereutectic Keith Black pistons avail. on ebay for $189. Using chevy stroker 6.125 rods. ($125.) 330 crank destroked to 3.7" with mains turned for 291 and rod journals for 350 chevy. ($450.) Works out to 0.0" deck. and about 8.0 to 8.5 cr. Heads could be milled to increase cr. but I'm going with a blower so need for more cr. Making intake - Desoto flanges avail for $55. (and exhaust flanges same price). Main body of intake (box) is piece of U shaped thin structural steel used in pre-fab metal buildings. Using 1.94 valves from 330 and pontiac exhaust valves in the 291 heads. Still, trying to watch the pennies it is still VERY expensive.
Desoto 291 stroked to 330
409 chevy engines
2 Impalas
1930 Ford Coupe

jimstandefer
Posts: 3
Joined: Wed Dec 12, 2007 5:36 pm

Re: Cheap 291 pistons

Post by jimstandefer » Thu Apr 03, 2008 12:43 pm

jimstandefer wrote:I'm using chevy 305 flat top (no valve notches) hypereutectic Keith Black pistons avail. on ebay for $189. Using chevy stroker 6.125 rods. ($125.) 330 crank destroked to 3.7" with mains turned for 291 and rod journals for 350 chevy. ($450.) Works out to 0.0" deck. and about 8.0 to 8.5 cr. Heads could be milled to increase cr. but I'm going with a blower so no need for more cr. Making intake - Desoto flanges avail for $55. (and exhaust flanges same price). Main body of intake (box) is piece of U shaped thin structural steel used in pre-fab metal buildings. Using 330 valves valves in the 291 heads (large exh. valve better for blower). Still, trying to watch the pennies it is still VERY expensive.
Desoto 291 stroked to 330
409 chevy engines
2 Impalas
1930 Ford Coupe

jimstandefer
Posts: 3
Joined: Wed Dec 12, 2007 5:36 pm

Re: Cheap 291 pistons

Post by jimstandefer » Thu Apr 03, 2008 12:53 pm

jimstandefer wrote:
jimstandefer wrote:I'm using chevy 305 flat top (no valve notches) hypereutectic Keith Black pistons avail. on ebay for $189. Using chevy stroker 6.125 rods. ($125.) 330 crank destroked to 3.7" with mains turned for 291 and rod journals for 350 chevy. ($450.) Crank counterweights must be turned down .300" in lathe to clear bottom of cylinders. Works out to 0.0" deck. and about 8.0 to 8.5 cr. Heads could be milled to increase cr. for normaly aspirated but I'm going with a blower so no need for more cr. Using 330 valves in the 291 heads (large exh. valve better for blower). Using blower intake fabricated by Jack Wagner in Lawton, Ok. (beautiful intake !!) Still, trying to watch the pennies it is still VERY expensive.
Desoto 291 stroked to 330
409 chevy engines
2 Impalas
1930 Ford Coupe

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