Mopar 350 Stroker

[Garrett Ellison]

And, as Rusty said, here’s your guide from Ross for measuring pistons.
https://www.rosspistons.com/wp-content/uploads/2016/08/Piston-Install-Auto-Ross.pdf

 

[Racingcowboy89]

not with it filled with concrete, no.


yes, but no, but also yes and no.

Being with concrete I have to run the engine for drag racing only? I understand that I have to run a big huge oil cooler. There is a 25 inches between the concrete and top of the block.

 

[Garrett Ellison]

It depends on how far from the bottom of the water pump holes on the front of the block the concrete comes up. If it’s to the bottom of the holes, it’s pretty much a strip only piece at that point.
On your measurements… if the seller has the calibration standards with these, you should probably look into buying the three to four inch mic at a minimum.
[FOR SALE] - Starrett 436 .001" Outside Micrometers 0-1"- 1-2" - 3-4" Very Clean

 

[junkyardhero]

Being with concrete I have to run the engine for drag racing only?

i wouldn't chance it in any other capacity

i've heard of guys running half fill blocks on the street, but not for me thanks.

 

[Garrett Ellison]

I think maximum safe fill for street use is the point on the cylinder where the bottom of the piston skirts come to. But you’re loosing some coolant system capacity. Cooling is a pretty big factor with your location.

 

[Racingcowboy89]

It depends on how far from the bottom of the water pump holes on the front of the block the concrete comes up. If it’s to the bottom of the holes, it’s pretty much a strip only piece at that point.
On your measurements… if the seller has the calibration standards with these, you should probably look into buying the three to four inch mic at a minimum.
[FOR SALE] - Starrett 436 .001" Outside Micrometers 0-1"- 1-2" - 3-4" Very Clean

The concrete is below the water pump holes.

 

[Garrett Ellison]

How far below the bottom of those holes?

 

[Mean416]

I got micrometer that I am using for the piston as you guys were saying to get a micrometer.

Clarification. A a micrometer, in conjunction with a bore gage.

 

[RustyRatRod]

i wouldn't chance it in any other capacity

i've heard of guys running half fill blocks on the street, but not for me thanks.

I've seen people fill to the bottom of the freeze plugs and get by...but the cooling system has to be GOOD.

 

[Racingcowboy89]

How far below the bottom of those holes?

There what I got.

 

[junkyardhero]

I've seen people fill to the bottom of the freeze plugs and get by...but the cooling system has to be GOOD.

i done seen it too.

but you wanna know when i see those cars out on the street or at a cruise?

never. that's when.

 

[Newbomb Turk]

Okay. A little education may be in order here. 273/318/340 cranks all share the same stroke of 3.31 inches and 2.5 main journals and 2.125 rod journals. The only differences are cast or forged construction and balance factor. 273 and early (pre 1973) 318 cranks are going to be balanced for the smaller and lighter bushed rods that came in those engines. 340s are going to be balanced for larger rods and heavier pistons. Your early (pre 1970) 318 will have the most likelihood of having a forged crank. Being you don’t have a crank that was originally outfitted to your application, i myself would look at getting a mopar specific pre balanced rotating assembly and pistons. @PROSTOCKTOM here is a licensed Molnar and JE/Diamond/Icon dealer. First and foremost, though, I would be getting the cylinder bores professionally measured for concentricity and taper to see if what you have is usable before investing too much into it.

All true. But if you want rpm and you can do it with a stock stoke I’d use the 273 crank. Even with steel rods.

And I’d trim the counterweights down until I had to add a bit of Mallory to balance it.

If it’s a drag engine and the guy using it understands aluminum rods then I’d use those. You can trim even more off the counterweights.

 

[Newbomb Turk]

If your hoping to get 475 hp out of your short block, the attached parts should get you in the neighborhood with 12:1 compression.

106 would be my choice on the lsa, but Keven @Schnidercams will know what it’s going to take.

View attachment 1716489105



View attachment 1716489107

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I love that windage tray. Spanky!!

 

[Newbomb Turk]

I am hoping this is more readable
View attachment 1716489134View attachment 1716489136

That’s 3.9685 or damn close to it.

 

[Illahe]

I love that windage tray. Spanky!!

That windage tray is from J Rob‘s 371 build. I built one very similar for my 340 and the throttle response and RPM wicking so to speak is phenomenal.

 

[Newbomb Turk]

That windage tray is from J Rob‘s 371 build. I built one very similar for my 340 and the throttle response and RPM wicking so to speak is phenomenal.

Ultra damn nice piece. I’d love to test it if J Rob hasn’t.

 

[Sterling]

I don't see any valve reliefs in the picture of the piston, not sure how that would work if it was close to zero deck

 

[Newbomb Turk]

I don't see any valve reliefs in the picture of the piston, not sure how that would work if it was close to zero deck

Yup. There is so much wacky with his stuff I don’t know what to make of it.

 

[Garrett Ellison]

It’d have to run some pretty conservative cam numbers to keep the pistons out of the valves. You could send the pistons to Ross to have valve reliefs added to them. I could probably make use of that with my 3.51 inch crank and some open chamber heads.

 

[33IMP]

Yup. There is so much wacky with his stuff I don’t know what to make of it.

Yep. It's a mess.
A probable drag-only block, custom pistons with no valve reliefs, only 318 displacement with unnecessary complications of chevy parts. And the crank that might make sense of the chevy parts is missing in action. What in the world was the original plan?
What is the plan now? A drag engine for a drag car that doesn't yet exist?

 

[junkyardhero]

Yup. There is so much wacky with his stuff I don’t know what to make of it.

i don't think any of it goes together.

you know how it goes: have race mo-tree, something goes wrong with race mo-tree (dropped valve), blow apart mo-tree for fix, big expensive to fix, lose interest, scavenge parts for other mo-tree, circle back years later and sell leftovers and can't remember what went with what or what's missing.

there's a reason the crank & heads aren't here. what that reason is? who knows...

 

[Racingcowboy89]

Yep. It's a mess.
A probable drag-only block, custom pistons with no valve reliefs, only 318 displacement with unnecessary complications of chevy parts. And the crank that might make sense of the chevy parts is missing in action. What in the world was the original plan?
What is the plan now? A drag engine for a drag car that doesn't yet exist?

Wow you know all that I got is just the engine to build for drag engine as I haven't went to find a home for yet as I been trying to get the engine done so I can go find a car or truck to put it into.

 

[ch1ll]

Assuming it's a 3-4 Mike, 3.9685.

 

[Racingcowboy89]

Assuming it's a3-4 Mike, 3.9685.

Wow okay

 

[ch1ll]

I think those are NOT a 3 inch mic. may I suggest I measure them.

View attachment 1716489143

And asses.