? about that 3.65” crank

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greymouser7

greymouser7

Vagrant Vagabond “Veni Vidi Vici”
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That one seller on eBay sold those Mopar length connecting rods with Chevy sbc sized wrist pins.

couldn’t someone match a set of Chevy pistons with that crank and those cheap rods up to a 340 , R, X, or 318 block? (Fairly easily?)

if the big league guys here are not jumping on that it might help the seller.

what do you guys think?

<{(24 hours from now I am done with my algebra 2 midterm woohoo!)}>
 
greymouser7 said:
That one seller on eBay sold those Mopar length connecting rods with Chevy sbc sized wrist pins.

couldn’t someone match a set of Chevy pistons with that crank and those cheap rods up to a 340 , R, X, or 318 block? (Fairly easily?)

if the big league guys here are not jumping on that it might help the seller.

what do you guys think?

<{(24 hours from now I am done with my algebra 2 midterm woohoo!)}>
Click to expand...


By the time you screw around with all that, you can buy a custom piston. I have a 3.79 crank out there for my R block W2 deal, and I’m just buying a custom piston. Then you get what you want and not a compromised shelf piston. I don’t believe a W2 head can feed a say...419 inch engine at anywhere near 7500. I doubt it’s even realistic to expect a head like that to really feed a 4.08 by 4 inch deal (419 inches) at 6500 without a ton of cam timing and a tunnel ram. So I’m going to see about feeding 390 inches at 7500 and look at what the cam numbers look like.
 
greymouser7 said:
That one seller on eBay sold those Mopar length connecting rods with Chevy sbc sized wrist pins.

couldn’t someone match a set of Chevy pistons with that crank and those cheap rods up to a 340 , R, X, or 318 block? (Fairly easily?)

if the big league guys here are not jumping on that it might help the seller.

what do you guys think?

<{(24 hours from now I am done with my algebra 2 midterm woohoo!)}>
Click to expand...
Yes you could. In the end, it is really all about where you want to end up with the build. Even a Chevy slug would have to be a custom order and probably more so since there valve angle is 23* & not 18*. You can have a MoPar piston custom done with a Chevy pin size EZ enough. Just as easy to just grab some Eagle con rods and couple it with a custom MoPar piston. It’ll be equally pricey for a custom slug.

This would not be cheap ether way. Just the rods. The more you customize a piston, the more it’ll cost. It could start off setting the savings.

It’s .07 more stroke, which can be huge on the piston side of things. If it was less .07 in stroke, that would be different and possibly use a 360 slug.

Figure $650 for the crank, $1,000 for pistons, 5140 steel I beam rods (500 hp) for 278 - Eagle SIR I-Beam Connecting Rods SIR6123CB

$1928 .... rings and bearings not included, balancing extra.

Or for $490, get upgraded rods to 750 HP handling capacity.
Eagle H-Beam Connecting Rods CRS6123C3D
Total $2140

Might as well get the better rods and supercharge/turbo the engine at the rate we’re going here! LMAO! Still, it is a cool crank and adds 7 cubes vs a 3.58 crank. Boost that 340 another 40 cubes right quick.

Good luck on the math test!
 
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greymouser7 said:
That one seller on eBay sold those Mopar length connecting rods with Chevy sbc sized wrist pins.

couldn’t someone match a set of Chevy pistons with that crank and those cheap rods up to a 340 , R, X, or 318 block? (Fairly easily?)

if the big league guys here are not jumping on that it might help the seller.

what do you guys think?

<{(24 hours from now I am done with my algebra 2 midterm woohoo!)}>
Click to expand...

Soon as I saw that crank, I knew you'd fall all over it. Just stick with stock stuff man.
 
I get ya. It is an interesting crank. It would be a lot cheaper and only a few cubic inches smaller in the difference sticking with stock parts. For general Hot Rodding and a lot of racing applications, which most people are not seriously racing, a standard crank and EZ off the shelf pistons are a lot cheaper and just as effective. Building an engine with this crank is something I’d like to do just for fun. It would be cool to couple it with a race block bored at 4.180 and make a really nice short stroke 400 cubic inch engine. Now that would be cool. But this would take a whole lotta dough!

LOL, give that combo a good set of heads and watch it scream down the track.
 
Demonic said:
Build a 4" stroker with a popular kit, then build one with this crank - see what the shorter arm really gets you.
Click to expand...

*It Should* net you more upper and higher RPM HP vs the longer stroke. The shorter stroke will have more cycles (suck, squeeze, bang, blow..) per second (because of the shorter distance the piston travels) than a 4.0 arm crank there by creating more available HP.

This is why a 340 is a better bore and stroke set up than a 360 for racing. The Italians demonstrated this very effectively throughout history with there short stroke/big bore engines in there super cars from the early days of racing to modern times.

The draw back is this set up needs a lot of RPM to shine which makes it a harder working engine based on, more RPM’s is working harder to produce the power. If you don’t have your crap straight, you’ll kill the engine.

Americans did the reverse. This is mainly due to the nations topography and the general usage and need for what we need the engines for. Hauling and moving big heavy things. Unlike Europe, moving smaller and lighter things.
 
Wallace Racing Calculate Piston Pin Height

3.65 stroke
6.125 rod
9.6 deck height

A piston with a 1.65 Compression Height (CH) would work... zero deck



Back in the day before Mopar stroker pistons were readily available I used an off the shelf Forged Diamond chevy piston with my 3.79 crank. Diamond Piston only charged $64 extra to customize the Mopar valve reliefs.
 
Nice! Thanks for the calculations.

Just shows you really don’t know until you crunch the numbers.
 
Yeah Rob, I’m at work and don’t have the time to search a piston but it seems that a ford 351C piston has the correct CH, but the wrist pin is a different diameter.
With today’s CNC programming most piston manufacturers can modify their CNC program and provide a custom piston relatively inexpensive...

BTW, the LIRR trains are empty!!
 
Yes! Very empty!

I (obviously) didn’t do any cross referencing to what could work. Being creative will save a lot of dough though!
(Still day dreaming about a 4.18 X 3.65 Victor head build. WOOOOOO!)
 
greymouser7 said:
I don’t want it, just wondering if a guy like you could find a Chevy piston that would work.

it would help the seller, or someone here
Click to expand...

I'm sure. But by the time you find everything, you've eclipsed what it would cost for a stroker. I would love to help the seller too, he's a good dude, but that's the honest truth. That crank is for NASCAR stuff. With the 3.65 stroke and a 3.91 (318) bore, you get 350 cubic inches. The NASCAR limit is 358 cubes. So the rest can be made up with an over bore. There's not an off the shelf piston for that, unless I am mistaken.....and I could be. Mopar Performance "probably" made pistons for that combination back in the day when they actually supported us......but no more.
 
@Bighead440 is really exceptional with this kinda stuff. If anybody knows if there are off the shelf pieces to make it work, it will be him.
 
RustyRatRod said:
@Bighead440 is really exceptional with this kinda stuff. If anybody knows if there are off the shelf pieces to make it work, it will be him.
Click to expand...
MiradaMegaCab said:
Wallace Racing Calculate Piston Pin Height

3.65 stroke
6.125 rod
9.6 deck height

A piston with a 1.65 Compression Height (CH) would work... zero deck



Back in the day before Mopar stroker pistons were readily available I used an off the shelf Forged Diamond chevy piston with my 3.79 crank. Diamond Piston only charged $64 extra to customize the Mopar valve reliefs.
Click to expand...
Looks like stock shelf pistons work:
“A piston with a 1.65 Compression Height (CH) would work... zero deck”
Rusty maybe you remember, but I don’t have the same budget. (Am not in the $$navy) As I said am not interested-“am sticking with stock.”

I just thought it could help someone out.
 
RustyRatRod said:
@Bighead440 is really exceptional with this kinda stuff. If anybody knows if there are off the shelf pieces to make it work, it will be him.
Click to expand...
MiradaMegaCab said:
Wallace Racing Calculate Piston Pin Height

3.65 stroke
6.125 rod
9.6 deck height

A piston with a 1.65 Compression Height (CH) would work... zero deck



Back in the day before Mopar stroker pistons were readily available I used an off the shelf Forged Diamond chevy piston with my 3.79 crank. Diamond Piston only charged $64 extra to customize the Mopar valve reliefs.
Click to expand...
Looks like stock shelf pistons work:
“A piston with a 1.65 Compression Height (CH) would work... zero deck”
Rusty maybe you remember, but I don’t have the same budget. (Am not in the $$navy) As I said am not interested-“am sticking with stock.”

I just thought it could help someone out.
 
The CHEAPEST thing to do with it would be to use negative deck 360 pistons. The stroke increase is minimal (.070"ish), so many pistons with a .984" pin and compatible height exist. One that comes to mind with generous valve reliefs (4) is the H405CP, with a 1.637" height. I used these (with head milling and block decking) to make a 367" (.040" over) 360 with a stock crankshaft. Got 10.5:1 with J-heads and ran 96mph in the 1/8mi with a .508" cam and unported RPM intake. You'd have similar compression without expensive decking/milling, even more with smaller chamber heads. Of course all the forged TRWs would work, but no valve reliefs unless you ($$$) have them cut. You'd have to get the small end of the Chevy 6.125" rods honed (after removing the bushing) for a press-fit .984" pin. I have a set of those rods myself, no big deal. Speed-Pro Hypereutectic Pistons H405CP
 
Last edited:
greymouser7 said:
Looks like stock shelf pistons work:
“A piston with a 1.65 Compression Height (CH) would work... zero deck”
Rusty maybe you remember, but I don’t have the same budget. (Am not in the $$navy) As I said am not interested-“am sticking with stock.”

I just thought it could help someone out.
Click to expand...

I understand, which is why I am keeping the conversation going. That's why I tagged Rodney. He's all about putting together affordable badass bottom ends. If anybody knows, it's him.
 
Bighead440 said:
The CHEAPEST thing to do with it would be to use negative deck 360 pistons. The stroke increase is minimal (.070"ish), so many pistons with a .984" pin and compatible height exist. One that comes to mind with generous valve reliefs (4) is the H405CP, with a 1.637" height. I used these (with head milling and block decking) to make a 367" (.040" over) 360 with a stock crankshaft. Got 10.5:1 with J-heads and ran 96mph in the 1/8mi with a .508" cam and unported RPM intake. You'd have similar compression without expensive decking/milling, even more with smaller chamber heads. Of course all the forged TRWs would work, but no valve reliefs unless you ($$$) have them cut.Speed-Pro Hypereutectic Pistons H405CP
Click to expand...
What fuel (octane) did you run with that build? Thanks!!
 
Bighead440 said:
The CHEAPEST thing to do with it would be to use negative deck 360 pistons. The stroke increase is minimal (.070"ish), so many pistons with a .984" pin and compatible height exist. One that comes to mind with generous valve reliefs (4) is the H405CP, with a 1.637" height. I used these (with head milling and block decking) to make a 367" (.040" over) 360 with a stock crankshaft. Got 10.5:1 with J-heads and ran 96mph in the 1/8mi with a .508" cam and unported RPM intake. You'd have similar compression without expensive decking/milling, even more with smaller chamber heads. Of course all the forged TRWs would work, but no valve reliefs unless you ($$$) have them cut. You'd have to get the small end of the Chevy 6.125" rods honed (after removing the bushing) for a press-fit .984" pin. I have a set of those rods myself, no big deal. Speed-Pro Hypereutectic Pistons H405CP
Click to expand...

Told you he would know. Than you drive through. lol
 
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