NOS 3.51" mopar stroker crank in a 318?

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m880

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I have had the crank for at least 15 yrs,bought it from Mancini racing.
Question is has anyone ever found a forged piston that has the 1.72"-1.74" CH.
I've ran across truck cast pistons but that defeats the purpose of a forged crank.
And to me the gained stroke doesn't justify custom pistons.
Heavy *** crank,shame they didn't drill the front and rear rod journals.
 
Those "NASCAR" car is are very much a part that you ether need to run in your respected class or you WANT to do something odd ball.

I have one that was part of a parts deal that may get used next year. It is designed to destroys a .030 overbored 360 down to under 355 cubes. Actual displacement is 352 instead of 365. The 13 cube hit in size isn't a big thing.
It is a 3.45 stroke crank.
 
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rumblefish360 said:
Those "NASCAR" car is are very much a part that you ether need to run in your respected class or you WANT to do something odd ball.

I have one that was part of a parts deal that may get used next year. It is designed to destroys a .030 overbored 360 down to under 355 cubes. Actual displacement is 352 instead of 365. The 13 cube hit in size isn't a big thing.
It is a 3.45 stroke crank.
Click to expand...

Ok i need to ask as i to have been sitting on one of these cranks for 10 years, I have a fresh machined 30 over 340 block, any input on what pistons to use with this crank, it has been very hard obtaining any info on this crank, I have a set of custom pistons that were made years ago from diamond racing, but the shop went under and i never really know if they would work? the custom piston card says , bore= 4.070, comp height = 1.704, effective volume= -6.8cc, valve depth intake 0.292, exhaust 0.224, piston weight 561 Grams, Top ring 1/16 2nd ring 1/16 oil ring 3/16 my wife had them made as a gift and surprise under the direction of the shop owner but it went under some time ago. Thanks for any help.

ps trying to figure if I can use this or look for a diff crank and piston combo?
 
Piston companies like Diamond and Others can make custom Pistons for your needs. Last I checked Racetek (not sure if spelling is correct) was reasonably priced.
 
Rocket said:
Piston companies like Diamond and Others can make custom Pistons for your needs. Last I checked Racetek (not sure if spelling is correct) was reasonably priced.
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cool but how do i know what to ask for as this is an off the norm stroker crank? Do I just tell them the crank is a 3.51 stroke, 30 over boar 340?
 
crank stroke, rod length and what compression you're looking for........cc of the head you're going to us.
They may ask other questions as well, but if you can give him/them this info. you will be on your way to a answer.
 
What you need to do is bring it all down to a machinist so he can have a look at it all.
 
Sell it and buy an affordable crank that you can actually get affordable off the shelf pistons for.
 
I guess maybe so. But I wouldn't like being limited by some dorky NASCAR crank. That was its sole purpose, to meet the 358 CI rule. Unless he is using it for some type of limited CI rule, it's kinda pointless.
 
RustyRatRod said:
I guess maybe so. But I wouldn't like being limited by some dorky NASCAR crank. That was its sole purpose, to meet the 358 CI rule. Unless he is using it for some type of limited CI rule, it's kinda pointless.
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This is true. but he HAS it and because of the very reasons you post, I doubt there will be many buyers and they wont want to pay him anything.
In fact, Id offer him maybe $200.00 USD plus shipping for it. A little less if it has 8 crank bolts.
 
I don't know nothing about this crank, but this is what is running through my mind.
318 with 360 head put the compression in the toilet!!!!
A 10.1 318 with better breathing 360 heads. all for the price of a custom piston.
that's the road i would be trying to go down if my option was a 318 and that crank!!!
If you can put a 4" crank in a 318 you sure can put a 3.51 crank in without the rist pin sharing the oil ring groove!!!!
Machine shop can crunch the numbers.
 
m880 said:
I have had the crank for at least 15 yrs,bought it from Mancini racing.
Question is has anyone ever found a forged piston that has the 1.72"-1.74" CH.
I've ran across truck cast pistons but that defeats the purpose of a forged crank.
And to me the gained stroke doesn't justify custom pistons.
Heavy *** crank,shame they didn't drill the front and rear rod journals.
Click to expand...

If you are close to Merritt Island FL call Brevard Cylinder Head 321-253-3317, ask for Victor. He is very good, won't BS you, and knows Mopar.
 
scott hoffman said:
Ok i need to ask as i to have been sitting on one of these cranks for 10 years, I have a fresh machined 30 over 340 block, any input on what pistons to use with this crank, it has been very hard obtaining any info on this crank, I have a set of custom pistons that were made years ago from diamond racing, but the shop went under and i never really know if they would work? the custom piston card says , bore= 4.070, comp height = 1.704, effective volume= -6.8cc, valve depth intake 0.292, exhaust 0.224, piston weight 561 Grams, Top ring 1/16 2nd ring 1/16 oil ring 3/16 my wife had them made as a gift and surprise under the direction of the shop owner but it went under some time ago. Thanks for any help.

ps trying to figure if I can use this or look for a diff crank and piston combo?
Click to expand...

In your situation ....your 1.704 compression height is good....

3.51/2=1.775+6.123+1.704=9.5882.......340 block should be around 9.60 deck height....piston would be down in hole about .018...

have the block squared and decked to 9.588...or run it with a thin head gasket....028
 
I have a similar or same crank (It's been a while since I looked at it) ready to go into a 360 block. (It has the larger 360 mains) It is designed to destroke a .030-360 down to meet the rules. I have it all. It makes the engine into a 352. Think of it like a 340 with more stroke or a .030-360 with less stroke.

There's worse things in the world. It will still move an A body really well. I just wouldn't want to order custom slugs. MP used to have all of this on a shelf waiting.

Personally, if I was in the position of having a 318 & this crank, I think I'd opt. for a 340 block.
4.04 X 3.51 = 359.96
4.07 X 3.51 = 365.32

The (possible) 8 bolt flange is not a big deal. You just have to take an extra 2 minutes to look a little deeper to find what you need and it is not terribly expensive.
 
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I want to thank every body for the input, sorry to hyjack the original post just figured we might both learn a thing or two. presently there are 4 of these cranks on ebay going for a fair price, can not remember what I payed but it was cheep and new in the box. it is 8 bolt and the fex plate was easy to find. the rest is just eagle rods, the diamond custom pistons that I already have, fresh X heads, hughes special grind cam for this crank, and eddy Air gap manifold, Harland sharp rockers, and hughes hold downs. I do not trust many shops in my neck of the woods, and i drive past Phantom Works every day on the way to work, I am going to bring the build to north carolina nascar countryshop that only does mopars and has a 3 month back log on there builds, for the wait I will get a video on youtube of the breakin. Thanks again for the input.
 
Best of luck with it all!
Keep us posted!
 
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