Author Topic: Think the 318 crank will handle it?  (Read 6633 times)

Offline aris_unlimited

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Think the 318 crank will handle it?
« on: April 15, 2015 - 07:32:31 PM »
Basically planning a 318 centrifugal supercharged build. 9:1 compression boost at 7 lbs or lower. Goal is 500-550 hp probably similar torque. Forged rods and pistons, just didn't want to have to go with a forged crank if I didn't have to. Don't really plan on going over 5500 rpms. Thoughts?
« Last Edit: April 15, 2015 - 07:35:19 PM by aris_unlimited »
Cuda is gone :(

74 satellite, daily driver/project now




Offline cudabob496

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Re: Think the 318 crank will handle it?
« Reply #1 on: April 15, 2015 - 07:38:06 PM »
no expert, but I would get a forged crank

read that there are not enough head bolts to support a
blown 318
« Last Edit: April 15, 2015 - 07:44:53 PM by cudabob496 »
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline aris_unlimited

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Re: Think the 318 crank will handle it?
« Reply #2 on: April 15, 2015 - 09:14:24 PM »
I have never heard that about the head bolts. It may be true under high levels of boost, but honestly I am hoping to keep my boost around 5 lbs (it might see 7 for a bit before I get it all sorted out).
Cuda is gone :(

74 satellite, daily driver/project now

Offline cudabob496

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Re: Think the 318 crank will handle it?
« Reply #3 on: April 15, 2015 - 09:28:13 PM »
I think there is only 10 bolts.
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline mopar jack

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Re: Think the 318 crank will handle it?
« Reply #4 on: April 15, 2015 - 11:24:43 PM »
back in the 70's if you wanted a strong 318 crank you would find it in a truck. Direct connection recomended them because they were forged with hardened journals.

Offline cudabob496

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Re: Think the 318 crank will handle it?
« Reply #5 on: April 16, 2015 - 12:06:15 AM »
use studs on the main caps


In this article, they swapped in a forged crank, just to make 400 hp!

http://www.hotrod.com/how-to/engine/mopp-0409-318-engine-build/

However:
http://www.moparchat.com/forums/showthread.php?t=67298
« Last Edit: April 16, 2015 - 12:14:42 AM by cudabob496 »
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline Chryco Psycho

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Re: Think the 318 crank will handle it?
« Reply #6 on: April 20, 2015 - 03:56:05 PM »
A 318 forged crank should be easy to locate , good peace of mind IMO

Challenger - You`ll wish You Hadn`t

Offline HP2

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Re: Think the 318 crank will handle it?
« Reply #7 on: April 21, 2015 - 01:31:49 PM »
Its a 318. I'm sure there are a million replacement cranks, and blocks, out there after you crack this one.

Offline aris_unlimited

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Re: Think the 318 crank will handle it?
« Reply #8 on: April 21, 2015 - 11:51:08 PM »
Its a 318. I'm sure there are a million replacement cranks, and blocks, out there after you crack this one.

lol the goal is to not crack it. I try to do everything right the first time so I don't have to redo it.

Anyone have any advice on finding a forged 318 crank? I have no idea how to go about finding one from other vehicles, and have pretty much assumed I will have to buy a new one.
Cuda is gone :(

74 satellite, daily driver/project now

Offline cudabob496

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« Last Edit: April 22, 2015 - 01:22:31 PM by cudabob496 »
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline HP2

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Re: Think the 318 crank will handle it?
« Reply #10 on: April 22, 2015 - 10:23:53 AM »
Then you need to look for any pre '72 318 car crank , and 318-3 truck crank, or any 64-67 273 car crank.

The forged crank will allow it to flex more if your tune is off or your waste gate fails, but a cast crank can be built to hold up reasonably well if you radius the journals and oil holes and have proper bearing clearances.

Offline aris_unlimited

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Re: Think the 318 crank will handle it?
« Reply #11 on: April 26, 2015 - 01:07:15 AM »
DL searches all craingslists in US

http://www.dailylister.com/Search_Results.cfm?q=318+crankshaft&as_oq=&cx=006225133476456637497%3Anhut7xqnd70&as_occt=Title&cof=FORID%3A11&ie=UTF-8&sort=date&newwindow=1


Thanks a bunch for that. I found a forged crank from a 273 in AZ and with shipping it will cost me $140. Saves me a tad over $600, over a new one.
Cuda is gone :(

74 satellite, daily driver/project now

Offline cudabob496

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Re: Think the 318 crank will handle it?
« Reply #12 on: April 26, 2015 - 01:17:05 AM »


Thanks a bunch for that. I found a forged crank from a 273 in AZ and with shipping it will cost me $140. Saves me a tad over $600, over a new one.

Way Cool!
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline TelisSE440

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Re: Think the 318 crank will handle it?
« Reply #13 on: April 26, 2015 - 06:00:39 AM »
Good luck with your build, send photos if you can when ready  :thumbsup:

Offline aris_unlimited

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Re: Think the 318 crank will handle it?
« Reply #14 on: April 26, 2015 - 03:21:36 PM »
Good luck with your build, send photos if you can when ready  :thumbsup:

I'm sure I'll post pics, but right now I am in the stage of getting parts lol.
Cuda is gone :(

74 satellite, daily driver/project now