318 steel crank or not?

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68383GTS

68383GTS

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I just bought a 1974 rebuilt 318 and was wondering how can you tell if it is a steel crank or not.It looks to me to have the thinner balancer on it which makes me think its a steel crank engine.I had a 73 340 years ago that had the wider balancer on it .So I always assumed the 340 was a cast crank motor.I know the general rule on a 383-440 is wide balancer is a cast crank engine.
Any ideas?I do have to change out the oil pan so is there anything to look for here that may help?

Thanks,Jim
 
71 and older 318's had steel cranks, after 71 should be cast. From what I understand the poly 318 had the same dimensions of the LA version and it was steel. If I'm mistaken I'm quite sure someone will chime in.
 
If it is stock. There will be balancing weights on the dampner for a cast crank motor as they are externally balanced.
 
it's cast crank.

very few 318's had steel cranks and it was not a 70 & up or what ever deal that people say.
some truck motors had steel crank.
pre '68 273/318 had steel cranks.
 
my 67 318 came with a steel crank

either way...unless you plan on pushing big power out of it or plan on running some form of forced induction or something. You won't have any durability issues with a cast crank.
 
If you're taking the pan off, look at the parting line on the crank. You'll be able to tell from that. A thin parting line will be a cast crank, and a wide parting line will be forged. If it's a rebuild, I wouldn't assume that the crank is original to the block. I would also guess that it's probably cast.

There are a couple of pictures at this site to show what I mean.

http://www.jalopyjournal.com/forum/showthread.php?t=118441
 
needsaresto said:
If it is stock. There will be balancing weights on the dampner for a cast crank motor as they are externally balanced.
Click to expand...

That's true with a lot of engines but not always the case. I had a buddy with a 76 318 that had a cast crank and it used a neutral balancer. I'm sure it was original too. As long as the crank is heavy enough to balance you can use a cast crank and internally balance it. My new 408 I built has a cast crank and balanced out just fine internally without adding Mallory metal. The super light weight Wiseco forged pistons and lighter than stock SCAT I-beam rods I used helped a lot.
 
fishy68 said:
That's true with a lot of engines but not always the case. I had a buddy with a 76 318 that had a cast crank and it used a neutral balancer. I'm sure it was original too. As long as the crank is heavy enough to balance you can use a cast crank and internally balance it. My new 408 I built has a cast crank and balanced out just fine internally without adding Mallory metal. The super light weight Wiseco forged pistons and lighter than stock SCAT I-beam rods I used helped a lot.
Click to expand...

Agreed.

My factory crank in my 67 318 was a steel crank and the journals had been chewed up pretty bad and it was going to cost me just about the same to have my crank turned as it would cost for me to get a remaned .010/.010 crank WITH bearings...so I went ahead and went that route.

only difference was that the new crank was a cast crank.

BUT it was internally balanced just as my steel crank had been so I had to do nothing more to it, just swapped my dampner from the other crank on.

and she runs smooth and purrrrrrs!
 
needsaresto said:
If it is stock. There will be balancing weights on the dampner for a cast crank motor as they are externally balanced.
Click to expand...

that is not true with 318....

the rotating assembly of a 318 is light enough that the cast crank can be internally balanced....

internal/external balancing..depends on the rotating weight of engine vs the counterbalance weight of the crank

there are forged cranks that need mallory metal to get internally balanced...
 
fishy68 said:
That's true with a lot of engines but not always the case. I had a buddy with a 76 318 that had a cast crank and it used a neutral balancer. I'm sure it was original too. As long as the crank is heavy enough to balance you can use a cast crank and internally balance it. My new 408 I built has a cast crank and balanced out just fine internally without adding Mallory metal. The super light weight Wiseco forged pistons and lighter than stock SCAT I-beam rods I used helped a lot.
Click to expand...


According to Larry Shepard;

All the following cranks are 3.31 stroke.

64-66 273 had a forged crank.

67 273 and 318 had forged cranks.

68-71 340 had a forged crank.

His list only goes to 1980.
 
needsaresto said:
According to Larry Shepard;

All the following cranks are 3.31 stroke.

64-66 273 had a forged crank.

67 273 and 318 had forged cranks.

68-71 340 had a forged crank.

His list only goes to 1980.
Click to expand...

I already posted this info above earlier but..

the reason the 64-66 LA cranks are listed separately is because they have small convertor registers/hubs and will not accept the later[68&up] trans /convertors, however I'm pretty sure the OD of the register is the same for all years 'LA' so that flywheels will interchange in that aspect in all LA years.
2 ways to overcome this is ...to open up the ID of the register to accept the later '68&up tranny/convertor snout, or use the early tranny/convertor. BUT you can NOT fit later convertor guts into a early convertor case.
The other way around [newer crank to older trans/convertor] you can have the early convertor guts installed in a later convertor shell 'so that the splines match' , I've done this and had it cut for a higher stall at the same time=$179 total, or you can make a spacer.
just a fyi
 
I will have to get a pic of the banlancer and crank.I need to know if its cast or steel so I can buy the right flywheel for it.The engine came out of a 74 Valiant and my best friend rebuilt it.I am sure the crank is original to the motor.

Thanks,Jim
 
I have a flywheel I would sell.

It is for a 727 , not sure if you have a 904 or a 727?

I took it off my 318 because I ended up running a 904 auto and had to get a 904 flywheel for mine.

if you are interested just PM me

but if you have a stick...than I am of no help HAHA
 
this is the way i have always told it.

All 273/318 are Internaly ballance and have NO off set balancer on the front, whether they are cast or steel.

All 360 are cast cranks and have a off set balancer for External balancing.

the 340,Up to 73, they were steel cranks and internally balanced,

73 was the only cast/ Externally balanced, with its own special offset balancer

I know this don't answer you Question completely.
 
1wild&crazyguy said:
does the guy have an auto or a manual??
...and there ain't no 727/904 flywheel man, come on.lol
Click to expand...

I meant to say flexplate not flywheel lol

the difference between 904 and 727 flex plates are ....A904 Automatic Transmission uses a 10 Inch Bolt Circle flex plate

where a 727 Automatic Transmission uses a 11-1/8 Inch Bolt Circle
 
68383GTS said:
I will have to get a pic of the banlancer and crank.I need to know if its cast or steel so I can buy the right flywheel for it.The engine came out of a 74 Valiant and my best friend rebuilt it.I am sure the crank is original to the motor.

Thanks,Jim
Click to expand...

Jim I'll be PM'ing you in a couple minutes about when I can come up to get the 400. Maybe then I can look at your 318 and help.
 
I have a neutral balance 130 tooth flywheel for a 318 I am not going to use PM me if you are interested
 
Look on the front balance weight for a clock looking diagram, this tells you it is cast. My '73 crank has one. I think all 318s after '71 or so had cast cranks anyway.
 
needsaresto said:
If it is stock. There will be balancing weights on the dampner for a cast crank motor as they are externally balanced.
Click to expand...

All 318's are internal balanced whether they had a steel or cast crank. It was the 340 cast crank and all 360's that were external balance.
 
I've ran across quite a few steel crank equipped 318's. I find them to be mostly in '68-'70 stuff, lots of trucks as well. My '71 Duster has a cast crank though...
 
dgc333 said:
All 318's are internal balanced whether they had a steel or cast crank. It was the 340 cast crank and all 360's that were external balance.
Click to expand...

Ah your right! My memory let me down on this one,lol!
 
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