318 cast/forged..John Kunkel?

[dave571]

What year did the 318 La engine start to use a cast crank?

I seem to remember reading that the small blocks were the first to go, 69 being the last year of forged production(except for 340). I've theorized that production was split in 69, as I dissassembled a 69 273 that had a cast crank in it. I'm almost positive that the engine had not been messed with as I knew the original owner of the car, and it only had 120 thousand miles on it.

I have directed this question to John Kunkel, because he seems to have pretty good access to this sort of technical info, on a regular basis. ANYONE who has some info on this can PLEASE answer as well.

This question came up on the "383 steel crank or 440 cast??" thread.

[John Kunkel]

From what I've been able to gather, the change took place about the same time as the 340 which was mid '72.
From '73 on they were all cast except the 318-3 truck crank which was forged.
To my knowledge, no 273 ever had a cast crank. After 35+ years you're liable to see anything.

[VernMotor]

yes I was led to beleve all 273 had good forged cranks in them..

[dave571]

I was under that impression as well(that 273's were all forged). That's actually why I was taking it apart. I wanted the crankshaft.

It was definately the original engine to the car, like John said, after 35 years anythin is possible. Although, It was 93 when I took it apart, so at that point it was only 24 years. If the engine had been apart, it was done right. I think it was the Direct connection engine book(the one with shelby on the back) that I saw it was 69 where the cranks changed. Sorry I don't have the book here right now. It made sense to me that if the 318 was cast in 69, then late production 273's might have been as well(due to production line mix ups)

Let's say it was 72 that the change took place(and it probably was)

The source of confusion seems to be that some people think the 318 didn't come with a cast crank(ever), because it is internally balanced. The 318 is an example of a cast crank engine that doesn't have an obvious external difference in balancers, ect.

[Brian Mills]

To my knowledge 1968 was the last year for the 318 forged crank. I have one hanging in the garage. In 68 the 318 piston was 0.020" taller than 69 and on. 273 I never had one.

318-3 truck motor, disassembled a 1974 model, and it had a cast crank.

Rumor has it that 400 B in a truck with a 4 speed equiped with bull low had a forged crank. An oddity?

[dirty dan]

Originally posted by dave571
The source of confusion seems to be that some people think the 318 didn't come with a cast crank(ever), [/b]

The people of wich you speak,need to get out more.
I don`t do small blocks for my self but I knew they were both steel and cast.
As for when they changed I didn`t know.
But I would say it was the same time they changed the exhaust manifolds.
Does anyone know when that was?

[John Kunkel]

For written reference, the old Direct Connection Racing Manual states that the 318 used a forged crank through '72. The Hollander Interchange shows a change in the 318 crank in '72 although it doesn't actually state the difference.

[VernMotor]

Well I have a 71 400B motor with a forged crank. came out of a imperial . I was told t is the only car only year they did it. yes been told they did put them in trucks.

[dave571]

I found this chart in a book called "How to rebuild your small-block mopar" Published in 82. Written by Don Taylor and Larry hofer. I have to type it in, as I don't have scanning ability here.

year cid material cast#/forge#

64-67 273 forged 2128278, 2128869, 2205700

68-69 273 cast 2658268, 2658393

67-73 318 cast 2658278, 2658393

74-86 318 cast 2658278, 2658393, 3462387
2658391

68-72 340 forged 2532457, 2843868

73 340 cast 3462387

71-86 360 cast 3418640, 3418641, 3418642

The chart also had journal diameters, ect, but I left that stuff off to speed up the typing.

The book also has a chart for dampener ID and con rod ID

Whether or not the chart is accurate, I have no idea. I can only assume it to be reasonably close, as I have not seen a factory chart to contradict it. Perhaps someone has access to something the part #'s can be crossed to?

This book is clearly not a factory service/reference manual, so take it for what it's worth.

[dave571]

clearly the chart didn't come out like I typed it in.

In any case, I think you can see jist of it.

year, cid, material,part#, then the extra #'s spilled onto the next line.

Is it readable?

[Brian Mills]

That is pretty cool Vern. Until recently I had very little regard for 400's. Sort of like the thing that marked the end of an era.

Dug into the Engines book, seems 318 and 340 both had forged cranks 68-72. They were not the same cranks however just both were forged.

318-3 truck crank was forged and hardened.

Whoa, hold the phone. 8 pages later there is a crank general info chart. It shows 273 and 318 as having forged cranks till 67, and then cast from 68 on. Shows a 318 in 1967, I always thought 1968 was the year. Don't ya just love this sh*t.

64-66 273 auto 2463551-forged

64-66 273 manual 2268119-forged

67 273&318 2268119-forged

68-71 273&318 2843699-cast

Then all cast except for 68-71 340.

[Tarrbabe]

I am no expert but I usually go to the Mopar engine book and it tells me that the 318 used the forged crank until 73.