[xafalcon]

I have a couple of 400M cranks. Is it possible to use these to make a 4" stroke cleveland? The main jurnals would obviously need to be turned down. The perhaps using a 302C rod there may be a piston that would be suitable?

Any ideas or experience with this?

Cheers
Tris

 

[brenx]

It's not a conversion I've seen done. Although I have heard of it. I wouldn't imagine it'd be cheap?

 

[xyfmtjoe]

I would say it would be an easier conversion in a 351windsor block as I think they drop straight in.

 

[Rhett]

I've read somewhere that it takes a heap of machining, then balancing, and you still only end up with a weakened cast crank.

 

[davis]

I have a couple of 400M cranks. Is it possible to use these to make a 4" stroke cleveland? The main jurnals would obviously need to be turned down. The perhaps using a 302C rod there may be a piston that would be suitable?

Any ideas or experience with this?

Cheers
Tris

The short answer is that the 400 (no M) is already a 4" stroke Cleveland. Just put a set of good heads on it, use a decent inlet and some extractors.

I definitely would not recommend turning down the main journals to fit the Cleveland main size. You'd have to take them down by a quarter inch. As Rhett says: it takes a heap of machining, then balancing, and you still only end up with a weakened cast crank.

There is no way that a 400 crank will ever fit in a 351 Windsor block. They both have 3" mains, but the bearing spacing is different and so are the bearing thrust surfaces. You can't even reasonably machine a 400 crank to fit a 351W.

The 400 crank will drop in to a 351M.

The Scat 9000-series "cast steel" cranks (and other manufacturer's corresponding components) are very low cost. Unless you happen to own a machine shop, they are a much cheaper option than cutting down a 400 crank to fit to a 351 Cleveland block.


:davis:

 

[Racer]

There is no way that a 400 crank will ever fit in a 351 Windsor block. They both have 3" mains, but the bearing spacing is different and so are the bearing thrust surfaces. You can't even reasonably machine a 400 crank to fit a 351W. :davis:

I beg to differ. I used to own one until just recently.

The 400 crank was turned down and fitted with Chrysler 265 rods. It came out at around 426ci. It used to be a fairly common conversion down here (in a 351 Windsor).

But its not the thing to do these days, with cheap stroker cranks available. The cost of mallory alone would buy you a finished, purpose built crank.

We also used to fit Cleveland cranks into 302 Windsors - but thats another story...

 

[davis]

I beg to differ.

Don't waste your time. Do they "drop" right in? No. Is it even reasonable to machine one to fit? No. There is nothing to "differ" with.


:davis:

 

[xdclevo]

Don't waste your time. Do they "drop" right in? No.
:davis:

davis, i don't think he is machining one up right now. Have you been on the heavies :beerbottl

 

[xafalcon]

Haven't checked this thread for a few days and look what's happened. All hell breaking loose. PAW (Performance Automotive Wharehouse, USA) makes a 427W stroker kit using a machined down and offset ground (4 1/8" stroke) 400M crank and uses chrysler 360 rods and a KB off the shelf piston. From what I've read, no mallory is needed. It is balanced in combination with a 50 oz-in flexplate and balancer. The kit retails for US$400 over a basic 351W kit so the machine work can't be too drastic.

So I thought rather than attacking the rod journals like the windsor conversion above, why not reduce the main journals and it becomes a 4" stroke cleveland crank. Won't be any weaker than a standard cleveland crank, and how often do they fail? Thought somebody may have done it before. But by the sounds of it this is not the case. Probably a good reason not to have a go myself - if it was practical someone would know someone who has done it before.

Thanks for the input though. Always appreciate another opinion.

Cheers
Tris