barelyrunshalfthetime

Okay, I am rebuilding my engine after having a spun rod bearing. I sent it off to the machine shop and had them grind the crank/check the block. Now, is the cradle that sits underneath the engine and basically holds the crankshaft in engineered only to fit on the block it was put on from the factory? In other words, are they interchangeable? Mine has small stress cracks that you can see from just the right angle. My dad thinks they are engineered specifically for the block they came on. Please gimme some good news!

Spidey944

ummmm a cradle is a cradle as far as I know.....

alperin

If you are talking about the lower crankcase section, the girdle, then they are not interchangeable. It is machined together with the upper crank crankcase section and then cut off.

MichelleJD

What he said ^^^ Sorry.

Dal Heger

The crank cradle is matched to the block. They are not interchangeable. Well, they are, but you have to re-machine them (line bore them).

Tom M'Guinn

What he said. Also, wonder if your girdle can be welded up?

Spidey944

i thought he was talking about the x-member. Never heard of the crank jornals being called a cradle b4. Sorry!

StoogeMoe

That's why they have numbers machined on them so you can match them up to the right block.

This also is true for the balance shaft covers.

barelyrunshalfthetime

Sorry but I didn't know the exact termonology for the "crank journals," I heard my dad say cradle so that is what I used. Regaurdless, is there any way to repair the stress cracks in there? Has anyone seen stress cracks there before? How much risk is there of the damn thing breaking apart while driving? This will be a total rebuild and I don't want any loose ends not tied up...

Tom M'Guinn

Have you had it checked by a machine shop?

KuHL 951

Have you had the girdle actually dye checked for cracks? There are all sorts of odd looking marks in the casting on those things. I just can't see the girdle developing cracks under normal conditions. It's worth a professional look to make sure it's actually a problem. The lower ends on these things are built hell bent for stout unless something really serious happened to your crank in an earlier incident; usually a rod bearing/piston/valve fails long before the bottom end. Just a thought.

V2Rocket

You could detonate a nuclear bomb inside one of the NA motors and it would fire right up. No need for a warmup either :]

JimV8

A lot of girdle talk.