Hello Guys,

When people call a crank "steel" is that the same thing as a forged crank?
The other alternative is a cast crank correct??

Have you guys ever heard of corrosion due to anti-freeze going through the inside of the cylinder (the interior of the block) and make marks on the cylinder walls. This would supposidly create "spots" on the cylinder walls? I might need some pictures to describe this better.

Thanks in advance,

yes, there's either forged steel or cast iron. steel is better. some the CHina cranks being sold are claimed to be cast steel, which is indeed possible.

spots on the cylinder walls: yes water leaking in can do that, it makes little rust spots that get worn off by the rings, leaving visible spots. rings usually aren't too happy about the whole deal. These's also condensation, which is hard to avoid. be guided by the history of the car, whether or not the car uses water consistently. radiator shops have a little pump up tester, goes on instead of the radiator cap. pump up 15-17 lbs pressure, wait. it should be able to hold the pressure, not leak off. if it does leak off then the hunt is on to find the leak. No sense in overhauling the engine if there's a pinhole leak in the radiator or heater core.

Hey thanks Tom,

The engine in question is sitting on stand with the heads off, it is basically a short block. The pistons and crank are assembled and are able to turn over. It is a 350 SBC.

Actually the guy thought the leak came from inside the block (in the coolant passage area) and passed through the outside of the cylinder bores and then made marks on the cylinder walls. I can't see how this could happen? I mean if there is that amount of corrosion wouldn't the structal integrity of the cylinder be off?? Even if it is a trace leak pinhole leak I think the cylinder walls would be damaged a lot more?

Hey thanks Tom,

The engine in question is sitting on stand with the heads off, it is basically a short block. The pistons and crank are assembled and are able to turn over. It is a 350 SBC.

Actually the guy thought the leak came from inside the block (in the coolant passage area) and passed through the outside of the cylinder bores and then made marks on the cylinder walls. I can't see how this could happen? I mean if there is that amount of corrosion wouldn't the structal integrity of the cylinder be off?? Even if it is a trace leak pinhole leak I think the cylinder walls would be damaged a lot more?

i would really like to see pics of this. however it is possible that you could have a leak path from the coolant jacket to the cylinder wall i suppose. since the block is a casting virtually all castings have porosity to some degree. normally the casting is designed so that porosity is not formed in critical areas but nothing is fool proof. one scenario i could imagine is that there was an oxide stringer or piping porosity in that area of the casting. say it stopped short of the cyl wall around .005"/.006" when it was newly machined. it probably would have passed a pressure test at that point. then after years of wear on the cylinder and possible growth of the inclusion defect caused by thermal cycling and vibration, it is theoretically possible that the defect barely broke thru the surface allowing a "weeping" or leaching of the coolant thru the wall. if that is the case then you would not want to use that block. i would think that if you had access to someone who could do an ultrasound test on it you could confirm the wall integrity. keep us posted and put up some pics if you can i would be interested in seeing that condition.

Thanks Bill,

I got a digital camera for my birthday so now I have to start to work on getting it going. It may take awhile but I will try to load the pics to you.

It doesn't seem like something that could happen.

Thanks
Kris

There are gray-iron cranks;

Next, nodular-, (ductile-), -iron cranks; and about 4 or 5 different steel cranks, both cast and forged.

The cast steel cranks are just that, a steel alloy that can be cast.

The forged steel ones are, well forged, out of the 4 or five forging steel grades.

And finally billet cranks that are machined out of great big solid rolled/forged steel "dowel" of the steel material you want.

Pricey to say the least!

SCAT's site should have a very good write-up on all this if you can find it?

pdq67