Thread: Crankshaft Question

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I'm about to start on a 327 build and I've run into a little problem with the crankshaft. It's a small journal steel crank. I was cleaning the oil passages out today and noticed it has some pitting on the main journals and it's been turned. The block I pulled it and the rods out of was busted. The rods are good, had them re-conditioned, but I knew the crank had some places on the main journals in the area of the oil groove in the upper bearings where there was a little crusty buildup. I was concerned about them but I thought that turning the crank would fix it. If wasn't for them it wouldn't have needed turning. Anyway, the machine shop here in town doesn't turn cranks, he sends them to another guy that does it. He told him if it didn't look like .020 would clean it up to call him. The guy told him it cleaned up at .010/.010 and sent it back. As I understand he's been turning cranks for a long time. He also drilled and tapped it for a balancer bolt. When I picked up all my stuff I didn't lay it down and really check it out. I just glanced at it and the journals were nice and slick. Well today is the first time I really looked at it and the main journals have some small pitting. They're slick as glass but they have the pits so now what? I'm pretty sure another .010 won't get rid of them. Why would a shop that turns crankshafts send one back as good. I don't think the guy at my shop really looked at it to be honest. I think he took the guys word since I know he would have mentioned it to me. I know him. Is there any pitting like this that's acceptable? I assumed it's not a good idea to use it that way. I have been told it won't hurt anything since it's been ground and polished. Anybody have any thoughts? If I have to find another one it's gonna suck since they're not a bunch of them laying around.

it is ok pitts will hold oil it ok .hi spots get in trouble on a crank . so fresh ground no hi spots it nice s to have no pitts but it will work long as it radial with the journal and not a cross the journal or big rusty low spots were there is more pitts then anything

99.9 % of the surface is good .. as pat said .. use it

Not tryin to throw a hair in your biscuit.

Did you get "Your" crank back.

Is it truly "pitting" or has the crank been welded on. I have seen a few/bunch welded crank jounrals that have pitting on them.

I ground cranks for a "major" rebuilder for 7 1/2 years and yes we welded a bunch of them. The older 2pc rear seal cranks would eat up the thrust bearing surface and need to be welded and ground back to size.

BTW the older buick 231 V6 split pin cranks were the worst ones for eating up rod bearings and thrust bearings.

I alway mark my stuff before sending it to the shop so I know what i'm getting back.

i been at for for some time . i seen were the upper half of the main bearing shell as its 180 groove will pitt rust will pitt a crank. not just a poor weld job....were the oil gets water/ junk in it and eat the crank in time . this is some thing i seen more then one time on older engines the two pc seal surface can be ground if not bad from wear in or rust pitts or you can buy a off set seal has well . i have filled small pitts on only the seal face with Jb weld and hit it with the crank shaft polisher most of the welding on rods are EZ to tell when they been welded has not many make the oil hole s look like they have not been welded i would think a small shop would not wast to much time welding more then one or two jorurnals on a crank thats not hard to get a good core. just the time to weld puts the crank over the value of a common crank like this .has a engine builder on most stock stuff will not get welded less hard to find .when the crank thurst is gone the crank is NFG

Oh no, it's not been welded on. The crank and rods came out of a motor that probably had never been torn down. It was a standard bore block and came out of a 65 4 door Impala. I think what happened to it is what Pat was talking about. The areas that are pitted are where the cruddy places were and they were at the upper bearing locations. I figured they would clean up but there is no telling how long this motor had set up. I couldn't use the block as it had a pretty bad crack in the lifter valley. I didn't give anything for it since it was cracked but I got the crank and rods. I'm going to use it anyway. I've had about 6 people tell me it should run just fine. A couple have told me they've seen this before on older cranks. The seal area is pretty slick so I think it will be ok. I may get an offset seal just to be on the safe side.

i have done older engine like said the last was a 36 caddy and was like yours have a 65 283 the same way as well

Originally Posted by pat mccarthy

...... just the time to weld puts the crank over the value of a common crank like this .has a engine builder on most stock stuff will not get welded less hard to find .when the crank thurst is gone the crank is NFG

Thank you! I tryed to tell them this for years.
(Per Journal)
Welding time. 10-15mins.
Rough griding. 10-15mins.
Filling pit holes missed by welder. 5-10mins
Rough grinding #2. 4-5mins
Dressing oil holes. 2-4mins.
Redressing radius and wheel 5-10mins
Finish grinding.2-3mins.
Checking for size/taper/side clearance/s. 2-3mins
Now you have 40-60mins of labor for one common 350 cast crank journal. It just anit worth it.
Plus the warrenty problems. JUST ANIT WORTH IT?

Tidefan, Pat

Please dont take what I posted the wrong way I just threw that out there for something to check and make sure you didnt get jacked.

J Boss looking for advice!
Back of the thrust bearing went out, pulled the crank it was bad on the back side of the thrust bearing, had it rewelded and turn down, and noticed there are pits. Could you tell me if this will cause problems with new bearings?
thanks
T Lillie