MN71W30

I bought a 69 455 short block with new pistons and bearings, never ran. I needed to have it drilled for a 4 speed. After getting that done I reinstalled the crank and used a Federal Mogal assembly lube that was a tar like substance.
After torqueing down the main caps I noticed I couldn't spin the crank by hand. I needed to use a 3/8 socket extension poked into a hole in the crank shaft counter ballance holes to spin the crank. It wasn't hard but I couldn't do it by hand.

Question 1. Could the tar like lube be causing increased drag on the main caps?
#2 Is it worth the trouble to pull the pistons and try a different oil lube on the mains?
#3 Wouldn't it be solved after a few minutes of running? Is that one reason they reccomended a breakin?
#4 Should I get it line bored?
Thanks for any help.
Dave

J-(Chicago)

What were your clearances?

MN71W30

The engine was just assembled by a shop in Hastings MN. I didn't bother to re-check their work. But I guess it's the place to start.
Dave

Danny Wiseley

If you were turning it easily with all the pistons installed, I don't think you have a problem. You should be able to turn the crank by hand BEFORE you install the rods/pistons, but after they are installed your hand needs a little help. Turning it easily with a short extension speaks well of your builder.
DW

MN71W30

When I talk about turning the crank it is before the rods were connected. I pulled the main caps and it seems the rear main cap has wear already on one side. I'll try to get a pic to show the problem. It takes 30 to 40 ft lbs to get the crank to start spinning with the pistons. Once it is started it drops to 20lbs then increases to 40 at one point in the rotation.

88 coupe

Always check everything.

Debris under the bearing?

Norm

MN71W30

The sufaces below the bearing are clean. Ah yes, rechecking their work you hit a sore spot.
It seems the older I get the more cynical I become. I dropped of a BBC block a few weeks back to get the cylinders checked at a major machine shop in MPLS MN. and was told they had .006to .008 taper and needed a re-bore and of course new pistons etc. that they would be glad to sell me. I rechecked the cylinder taper and it is .0000 it was the same motor I had a professional assemble and it ran only 20 minutes and had enough blowby to make your signature statement about classic blowby very possible. I took him to court, the only time I have ever sued anyone in 45 years, And lost. He was the builder that drilled into my water jackets on my heads while installing seats and charged me $180 for 3 attempts to get them to stop leaking with epoxy, anyone need a boat anchor?
I dropped another set of heads off to a different reputable shop earlier this spring and they are still there collecting dust in his shop. It seems I can't win with machine shops. I could go on with several other stories but won't.
Hers a pic of the bearing surface.

My442

Crank journal is not strait, or it could be bent.

With just the crank, it should spin easily by hand.

AJCDFIN

Hey; If that wear mark has appeared from just turning crank over by hand you have a problem. Remove bearing and re-clean checking for any debris between brg. & cap. Plastigage everything correctly, you fill find out whats going on. Good luck

cts-v

FYI, I reassembled my 455 about a month or two back. Main bearing clearances were all within spec (#1-4 were all about .0015-.0020 and #5 clearance was about .0025). It spun very very easily by hand w/o rods and pistons installed. I used an assembly lube that was more like white lithium grease, and it spun just as easily before and after I applied the grease (comp cams brand engine install lube).

If you don't have a manual, the clearance specs are...

.0005-.0021 clearance for #1-#4
.0020-.0034 clearance for #5

(this is from a 1970 service manual).

Hope this helps. Tom.

64Rocket

Get rid of that rope rear main seal. Use the split rubber seal from a 460 Ford.
70 to 86 Ford 460. If the parts person can't figure that out, tell them an '83 Ford truck 460.
Also make sure the crank is straight. The machine shop may have drop it or let it fall or something when they drilled the crank Take it to a crank grinder, he can check it.
Gene

MN71W30

I'll swap ot the seal, thanks for the tip. I'll drop off the crank and get it checked. The rear cap bearing had the wear spots before I pulled it out to get it drilled.
Thanks

My442

You also should check the alignment of the main bearing caps.

MN71W30

You nailed it rocket! I pulled the rope seal and reinstalled the rear cap and the sucker spins like a top. I'll be picking up the seal tomorrow.

My thanks to all you guys for the help and ideas.
Dave

442_Mustang

Have you ever tried Wheeler in Blaine?

MN71W30

I've been there at a dyno run and they have a good reputation. I think I may try them next.
Dave

442scotty

With the rubber seal do you not have to polish the crank at that location? Also I would still get the crank checked to make sure it is straight...Cheap insurance

MN71W30

I was thinking of stting up a dial indicator on the main cap surfaces and giving it a spin. That should tell me if I got a bend in the crank.

Good question on the seal surface. I need to know that.

64Rocket

I have not had that area polish for the seal. But when they polish the crank after grinding they always polish that are also. I imagine just to take the rough edges off. I have not ever seen anyone polish it smooth. Just make sure you put the beveled edge facing the back of engine.
Gene

MN71W30

You da-man Gene.
Thanks

kaz442

Hold on if you have that kind of wear on the bearing from just spinning the crank by hand. What do you think its going to do at 5000 rpm? Theres something not right. Were the mains line bored? Was the crank cut and checked for straightness? Trust me I have been around the block when it comes to keeping bearings in an Olds. Ask the builder what he set the clearances up at. I like them on the loose side .0025-.0030 on the rods .0030-.0040 on the mains.
Check it now or plan on redoing it later.
Just my .02 JKaz

citcapp

A clarification please. I have read elsewere in the big block forum that storing the crank flat on the floor or on a bench can cause the crank to bend, is that true? If so could that be the origination of this problem? I Agree on having the crank checked that wear just doesn't look right.

dan2286

I have heard that also from some old school engine builders, but I don't know how true it is. If you look at the crank standing straight up, you can tell that the counterweights can still cause the crank to "bend" over time the same way if it was sitting flat on a floor.

I noticed in a machine shop I was using that they had all there cranks standing up, but it could have been to save space.

I would think the best way to store a crank is in a block or just make some type of fixture to support the mains like if it was in a block.

MN71W30

I bought the short block assembled from a guy who had it built by a shop about 25 miles from me, since then it has sat a couple years because the project he had fell through.
I'll check the clearances before I install the pistons. I don't have any reciepts or paperwork. I'll pick up some plastic gauge and see where I'm at with the rods and mains. I don't have a mic the size I need. Thanks for the heads up.
Dave

MN71W30

I checked the main clearances with plastic gauge and when they were inbetween the gauge sizes and I estimated the best I could. The crank wasn't completely without oil.

1. .0028
2. .0032
3. .0025
4. .0028
5. .003
I took the reading on the 5th cap exactly where the shiney area is and it came out at.003
The rope seal area on the crank looks to have machined crosscut grooves where the rope would be.
The crank numbers are 39736 N
I'm thinking it's going to work.
Dave

Warhead

That bearing does not look right.
Put the crank in a set of v-blocks, or put the end bearings in the block, and use a mag base/dial indicator on the #3 main to see how much bend is in it while it spins.
I would rather you be safe, than sorry.
Jim

MN71W30

I checked the runout with my dial indicater and the cap with the scrape has a .001 wobble in it. I need direction, Thanks

442scotty

Thats a good question...

64Rocket

I would take it to the crank grinder and have them check for run out.
NOT the machine shop who did the engine, an actual crank grinder. They have the tools to check run out.

Gene

MN71W30

The measurement should be very accurate. I have set up many rear ends over the years and understand runout and tolerances. I used a dial indicator on a stand. I did call a local machine shop that drilled my crank for a pilot bearing and he said it should be fine. I was surprised with his answer because he had a chance to make some money and didn't. I was expecting and answer like "you better bring it in and we'll turn it another .010."
Thanks,
Dave

MN71W30

The Olds is running again.
The Oil pressure is good, The engine runs strong, no shakes, no blowby, LOTSA RUBBER.

Thanks for all the help guys.
Dave

citcapp

Congrat's now your smiling again thats good