Cascade Crew

townaj · Posted: Sat Aug 08, 2009 12:42 pm Post subject: Crank Issues. Help!!!

Ok so I have a 383 4 bolt main that I am putting together to throw in my Z28. I am in the process of assembling it, but I have run into a problem with the crankshaft. When I tighten down the very last main cap, the one with the rear main seal, the crank will NOT turn. It won't even budge. I can tighten down all the other caps and it turns easily. This isn't normal is it? Wtf is going on? I need to get this damn thing in the car already. Any help is appreciated, thanks.

kurfbird · Posted: Sat Aug 08, 2009 2:38 pm Post subject: Crank

Are you sure that you ahve the rings in right. I had a friend that had the same problem. He hacd the pistions rings in wrong. It sound slike the same thing.

Twilightoptics · Posted: Sat Aug 08, 2009 5:38 pm Post subject:

I'm assuming no connecting rods are on yet?

You have the block surface nice and clean, the bearings with the holes and tangs the right way and lots of assembly lube on the bearings?

What about loosening 1-4 and torquing #5? What happens then?

Using a plastigauge like you should?

townaj · Posted: Sat Aug 08, 2009 5:47 pm Post subject:

No rods or pistons yet. I just had the block hot tanked so its super clean. Bearings are where they are supposed to be. Even #5 torqued on its own won't let the crank move. I was using plastigauge but I ran out. One side of the lower half of the bearing is super tight. So....what now? I don't want to modify anything until I'm sure it won't destroy the engine later. Thanks for the help.

chevymad · Posted: Sat Aug 08, 2009 6:09 pm Post subject:

Get more plastigauge. Also check the size #s on the back of the shells for that main. I had a set where half the bearings were one size, and half another. Didnt catch it til the motor was running.

townaj · Posted: Sat Aug 08, 2009 6:23 pm Post subject:

Ya I'm gonna see if anyones open tomorrow. If not I'm gonna have to wait til monday. Another delay Rolling Eyes

. It's just so weird that that one is so much smaller. I didn't check the #'s yet though. I already closed up shop after getting too frustrated lol. Plus the shop doesn't have lights so I can't see anything. I thought this thing was gonna go together so fast once I got all the parts...boy was I wrong lol.

townaj · Posted: Sun Aug 09, 2009 2:53 pm Post subject:

Ok so I went and checked the bearings to make sure they were all the right size and unfortunately they were. So much for an easy fix. I'll have to go get some plastigauge tomorrow and see where its tight.

Twilightoptics · Posted: Sun Aug 09, 2009 6:13 pm Post subject:

What's the status of the crank? Is it freshly turned? STD? What are your bearings? STD, 10, 20 etc. Was the block line bored?

townaj · Posted: Sun Aug 09, 2009 7:47 pm Post subject:

Crank is brand new from Scat. They are all standard sized bearings, I went out and double checked this morning. Block wasn't line bored though. Would only one cap be that out of line though? I can torque down all the other caps and it still turns as free as if they weren't there. How much does line boring usually cost?

chevymad · Posted: Sun Aug 09, 2009 7:59 pm Post subject:

Where did you get your bearings? Alot of aftermarket cranks require a special bearing. The fillet radius is different, larger, on the aftermarket cranks. So they tank a bearing that has more space to match.

townaj · Posted: Mon Aug 10, 2009 6:22 am Post subject:

They are Clevite bearings that came with the rotating assembly. I bought a complete 383 assembly and thats what came with it. So I should try to buy a new bearing? Do they even sell bearings one at a time?

Twilightoptics · Posted: Mon Aug 10, 2009 9:10 am Post subject:

You need to measure.

townaj · Posted: Mon Aug 10, 2009 10:36 am Post subject:

Nows the time I wish I knew someone with micrometers. I'll have to take it to the machine shop sometime and have them do it I guess.

townaj · Posted: Thu Aug 13, 2009 7:02 am Post subject:

Ok so the rear main cap was the wrong one. So I took the engine back to the machine shop and am making them find the right one. Pissed is not enough to describe how I feel. So hopefully I'll have the engine back and in the car soon.

chevymad · Posted: Thu Aug 13, 2009 5:05 pm Post subject:

Umm. wow! How does a shop that does an align bore get the wrong main cap on the block when its finished?? Shocked

Good job paying attention though.

Twilightoptics · Posted: Thu Aug 13, 2009 5:24 pm Post subject:

How'd you figure out it was the wrong cap?

What machine shop did you use? It wasn't Modralls was it?

townaj · Posted: Thu Aug 13, 2009 8:16 pm Post subject:

I have no idea how it happened but now I won't have the block until monday Evil or Very Mad

. I have no idea how I caught it. I just decided to take the bearings out and tighten down the caps, just to see. Turns out that there was a HUGE difference in how they lined up. I wish I had taken a picture. Basically the bore on the cap was not in line with the bore in the block. I know its clear as mud, but I'll see if I can draw a picture.

No I didn't use Modrall's. I unfortunately don't live in the PNW anymore. Im down in Texas. This machine shop came highly recommended. They do work for all the race teams around here. Circle track and drag racing. So far I'm not impressed. At all, it takes way to damn long for them to get work done. I gave them the engine yesterday and it won't be done until Monday. Bashy Bashy

chevymad · Posted: Thu Aug 13, 2009 8:45 pm Post subject:

Well i've waited months for machine work. So the time frame is ok, but swapping main caps is a huge mistake.

townaj · Posted: Fri Aug 14, 2009 7:28 am Post subject:

Yea I'm pissed. I wanted to have this done by the time school starts on the 24th but who knows if I will now. Oh well now I have more time to work on the exhaust. Any tips for running a 3 inch true dual system? I have glasspacks instead of mufflers since they were cheaper and smaller. I'm not sure how loud they'll be though.

Quasi-Traction · Posted: Fri Aug 14, 2009 8:29 am Post subject: