New, need help with assembling a v8 60

[rwrj]

Good Afternoon. I have been on the HAMB for awhile, and lurked on here, but haven't posted before. I have a thread over there on a '37 tin side v8 60 that I am trying to get running. It's not a complete rebuild, I just popped in a couple of sleeves, honed it and put in new rings, the crank, rods, and bearings seemed fine. Here's the problem:

I'm re-assembling the motor, but when I torque the L1 rod cap, the engine will not turn. I am using the same rods, caps, and bearings that were on it before. I was careful not to get them mixed up. Nothing was dropped or mishandled, so no tolerances should have changed (I did not measure the crank, rods, or bearings, since I was re-using everything). Valve train and cam are in, heads are off. The rods and caps are marked L1-L4, R1-R4. They are all matched up and installed with the numbers on the outside, facing forward, 1234 from the front. Main caps are on, torqued to 45lbs. With seven rods torqued to 25lbs and the L1 nuts snugged up but not torqued, the motor will spin with a wrench on the crank, a little stiff, but doesn't take too much effort. With even 10lbs of torque on L1, it's stuck so that I can't turn it with the wrench. Didn't try to force it with leverage or anything like that, but it sure feels tight. I have researched fitting floating rod bearings with a mallet, but should that be necessary when I am re-using everything? The motor turned by hand before I tore it down.

I hate for my first post to be begging for help, but I don't want to mess this little motor up. It sure is a slick little thing.

Thank you in advance for any help, Wes White

Edit: Forgot to mention that everything was well oiled before assembly. Sorry about that.

[Seth Swoboda]

You should let us know your approximate location so that we may further help. Especially if there is someone here located really close to you.

[rwrj]

I am in Southwest GA. Just north of Tallahassee, FL.

[flatjack9]

With the rods off the crank, see if the bearings will turn freely on the journal. Then insert the bearings in the rods and torque to spec. See if they turn freely. Adjust as needed.

[rwrj]

I know they spin on the crank. I'll drop those two pistons and check the rods. Thank you.

[Ronnieroadster]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by rwrj

I know they spin on the crank. I'll drop those two pistons and check the rods. Thank you.

If the engine turned prior to you taking it apart and since your using the same bearings then I would look at the rod caps you may have placed one on the rod reversed that would cause the locking up troubles if everything turned freely before taking things apart.

[rwrj]

I have triple checked those rod caps. At least triple. They are all marked, and I checked when I was tearing it down, all the marks were matched and lined up. Even took pictures with my phone. I left the bearings zip-tied in place on the crank journals, stored the rods with the caps on, nuts loose. I am positive everything is in the same place and orientation it was. Flatjack9, I tried what you said, and that rod clamps down on the bearing so that it won't spin. Just for fun, I reversed the rod cap and tried it again, still clamped. I know the old way of adjusting these is to measure and tap with a rubber mallet, but they seem to fit the journal and the other rod just fine, so I'm not sure how to deal with this. Is it a stupid idea to cut some shims for each end of that rod, where the bolts are, kind of like a Model A? I didn't notice any of the rod bolts seeming loose when I tore it down, but the only thing I can figure is that these two must have been barely torqued.

[rwrj]

Ok, you guys please tell me if this is wrong. I got the micrometer and measured both big ends of the rods that share that bearing. The one that was tight was about 7 thousandths out of round. It was wider (bolt to bolt) than it was tall (measured perpendicular to the cylinder). I know they are relieved right at the rod/cap joint, didn't measure it there. I have some shim stock is about 5 thousandths, and some that is about 2. My solution was to make tiny little Model A style shims that fit around the rod bolts. I made sure that they didn't interfere with the bearing, flange, or other rod. Math got me close, but I had to take it apart and put it back together a few times to get it right. As it is now, torqued down, the rod won't quite fall under its own weight, but it rotates easily with light pressure. I just matched it to the other one. Put it all back together and torqued to 25 lbs, engine rotates with moderate pressure. Feels about right to me for a fresh hone and rings, but I've never fooled with a flathead before. Like I said, if there is a catastrophe looming, please let me know. I sure do appreciate the help. Wes

[Bob C]

If it was mine I would have the big end honed, not sure how much this
would throw the balance off.


Bob

[J Franklin]

How did things change during disassembly?

[rwrj]

Only thing I can think of is that whoever was last in this motor just didn't torque that cap enough to bind it. I didn't notice when I tore it down, but I was cracking each nut loose and then going back through, might have just thought I had already cracked those when I got to it? After measuring it, I'm sure it couldn't have been turning if it had been torqued up.

[Ronnieroadster]

I agree with Bob I would have the big end honed to size. Using shim stock is not the best idea your going to end up with an oval shaped bore.

[rwrj]

I don't get it, guys. According to my measurements, the bore was oval to start with. The shims moved the cap away from the rod far enough that the bore now measures round with the micrometer. I may not have explained it well. I did not shim the bearing or any bearing surface, but the spaces where the rod and cap meet, where the bolts are. In a normal set up, that gap would be asking for a spun bearing, but these are floating bearings, so that's not an issue. I'm not trying to be one of those guys who asks for help and then argues, just want to make sure I have been clear about what I have done. You are probably right, though. The best thing would be to to get the big end honed back round.

[flatjack9]

I would have to agree with the others. Have the rod honed to size. Did you check the spread on the bearing from end to end? Is it tapered?

[rwrj]

I did check it, its not tapered. I also tried it turned around, same rod was tight on each end of the bearing. I'll take it to the machine shop after the holiday and get it bored. I appreciate the help. Wes