51 Commodore 8

[Deleted User]

Well I found the knock, one of them anyway. The thrust bearing had about a forth of the babbit pealed off. The crankshaft looks ok except for a few dark streaks about half way around the journal. It feels smooth to the touch but I hope the journal is not out of round. Anybody got any good news I've only got number 2,3 and 4 main caps off and the crankshaft and bearings on those don't look bad at all. Does anybody know of a good way to get the top half of the bearing out. The problem is not the screw, it is that I can only drive it around so far and then I run out of room to drive it on out because of the curve around the crankshaft journal. Does anybody know of any curved object or tool I can use to get the top bearing the rest of the way out?

Buck McGill

Unknown

Loosen all the mains and the bottom cap screws holding the timeing cover on so the shaft can drop down a few thousands. .002 or 3 should do it. Been there done that.

[Deleted User]

Hello there Billy. Yes I thought of that but a guy told me that it takes a puller on number 1 and 5 to get the cap off. He said he has the puller. Do you know anything about this?

Unknown

bmcgill wrote:

Hello there Billy. Yes I thought of that but a guy told me that it takes a puller on number 1 and 5 to get the cap off. He said he has the puller. Do you know anything about this?

Yes you need a main bearing puller to remove the front and rear caps on the Hudson engines but just to lower the shaft a few thousands just loosen the nuts and bolts in the timeing cover a little bit and pry the shaft down. I have a puller that was made in the T.V.A. machine shop at Kentucky dam in early 1940s.

Park_W

Buck, lacking a puller for the "end" mains, you can do it this way: put the two oil pan bolts back in the cap, with a washer, and using the sharply bent end of a small crowbar, place the end of the bar under the bolt/washer, with the fulcrum against the adjacent oil pan surface. Pry the cap down a little at a time, switching back and forth from one side to the other so you're not cocking the cap in the block. I pulled them this way many times before I found an original puller at a flea market.

[Deleted User]

Thanks Park for the advice but I know a guy who has a puller that I can borrow. The problem is now, finding a set of main bearings. Do you know of any I can get. Like you may have already read, about a third of the babbit is pealed off of the thrust bearing cap.

Park_W

Buck, it's pretty difficult to find "ready to use" main bearings for these critters. And of course you'd need to "mike" the journals first to know what size they are. Even if you know the journal sizes, there's the problem of taking a "semi-finished" rebabbitted shell and machining it to the right size. One has to have a jig of some sort to hold the two halves in precision alignment, and most shops don't have such a rig. Finally there's the question of whether there's been enough block "aging in" to put the bearing saddles out of alignment, which is the situation in most cases. All this is to say that's why the standard approach is to have your main shells rebabbitted, then install them and have them line bored. That means the engine has to come out of the car. But just think how much easier it wouid be to clean it up and repaint it! Not to mention the frame and other underhood area.

Hudsy Wudsy

If I might weigh in here, Buck...I'd say that your at the point where you should probably resign yourself to pulling the engine and doing the bottom end (at least) properly. I don't recall if you mentioned the number of miles you think this engine has on it, but that much wear on the thrust bearing likely translates to a lot of where elsewhere. What I say here may not apply to your engine, but that kind of wear often comes from "lugging" the engine (old timers taking off in second gear) and not down-shifting early enough. That kind of laboring the engine is also very hard on valves. Have you checked the compression? Also, it really is likely that your new mains will need to be align bored in order to provide the years of service the cost of rebabbitting justifies. The following thread is one I started a while ago. In it, a few sources are mentioned for good, quality babbitt work at fair prices.



http://www.classiccar.com/forums/showthread.php?t=12383&highlight=rebabbitting



I'm sorry if all of this seems far more than you originally bargained for. A rebuild on an eight cylinder is an expensive proposition, but a '51 C8 is not a common car and one probably worth putting money into. Also, it's likely that, given the time of year, you would rather be driving than rebuilding. To disappoint you still further, the turn around time on this kind of engine work can be months. There's only so many qualified people still doing rebabbitting.

A possible compromise is to consider is buying a good running six cylinder engine to run in your car for the time being, while your eight is tied up. They're usually available without much searching. There are few fussy little matters in the conversion (exhaust, wiring, etc) but nothing of much bother. Sorry if my thoughts depress you, but good luck in whatever course you follow!

Park_W

Buck, I've used Harkin Machine out in S Dakota for two different rebabbitting jobs ... rods and mains both times. His turnaround time has been more like three weeks. Prices have been quite reasonable. Talk to him about current pricing and turnaround. His phone, as of Oct 2007 Hemmings: (605) 886-7880.

[Deleted User]

Hi James. This car shows 52 thousand miles on the odometer. I think your advice is right but money is the issue. I went to visit Doug Waldrick today and if anybody knows Hudsons he does. He loaned me a puller and sold me some uses main bearings that I think will work. He showed me things about the 8 cylinder that I did'nt know on how they oil and how to check the bearing clearance. Not only the money issue but if it was'nt for the fact that this engine don't smoke a bit, has 125 psi of compression on every cylinder and very little blow by and runs smooth as silk, I would pull it out. After talking to Doug, I think I can make these bearings work even if I have to shim them up. Other than the thrust bearing, the other bearings look pretty good and the crankshaft looks pretty good. I hope the crankshaft is not out of round like you mentioned. That is just a chance I'll have to take. By looking at it I don't think it will be. This car also has a hydramatic so lugging it might not be much of an issue even though it does seem to start lugging pretty good in high gear before it shifts down unless I press harder on the gas and then it seems to go down to second gear. I figure that is the nature of the old hydramatic. Thanks for your advice but I think I can make this work for now. Send back if you have anymore advice.

[Deleted User]

Hi Park. Thanks for your advice. I am pretty sure the bearing I got from Doug Waldric and the bearings in my engine are standard. I'll find out when I check the clearance. A poor man has poor ways. I think I can shim them up enough if I have to.

Hudsy Wudsy

I agree with you entirely. Given the low miles and the seemingly sound top end, I would do all that I could to try and make the botom end work as well. I didn't know that it was a Hydramatic either.