When cutting the con-rod to accept this, it cuts into the rod bolts about .050. It really isn't a good fix IMO. I've seen a few of these, only after they had done it,and ended up here because it had some problem. Something that doesn't get taken into consideration is these rods also have a side clearence that needs to be obtained when re-poured and when using inserts, you are unable to obtain that.

Also, I've heard that the insert rod bearings are much harder than the poured bearings and put a lot of wear on the crankpins.

I heard of two fellows who attempted to make the changeover in 1937=47 Hudson engined and I believe that in both instances, they went back to the poured bearings. I wasn't clear on what went wrong. Possibly the bearing WIDTH was too narrow for the journal, so there was movement from side to side.

I'd be interested in hearing from someone who has actually done the conversion (not just "had it done"), either successfully or not, to hear about their experiences. To judge whether or not it's a viable alternative without firsthand knowledge of the methods and components used is simply perpetuating rumor.
As with any such modification, there are a myriad of ways to do it incorrectly and but a very few ways to do it right.
I have done it and am very pleased(so far)and have just completed another insert conversion project.
The proof of the puddin' will be in the eating, of course, and it may take years/miles to know the results, but I'm not yet convinced that it's a bad idea......unless it's done wrong.....just like everything else.
Respectfully,
Frank

You are absolutely right, Frank. I'd like to hear more about your mod. Which bearing shells were used?...k

Well, I might be absolutely wrong, too. I was just challenging the nay-sayers to present some real discussion without just repeating the same old stuff they've heard from others. I'll agree that there are some obvious and some not-so-obvious considerations for the mod, but it can't be impossible to do it successfully. (did I say "can't"?)
It's an old argument that comes around every so often and there [i]are[/i] potential issues with it, for sure.
Such as......
"Particle embedment".....or lack of it:
A quality inherent in old poured Babbitt bearings that allows abrasive particulates conveyed by the oil or generated within the bearing to be embedded in it's surface. The Babbitt material, or "white metal" must be soft enough to facilitate this effect. Some (maybe most) modern insert type bearings don't have this ability (hence, the comment about bearing hardness). Why? they don't need it because modern engines employ a full flow type of oil filtration system, sometimes in conjunction with a finer "bypass" type of filter. If the particles don't reach the bearing to begin with, it's much less of an issue. Needless to say, full-flow filtration in a "Splasher" (or "Splashie", Down Under) isn't possible in the typical sense of the term due to lubrication system design. One [i]can[/i] make improvements, though.

Heat Transfer: A less effective (IMO) transfer of heat generated within the bearing from friction at the white-metal/crankshaft-journal interface is probably the most significant problem. Inserts work fine in pressure lubricated engines since there is a relatively high flow of oil through the vertical clearance. Heat is carried away by the oil effectively enough to prevent failure. The splashers are.......well, splash lubricated, so the oil flow through those bearings is substantially lower resulting the need for good heat transfer from the white metal to the rod itself (and subsequently on to the outside world via oil flow). Poured Babbitt bearings are the best at heat transfer since the Babbitt is cast directly into, and becomes "one with", the rod. An insert, unfortunately, provides an insulating effect at the insert/rod bore interface, somewhat reducing the necessary transfer of heat.
The solution? All one can do is provide the correct housing bore diameter to create proper "crush", a fine finish on the bore to maximize contact area, and take some measures to enhance oil flow though the bearing, thus improving the cooling effect.
There are some other factors about these engines that come into play as well, IMO.
I wouldn't be crazy enough to guarantee success. Only miles will tell [i]that[/i] story.
There are some procedural considerations for the project as well, but....

My finger is getting tired. ...hello? ............hello? is anyone still awake?
F

If I recall correctly I believe Kelly Hinegardner fitted shells to his Hudson 8. Kelly was a machinest and a darn good one, among other things. Unfortunately he's been gone nearly 10 years (passed away in 2005).

Hudsonly,
Alex Burr
Memphis, TN

Frank, I agree with your observations totally and think you're right on the money about the lesser volume of oil in the splasher system. You might want to get hold of Buzz Stahll on this subject. He and Ivan Zaremba were building an eight cyl. engine a few years ago with pressure oiling but got sidetracked by other things. Steve

Steve,
Buzz, Ivan and I have kicked this stuff around in the past. The Railton engine to which I assume you are referring has no pressure lubrication at all but does have a Mini Cooper pump driven from the cam front that delivers oil to an external manifold with noozles directed at the rod dippers, ala Stove bolt Chevy, the intent of which was to prevent oil starvation under high G forces encountered in road racing conditions. I don't know of a pressure lubrication mod for their eight, although I know of it being done by others. It's not possible on a splasher six for several reasons, but it can be done on an 8.....not a small project for sure.
An eight left as a splasher will perform well for longer than you and I if it's built right and taken care of.
F

Hi Frank, Yes you are correct and I stand corrected. It's been quite a while since Buzz and I had discussed the mods to that engine. It ought to be a heck of a good runner when they get it done though!

Unless we're talking about two different projects, The Railton 8 has been running for some time and Ivan had it at the San Mateo Meet in '13.
My first exposure to it was at the Spokane Nats where Buzz showed me a photo album of their work. Intriguing stuff. I borrowed their rear main seal mod method for our 212, more as a part of a PCV system than anything else.
F

Hi Frank, yeah, we're talking about the same engine/car. Like I said, it's been a while since I discussed this with Buzz, glad to hear they've got it running. Steve.

Hello Frank. I have been following this thread, but have been too busy to respond sooner. There are so many variables here. What is the application you are wanting to use this engine for?. In racing, as you know, R&D is an absolute necessity, and as you have defined, It DOES DEPEND ON WHO IS DOING WHAT/how. Suggesting it hasn't been done successfully yet is because of incompetence or lack of ability or knowledge?. Anything can be re-engineered to better apply for my/our use of it, BUT if the way Hudson did it originally still works totally and sufficiently for my application-WHY WOULD I CHANGE THAT? Again, the same applies here for a stock design Hudson engine as does the modified application of your choice. It depends who is doing it,the R&D and/or the complete rebuild of the "STOCK" old babbit poured bearings from factory. I have personally run the heck out of many 8 cylinder Hudson engines, all in the last 40 years. Modern oil has made a tremendous difference in the way parts wear.If you want to re-engineer the rod bearings to accept inserts, why not do the mains too?. It all can be done, but the $$$ need to be comparable to the re-pour of factory parts. By the way, I have seen Ivan's Railton, and I think it is absolutely GREAT !-gotta be the fastest Hudson eight cylinder in exsistence. It is quite entertaining!-Go Ivan

I'm not suggesting that it hasn't ever been successful.....I believe it has. However, it seems that every time the subject comes up (as it quite often does) the only responses are from those who shoot down the notion that it can be done with success, apparently without first-hand experience of actually doing it. I'm not opposed to a proper job of re-Babbitting Hudson rods and I'd do it myself if I had the experience, knowledge and equipment to do so. It's a dying art and my hat's off to those who provide that service. Sometimes we gearheads just do stuff because we can.....it doesn't necessarily mean we think it's an improvement. Consider the Kevlar clutch facing discussion or the Toyota 5 speed trans conversion. I see some ask why you'd want to do such a thing....."why would you want to shift all those gears?". Because we like to, that's why.

"........why not do the mains, too?"

I'm sure that's possible as well but it would be quite another project to ID and adapt suitable inserts.

I'm a little fuzzy on your question about what the application is for "this engine". It wasn't my project that began the discussion. I was reacting to the comments implying that it was a bad idea by citing my experience as an example that it can be done successfully if the methods and parts are appropriate. I can't imagine that others haven't done it as well.
Your point regarding the cost of conversion as compared to a re-pour/machining job is well taken. I wouldn't suggest that it's a less costly way to go. I reiterate: sometimes we just do this stuff 'cause we can and we like to.
I'll post some photos of my version of the mod later if anyone cares to see them.
Cordially,
Frank