Has anyone used insert bearings? If so, how do you like them. I have bought a new SCAT crankshaft and I am considering buying the new rods with insert bearings.
You didn't say which crank. I assume it would be the Stroker crank for Model A type rods. IMO inserts should only be used on a full pressure oil system. Inserted bearings are washed with clean oil from inside out.
Our T Model engines are splash and because of the lack of an oil filter all of the wear, carbon and iron is in the oil. The babbitt that is poured and bored in a standard engine will absorb that for a long time giving good service life.
Modern inserts have a very thin coat to the bearing surface and would not last long with out clean oil all the time.
Even though SCAT offers the Model A stroker and the stock size Model T crank in drilled version, I agree with Mike that insert rods or mains should be used only with a pressurized and filtered system.
The suppliers recommend a pressurised oil system.
And if you have to replace the inserts in 15 or 20 years, what guarantee do you have that they will be available???
Good comment, but if all else fails you can always go back to Babbitt. I could be wrong here but the inserts are only available for the rods, this is more of a question than a statement.
I agree with you that you can always go back to babbitt.
I believe there is a shell that can be used with model A size main bearings. As I recall you put two pairs in the front and centre main and three in the rear main. I believe the suggestion was to install halfs of bronze thrust washers on the rear caps.
with a pressure oiled and souped up engine I would sure consider the shells. Just by design they will take more bearing load. In a relatively stock engine it would not make much sense to me.
Here are some some shells used in a stock no pressure Model A with less then a 100 miles on it.
They just can't get rid anything that the oil carries.
Well known Builder.
Those look like the shells I have seen. I thought they were for a Wisconsin or something like that.
Snyders sells new rods with dippers, designed for solid babbitt inserts and no oil pressure. Has anyone tried these?
I have no idea what was the Original App. was, but were used here.
I work mostly for other engine builders, and this was an engine that came to them after it blew up, not there's of course.
That's where I get a lot of Motor screw up pictures, they are from other builders, always interesting!
Snyders sells new rods with dippers, designed for solid babbitt inserts and no oil pressure. Has anyone tried these?"END QUOTE"
They also have the New rods with out being machined for for inserts, and Babbitted instead.
But they are using lead babbitt in them instead of High Speed!
I see they claim they are forged 4140. If that is true then I am impressed.
You say the bearings are lead babbitt. Did you have the material analized at a lab?
Don't need it analyzed, its my job to know.
Don't lay any money on it not being lead, you will loose!
Maybe this will help you to see the difference.
Lead is on the left.
Lead is on the left.
Lead is on the left.
Again Lead. Snyders
Tin Babbitt with out X grooves.
Tin Babbitt with X grooves.
Not only may it be lead babbitt, it might be RECYCLED BABBITT. Old babbitt generally retains that dull gray blue color even when it is melted, skimmed, and poured into chills. It also may be good new babbitt that is handled improperly. Melting more than you need, keeping it hot for a long time and melting/solidifying babbitt multiple times also makes it less suited for the job it has to do.
That freshly machined tin babbitt is flat out beautiful!
Last winter we used a set of the inserted rods from Snyder's on a rebuild.
The rods were .020 undersize and machined to fit on the crankshaft. The engine has no oil pressure system it run for about 5000 miles this season without any problem. So I think the inserted rods will work.
I have no pictures of the rods after they were machined but they were clean .
I like the idea of the insert con rods. I have made some shells for a 8-38 Briscoe engine. I made them from bronze and precision bored them in a fixture to .008 clearance. I then babbitted them (with Harris heavy pressure) and rebored them for the right fit. The shells had .002 of "crush" total so they clamped in nice and tight and gave me .0015-.002 running clearance
I am not sure I would have enough faith in a straight cast Babbitt shell but Babbitt lined bronze is hard to beat.
I also "stretched" them curvature wise so they pressed in by hand nuggly into the rod.
About 10 years ago I had Federal Mogul run off a couple hundred sets for some equipment we built for the oil industry. They were quite co operative and fair price