Conversion to insert bearings?

[alexiskai]

OK, so you're saying that AER's statement, "Insert main and rod bearings work fine without any changes to oil system. Bearings work with or without pressure oil system" is false? AER, the guys who built thousands of insert bearing engines? Those guys are using an oil groove design where "bearings are constantly starving for oil"?

 

[Synchro909]

That’s a pressurized groove. The gravity grooves are different and spread the oil across the entire bearing.

In a bearing like that one, the annular groove carries the oil to the the bevelled edges of the inserts where it is spread across the bearing. As I said above, I have done many ten of thousands of miles with inserts and original oiling system. The ONLY time I had a problem was when 20W60 oil was all I could get. During the 2,000 miles trip home, the rear main was scored. The previous 5,000 miles were done with 15W40 oil (as have all the miles that engine has done) without issue. I figured the heavy oil was not flowing quickly enough and so gave inadequate cooling.
How long have AER been doing this and are they still in business? IMO, the answer to that will tell you whether it is OK or not. I understand the theory behind what you are saying but reality often hasn't learned the theory.

 

[Dodge]

JeepGuy,
I just saw your post, Jay Jay pretty much hit it on the head. The engines can and have been done by the home builder, but you should have a pretty good understanding of engines if your going to do it. The connecting rods are the main thing that needs the balance corrected.
The Burtz assembly instructions are very good and should be strictly followed.
I check the balance on every engine, aside from the rods the rest of the engine can be checked in less than an hour. There are a few other tricks when doing these, every builder has his own secret sauce.

 

[Sunny the Model A]

OK, so you're saying that AER's statement, "Insert main and rod bearings work fine without any changes to oil system. Bearings work with or without pressure oil system" is false? AER, the guys who built thousands of insert bearing engines? Those guys are using an oil groove design where "bearings are constantly starving for oil"?

just because they made thousands doesn't necessarily mean it's the best way to do something. Henry made almost 5,000,000 A engines and every single one left the factory with babbitt bearings. and if we add the T and the B into the mix we are talking over 20 million engines with babbitt. and for the record yes the insert engines do starve particularly in high load low rpm situations like flooring it in third gear at low speed. under the load the crank is going to want to shift downwards against the lower cap and since there is no oil pressure it will squeeze the oil out of the bearing. i've taken apart several A engines that have been converted to inserts and either seized up or spun due to the oil starvation or excessive rpms. and i've had later engines in cars i owned myself with the same bearing failure. that's why i sold them off and only trust babbitt bearings.

 

[The Master Cylinder]

I'm sure Ol' Henry would have been using inserts if they were common in Model A years. For nothing else they would have been cheaper and faster than pouring and machining babbitt. Packard didn't start using inserts until 1935.