Conversion to insert bearings?

FWIW,
The oiling system should really be upgraded for the inserts.
Positive oil pressure minimum to mains and even better drill the crank to oil the rods.

IMO, every insert bearing failure I have witnessed has been attributed to the above statement.

J
 
I would price out a Burtz and the conversion/rebuild to insert bearings and see which one makes financial sense.....
 
Even if the conversion is less expensive I would go with the Burtz block and crank. 5 main bearings, pressure lube, 2 inch diameter bearings, etc, etc.
 
johnneilson said:
FWIW,
The oiling system should really be upgraded for the inserts.
Positive oil pressure minimum to mains and even better drill the crank to oil the rods.

IMO, every insert bearing failure I have witnessed has been attributed to the above statement.

J
Click to expand...

I have run an inserted engine without changing the lubrication system for a long way. All I did was use thinner oil in that engine. I guess that is upgrading the system anyway!
 
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nkaminar said:
Even if the conversion is less expensive I would go with the Burtz block and crank. 5 main bearings, pressure lube, 2 inch diameter bearings, etc, etc.
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When pricing a Burtz be sure to account for parts (mostly cast iron) that you may or may not bring over from your original engine. You may wish to keep them with your original engine to make it more attractive to whoever takes it. I did not account for that and ended up with several hundred dollars unanticipated “extra” in my Burtz build for things like flywheel cover, oil pan, manifolds, timing gear cover, valve cover, etc. Once you start down the road of “well, it’s a new engine, may as well give it a new water pump/distributor/oil filter housing/whatever” it’s a slippery slope.
 
I just finished a Burtz motor and Stock Block Motor built to Touring specs.
By the time they were both done there was only a $1600 spread between the two.
Plus the Burtz can be built in 1/3 of the time it takes to do a stock block.
I vote for the Burtz.
 
Dodge, in your opinion does the Burtz “Kit” require machine work (balancing in particular) like any other engine build or does the Burtz arrive ready to assemble. I’m hearing that the Burtz does indeed require balancing etc, it’s not a drop it in and go type of thing.
 
I did not balance mine and it is smooth running. No machine work. It is really an assembly kit. You have to clean the block and crank and deburr in places. The lighter flywheel will throw some torsional vibration at you but that can be minimized by redoing the rear motor mounts by replacing the old rubber pads at the frame. If you have Float-A-Motor rear engine mounts you should replace the rubber pads and tighten the through bolts a little more than when they stop moving up and down.
 
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Dodge said:
I just finished a Burtz motor and Stock Block Motor built to Touring specs.
By the time they were both done there was only a $1600 spread between the two.
Plus the Burtz can be built in 1/3 of the time it takes to do a stock block.
I vote for the Burtz.
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Antique Engine Rebuilding was about 1/2 the price of a new Burtz a couple years ago. They no longer have the prices on their site but it arrived assembled. Our Coupe has one of their touring engines built by the last AER owner.

jeepguy1948 said:
Dodge, in your opinion does the Burtz “Kit” require machine work (balancing in particular) like any other engine build or does the Burtz arrive ready to assemble. I’m hearing that the Burtz does indeed require balancing etc, it’s not a drop it in and go type of thing.
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Check the build book for the Burtz. https://drive.google.com/file/d/1--hr5iQERvjGQ3tHk_IXlmzA2vxg-c2g/view It lists all the things you need to do to assemble it. Since the parts are new it's wise to check that ALL are within spec. You never know how some guy may pack your order when he's late for lunch.
 
jeepguy1948 said:
Dodge, in your opinion does the Burtz “Kit” require machine work (balancing in particular) like any other engine build or does the Burtz arrive ready to assemble. I’m hearing that the Burtz does indeed require balancing etc, it’s not a drop it in and go type of thing.
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I'm like Dodge - I did a conventional babbit engine two years ago and right now I am right in the middle of assembling my Burtz - got the crankshaft and the pistons mounted today. To a certain extent it is an assembly process, but this is precision assembly - you have to know what you are doing. You will be assembling parts obtained from several sources - the Burtz kit, your piston and ring source, your bearing source, among others - and you need to make them all work together. Maybe you could "drop in and go" (I wouldn't) but you'd run the risk of a mediocre result.

To start, you need to drill a couple of the main bearing shells to allow oil flow, and do so without horsing up the precision clearance of the bearing. In addition, if you use a five-journal camshaft like the Burtz cam you will need to remove two cam bushings from the block, drill oil holes in them, and then reinstall. All without disturbing the line bore. This required a homemade bushing puller, part of which I borrowed from a club member and part of which I made on my lathe from a hunk of aluminum stock.

I spent a fair bit of time measuring up journals and bearing clearances to be sure that I have sufficient oil clearance. I found I had to dink with the bearing shells a bit to get them to fit into the rods (the Builders Guide discusses this, the cuts for the bearing shell tabs were too narrow). Not difficult, but you need to know what you're about. The mains fit fine. (BTW, ideal oil clearance for the mains and rods is 0.002", acceptable is 0.001"-0.0035". Mine have been coming in at 0.0015"-0.002", a bit tight but acceptable.)

I found that although the four connecting rods were within a couple of grams of each other in total weight, they were way apart in small/large end balance. I spent most of a day balancing the rods with the pistons and pins to get the oscillating assemblies balanced. I did not rebalance the crank or the flywheel, as I felt that the factory likely did a decent job and I'm not building an engine that will ever see over about 3000 rpm. I'll wait and see how it turns out.

I found that the valves did not lap into the seats quite the way I'm used to. I touched off the new valves on a valve grinding machine before I attempted to fit them (as I always do with new valves). I'm not sure whether the valve angle from the grinder was off or the seat angles were wrong (I did not touch the seats, I used what the factory sent) but they didn't match. it took a good deal of lapping to get a good pattern. I'm happy with what I ended up with, though.

So to summarize, building a Burtz engine is not like buying a Lego kit and following a set of directions to assemble it, like my grandkids do. The Burtz package is a wonderful bit of engineering, and for the most part I've been delighted in how it's coming together. And support from the Burtz technical crew is outstanding. But you do need to be a reasonably competent wrench with experience assembling engines to do this project. The Builders Guide is a great resource. If you are considering building a Burtz go out to the website (burtzblock.com) and download the Builders Guide to see what you're up against.

And at the end of the day, one more thing - you've done it yourself, so you know it's been done right.
 
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I'd run far away from insert bearings of any sort. I bought the line boring machine from Gene French along with the molds and i Babbitt regularly. the inserts used in the A engines do not have the oil groove which is critical for a gravity fed system so the bearings are constantly starving for oil unless the system is pressurized. and to add that inserts do not have the ability to be adjusted the same way as a babbitted engine, if the bearing gets loose just take a shim out and retorque to spec. easy-peasy. insert failure is the exact reason i won't touch engines equipped as such and i'm working on a project to develop a method to convert molested engines back to the way they should be.
 
Sunny the Model A said:
the inserts used in the A engines do not have the oil groove which is critical for a gravity fed system so the bearings are constantly starving for oil unless the system is pressurized.
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What are you talking about, the groove is plainly visible. These are the inserts sold by Snyder's and AER.
 

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that's correct, the oil groove that only goes around the circumference is not sufficient. the groove needs go from front to rear in a helical pattern, sort of like a screw. in that fashion the oil is sucked into the bearing by the turning crank and is spread along the bearings length. just having it in one localized spot is only sufficient if the oil is pressurized since the pressure will force the oil to creep along the bearing and out the ends.
 
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