Burtz engine oil pump

[Arlyn Bieber]

According to Burtz engine Builders Guide---- A stock Model A oil pump with close fitting gears has been found to provide more than adequate volume and a relief valve is needed etc. Has anyone tried using a stock Model A oil pump on the Burtz engine and will it provide about 25psi at 50 MPH??? Your thoughts Please.Arlyn Bieber San Diego

[Synchro909]

I modified the A pump as described in the assembly instructions so that it would put out more oil. I found that adequate but just adequate. Pressure at an idle with a warm engine was so low it didn't register on the gauge but enough that the engine survived. 25 psi at 50 mph? Not with an overdrive and I doubt without.
I ended up using a modified V8 oil pump. 25-27 psi at 50 mph with O/D and 12-15 at warm idle.

[johnneilson]

IMHO the stock Mod A pump is just barely adequate for a mild build
The gearset is just a little too short
Cliff Williamson Der Meece machining used to make a modified V8 pump for the A and B motors
There are many articles written about reversing the pump and the ports to make this conversion
On the other hand the pump can be inverted to correct the rotation and adapted to A or B motor
J

[emf]

I modified a standard Model A pump as described in the guide. Using 10W-30 with a warm engine and a 30 psi relief valve, I get 30 psi at 30 mph and 10 psi at idle. I am about to try 10W-40 to see if it improves.


I modified two more pumps and have them available at $250 each if anyone is interested.



Frank

[mcgarrett]

What's the process to modify the pumps as you describe? Can you provide concise photos showing the modifications?
Thanks in advance.

[JayJay]

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Originally Posted by mcgarrett

What's the process to modify the pumps as you describe? Can you provide concise photos showing the modifications?
Thanks in advance.

There is a procedure by Terry Burtz on the Burtz Block website, see https://drive.google.com/file/d/1MPc...URp/view?pli=1.

[emf]

You essentially turn down the shaft to allow more oil to move up from the gears and then open the ports to do the same. Lathe and milling machine are mandatory...


Frank

[mcgarrett]

Thanks,
Never modified an oil pump for a V8 or Model A, so wasn't familiar with the process.

[Synchro909]

Originally Posted by emf

I modified a standard Model A pump as described in the guide. Using 10W-30 with a warm engine and a 30 psi relief valve, I get 30 psi at 30 mph and 10 psi at idle. I am about to try 10W-40 to see if it improves.


I modified two more pumps and have them available at $250 each if anyone is interested.



Frank

Many people fall for the trap of thinking that the higher pressure obtained by using thicker oil is a good thing. The whole purpose of oil in an engine is to keep the bearings cool. The fact that it is slippery helps,
A thinner oil flows through the bearing more quickly, keeping it cooler so long as it has enough "slippery". Thicker oil will take more pressure to get it to flow but is likely to not flow any more oil, thus not improving the cooling.
Sometimes, it helps to demonstrate a point by taking it to an extreme and seeing what would happen. Let's say you used an oil the engine that was as thick as the oil you put in the gearbox or differential. It would be so thick, the pressure gauge needle would slap the stop pretty hard, yet there would be so little oil going though the bearings that they would overheat and destroy themselves. The correct oil is a balancing act.
I learned that the hard way when I was on an outback trip and the town I was in when I needed to change the oil had a limited range available. I used a grade heavier than I usually did and by the time I got home, the rear main bearing was ruined. The oil pressure gauge showed I had plenty of pressure (more than with the usual oil) but there was not enough cooling happening back there.
Please be careful trying to get more oil pressure by using thicker oil. You may be doing your engine a great disservice.

[emf]

I only made the suggestion to go to 10W-40 because Terry Burtz stated he preferred the heavier oil in his engine. Of course, there comes a time when the oil is too heavy for the application.



Frank

[Synchro909]

Originally Posted by emf

I only made the suggestion to go to 10W-40 because Terry Burtz stated he preferred the heavier oil in his engine. Of course, there comes a time when the oil is too heavy for the application.



Frank

Don't get me wrong. I have no objection to 10W40 oil in the engine. I have run for years with 20W50 with no problems but say, 20W60 is not on.