leaking head gasket?

[alexiskai]

Originally Posted by johnneilson

Some will cringe here, but I use a stud and hardened washers to test the block. Assemble and torque each hole location. If you pull the threads it is easier to fix without the head in place.

I'm actually doing the editing right now on a video showing how to do this, using Larry Brumfield's procedure described here. Should have it up on YouTube by the weekend. (Not that any of you folks need a video, of course.)

[Ordsgt]

Anything helps me. This is my first model a and has been a great education. I have only had it since September but really enjoy working on it and driving it. Put 1000 miles on it since I got it running in late October

[old31]

I wouldn't go to a 5.5, but go to a 6.1 instead.

The cost is the same, but the performance is better. I originally had a 4.2, then changed it to a 5.5 and was very happy with the difference. Then changed to a 6.1 and was even happier.

Before you install it, for piece of mind bring it to a machine shop and check for straightness.

And yes, change out your studs.

[JayJay]

Originally Posted by old31

I wouldn't go to a 5.5, but go to a 6.1 instead.

The cost is the same, but the performance is better. I originally had a 4.2, then changed it to a 5.5 and was very happy with the difference. Then changed to a 6.1 and was even happier.

Before you install it, for piece of mind bring it to a machine shop and check for straightness.

And yes, change out your studs.

Isn't conventional wisdom that you should only run rod babbet bearings up to 5.5, and insert bearings higher than that? Or is that because the original "police" heads were 5.5?

JayJay

[alexiskai]

Originally Posted by JayJay

Isn't conventional wisdom that you should only run rod babbet bearings up to 5.5, and insert bearings higher than that? Or is that because the original "police" heads were 5.5?

JayJay

The issue of babbit vs insert is sort of a red herring; what that argument is really about is the overall condition of the engine. Babbit bearings in good condition, with proper clearance, good rods and crank, etc., will handle 7:1 compression and higher no problem. The reason it gets framed like that is that, considering all the engines together, a babbit engine likely hasn't been overhauled as recently as an insert engine. The older the engine, the more likely it's had some wear, parts out of spec, etc. So you end up with a correlation between insert engines and handling high-compression well that tends to mislead about the actual causal connection.

[alexiskai]

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Originally Posted by alexiskai

I'm actually doing the editing right now on a video showing how to do this, using Larry Brumfield's procedure described here. Should have it up on YouTube by the weekend. (Not that any of you folks need a video, of course.)

Video has been posted.
https://youtu.be/ibaPf0FQnZM

[J and M Machine]

Originally Posted by alexiskai

The issue of babbit vs insert is sort of a red herring; what that argument is really about is the overall condition of the engine. Babbit bearings in good condition, with proper clearance, good rods and crank, etc., will handle 7:1 compression and higher no problem. The reason it gets framed like that is that, considering all the engines together, a babbit engine likely hasn't been overhauled as recently as an insert engine. The older the engine, the more likely it's had some wear, parts out of spec, etc. So you end up with a correlation between insert engines and handling high-compression well that tends to mislead about the actual causal connection.

Babbitt in Model A engines; Specifically Con rods is thick and even in good condition can take up to 6 to 1 compression. anything over that will create pressure and damage the babbitt. Only way you can go over this ratio is to go with inserts or thinner babbitt. can't beat physics.

[old31]

Originally Posted by alexiskai

The issue of babbit vs insert is sort of a red herring; what that argument is really about is the overall condition of the engine. Babbit bearings in good condition, with proper clearance, good rods and crank, etc., will handle 7:1 compression and higher no problem. The reason it gets framed like that is that, considering all the engines together, a babbit engine likely hasn't been overhauled as recently as an insert engine. The older the engine, the more likely it's had some wear, parts out of spec, etc. So you end up with a correlation between insert engines and handling high-compression well that tends to mislead about the actual causal connection.

I agree 100% on what you said.

Babbits or inserts, a bad engine will have trouble with a 4.2 head.

[johnneilson]

Originally Posted by old31

I agree 100% on what you said.

Babbits or inserts, a bad engine will have trouble with a 4.2 head.

Yes and a bad driver not familiar with timing will hurt either.

J