block quandary
 

I have a 59a block thats a spare for our 33,
I have two sets of pistons for it one set plus .040 and the other plus .125
I have a new 4 inch crank , and all the other internals new
I did a trial clean up bore on the block,it will clean up nice at .040.
I,m a bit reluctant to bore it out to the .125 (276 ci) and waste the block for later rebores.as its a nice block
The engine will be a spare for our 33 and will take a lot of miles at .040 before it needs a rebore ,maybe out live me.
Would the difference in torque be that noticeable between the .040(262ci) and the .125 (276ci).
The engine in our 33 is 262ci and it goes great,it also has a few miles on it now.
Lawrie

Re: block quandary
 

on a dyno maybe but to drive it around dont think so and as you said why waste further rebores my thoughts go the .040 and save the rest for a later date

Re: block quandary
 

I forgot to mention, the .040 are 4 ring and 56 Grams heavier than the .125 which are 3 rings
Lawrie

Re: block quandary
 

Unless there's a problem with the block, I'd do the .125 overbore. Even with that, there are probably at least 3 more "clean-up" bores left in the block. After that, it can be sleeved. Think about it; the 14 ci increase in displacement is over 5%. I would expect that you should be able to see that much difference. It's kinda like when Chevrolet increased the 265 to 283 and you know what that meant.

You are considering putting a modified 59A in a '33 Ford; that makes you a "Hot Rodder". This is what we do; look for every bit of HP we can find.

I just saw your last post, which to me makes the decision easy. Unless you are planning to use some pre-war rings, the 3 ring pistons are a "no-brainer", as they will decrease friction, plus provide an increase in displacement. On my last engine, a 258" with a stock stroke and a .125 overbore, I left out the bottom rings after a lot of back and forth here. It was the correct decision.

Re: block quandary
 

I'll add some more food for thought.

On my 296 ci build, we wanted to try and reduce friction and wear as much as possible. Went with Ross pistons with metric rings. Since the bore went 3 3/8" +.030, the rings were not from Total Seal, but came in a Ross-branded box.

According to Ronnie, they were a little different than Total Seals and one of the rings was tapered even more to reduce the "face".

The motor turns over quite easily with this piston fully loaded in their bores.
This piston/ring set up was not cheap, but I think the extra $300 compared over a set of cast ringed pistons will pay off in the long run. Less wear, less heat, more power, more efficient combustion.

Something to thing about if you are indeed going to put pistons in this motor.

Re: block quandary
 

I'd go the larger with the three rings if you're comfortable with it, dont worry about what may happen 'later' Lawrie because the way you build things it will probably outlast you and I ! Anyway whats to say in time another really nice block will land in your lap..

Re: block quandary
 

Agree 100%

Re: block quandary
 

The Merc crank makes 10x more difference then the bore. If you are just driving around and not racing, I would leave it at .040. In fact, I have a NOS 59 series engine in my 40 coupe and left it with stock 3 3/16 bore, swapped out the crank for a 4" stroke, Ross pistons with metric rings, mild cam and 390 4bbbl Holley and it has LOTS of power. No way was I going to bore some life out if it just because I could.

Re: block quandary
 

How could this be? A .125 overbore produces 258" engine with a stock stroke, while at 4" crank gives only 255" with a stock bore. Plus the stock stroke engine will have slower piston speed, which is more efficient. Sure flatheads are not high reving engines, but 10 times? I believe that figure is just hyperbole.

Re: block quandary
 

I would go with the .125 bore. It could always be sleeved in the future if needed, by how many miles are you or anyone else going to be putting on it? With care and modern oil it should run a long time.

Re: block quandary
 

Yeah, 10x is an exaggeration but for changes you can feel, the crank (and pistons) are the single most effective thing you can do. I currently have 5 running cars with flatheads in just about every configuration. (2 32s, 33, 2 40s)
As it is with any car--it's yours to do what you want, if boring it to the max is your thing, go for it. The poster asked for opinions, I gave mine.
The engines I have that have been bored, the sonic test determined how far it could go leaving minimum of .100 cylinder wall, not an arbitrary number pulled out of the air. Rust and core shift are real considerations. That is just my 2 cents.

Re: block quandary
 

Go with .040 over and put the piston through the lathe and milling machine.

Re: block quandary
 

Dont suppose you could go further on that one John.. where to cut and mill?

Re: block quandary
 

I think to reduced it's weight.

Re: block quandary
 

One thing looks like I must do is a sonic test,
I have not got one.
Can some one advise a good unit to get
And I looked at my pile of blocks.Looks like about 3 more std bore 99a and a couple of 8ba and one 58a std bore,
Lawrie

Re: block quandary
 

Cam grinder Pete recommended one he gets on EBay for cheap. Send him a PM and see what he says. He’s a great resource.

Re: block quandary
 

Lawrie, if you read my book again you will see the unit which has worked best for me. I have used several different "brands" and the unit from NDT Systems has been superior for me.

Re: block quandary
 

Use the .040 pistons now and use the .125 on the worn engine you replace now in your car as a spare .

Re: block quandary
 

Lawrie,
The application determines the need to make certain modifications. Ross pistons and Metric rings will make allot of difference is a race engine or one that will see very high RPM's. A street engine rarely sees 4 K . Compression and camshaf determine the lowend torque. I'd just go with the 4 ring pistons and leave the bottom ring off. An old stock car mod was to cut the bottom of the piston as well, this brings the weight down. There are many things you can do to a flathead and they all have their place in their application.

Re: block quandary
 

The bigger the engine gets, the more of a mover & shaker it will be. A lot depends on what you want to do with the car too. If a person wants a go fast car then that sets the build to get it that way. If it's still just a fun around town car then the build would be more mild. Reliability and good torque would be just fine.