The Ford Barn

hardtimes · 04-24-2013, 03:49 PM

I just got an A block that is stripped down and looks pretty good. I have a B crank (first style/no counterwts). I also have four good B rods with new/unused babbit at .010. Prefer start with B block, but use what ya got,eh

No babbit in block. My question: with babbit out of block..would I be just as far ahead to have this A blk cut for inserts? And, if so can I use the old style B crank and babbit B rods in A block??

tudoor · 04-24-2013, 05:09 PM

With all the machine work that will need to be done to the crank grinding and block work. I would buy the new counterbalanced crank for the A engine. And had new babbit poured. That's what I did and is very happy with the purchase. If you run inserts you need to oil pressurize the mains. Also if you have inserts installed and spin a bearing you will probably ruin the block. Stick with babbit.

James Rogers · 04-24-2013, 07:18 PM

Quote:

Originally Posted by tudoor

With all the machine work that will need to be done to the crank grinding and block work. I would buy the new counterbalanced crank for the A engine. And had new babbit poured. That's what I did and is very happy with the purchase. If you run inserts you need to oil pressurize the mains. Also if you have inserts installed and spin a bearing you will probably ruin the block. Stick with babbit.

Not true! I have many engines with inserts running and none have pressure. It is the opinion of all the builders I know that pressure is not good and a waste of time for all the problems it will cause.

MikeK · 04-24-2013, 07:38 PM

Quote:

Originally Posted by tudoor

With all the machine work that will need to be done to the crank grinding and block work. I would buy the new counterbalanced crank for the A engine. And had new babbit poured. That's what I did and is very happy with the purchase. If you run inserts you need to oil pressurize the mains. Also if you have inserts installed and spin a bearing you will probably ruin the block. Stick with babbit.

Absolutely not! and Absolutely not!

If you run B rods with an A pan you may have a tiny clearance problem, easily corrected by heating and bumping out two spots on each rail. Line bore the block for the AER inserts, have the crank re-ground by a competent crank shop and run the B rods. Watch the clearance on the rear AER bearing, looser is OK, tighter will cause it to score. The larger diameter B throws will give superior service over A babbitt rods, and by having the block done with the AER inserts, if you later want to change rods and cranks, it is just a parts swap to replace everything.

You do not need to have counterweights added to the crank. Seat of the pants vibes will not significantly improve with them. The real advantage to those weights is to save the main bearings from load, and by going to inserts instead of babbitt you won't have that problem. Just make sure the crank is balanced after re-work.

Crazydaddyo · 04-24-2013, 07:39 PM

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Cost wise, with out buying a new crank, you are probably better off boring the mains for Corvair rod bearings and grinding the B crank to fit them. Corvair rod bearings are 1.800" and that is the biggest dia. that you can go with the A block. the main bolt spacing on the A block is narrower then the B. You don't have to run pressure with insert bearings.

A counter weighted crank is best. you can have counter weights welded to your B crank before it gets ground. Still cheaper then buying a new crank.

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04-24-2013, 03:49 PM	#1
hardtimes Senior Member Join Date: May 2010 Location: South California Posts: 6,188	parts fitment Q... I just got an A block that is stripped down and looks pretty good. I have a B crank (first style/no counterwts). I also have four good B rods with new/unused babbit at .010. Prefer start with B block, but use what ya got,eh No babbit in block. My question: with babbit out of block..would I be just as far ahead to have this A blk cut for inserts? And, if so can I use the old style B crank and babbit B rods in A block??

04-24-2013, 05:09 PM	#2
tudoor Member Join Date: Jul 2012 Location: New Hampshire Posts: 62	Re: parts fitment Q... With all the machine work that will need to be done to the crank grinding and block work. I would buy the new counterbalanced crank for the A engine. And had new babbit poured. That's what I did and is very happy with the purchase. If you run inserts you need to oil pressurize the mains. Also if you have inserts installed and spin a bearing you will probably ruin the block. Stick with babbit.

04-24-2013, 07:39 PM	#5
Crazydaddyo Senior Member Join Date: May 2010 Location: Orange, Ca. Posts: 197	Re: parts fitment Q... Sponsored Links (Register now to hide all advertisements) Cost wise, with out buying a new crank, you are probably better off boring the mains for Corvair rod bearings and grinding the B crank to fit them. Corvair rod bearings are 1.800" and that is the biggest dia. that you can go with the A block. the main bolt spacing on the A block is narrower then the B. You don't have to run pressure with insert bearings. A counter weighted crank is best. you can have counter weights welded to your B crank before it gets ground. Still cheaper then buying a new crank. .