How much better is a B block than an A?

[brett4christ]

I've had my 3 Model A engines for a while, but haven't done anything with them yet. I have recently obtained a B block and counterweighted crankshaft. My intentions were to put the B crank in one of my A blocks, that is until I saw the difference in main journal diameters.


Now for the big question...


Is it better to machine an A block for the B crank, or clean up the B block and use my extra A stuff to finish it up?

[P.S.]

Use the A block. The B blocks are well known for their ability to develop cracks for no good reason.

[CarlG]

Better to machine the B crank to fit the A mains than to do it the other way round. (or so I've been told by the master mechanic in our club.)

[Synchro909]

Originally Posted by CarlG

Better to machine the B crank to fit the A mains than to do it the other way round. (or so I've been told by the master mechanic in our club.)

I go along with that. To take this thread to the next stage, what would you use for bearings. I believe there are a few options for inserts that will go in with a slight relief at the bolts or is it better to just buy a new counter weighted crank shaft and be done with it?
I ask because I have a B crank here but as expected, the block was cracked. I have plenty of decent A blocks though.

[brett4christ]

Thinking about this, would it not be perfectly fine to run poured babits? The whole idea of running a counterbalanced crank is to 1) reduce vibration, which will 2) lessen the dynamic load on the bearings. Obviously, inserts would be optimal, but I would think poured bearings would hold up just fine in a street/touring A-banger.

Thoughts???

[juke joint johnny]

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Why not have the B block crack tested ,Let that be the decider .
Get a copy of Jim Brieleys book "4 bangers and Me"
Lots of good info in there also see what he has acheived with Babitt.

[Synchro909]

Originally Posted by juke joint johnny;1616152[COLOR="Red"

]Why not have the B block crack tested ,Let that be the decider .[/COLOR]
Get a copy of Jim Brieleys book "4 bangers and Me"
Lots of good info in there also see what he has acheived with Babitt.

As far as I can see, the ratio of cracked B blocks to sound ones is about 10 to 1 and if it's not cracked now, it probably will be soon.
Babbit has a lot going for it. I think many opt for inserts because A, they have had some bad work done with babbit in the past or B, they have heard stories and imagine that inserts must be better. It ain't necessarily so!

[Dodge]

Six of one half dozen of the other. Both have their pluses and minuses. Pick the one in the best overall condition and start from there.

[M2M]

As discussed on this forum recently; a Russian made B block, if you can find one, might be the way to go.

[Chris Haynes]

Originally Posted by juke joint johnny

Why not have the B block crack tested ,Let that be the decider .
Get a copy of Jim Brieleys book "4 bangers and Me"
Lots of good info in there also see what he has acheived with Babitt.

Also have it Pressure Tested.
I am in the process of building a B with a Yapp Riley OHV. The much larger bearing size is the plus I can't ignore. After all the larger bearings were Ford's idea.
Cracking comes from overheating. During the last eighty some odd years cars were used and abused. These days owners of our fine Fords don't subject them to the abuse they suffered in the past. Better cooling systems kept clean and rust free help a lot.

[Chris Haynes]

Originally Posted by Synchro909

As far as I can see, the ratio of cracked B blocks to sound ones is about 10 to 1 and if it's not cracked now, it probably will be soon.
Babbit has a lot going for it. I think many opt for inserts because A, they have had some bad work done with Babbit in the past or B, they have heard stories and imagine that inserts must be better. It ain't necessarily so!

Inserts are definitely better if you are running a high compression head. Babbitt was designed when engines had 4 to 1 compression.

[Chris Haynes]

Originally Posted by Synchro909

I ask because I have a B crank here but as expected, the block was cracked. I have plenty of decent A blocks though.

Cracks around the valve seats can be easily fixed.

[brett4christ]

If I try to go with the B block, will I have to use the B bellhousing/transmission/oil pan? Or can I use my A parts?


(Showing my ignorance...sorry)

[johnneilson]

Brett,

good question, you can use the "A" trans, bell housing and pan but the pan will require a little work. You see, the rear main is larger on the "B" motor so the radius at the rear will need to be opened up, also, the "B" rod nuts will hit the side next to the rail edge. This can, and should be corrected by using APR rod nuts which are smaller OD and much stronger.
Or, you can cut the bell housing extension off the "B" pan.

OK, you mentioned the "B" block is cracked, where? Valve seats can be replaced/installed but it must be done correctly. Otherwise you will have leaks at the seats. This applies to "A" motors as well. One of the biggest problems I have seen are the head studs and repairs that someone has attempted. From drilling off center to butchering the holes down through the boss etc.

A friend of mine always mentions that perfect blocks do not exist, it is a matter of your persistence to use old junk. Do not despair though, keep looking, there are many good serviceable blocks around.

J

[brett4christ]

Originally Posted by johnneilson

Brett,

good question, you can use the "A" trans, bell housing and pan but the pan will require a little work. You see, the rear main is larger on the "B" motor so the radius at the rear will need to be opened up, also, the "B" rod nuts will hit the side next to the rail edge. This can, and should be corrected by using APR rod nuts which are smaller OD and much stronger.
Or, you can cut the bell housing extension off the "B" pan.

OK, you mentioned the "B" block is cracked, where? Valve seats can be replaced/installed but it must be done correctly. Otherwise you will have leaks at the seats. This applies to "A" motors as well. One of the biggest problems I have seen are the head studs and repairs that someone has attempted. From drilling off center to butchering the holes down through the boss etc.

A friend of mine always mentions that perfect blocks do not exist, it is a matter of your persistence to use old junk. Do not despair though, keep looking, there are many good serviceable blocks around.

J

John,


Thanks for the reply! First off, I have no idea of the condition of my block, so questions concerning my use of the B block are purely hypothetical. As I get closer to discerning my direction, I'll be more thorough in my inspections.


Secondly, will the B crank accept A rods? I'm guessing , since I must turn down the main journals, that I would be required to turn the rod journals as well to use A rods. Would that not eliminate the rod nuts and rail edge from occupying the same real estate?


Finally, thanks to all that have commented here! I'm still learning and want to make good decisions when I finally start assembling my banger.

[johnneilson]

Brett,

OK, understand, you are doing some worst case investigation prior to the surgery.
Kind of like getting the second opinion before the primary care appointment.

You have to ask yourself truthfully the intended use of the motor/car.
If stock configuration for enjoyment, some modifications are beneficial and some just overkill.
That said, "B" block allows for more HP and has a pressure fed oiling system to mains with larger journals. This along with drilling the crank to feed oil to rods and some compression will yield a nice motor that will last a long time.

I do not recommend drilling the "A" crank for oil to the rods as the journal is so small the potential to break increases substantially.

I have put the "B" crank in the "A" block before, not recommended in my opinion.

Either Babbit or inserts if done correctly are satisfactory, since I do not have access to a good Babbit facility, I use inserts.

Of course you have to understand that these opinions are just that, my opinions. YMMV

Best of Luck, Mr. Brierleys book is very good, you may hear opinions that do not agree with him but I doubt that those opinions have as much experience.

John

[brett4christ]

Again, I say thanks John.


My intent is for a nice peppy banger for my '31 Tudor. Its going to be a little hot-roddish for this site, but since you asked....


The car will be basically a stock sedan with '40 juice brakes and a dropped front axle. Not much else done mechanically, except for the motor. I'd like to lighten the flywheel and adapt a V8 pressure plate.


As for the engine, I have a police head as well as the "C" head from the B. I also have an alloy aftermarket downdraft intake and an assortment of Ford/Holley 94s. The only other "trick" part I have is a Mallory distributor.


At some point, I have a Halibrand 201 center section that I would like to stuff my '40 rear parts into. That would give me tunable gearing for my style driving.


Thanks again for all the answers and opinions...and keep 'em coming!

[Chris Haynes]

With the weaknesses of the "B" Block known I am hoping that someone will start reproducing them with the weakness upgraded.

[Charlie Stephens]

Originally Posted by Chris Haynes

With the weaknesses of the "B" Block known I am hoping that someone will start reproducing them with the weakness upgraded.

There would probably be a better market for an A block with the improvements that were made to the B block. I have 2 Model B vehicles but can't put my finger on any more (except for a few that show up at meets).

Charlie Stephens

[johnneilson]

Originally Posted by Charlie Stephens

There would probably be a better market for an A block with the improvements that were made to the B block. I have 2 Model B vehicles but can't put my finger on any more (except for a few that show up at meets).

Charlie Stephens

see this thread https://www.jalopyjournal.com/forum/...-works.616056/

John

[Flathead]

Does anybody know the status of Tod's new blocks?

[johnneilson]

One detail about making new blocks, the audience of customers is very small, especially since the blocks cannot be used in Vintage racing.

John

[Chris Haynes]

Originally Posted by johnneilson

One detail about making new blocks, the audience of customers is very small, especially since the blocks cannot be used in Vintage racing.

John

Not everybody is a racer.

[Flathead]

A three main A block set up to take a B crank with the bigger main bearing diameter would be a winner for me. The ultimate foundation for a rugged touring motor. Pressure to the mains would be nice but original A system would be OK. Just sayin'

[hardtimes]

Originally Posted by Flathead

A three main A block set up to take a B crank with the bigger main bearing diameter would be a winner for me. The ultimate foundation for a rugged touring motor. Pressure to the mains would be nice but original A system would be OK. Just sayin'

For those here who may not be aware, YOU have just described the current projects being under-taken by TOD, a member here.


When you say...'ultimate' is 3 main B bottom , A block, that is not accurate tho.
Tod is making the A looking block with FIVE mains and that is the ultimate , IMV !


For those who care, and/or paying attn. to this type subject, Tod has already made a stock running Model A block (utube(?).
He has also made two experiment aluminum blocks modeled after the things that you want. First is an alum three main blk and the second is a five main alum version. Both are currently being worked.
At the same time, 5 main cast iron blk (tooling) being worked on.

[Chuck Sea/Tac]

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Originally Posted by Chris Haynes

Inserts are definitely better if you are running a high compression head. Babbitt was designed when engines had 4 to 1 compression.

Diesel requires more compression than gas, I’m pretty sure they used Babbitt as there was nothing else. By the way, the first compression fired engine was before 1900. I understand the concept your saying, but “Good” Babbitt will handle 7:1 and easily 6.1 what wipes out Babbitt is lugging under load and advanced timing.

[johnneilson]

Originally Posted by Chris Haynes

Not everybody is a racer.

Chris, exactly my point.

The market for an improved "B" block would be very limited by the fact that Vintage racing does not allow for aftermarket blocks. BTW, that market would benefit most as the output easily triples (and more) the original design power levels. Donovan I understand has sold the last one known as the "D" block. I do understand that there are a few around that can be bought, you have to look, and bring a stack of bills.

The "perceived" notions that "B" blocks are inferior to "A" blocks is IMHO an old wives tale. Sure, every production motor design/production can have flaws or weaknesses when power levels start to rise above design. This applies to lawnmower motors up to big diesel motors.

Babbitt bearing design goes back to the railroads, very large and heavy applications. Designed properly, alloyed, installed and lubricated properly it is very forgiving and will withstand much abuse. There is a well known person around here who ran a babbitt rotating assy in a "B" motor, OHV and Turbocharged on methanol at Bonneville. It is reputed to be his preparation for the races to just dust off the motor after removing it from storage and install into car.


John

[Bob C]

Here's the video of Tod's new engine. https://www.youtube.com/watch?v=dhVs0brJukQ

Bob

[Chris Haynes]

Originally Posted by Bob C

Here's the video of Tod's new engine. https://www.youtube.com/watch?v=dhVs0brJukQ

Bob

I'd like to see it on a dyno.

[hardtimes]

Originally Posted by Bob C

Here's the video of Tod's new engine. https://www.youtube.com/watch?v=dhVs0brJukQ

Bob

Hey Bob,
Thanks, I don't know how to do this type procedure / reference .
Since that engine was made from a NEW A block and from USED spare model A parts, I'm thinking that it would/should make about 20 HP +/-, like Fords original ?

[brett4christ]

OK, a little more info requested...


I went back to snap a shot of the engine number stamping yesterday, but the pad on the side of the block was blank. I have since learned that, on B engines, this pad is blank and the B number is on the flywheel housing. My problem there is...I don't have the housing!




Now mind you, the oil pan stops at the rear main cap and has a knife-edge (not a rolled lip) that creates the seal. Pulling the pan, the crank is definitely counterweighted and the cam has a fuel pump lobe. I don't remember seeing a fuel pump boss or port through the side of the block.






Could this be a service replacement "A" block that came from Ford with a counterweighted crank and B cam? If so, would the crank be turned down to fit the A block, or would the block have larger journal bores? (Like a dummy, I didn't have my calipers to measure the rod journals!!)


Any ideas???

[brett4christ]

Finally got a good look at all sides...found the fuel pump boss!


It's a Model B!


Going to get it home and try to make a silk purse from this sow's ear! Wish me luck!

[Terry, NJ]

Hey who says the A block is so great? They crack too! Go to any rebuilder and they'll tell you they have go trough 4-5 A blocks to get a good one.I think it's a combination age, temperature, clogged cooling systems, and too light iron in some places. The B blocks are even worse! However, The Russian blocks (GAZ) are free of this problem or so I'm told. I don't know about the German G-28 blocks. Some people say I'm wrong, but I believe metal "ages" even without external influences such as moisture, etc. This is especially true of castings.
Terry

[brett4christ]

Speaking of Russian/German blocks....How on earth would a common North Carolina grease monkey obtain one of these blocks? And I don't think I need to remind you all that NC grease monkeys don't maintain large bank accounts!!

[johnneilson]

Originally Posted by brett4christ

Speaking of Russian/German blocks....How on earth would a common North Carolina grease monkey obtain one of these blocks? And I don't think I need to remind you all that NC grease monkeys don't maintain large bank accounts!!

Luck, it is the only true explanation.............

Being in the right place at the right time.

Don't write off the block you have, do the cleaning and inspection.

I have found good blocks in seemingly the worst condition caked with mud and grease that most people will walk by, or run.

J

[Jim Brierley]

John, The guy you speak of does more than just dust his engine off. First ran the turbo in '08, and every year after thru '13. In '13 it ran 167 MPH. The pan has been off twice, all OK both times, no new parts installed. This is on babbitt mains only, because of many drag racing years before, the pistons got tired so Ross forged pistons and Eubanks rods were installed. Before that babbitted B rods were used. 6200 RPM was max while drag racing, 6,000 on the Salt. This is on an early B block, 4" bore, no cracks ever. The worries now are the 'C' crank, so a 5-main crank and girdle are in process.

[Terry, NJ]

I don't know how or where one obtains a GAZ or G28 block. I know there are a few in the US, but your chances of finding one are slim to none. However, I mentioned it only because, first, both were made up until the 50s and second, the Russian and German engineers designed their casting cores with more "meat" in the critical areas. You will notice that most engines with a cracking problem, all crack in the same places so it's a known phenomena. You're not dealing with bad iron, your'e dealing with design flaws. Also I don't even know if a German or Russian block is better. I'm just repeating what I've heard.
Terry

Originally Posted by brett4christ

Speaking of Russian/German blocks....How on earth would a common North Carolina grease monkey obtain one of these blocks? And I don't think I need to remind you all that NC grease monkeys don't maintain large bank accounts!!

[johnneilson]

Originally Posted by Jim Brierley

John, The guy you speak of does more than just dust his engine off. First ran the turbo in '08, and every year after thru '13. In '13 it ran 167 MPH. The pan has been off twice, all OK both times, no new parts installed. This is on babbitt mains only, because of many drag racing years before, the pistons got tired so Ross forged pistons and Eubanks rods were installed. Before that babbitted B rods were used. 6200 RPM was max while drag racing, 6,000 on the Salt. This is on an early B block, 4" bore, no cracks ever. The worries now are the 'C' crank, so a 5-main crank and girdle are in process.

I wonder where the Girdle came from.

All I can say is that I am sold on that combination, it held together when the drive shaft sheared pulling about 6200 revs on the dyno.

John

[hardtimes]

Originally Posted by brett4christ

Finally got a good look at all sides...found the fuel pump boss!


It's a Model B!


Going to get it home and try to make a silk purse from this sow's ear! Wish me luck!

'wish me luck' !
If you are at all dependent on luck, in this type situation....you're most likely in for anything but !


There is no replacement for experience/skill/knowledge, etc. when going at this task. That's why most without these qualities , hire a good engine rebuilder....and communicate closely with that person for what you want.
Even the best here among us, have their detailed machine work done by expert machinist who do this for a living.


You might have heard this before, but if not....buy the two books that Jim B, a member here, has written on this specific subject(i.e.-engine building).


You/me anyone doesn't get that type of knowledge without going thru a LOT of trial/error...and heartache (read: money/failure)! Maybe cheating to learn from books and others, but I'm all in on that. See what I'm saying...excluding 'luck'.


Even some 'engine rebuilders' are unscrupulous sobs, so do your homework there also. If you were on the left coast, I would not hesitate to make a referral for excellent engine work and maybe who not to go to.


It is often said , about engine work wanted/needed...what is your intended use/purpose for the engine ? If you have to ask why this question, study up on the subject before spending a cent for parts and/or labor.

[brett4christ]

Thanks @hardtimes I know "luck" has very little to do with it!

I'm wanting a simple early pre-war hopped up Sedan that I'm not afraid to drive around town and maybe on some backroads. No speed demons here!

As far as acquiring knowledge, I've already ordered the Breirley book and I have both Les Andrews books. They will be my references going forward.

My hope is to piece together a sound engine from most of what I have. If it becomes a money hole, I'll part out the motor and move on with an off-topic powerplant.

And BTW, I'm on the right coast!

[hardtimes]

Originally Posted by brett4christ

Thanks @hardtimes I know "luck" has very little to do with it!

I'm wanting a simple early pre-war hopped up Sedan that I'm not afraid to drive around town and maybe on some backroads. No speed demons here!

As far as acquiring knowledge, I've already ordered the Breirley book and I have both Les Andrews books. They will be my references going forward.

My hope is to piece together a sound engine from most of what I have. If it becomes a money hole, I'll part out the motor and move on with an off-topic powerplant.

And BTW, I'm on the right coast!

Hey brett,
Sounds like you are getting a handle on moving forward thru knowledge.


A note about your original question.
Everyone has an opinion, and they are entitled to that, IMV !
My experience is that hearsay is too often used to distract from fact/truth,eh. Myself, I only use B blocks for the same reasons they were made by Ford instead of continuing A blocks.
I spoke with a very senior member here, who told me that he has done experimentation with A and B blocks, i.e.- 'cutting them up' to examine them to prove or disprove 'old wives tales' about block differences/deck thickness, etc. He says that he did not find evidence to support the tooo often repeated myths of differing block thickness.
Now, understanding that most existing 80 some year old A/B blocks have gone thru use doing their existence, it would be common sense that HOW such blocks were used/abused , is a major factor in their cast iron thickness. It is also a fact, that BOTH blocks crack. Freeze cracks; improper storage abuse rusting away; overheating cracks; foundry flaws and whatever the cause/effect.


Some time ago, I went to a 'rebuilder' of A/B engines. I had two A blocks. He took one as a core and knocked the side out of the other with a hammer. He took the BO block out back and placed it on a pile of about 50+ blocks (scrap metal). Most of what I say and what he advised were A blocks, I bought a nos Russian B block from him and we proceeded from there. What does that tell you ? Doesn't tell me a darn thing, but that scrap iron was cheap per 100wt.



Finally, there are guys here/otherwise who I have tried to learn from, who ONLY use B blocks..ever. What does that tell you (insert smiley quizzical face here) ! Your choice, your money.

[Chris Haynes]

Originally Posted by johnneilson

Chris, exactly my point.

The market for an improved "B" block would be very limited by the fact that Vintage racing does not allow for aftermarket blocks.
John

John,
If the new block was made correctly no one would know it was new.

[M2M]

Originally Posted by brett4christ

Speaking of Russian/German blocks....How on earth would a common North Carolina grease monkey obtain one of these blocks? And I don't think I need to remind you all that NC grease monkeys don't maintain large bank accounts!!

Yeah, you're about 25 years too late as you could have swapped a pair of button fly 501 Levis for a NOS B block in the early 90s.

How heavy is a B short block with no internals? Air cargo on Aeroflot to JFK could be an option.

[M2M]

Here's one for sale from last year for 20,000 rubles :

http://cars.rare.su/2017/03/11/%d0%b...-%d0%b0%d0%b0/

[Terry, NJ]

So what did it actually sell for?
What does "Prodaga" mean? So many words in Russian begin with "Pro".
It is a pretty complete (Magneto) GAZ AA engine, What "gody"is it ? Before the war or after? Twenty thousand of anything for a GAZ engine sounds like optomistic dreaming!
Sosibo, Terry

Originally Posted by M2M

Here's one for sale from last year for 20,000 rubles :

http://cars.rare.su/2017/03/11/%d0%b...-%d0%b0%d0%b0/

[M2M]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by Terry, NJ

So what did it actually sell for?
What does "Prodaga" mean? So many words in Russian begin with "Pro".
It is a pretty complete (Magneto) GAZ AA engine, What "gody"is it ? Before the war or after? Twenty thousand of anything for a GAZ engine sounds like optomistic dreaming!
Sosibo, Terry

I don't know the details of the engine and I'm not sure if he sold it. Maybe try ringing him on that cell phone number. Don't worry about language problems just start repeating:

GAZ AA MOTOR! AMERICA! DOLLARS!!!

[Terry, NJ]

I'll try it!

Originally Posted by M2M

I don't know the details of the engine and I'm not sure if he sold it. Maybe try ringing him on that cell phone number. Don't worry about language problems just start repeating:

GAZ AA MOTOR! AMERICA! DOLLARS!!!

[daren007]

Use the "B" block as a lawn ornament and spend the money elsewhere.

[Dick Carne]

I am currently running a B block in my '29 Town Sedan, but if I had it to do over, I would go with an A block with inserts and a counter-balanced crank. Years ago when I acquired this B block, I had selected it because of the heavier and counter-balanced crank. Those improvements are now available for A engines. Given the updated A engine components now available, I would go with an A engine over a B, if for no other reason than to keep your car more original. From a driving perspective, I can't tell much difference (if any) between the B engine and an A engine. By the way, I still have the matching numbers engine that came with my Town Sedan, and will rebuild it when the B engine begins to show signs of "need". Hope this helps.

[Jim Brierley]

The crank in Brett's engine is a BB, the heavy counterweights were installed by official Ford rebuilders, never from the factory. Reducing bearing diameters takes away some of the rigidity of the B, BB and C cranks, one of the main improvements over the A engine. A rods are smaller in I.D. than B's, so even less rigidity. I'd go with the B block, even if a small amount of cracks need repairing. Terry Burtz is also working on a new block, with 5 main bearings, full pressure, and other improvements. It will be very nice!!!