Technical New Model A Banger block Poll

I take it you are NOT a purist?

Tod

 

The Donovan D is still available.

http://www.donovanengineering.com/Blocks/ModelDBlock.html

 

Actually, I just found the Arias Iron Duke block with all those features. Ouch! They sure are pricey!

Man, that Donovan block is pretty!

 

Hey Carl,
Well, your 'dream' can still come true, as plenty Donovan blocks are on the 'shelf'. You just have to win that lotto,eh !
No they are NOT in museums...by a loong shot ! I know a guy who lives in Simi, Ca ..nearby. He has a Donovan decked out as you dream about it..with OHV head and two carbs , etc, etc... That engine smokes BIG tires on the rear !! I think that he told me that he has something like 25K in the engine alone ! Yup, he's got the same sickness as us....

NOTE:
Please notice the DOUBLE row of bolt holes on both sides of the oil route at the bottom of the valve side cover. That should definitely be part of the new block, thank you !

 

If you go to Piranios web site http://www.modelaparts.net/hiperf.html/hiperftxt.html you will get a much better idea as to the equipment and accessories offered for the Donovan aluminum engine, a basic idea for the cost and also the new "Crawford" 4 port Riley head that they have been developing for this engine.... Too bad that for probably 99% of us, it is just out of reach of our savings accounts!
Check out their services & parts department - a very interesting read.

 

Whoever voted for the 2 or more of the AR cam journal version please contact me by PM or by email at blockheads2014@yahoo.com.


Tod

 

I was just thinking about this project last night. This is a great endeavor.

I went through 4 "B" blocks before I got one that I could repair. Factor that into your next build.


.

 

It just always strikes me fundamentally wrong to have to fix a block before starting a build. The best part is when the build is for OHV and the mucked up ports and seats are not needed. Then it is just a matter of getting the orings cut into the deck without touching each other.

John

 

Hey Tod,
Is the first block machining completed yet ? Pictures please...

 

Not yet. This past week was a whirl-wind week. I had to let it sit while other, more important things, got my attention.

But I did model up one of the new main cap designs for pinned A caps and started on the pinned B caps.

I'll email everyone pictures that has requested updates when I get more completed. I need to make up permanent machining fixtures, also.

With all I have to do I cannot work on anything with complete focus. I'm probably working on at least a half dozen projects right now.

Tod

 

I am restoring my model A Drivetrain and Ch***is right now and a stock A block with B friendly parts would be awesome, getting some more mph's is always nice

 

My question for the A block with B friendly internals guys is this - Are you planning to use original B parts or have I been misinformed about the availability of new B cranks, etc...?

I was having this discussion with someone this past week, and I said that it is not my business if someone wants to buy a specific block version. For all I care, they can make a coffee table out of it. But my guess was that people wanting B journals is that they actually have the parts and want a block to put the stuff in.

Tod

 

**** and others produce B cranks not sure about AR cams though although there should be a few about

 

Thanks to 3 cracked and un savable B blocks, I have several B cranks to us in a projuct like this. **** also makes a crank with B mains and A rod journals.

John Neilson makes cam blanks with 5 bearings. I think Bill Stipe does too.

I don't necessarily want an A block with B internals or 5 mains. I would rather have the B block with B internals or 5 mains. But if the out side looks like an A and has what I want on the inside, then I'm OK with that.

.

 

Tod,

"B" internals are still in good supply, not hens teeth yet.
I had another thought on the 5 main version, on the 1,3,5 webs it would be nice to be able to run a 2.5Ø bearing. This would mean to just leave enough material to space the studs out far enough. I think once you get to that level of getting the crank made you would not want to thru bolt them anyway.

J

 

What is the differences between A and B blocks externally? Besides the fuel pump...

Posted using the Full Custom H.A.M.B. App!

 

B block has no oil return boss. It also has a oil supply galley below the valve chamber.


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thanks, I couldn't for the life of me remember what else.

 

Hey Tod,
As said, B parts are still obtainable , especially for the THREE main B internals. As to your question regarding availability of NEW B cranks, a guy would have to either..A: scrounge up a good original B crank , or B: have a B crank made by one of a number of new crank makers. Your talking close to 2K +/- for new three main. Now for a 5 main crank (which would have to be NEW), I've been told by at least two (who have purchased) to expect close to 3K +/-. Five bearing cams can be made for 5 hundred +/-. I know that a machinist (Bill Stipe)does that work.

Specifically, to your question on crank availability (relative to block production). Yeah, my 'guess' is that MORE guys would use the least path of expense..that is ..3 main crank, due to cheaper to obtain/use. This verses guys who want and would spend the $ to have the 5x5 crank/cam built(includes me,eh). The other B internal parts are, as said, available.
Hope this helps you.

BTW guys, **** only makes a B crank that has B size MAINS and A size RODS..go figure. When I spoke with ****man, he said that's the way it is ! I said that that made NO SENSE..as it's a weaker crank and why would a guy spend $1600 +/- for a weaker crank when you could just make a B rod journal ? I elected to just get a good stock B crank..still available.

 

Sounds like my guess was right then. With so many people on this forum and the FB voting for B internal A blocks it stands to reason that there just has to be parts to put in one. And so what, if I only sell 50-100 of them ever? It will be worth it for me to make the few pattern expansions to accommodate that niche.

Tod

 

Exactly that.

If it came down to having to buy a new crank I'd swing towards a 5-bearing bottom end.

 

Hey Tod,
Ha, IMO, your your modest and conservative ! I still think that you WILL be surprised, especially if you can serve up the variety of combinations that you say. Even if only 1% of model A/B guys world wide participate...wow !

Oh, BTW, I woke up about 2am (PST) and thought...what is HE going to do about: making the A block external APPEARANCE (with oil tube/openings) versus B valve chamber cover with OIL GALLEY at bottom ?

 

The block is fashioned after the A. There is no B style oil galley. The main oil galley to pressure feed oil to the crank and cam journals is interior and will be out of view when the block is all ***embled.

Tod

 

Two things occurred to me in the past couple of days, and when I started typing just now one of them completely disappeared (must have accidentally hit the "delete" key!). So let's start with the one I haven't forgotten in the last 30 seconds. 1) I figured, rather than make pinned A as well as pinned B caps, why not just make the larger B caps and use them for BOTH pinned A and B journals? Is it going to hurt the A guys if the caps are pinned AND beefier? This regards the 2 smaller ones and not the rear, unless I can make that work as well. Any problems with that idea?

Being that they will be beefier anyway, I was thinking about just casting caps out of ductile, which will be plenty strong enough, and will save time and material. I could offer billet steel caps to people who want to special order them.

Sorry, but I have no idea what the second item is that I wanted to bounce off of you guys.

Tod

 

Just a follow up note here; no matter what gets thrown out in terms of the NEW block & its internals, are we then talking about an A' size rear main bearing cap with a B' size crank journal = the B' oil pan will not fit on an A' rear main bearing cap.... or .... a B' rear main bearing cap with B' crankshaft O.D. and then the A' oil pan does not fit without a fair amount of bending & shaping....? How good are you with a hammer & dolly?
Tod: you might just need to make 2 different rear main bearing caps to fit what ever style crank & oil pan the potential customer intends to install into your new creation, and leave enough material around the main bearing bolt areas that both the A' & B' crankshaft / main bearing caps can be bored to accept the customers choice of cranks?
Does anyone reading this understand what I am trying to explain? The choice of your new block will need to be both crankshaft & oil pan specific; "A or B"...what do you have on hand, what do you intend to use?
Tod can't possibly build one block that fits either an A' crank or a B' crank
or one that accepts both an A' & or a B' oil pan, because the crankshafts will be both rear main bearing cap & oil pan specific! In this case, size does matter - bigger means stronger and B' cranks are bigger & stronger, just ask the people that run their cars at Bonneville or the 1/4 mile antique drags. What about every person that just wants to keep up with traffic?
This issue needs to be discussed and understood by every potential customer so that Tod is not spending his nights & weekends in the pattern shop modifying or rebuilding his patterns for every single new casting.

 

Steve,

I understand your concerns here. Fortunately, I can do the work necessary to accommodate the choices. I can make an A block that has BOTH rear snouts available. Right now I am going to go with the advice of Snyder and Prus and make stock A, which they think will be the largest seller, and make pattern accommodations for the B internals/caps. I will also be making the equipment for the 5 main crowd. It really isn't that tough.

Tod

 

After looking at an A rear cap and a B rear cap, I don't see why I can't make a pattern for ductile caps that can be machined for either a B or A oil pan. If I make the caps for the larger outside, they can always accommodate smaller cranks.

One thing that I just don't get though, is why don't the stock caps match the outline of the block when they are bolted on? The caps don't match up to the blocks. Anyone care if the caps actually match the block?

Tod

 

Clearly you have your hands full getting this project going but given any thought to what you would do next? Perhaps a 1928 Chev block and head?

 

Not without a market for them.

Tod

 

Anything else going on other then stuff over my head ?? 17 month bump .... just for a look see.