Boring a 125ci AF motor to a 200ci A motor

[AF31FAB]

hello someone know if it's possible to boring a AF 125ci block (european) to a 200ci A block without falling in water chamber.

Thanks

[Mike V. Florida]

Rowdy has one AF block that has the standard A bore so I would say yes. You will need an A head of course.

[d.j. moordigian]

.AF31FAB

Look at this post...I believe this could be your style block? BTW,..what is the
standard bore size for your engine?

............... England engine build numbers...................

[columbiA]

If theAF block block has water jackets the same thickness as the A blocks,then I dont think it would be possible.It doesnt make sense to me that the OD of the A & AF cyls would be the same as that would make the AF water jackets very thick-But,I could be wrong.

[Tom Wesenberg]

Originally Posted by columbiA

If theAF block block has water jackets the same thickness as the A blocks,then I dont think it would be possible.It doesnt make sense to me that the OD of the A & AF cyls would be the same as that would make the AF water jackets very thick-But,I could be wrong.

That is my thoughts also, but I have not worked with an AF motor.

[Rowdy]

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I wish I knew all of the history of that block so I could explain why it has a standard bore. At any rate it really needs to be be put in a RHD car. I have contemplated selling it, but since it has not gone to the machine shop for magnafluxing, so I am not sure what to ask.

I do not think most AF blocks can be bored to sdt. A bore size. I would imagine there is no cyl wall material out that far. I could be wrong on that. It would take some ultrasonic device of some sort to find out for sure. Rod

[Tudortomnz]

You really need to contact the Model A guys in England. Manchester & Dagenham Plants used both the small bore AF & standard size bore engines. You may be able to get a good full size block from there?
When new, the small bore engine actually cost more when fitted than the large engine. All AA trucks had the large engine.

[AF31FAB]

Thank you all for your answers

the post 'england engine build numbers' show interresting pictures, the aAFand A block are not the same, so I think it's not possible to bore a AF block to a A block.
I will ask english men, maybe some are on FordBarn....

Originally Posted by d.j. moordigian

.AF31FAB

Look at this post...I believe this could be your style block? BTW,..what is the
standard bore size for your engine?

............... England engine build numbers...................

[colin1928]

I have 1 of those AF and just measured with a caliper thru the water inlet and cylinder 2&3 there is not enough to bore to A engine spec

[Juggler]

Consensus around this English breakfast table is no it can't be done. 14.9 and 24hp blocks completely different. See gaps between cylinders in the castings as shown in the photos.






Rod can you post pics of your AF block? Does it have those same gaps?

Cheers

Juggs

[montanafordman]

Not meaning to skew the conversation, but why did Europe use smaller blocks / bore size? Was this all European countries or a select few? Was it because of a perceived safety issue, governments wanting to legislate or tax based on emission or fuel mileage, etc.? I saw the note about them in the recent restorer but it didn't seem to give a clear reason.

[johnbuckley]

Great Britain offered the smaller bore size because of the road tax system in place there at the time. (though the 3285cc engine in cars was also available as an option). The smaller diameter bore brought the fiscal horsepower rating of the car in at 14.9hp, the larger diameter gave a fiscal hp rating of 24hp and attracted a higher annual tax paayment. This tax system was meant to favour the UK vehicle home manufacturing industry ( think small engined Austins and Morris). But in fact it shot the Uk industry in the foot as their cars became less and less suitable to export. The larger bore Model A engine was used on commercial vehicles in the UK which had different tax regime.
The smaller diameter bore engines of the Model A were GB specific though a few obviously made it across to europe and the empire countries.

[Mike V. Florida]

Originally Posted by johnbuckley

Great Britain offered the smaller bore size because of the road tax system in place there at the time. (though the 3285cc engine in cars was also available as an option). The smaller diameter bore brought the fiscal horsepower rating of the car in at 14.9hp, the larger diameter gave a fiscal hp rating of 24hp and attracted a higher annual tax paayment. This tax system was meant to favour the UK vehicle home manufacturing industry ( think small engined Austins and Morris). But in fact it shot the Uk industry in the foot as their cars became less and less suitable to export. The larger bore Model A engine was used on commercial vehicles in the UK which had different tax regime.
The smaller diameter bore engines of the Model A were GB specific though a few obviously made it across to europe and the empire countries.

So the original AF stamped engine Rowdy states he has is most likely a commercial engine.

[Juggler]

Weren't the 14.9 engines available from new in France and Japan? Presumably for similar road tax/hp tax (read protectionist) reasons?

[montanafordman]

Originally Posted by johnbuckley

Great Britain offered the smaller bore size because of the road tax system in place there at the time. (though the 3285cc engine in cars was also available as an option). The smaller diameter bore brought the fiscal horsepower rating of the car in at 14.9hp, the larger diameter gave a fiscal hp rating of 24hp and attracted a higher annual tax paayment. This tax system was meant to favour the UK vehicle home manufacturing industry ( think small engined Austins and Morris). But in fact it shot the Uk industry in the foot as their cars became less and less suitable to export. The larger bore Model A engine was used on commercial vehicles in the UK which had different tax regime.
The smaller diameter bore engines of the Model A were GB specific though a few obviously made it across to europe and the empire countries.

Ok, That makes sense. Thanks! Now I understand why we drew a line in the sand with taxes on stamped paper and tea... I kid... I kid...

Does anyone know how the engine weight was affected by the smaller displacement? Practically speaking how much of a performance detriment was this really in top speed and hill climbing ability?

[Rowdy]

Mine came out of a Phaeton which was brought stateside from Australia. Vince's research turned up the fact it was part of a knockdown shipment and the car was likely assembled in South Africa. Rod

[johnbuckley]

Originally Posted by Rowdy

Mine came out of a Phaeton which was brought stateside from Australia. Vince's research turned up the fact it was part of a knockdown shipment and the car was likely assembled in South Africa. Rod

Gosh how intriguing! presumably the engine went to South Africa from England and the rest from Canada . What year would that be?

[johnbuckley]

Now I understand why we drew a line in the sand with taxes on stamped paper and tea... I kid... I kid...
IS THAT TEA BREWED YET?
Don't know the weight difference- I would guess not much.
Cruising speed is not much different, it's really on the hills that the cubes tell. Many over here have now been swapped for the 3.3 engine

[johnbuckley]

Originally Posted by Juggler

Weren't the 14.9 engines available from new in France and Japan? Presumably for similar road tax/hp tax (read protectionist) reasons?

Didn't know that. The knowledge you amass from this website is amazing.

[johnbuckley]

Originally Posted by Mike V. Florida

So the original AF stamped engine Rowdy states he has is most likely a commercial engine.

AF as used in UK was used only to designate small bore engine. If Rowdy has a UK 3.3 with AF stamped on it it has indeed been bored out ( see original question) or it's incorrectly numbered!!!