Putting 172 pistons in 134 block

FordNMan · Oct 18, 2018

Rebuilding my ford 620 engine and I want some extra pulling power. Will 172 piston fit in 134 block if bored out for them. [/b]

Fordfarmer · Oct 18, 2018

A 134 has a 3.4" bore, while a 172 has a 3.9" bore. I really doubt that your block can be bored a half inch without finding the
water jacket. I would think it would be easy enough to find a 172 block or complete engine. And then you get into possible issues
with how much power the rear end can take.

riveroadrat · Oct 18, 2018

I thought the blocks were basically all the same. It wouldnt make much sense to make a different casting for a smaller bore.

Dean · Oct 18, 2018

They aren't.

Dean

RickB · Oct 19, 2018

If they were the same they would have the same casting numbers. They do not.

Tim PloughNman Daley RIP · Oct 19, 2018

NO sir. Two different casting blocks, two different engines. There isn't much wall thickness distance between the cylinder bores and going larger to 3.9" will ruin the block. Simply scale roughly 4" across a bore and see for yourself before doing any machining.

Tim "PloughNman" Daley(MI)

riveroadrat · Oct 19, 2018

I see said the blind man. Too thick, you don't get enough heat transfer.

Fordfarmer · Oct 19, 2018

The 134 was developed first... the 172 came along a couple years later when they needed more power.

sunbeam · Oct 20, 2018

This site has a 3.5 bore sleeve set and 8n you could get pistons to run without sleeves is this an option for a 134?

Bern · Oct 20, 2018

We had this discussion about a month or so ago, about converting an old 5000 (4.2" bore) to a newer 5000 (4.4" bore). Most people said it
couldn't be done, and I replied by saying I've seen it done, but it's a little dicey with regards to the thin cylinder walls you'd be left
with.

What you're asking about is removing TWICE as much metal as the example above. Absolutely no way in my opinion. You'd be staring at the
internal cooling passages if you did.

Dean · Oct 20, 2018

There are options to increase displacement of the 134 CI engine but one must wonder why one would choose to do so.

It is so much easier and less expensive to simply replace it with a readily available 172 CI engine.

Dean

RBnSC · Oct 21, 2018

I have a good set of over size pop up pistons for a 134. You could have it bored. I am guessing it is a
sleeved block. You can bore it just like a nonsleeved block. If interested I'll post pictures.
Ron

Putting 172 pistons in 134 block

FordNMan

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Fordfarmer

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riveroadrat

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Dean

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RickB

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Tim PloughNman Daley RIP

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riveroadrat

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Fordfarmer

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sunbeam

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Bern

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Dean

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RBnSC

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