BIG Bore 260

[spmdr]

I was debating where to put this thread...


Question: Who has bored their 260 engine blocks to 4.00" ?

...And, what is the block casting numbers?


I know of one that is functional, casting number C40E- E, casting date is unclear.

...and one that was not functional (overheated), don't know the casting number.

I know this subject brings up a lot of discussion, I just want to start with some facts.

 

[Forrest39]

My stock car had a closet 302. 260 block bored out to 4", 302 heads and crank. PO said he ran it for years that way. My best guesstimate is that the cylinder walls are near .100 thick which seems a little thin to me. My thought was to sleeve all the cylinders back to standard, but the idea of spending $2k just in cylinder work to build an engine with lower power didn't add up. I have the block on the shelf and bought an already running 5-bolt 289 from a '63 comet.
I got the 260/302 running, but didn't trust it. The lifters pumped up after a bit and it made good oil pressure, but I only ran it for a few minutes. The freeze plugs were rotted so I couldn't tell if it would have overheated or not.
The block is C4OE 6015E with casting date 4F15.
-Kevin

 

[steven]

If you can get access read BON it goes into a fair bit of detail on NOT boring a 260 thin wall block

 

[0neoffive]

Out Of The Box Thinking

The old Ford guy down the street has a barnyard method of measurement. With the freeze plugs out, if you can stick a #2 pencil between the cylinders, it's too thin for radical punching. If the pencil won't pass, there's some meat there to play with. Sand casting flaws not withstanding, a sleeve requires .125 over bore size for press clearance. Therefore, I doubt if you could sleeve a 260 block to 4".

 

[michael-king]

If you can get access read BON it goes into a fair bit of detail on NOT boring a 260 thin wall block

Stven, i think you will find Dan is well aware of tbat info. As also.implied in his post... He's looking for actual real world examples....

Dan may not have written a book but his reputation is certainly known :------

 

[steven]

That subject is well written for every one that works many more will not so if someone says yes it is bored and runs well how many more have failed and are not mentioned

 

[michael-king]

That subject is well written for every one that works many more will not so if someone says yes it is bored and runs well how many more have failed and are not mentioned

Steven,

If youbread dans post he asks for info on blocks that have been overbored to that spec and for their casting number... I would hazard a guess he is trying to establish if certain runs had thicker wall castings that would allow to overbore without the well documented overheating issues due to thin walls....

 

[0neoffive]

More Opinions

I've got a client's 260 here that is bored .080 with some miles on it. No heat issues other than the normal stopped traffic headaches.

 

[michael-king]

I've got a client's 260 here that is bored .080 with some miles on it. No heat issues other than the normal stopped traffic headaches.

Rande... You forgot the casting #'s...

 

[0neoffive]

YUP

Rande... You forgot the casting #'s...

I'll crawl under it for the castings later . . . .If my pasta fed belly gets stuck, wait a few days for shrinkage.

 

[spmdr]

A study

I started this thread after some studying up on 5 bolt engine blocks.

Some sources have the casting number C4OE-6015-B as BOTH a 260 AND a 289 Block.

So I expected to find that number as the block one could bore out, and it may be- MAYBE SOME Blocks.

But at this point it is clear to me, so far, casting numbers, Alone, are NOT an indicator of common characteristics.

Of course, at this point, a population of Blocks under study have unknown History.

(...those Pesky Tiger folks boring THEIR 260s to 289 and skewing the "FACTS"...)


...we'll see how long before the C4OE-E number gets ADDED to the list of "289" Blocks....


Also, a similar situation is in the world of 5 Bolt 289 HiPo blocks.

Currently, there are examples of "HiPo" Blocks with virtually all 5 bolt 289 casting numbers.

...and how many of those are MADE into "HiPo", AFTER the fact (by those PESKY HiPo folks)?

 

[0neoffive]

More Opinions

And the minutia of the mania strikes again . . . . .

 

[spmdr]

In this time of FAKE news, Facts are in dispute.

This is an attempt to gather some Facts about 260 Ford Engine blocks.

Fact 1: there is one Original Tiger 260 engine successfully bored from 3.800 to 4.00.

Fact 2: Some people don't believe Fact 1.

So the question remains, what are the details of 260 blocks that CAN be successfully bored more than +.0030,

the CW MAX over bore recommended for ALL production small block Ford engine Blocks.


Some find my Pesky attempt at humor, Not humor.


The 260, bored to 4.000, casting number looks like this (It may be an Opinion what the reading of the Date code is, Mine, 5G26):

 

[0neoffive]

In this time of FAKE news, Facts are in dispute.

This is an attempt to gather some Facts about 260 Ford Engine blocks.

Fact 1: there is one Original Tiger 260 engine successfully bored from 3.800 to 4.00.

Fact 2: Some people don't believe Fact 1.

So the question remains, what are the details of 260 blocks that CAN be successfully bored more than +.0030,

the CW MAX over bore recommended for ALL production small block Ford engine Blocks.

Some find my Pesky attempt at humor, Not humor.


The 260, bored to 4.000, casting number looks like this (It may be an Opinion what the reading of the Date code is, Mine, 5G26):

Dan: Am I reading 5C26 ?? randy

 

[spmdr]

I have requested a better picture from the source.

But I'll buy 5C26, at this point, I was more focused on the first number.

I have not seen any other C4OE blocks with 5xxx Date codes, that I recall.

I have seen several 4xxx Date coded C4OE blocks, but I am just now paying MORE attention to those details.

 

[Warren]

Good humor

I've had 2 and the last one went to Dale about 2 months ago. If I still had it I'd go look . Maybe it's not fake news it's just a different language
But seriously it's a case by case . Maybe the engine study guy R.Fraser can steer you towards a answer.
I'm constantly hit with the question does it still have the 260 and when I reply no I get the too bad from dem dat don't own one. Funny nobody has asked about the Sunbeam V8

 

[KenF]

Has anyone had a 260 block sonic tested? A few years ago I had a 289 bored .040 over and the testing cost $100. Got a list of wall thicknesses of each cylinder 90 degrees apart, top and bottom. It'd be interesting to see what the readings are for that 4 inch bore 260.

 

[Forrest39]

289 vs 260 pix

Here are pictures to see the difference between the 260 and 289 cylinders. There is clearly more room between the 260 cylinders than the 289. Hope this doesn't confuse the issue...
Cheers, -Kevin

 

[DD (CA)]

Why is that block red orange...

The 260, bored to 4.000, casting number looks like this (It may be an Opinion what the reading of the Date code is, Mine, 5G26):

Those guys sure liked...
5x26

And boy that paint color looks awfully familiar...

 

[JimsCat]

Small Block Casting Variances

Close to 30 years ago, I had a telephone conversation with John Vermeesch of Ford regarding the then oft-quoted belief that 260 blocks with three freeze plugs per side were really underbored 289s with enough wall thickness to safely bore to 4 inches. He explained that block molds were made up of several segments that could be, and were often, mixed randomly so that certain visible features did not necessarily indicate a given set of physical characteristics. It would seem that this variability could also apply to any numbers cast into the blocks.

My apologies to the much more experienced members of this valuable forum if I misquoted or misunderstood -- I'll claim a senior moment!

Jim