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By grovedawg - 14 Years Ago
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A little history about what I have and want to do: I've got a 272 that I'd like to bore out at least to .030 or .060 over the size of a 292, add a ground 312 crank with new rods and pistons. Final bore is going to be close to 3.810.
Now I know that the bores are different between the 272 and 292. The 272 is bored to 3.62 and the 292 has a larger bore of 3.75. Otherwise the stroke is the same- so, same crank, journals and what not. Is there any difference between the two blocks other than bore? I'd like to know if the 272 is the same block as the 292, and can handle the same over bore work that a 292 gets when it's bored and stroked out.
I've got a machine shop that's going to sonic the walls, to determine if it was offset ground from the factory and can handle the .130 to .140 over a stock 272 bore. I'm sure all of the supreme beings have seen this question before, but I'm still a small little pleb. Thanks for the help guys.
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By crenwelge - 14 Years Ago
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My first impression is why not start out with a 292 block in the first place. There are plenty of them around and then you will have plenty of wall thickness in case you want to get more radical with cam and carburetion.
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By grovedawg - 14 Years Ago
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I'm definitely not opposed to using a 292, but I kind of like the idea of using the engine it was born with. Maybe that's a little wierd, but, I think it's kinda cool.
But, back to the point. There is a differnce in the two blocks then?
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By Gordie T - 14 Years Ago
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Grovedawg
I just went through all this with my 272. My engine rebuilder, whom I trust, sonic tested my block and suggest we only go 30 over...about to a 283. Yes, we could have gone bigger but he said he could give me more hp. by doing things to the engine...porting, better cam, improving rockers, improving oiling..improving valves and seats etc.
He suggested it was not economical to go to bigger pistons, larger bore etc. He had no problems getting all the parts he needed shipped next day for my 272.
Good luck.
Gt
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By grovedawg - 14 Years Ago
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If it's feasible my intention is to take the 272 to at least a 292 bore. Or a little more. And stroke it with a 312 crank.
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By Ted - 14 Years Ago
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Sonic testing will tell you up front if your 272 block is a candidate for boring out as far as you’re contemplating. Offset boring is a option if the block has core shift that would otherwise stop you from boring the block heavily if just centering up on the existing bores. Most 272’s will bore out to a standard bore 292 but there are a few with significant core shift which is why you sonic test to begin with. Going the extra amount of bore over a standard 292 will be a challenge and still have enough material remaining that you’re comfortable with what you have. Sonic testing in this case eliminates any and all guess work.
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By joey - 14 Years Ago
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Sounds like a very cool project, especially seeing as the Y-block is still intact. Here are a couple of web pages that might help shed a little light on your block: http://www.ford-y-block.com/Block%20identification.htm http://www.supermotors.net/articles/lfm-issue03-a2-1.php
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By mctim64 - 14 Years Ago
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When Bing did his engine he also wanted the block that came out of his truck (a 272) so after sonic testing I bored according to core shift and had no problem with .030" over 292 (3.780"). The shift in his was not too bad. Like Ted said Sonic testing will tell you up front if your 272 block is a candidate for boring out as far as you’re contemplating. |
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By Old Y Block - 14 Years Ago
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Howdy; I agree with crenwelge about using a 292. Punch out a 292 .090 over and you end up with a .040 over 312 bore. Use the 272 8.5:1 heads, compression will jump to over 9.3:1 with slight planing (.005 to .007 clean up) of the heads. I ran one of these for a long time and it ran good, did not get hot and had plenty of wall left. The old Ys are so much fun to mess with because of all the different variations you can come up with. Have fun!
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By BFOOTER03 - 14 Years Ago
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Howdy its not impossible to do what you want. As Tim mentioned I wanted the same and got pretty close. my local shop was not willing to go that far due to the shift but Tim as will. Don't feel bad about beign pushed into using a 292 as you are getting basicly the same responced I got when I mentioned the idea. It possible but it might be easier accomplished with a 292. Bing
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By grovedawg - 14 Years Ago
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I'm going to have it sonic tested hopefully this next weekend. That's a HUGE piece to the puzzle.
Is the 272 Block the same block as the 292 other than bore? Like, a 289 and a 302 are nearly identical other than cylinder skirt length. What differences are there between the two blocks other than bore?
And as far as the cams that are available between the 272 and the 292 (or even the 312) are there any differences?
It seems that it's a little bit of a toss up between guys that say use the 272, and others who say be safe and go with the 292. Kinda like, "do you like blondes or brunettes. I think the sonic test will determine that for me. Thanks for your responses thus far!
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By Hoosier Hurricane - 14 Years Ago
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The two blocks are the same except bore. All '55 and later Y block cams will interchange.
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By Old Y Block - 14 Years Ago
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Hi Guys; I wonder if we could find the original factory weight of the 272 and 292 bare block. I know the weight is approximately 155 lbs. and a lot of interchangeable parts, but did they actually make a thinner cast cylinder wall for a 272 than a 292? Whatever, let's just keep the old Ys running. Live long and drive Fords!
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By charliemccraney - 14 Years Ago
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Last year, I had to move a bare 272 block, and a bare 292 block several times. In that case, the 272 was heavier. I don't know by how much, though.
I think the cylinders were cast the same so the bore sizes would make a difference of around 10.5lbs. So assuming that all is the same but the bore, a 272 should be heavier.
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