65CudaDude
Active Member
would it be possible to bore a 273 to a 318?
273 to 318
- Thread starter 65CudaDude
- Start date
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Nope...
318 bore = 3.91"
273 bore = 3.63"
difference: 0.28"
That's over a quarter of an inch...
273 cylinder walls are probably not that thick...
318 bore = 3.91"
273 bore = 3.63"
difference: 0.28"
That's over a quarter of an inch...
273 cylinder walls are probably not that thick...
64dart170
Well-Known Member
Why would you want to?
I'd tade our swapped in 318 we have presently for the original 273 anyday!
But on the otherhand I am kinda old, slow, not too bright, and like things stock!
Don't listen to me just rambling drinking coffee readin the morning FABO!
Good luck with your project!8)
cavemanmoron
Well-Known Member
no, but you can use the 273 valve covers and timing chain cover/
water pump to make the 318 look like a 273. ;)
65CudaDude
Active Member
i like things stock too. we have two 273's, and my dad was just curious if he could bore one to a 318..
Or you could throw the 273 stuff on a stroked 360! ......only your machine shop (and your time slips) would know that really was under the hood.
harvenator
A fish called Wanda
Your 273 can be worked over to put out much more than the 318. Over bore by .040 brins you to an even 300 CI. Camcraft will grind a cam for you with solid lifters for about $200.00 total and a little carburetion will get you some impressive performance.
65CudaDude
Active Member
oh really? i'll have to look into that.
Using the formula: bore divided by 2, times itself (radius X radius, or, radius "squared"), time "pi" (3.1416), times the stroke, times the number of cylinders = displacement, we get 280.12 cubic inches, for a 273 that is bored .040."
Here's the math:
3.63 + .040 = 3.67
Bore divided by 2 = 1.835
1.835 X 1.835 = 3.367
3.367 X (pi) 3.1416 = 10.58
10.58 X 3.31 (stroke) = 35.01
35.01 X 8 (cylinders) = 280.12 cubic inches.
Not 300.
I'd drop a 360 Magnum in there so fast....:cheers:
IF you rebuild the 273, pistons are the hardest thing to come by. Look to Egge for pistons. They cast there own and to your spec for ratio. With this in mind, you may remember the D-dart? A 273 powered Dart for D-class racing that pumped out 275 HP.
I'll just say there are better cams with broader ranges of power these days rather than going back to a similar old tyme DC cam. Any whoooo!
A 318 (rebuilt and pumped up even a little) could be discused as the 273, like said above, and not only would no one know, but it will perform very well. At 45 cubes greater in size..........
I'll just say there are better cams with broader ranges of power these days rather than going back to a similar old tyme DC cam. Any whoooo!
A 318 (rebuilt and pumped up even a little) could be discused as the 273, like said above, and not only would no one know, but it will perform very well. At 45 cubes greater in size..........
65CudaDude
Active Member
yeah, i'd rather keep the 273 in the car. what i really want to do is rebuild our Commando..the guy who owned it before my dad destroyed it(running it without an oil pump). when my dad bought it from the guy it had like 3 gallons of oil in it. stupid move on that guys part.
OK, I'm with ya on that! Build whatcha got. Like I said above, egge can get pistons for you.
65CudaDude
Active Member
thanks for that info. i'll have to check it out when we are ready to rebuild it.
2 Darts
A-body Addicted
Interesting discusssion. I'm toying around with the prospect of vintage racing where the old SCCA A/S and TransAm limits were 305 CID. Using Bill's math, the closest I can come using the existing parts bin is 303 CID. This would be done with the .040 over and a 3.58 stroke crank.
However, without some sort rule constraint, a 360 would be a better basis for more power with very little weight penalty. A 360 with aluminum intake, heads, and replacing exhaust manifolds with headers ought to be lighter than a box stock 273.
However, without some sort rule constraint, a 360 would be a better basis for more power with very little weight penalty. A 360 with aluminum intake, heads, and replacing exhaust manifolds with headers ought to be lighter than a box stock 273.
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