273 Stroker for ***** and giggles

Which stroke do I use for an un-feasible build?

  • 3.58

    Votes: 7 28.0%

  • 3.79

    Votes: 4 16.0%

  • 4

    Votes: 14 56.0%
  • Total voters
    25
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gagembassett

gagembassett

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So I have just acquired a 273 for pennies from a junkyard. You hardly hear about them anymore so I figured for ***** and giggles Im going to make a stroker of it. Why? Because, why not? It doesn't have to make sense, it doesn't have to be perfect. Does a 318 or 36 have parts more readily available and make power easier, yep. But TWO SEVENTY THREE STROKER lol. So here's the debate, I can grab one of the extra 3.58 inch stroke 360 cranks I have sitting in the shop and have it turned, or I can try to snag one of the 3.79 stroke cranks made idealy for 340s, or we can get into some real dumb **** and do the 4 inch. Now we have one stroke that will keep it oversquare or two strokes that will make it undersquare. What's your vote? Pistons I'll have custom made, block will possibly be notched for 1.88/1.60 valves or might just work over a set of stock 318 heads with the 1.78/1.5
 
Put the four incher in that bad boy.
 
That would be like a 331 with a standard bore with a 4" stroke.
 
I poked the 4" arm box in your poll. I'm not fore sure it's the right choice. Just thinking out loud.
 
gagembassett said:
I could probably find chevy pistons and rods to run
Click to expand...
The 262 Chevy V8 has a 3.67 bore size. 273 is 3.63. Purdy dang close. But what for rods? Chevy rods are 5.7". I'm to lazy to do the math. lol
 
could possibly run a 5.7 rod and if needed trim some off the top of the pistons
 
gagembassett said:
could possibly run a 5.7 rod and if needed trim some off the top of the pistons
Click to expand...
Run over to the united engine and machine web site and use their deck clearance calculator and see what it says. I'm still lookin for a compression height for those and cannot find it. The GM 4.3 V6 keeps poppin up. It's a 262 also, but has a 4" bore.
 
RustyRatRod said:
Run over to the united engine and machine web site and use their deck clearance calculator and see what it says. I'm still lookin for a compression height for those and cannot find it. The GM 4.3 V6 keeps poppin up. It's a 262 also, but has a 4" bore.
Click to expand...
IF and I this is shear speculating while we look for the true number. On a 5.7 rod with a piston with a 1.5 compression height it says -.400 .... yikes
 
Need some 1.45 inch or so deck height pistons. Probably could do some custom chevy 18 degree pistons and 6.125 inch or longer nascar type rods. And since we're already unfeasible, then you could go for broke and run one of the available 4.125 inch cranks with the 2.0 inch journals for even more cubes. LS style 15 degree pistons could almost work but the smallest bore is 3.78 inches, and I don't think your block is going to stand that.
 
I am thinking 4 things.
1. That sounds like a fun idea.
2. You are going to have a LOT of money tied up into a motor that may not perform any better than a mildly updated 360 or 340.
3. With the 4" stroke, I would think there would be crank throw clearance issues.
4. I would think that heads and flow would be a problem. I was under the impression (I've never built a 273) that larger valves (even 2.02) will not work in a 273. So wouldn't you be limiting the amount of flow your heads are capable of up front?
 
I could probably think of a lot more reasons of why not to build a 273 stroker than to build one. If the deck height weren't so tall, I think one of the old trans am program 2.96 inch cranks or the (3.145 inch NASCAR crank that Crower has had on clearance since forever now, but it has 302 ford main bearing size) and a turbocharger might be more fun, just to hear high it could rev.
 
You might have got the block for pennies, but to build this 'special' engine will probably require special/custom parts that will be.....a lot more than pennies. It is called false economy. For the same money or less, you can build a more powerful engine using easier-to-get parts.
 
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