273 or NOT 273?
- Thread starter 67_Slimer
- Start date
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I understand why it's generally better to build 340/360 over 273/318, but can't understand why people can't wrap their head around if you put performance parts on a 273/318 or whatever it's gonna perform, for non stroker were generally talking 250-450 hp, easily obtainable power with the parts we have now days. Don't need to do a Nascar level build to get these powers numbers out of a 273/318 engine some might not like the results compared to similar hp 340/360 fair enough but can we stop acting like we need a Nascar type team to build a high hp 273/318 it's all similar parts as what a similar hp 340/360 would need.
Not the factory 4bbl 360 headed 318, pretty sure they had same pistons ?
It's just drives me nuts how people act like getting performance out of a 273/318 or 383 or whatever gonna be this crazy extra hard endeavor, like the laws of physics stops under a 4" bore sbm or a 4.32" bbm.
Say you put a set of J heads with 9:1, 650 airgap, headers and xe268h cam with the appropriate stall and gears for best 1/4 mile time for each, 273, 318, 340, 360 there all gonna perform decently not say there gonna do the exactly same 1/4 mile times but doubt there gonna be super crazily apart.
Gomer Pyle
Member
325 will do it, this is the most accurate online calc, I've found, Engine Horsepower Calculator From Trap Speed
And I just put out there my numbers to show that it doesn't take much. Anyone can do it. How many factory 340's ran 13.9's with 3.55's? Yet an untouched, used 318 block w/318 heads runs it with the most simple, affordable parts available.
That what I like about your builds, it proves what most of gibberish the other keep saying is wrong or at least has some holes in their theories. Mainly it don't take much even with a lowly 318 to get decent performance without breaking the bank, we need you try you magic on a 273 now lol
ValiantRacing
Well-Known Member
My 273 runs low 12s in my 65 Cuda, with a .400 lift cam, 318 heads, stock intake and carb, but there are so many other items it takes to make it go that quick, transmission is a big one.
Dan the man
Well-Known Member
Cam duration, Compression ratio, what's been done to the cylinder heads, carburetor modifications, transmission modifications, gear ratio, stall converter, type of headers, ignition system.
Be surprised if he gives away his secrets. I imagine it's the sum total of finding thousands of little advantages all over the car.
Dan the man
Well-Known Member
I'd start in the rear and work your way forward. I'd guess 4.88's, 8" converter, ...... keep swimming up stream! But still, it ran the number in a different way! I like his builds by the way.
Dan the man
Well-Known Member
I wonder what times he would've run if he put the same money and time into a 360? You got great results from your 360. Just saying
But that would just eliminate the purpose of his car's intent. It's just like my 360, there are a ton of faster engines and even parts that would move my Duster much faster, but for what I was doing it would diminish the intent. Now if the intent changes, then great, look for quicker times.
Probably faster but it would be mostly about the head intake etc.. Able to flow more air/fuel which is more overall potential.
let me elaborate some more on this^^^ . My first intent was to run a 13.99 with a stock 360 4bbl, stock exhaust manifolds, stock converter, and 2.45 gears. Everyone and their 2 yr old son knows those aren't go fast parts. But it was a personal challenge to myself. I've moved the goal just a little. But some do certain things for a class they are racing in. It's all about the intended purpose, not that all believe it's the "best choice" of all choices to go fast.
To protect me from the internet police
67_Slimer
Real Hot Rods don't shift themselves.
This is what I'm talking about!! I like it!!
ValiantRacing
Well-Known Member
I can do a run down for you guys, rear gear is 4.86, with a 26 inch tire, the transmission is the fancy part of the car, all aluminum drums and a lower first gear, A&A valve body, Converter is about 5300, i wanted 6k but not enough torque in the engine, crappy hooker headers, carb was done by a guy that does carbs for Stock Eliminator which is what this car is, and i think it is the best carb i have ever had, Compression is 12.2 with the factory dome, heads are stock ports with the right valve job and valves, and the ignition as always for me is Daytona Sensors. its not what parts you use, its how you use them, the right combination is the key. I have to weight min of 3115, i am at 3140, have all the carpet 2 seats, stock dash with AM radio and factory tach.
fat-360
Active Member
My 410ci goes to 7700rpm, they rev…
fat-360
Active Member
Cometic will make whatever you want.Matt Steen told me that. Pistons are now commonplace.
fat-360
Active Member
273 head is the same as 318 in port volume. If you put a 340/360 head on a 273, you’ll lose so much airspeed,compression,and shroud or crash valves etc.
The 273 doesn’t flow enough air to warrant big heads, 170ish cfm (stock) puts the engines peak horsepower potential at just over 6grand.
Not even close. I ran 1.88 intake J heads on a 273. My favorite engine of all time.
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