Critique/suggestions on 273 engine build
IF you could get an honest 350hp from a 273, it would be a PIG on the street. It would need 5.38 gears and a tiny convertor or 4 speed and would have a very narrow powerband. Gee, you could get that with a junkyard 360 with a cam and a little head work(and I do mean little). Chivalry is dead, embrace the modern days.
This bothers me in a way, I always hear everyone knock 273's for not being able to run.. Here's my just of my combo, it runs mid 7 seconds in the eight mile, and I drive it about a thousand miles or so every month.
-Block Bored .060"
-Stock replacement Badger (discontinued) .060 oversize 10.5:1 pop up pistons. Valve reliefs cut .110" for P-V clearance.
-Deck milled .030", lined bored, main studs, windage tray.
-1969 340 rods and crank, balanced.
-302 Heads, 2.02 Valves Intake (notched bore for de-shrouding), 1.60 Valves exhaust, ported and polished, angle milled to reduce chamber volume to 51cc's Head flow is at 220Cfm's on the intake @.550lift
-Compression is just over 12:1, and about 240 psi cranking compression.
-M-1 Single plane manifold, ported to match heads
-Quick Fuel built 850Cfm carb, 1-inch open carb spacer
-Custom Ground Solid lifter cam: 320 Advertised Duration,
[email protected] tappet rise, .510 lift at valve, 108 Lobe centers (intake and exhaust)
-Stock style Isky replacement Iron adjustable rocker arms, 1.5:1 ratio, Isky hardened Pushrods.
-Headman Hustler Fenderwell Headers, 1-7/8 Primary tubes, 3-inch collector, 2-1/2 exhaust to dual Flowmaster race mufflers.
The car is a 1966 Dodge dart, four speed, HAYS Strip Clutch (10.5 ofcourse), and a 8-3/4 packing anything from a 3.23:1 SurGrip, to a 4.89:1 Spool. But I usually run a 4.10 SureGrip for best overall performance..
With this set up the car is (in my opinion very diveable) for a car of its manor. I run it on 100 octane 76 Pro-Power Unleaded (there is like two gas stations left in my area that still sell this stuff) or 91 Octane with a little VP 110 octane mix. If I'm not beating on it, and its just being driven around it can be driven on just 91 octane (the car has a stock rebuilt 4-core 22-inch radiator and engine temp must be below 180). At 3,200rpm and with a full belly of just 91 Octane my wife and myself drove this car from Los Angles Ca, to Santa Cruz (in Central Ca) about 260 miles each way on our aniversary this year in January. No problems, whatsoever...
I'm hoping this help prove alittle bit that a 273 can be more than a dog.. I will say though before the car was a stick, the slush box made it a bit soggy on the low end, (burnouts where only done from a stand still start only w/no foot braking).. And it took me SIX difrent 273 set ups to figure out how to make it run.. My first 273 only made 145 Horsepower to the wheels! This on makes 371 @7200 rpm's.. Torque is around 300 @ 2500 rpms, and peaks out at 407@ 4600-rpm's I will try and post some pics and a vid sometime this week of this 273 engine in my Dart..
Hope this can help..
:cheers:
It's a toss-up...
What I want is a good running, mildly above stock 273 commando for my 65 barracuda project.
I have a 273 commando in the machine shop and I have questions. The block is .030 over with .030 domed pistons (previous owner) and is ready to go. ( all is or will be balanced) I will be running a 904 with a mild shift kit (runs like stock until you "call on it" and it is supposed to crispen up a bit)
- Q1) stay solid or go hydraulic? roller?
- Q2) domed or flat top?
- Q3) what cam?
- Q4) intake?
- Q4) what other factors? Heads?
I want the engine to look as stock as possible, may even just dump all ideas of pepping it up and go stock, but I still feel the need to improve a bit. I have pertonix, original carb (rebuilt) and am planning an 8 3/4 3.55 suregrip but that is debatable. I will be running the Formula S stock exhaust with resonator tip.
All advice appreciated!
Again, I want a stock appearance that is dependable and will squeak the tires if I have a notion to. Most driving will be cruising, not racing.
Thanks a-bodies family!!!:-D
