Finally it's in!

Durham Missouri

I think my engine should be close to those numbers. It's a 292 with mild porting and mild cam. With the 3x2 it should be running on the middle carb primarily and with the T85 od it should turn out to be a nice cruiser.

Durham Missouri

Ted is right on, My 312s poked and stroked gets well into the 20s on miles per gallon handily beating the sixes pulling the same heavy weight.


-Gary Burnette-

There are a multitude of factors when it comes to fuel mileage.  Besides the engine, the chassis must free wheel easily down the road and not have any drag.  Rebuilding the engine back to stock specs gets touchy and requires that the compression ratio is restored back to at least the original specs.  Having the compression ratio higher than stock can help the fuel mileage in most cases but the fuel being used must be considered when making these kind of changes.  Most stock replacement pistons have a higher placed wrist pin which drops the pistons further in the hole and in turn takes away some compression ratio; this in turn hurts the fuel mileage.  This helps to explain why many rebuilt engines do not perform as well or get the same fuel mileage they did when new when simply doing a standard rebuild.  Fuel mileage optimization also requires that the cam timing, ignition curve, and fuel atomization be correct for the application which tends to get overlooked on standard rebuilds.  Don't get me started on stock replacement rebuilt carbs as that's another story.  All this is doable as I did a 318” Y last year for a customer and on a 4500 mile trip, it averaged 23 mpg.  This is an engine that dynoed out at 385+ HP but has gobs of torque in the low rpm band.  Because of those good low end torque values, the overdrive transmission worked very well and those low rpms brought the fuel mileage numbers up.

Lorena, Texas (South of Waco)

I'm not too worried about fuel mileage. I'm putting the 292 in because I prefer it over the 6 cyl. I kept everything I took out so if I want to I can put it all back at a later date but I doubt that will ever happen.

Durham Missouri

Just don't scrap the 223-6. There must still  be some interest in those engines. I believe J. Mummert is offering parts to install a C-4 automatic behind them.
Those 223s were another engine that was largely ignored. However, I recall them being used in Oval track "B" modifieds & they did well.   


Paul

Yea... all that new HP and such but ....  future gas mileage may shock your sox off, a good running 223 can deliver over 20+ mpg and your new mill just ain't gonna'.
If your 223 bearings, mains & rods are OK, I'd ridge ream the cylinders, do a little honing, put in a new set of these modern chrome rings, do a valve job and then see how it runs ... mucho' better I'd bet.
I get all my overhaul parts from Summit Racing, good prices, free shipping over 100 bucks.

82warren

It's an Edelbrock 573 with Holley 94's. I don't think (hope) it will be that hard to tune. The middle carb is the only one with idle circuits. The linkage is progressive and the outside 2 don't come in until throttle is past the halfway point. The guy that set it up for me said it wouldn't be a problem at all. If it gives me much trouble I'll sell it and put on a b intake with a holly 4 barrel.

Durham Missouri

Good looking Y.  What intake are the dueses on?

You gotta have the right tools and know how to use 'em.

TC - Austin, Texas

NICE!