Truth or Myth

[GIT-R-DONE]

Ok, we all have heard stories about that someone, somewhere getting 30-40 mpg out of an old v-8 motor. I have always wondered if there were any truth to maybe some carburetor design got out into the public by mistake, or someone designed something that helped the motor get 30-40 or better mileage, and then came up missing. What have you all heard ? Stories/fact welcome alike. Always wondered, now I want your . 02 Don

 

[Hohn]

Here's what I know. Larry Widmer, cylinder head guru extraordinaire and all around engine genius accomplished some amazing things with a small block Chevy (small cam, 16:1 compression on pump gas!). He did the heads and engines on Bob Glidden's '85 Pro Stock car, and also did Bill Elliots '85 T-bird which STILL holds the Talledega speed record at 208+.



He dabbles more in Honda engines now. here's a quote from his site:

I cast some small block Chevy heads back in the mid 80's, and although I did rotate the deck to lessen the 23 degree valve angle, and reduce chamber volume. The plug position was optimised, and of course the ports were adequate, and the inlet ports were properly biased to promote swirl. The pistons were "unique" in shape... all I'll say is they had no dish, except two . 120" valve reliefs. They were certainly of the domed variety. Those small blocks were 358 cid. engines with 1. 75-1 rod length to stroke ratio, very short cam timing... 235 degrees @ . 050", and the intake manifolds were some of my Edelbrock "specials" with Murray Jenson prepared Holley 830 cfm carbs. Those engines had "over" 16-1 static CR, and dynamic compression was so high we had to use custom starters run off 24 volts.

They were installed in some Camaros and two pick-up trucks. They all ran 91 octane unleaded pump gas. They never detonated, the mileage was 37 (combined) for the cars and 25 for the trucks. The Camaro's had Turbo 400 automatic transmissions, and from off idle you'd swear that there was at least a 454 under the hood... the throttle response was almost too quick. Those "loaded" cars all ran 12's with ease. The trucks had pulling ability that no body imagined, and were a dream to drive, especially compared to their street counterparts.

So, yes. If something as crude as a small block Chevy can be that efficient, some of the more "modern" chambered heads can certainly do the same and considerably better.

This guy is so far ahead of the rest of the world in gasser engine design, I only WISH I could see what he's doing today.





Justin

 

[Hohn]

Check out more from Larry's site here



jlh

 

[DKayser]

MPG

I worked at a L/M auto dealership in the mid 80`s for 4 years. We saw the factory guys a lot,ie the technical gurus & engineers. At a small repair shop auction shortly after that, I saw the factory reps buy several orphan carburators that the old man there had been playing with. One had a H*&&^% float bowl with a movable venturi in the throat area. I later heard the old boy had claimed to have built a 40 mpg carb. Who knows?