Edelbrock tri-carb log adapter performance question

[Anonymous]

Interested in mileage change on early versions, not the larger or later manifold log.
For those of you who have installed an Edelbrock manifold adapter for the three carbs: How did it effect your gas mileage? I know it will decrease, but by how much.
Also which engines have you installed the manifoold adapter on.
144? 170? or 200?
Decrease in mileage information sought on any and all of above.
If you can, isolate the amount of mileage change due to the adapter, as much as possible.
Which carbs are used for what mileage etc etc.
Thanks.
DaveP kywoodwrkr

 

[mustang652]

Don't have mine running yet, having problems getting the adapter to seat, but from the conversations I have had with a couple who have done them including the guy who has become my local advisor , he built one several years ago, as long as you keep your foot out of it, it is only a slight drop. I've heard as little as 1 to 2 mpg, but if you dog it, you'll pay at the pump.

 

[Anlushac11]

8)

I agree. The linkage if set up properly allows the engine to run on the center carb until the throttle is depressed far enough to open the end carbs.

Keep your foot out of it and it mileage wont decrease by much, but thats always been the real challenge after adding more power hasnt it?

 

[CobraSix]

It effected my mileage about the same as my Aussie did. If I could avoid the lead foot, maybe 1-2 MPG decrease (Those outer carbs will still be using some fuel on the idle circuit). But the problem you'll have is that you are not going to want to keep your foot off the pedal as you'll get as giddy as a school girl each time you hit the gas. Expect 3-5 MPG decrease in actuality factoring the lead foot in.

Slade

 

[Anonymous]

Thank you one and all.
That is what I had surmised from previous situations but wasn't real sure about this particular application.
Logic told me there would, or rather could, be a relative small decrease in MPG.
1,2 or 3 is a doable thing.
If it had gone to half, well, then other plans would have to be made.
Appreciate the good feedback.
Thanks again.
DaveP kywoodwrkr

 

[CobraSix]

If you want to help mileage some, think of a T-5 or AOD upgrade too. My mileage went up some with the T-5 since I do a lot of highway driving. The 2.77 with 3.20 gears was rough at highway speeds.

Ignition upgrades can also help offset the mileage drop. MSD, DS2, DUI, Pertronix, Hotter coil...all will allow you to run a larger gap on the plugs generally resulting in better mileage and a little more power. Keeping the timing closer to stock helps too. I run my timing at 8-10* BTDC.

Slade