Mileage

[Bragor188]

I'm getting between 9 1/2 and 10 miles per gallon in my 1967 BJ8 on mostly back country roads. If that's less than is should be, what can I do to improve it?

 

[Randy Forbes]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by stuartsaft:
I'm getting between 9 1/2 and 10 miles per gallon in my 1967 BJ8 on mostly back country roads. If that's less than is should be, what can I do to improve it?<hr></blockquote>

While the Healey is no gas miser, you should be able to get 16mpg with reasonably spirited driving and perhaps 19 (at the old 55-60 speedlimit; mine hasn't been on the road since they were raised again) on the highway.

First step would be a complete tune up (including adjusting the valves, setting the points and timing, new plugs). Once the car is in an optimum state of tune, you can set about checking the carbs to be sure they are in sync. When was the last time the car was tuned/carbs rebuilt (needles and their seats have a finite lifespan).

BTW, when was the last time the airfilters were washed out and re-oiled?

Healeys are a throwback to a time when it was normal to do considerable maintenance on a car to keep it in top running order. Even though they don't accumulate alot of miles per year, that doesn't really get you off the hook for the maintenance

 

[ThomP]

I posted this before, hope it is heplful:

My BJ8 gets an exceptional 27 to 28 MPG on the highway and 14 to 15 around town. I guess that averages to the 18 to 22 mentioned above.

If you're only getting 9 MPG check that the carb floats are'nt sticking or clogged with stuff from the fuel system and being held open during operation. If there is "stuff" in the bottom of the fuel bowl, then it is probably interfering with the needle valve seal prior to settling in the bowl.

 

[John Loftus]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by ThomP:

My BJ8 gets an exceptional 27 to 28 MPG on the highway and 14 to 15 around town. I guess that averages to the 18 to 22 mentioned above.
<hr></blockquote>

Thom,

This does sound exceptional. Do you have special gearing (i.e. a non-overdrive gearbox with an overdrive added and 3.54 rear end?) Are you positive your odometer is accurate (using the rolling wheel calculation)? My BJ7 was getting around 20 on the highway with a 3.54 rearend. Not sure what to call average around town because I tend to have a heavy foot!

Cheers,
John

 

[ThomP]

John

I attribute the highway milage to having set the engine up using a CO meter rather than other methods. This BJ8 does not have that 3.54 (I sometimes covet), but it does have overdrive. I have to admit that I have not checked this mileage more than twice, nor have I done anything more than casually verify the odometer via measured mile highway markers. I would edit my around town number down from what I posted earlier, sometimes it's 14-15 MPG and sometimes less 12-13 MPG. I think this is the heavy foot you mention. It does seem heavier in the Healey and the grins do feel bigger.

Cheers....

 

[John Loftus]

Thom,

Thanks for the clarifications. The P.O. had set my car up on a dyno at one point and tuned for max. power which required going richer on the needle/jets or the like. This probably hurts gas milage but it does go well. I've also heard others say that the Healey engine likes to run on the rich side.

Cheers,
John

 

[Dave Russell]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by John Loftus:
Thom,
I've also heard others say that the Healey engine likes to run on the rich side.
Cheers,
John<hr></blockquote>

John,
This has been my experience also. The Healey combustion chamber design certainly does not lend it to lean burn technology.
D