Does a Carb Spacer increase MPG?

[LaGrasta]

Should I bypass it?

 

[CoupeBoy]

You are correct that the warm antifreeze in the spacer helps to atomize the fuel. Also longer runner length (log plus spacer) normally increases low end torque. You really have two questions in one.

1. Should I bypass the coolant lines that go through the spacer?
2. Should I remove the spacer?

My opinion is:
1. If that's what it takes to keep you on the road, you may notice that your car runs a bit different but I doubt it. I think you should search for a new (non-leaking) spacer though.

2. Nope, it will mess with your throttle linkage setup.

-ron

 

[ludwig]

1) Bypass the spacer. You will not notice any difference in operation where you live.

2) Don't remove the spacer. If you do, the stock carb will be turned 45* and the throttle linkage will be messed up (unless you go to cable).

Get a replacement (non-leaking) spacer. Keep it on hand if there is a problem with what you already have in place once you take the hoses off.

 

[addo]

What temperature does 50-50 water/antifreeze pressurised to 13PSI, boil at on a 60°F day?

What about on a 95°F day, all else remaining the same?

 

[Bort62]

Well, it boils at the same temperature regardless of what the ambient temperature is

 

[addo]

Exactly! Nor do conditions inside the spacer change - surface roughness, coolant speed, oxide layer conductivity.

I still argue that spacer's the best aid to imparting consistent temperature to the carb, as it has ability to act as a water-cooled heatsink .

 

[ludwig]

I still argue that spacer's the best aid to imparting consistent temperature to the carb, as it has ability to act as a water-cooled heatsink .

Something like the multi-layered bernoose in the Arabian world; you won't get any hotter out in the desert than you already are with five layers of wool blankets on.

As I understand it, the specific purpose of the spacer is to work against carb icing. Not generally a problem in southern Cali. Now the tie-breaker might be to see whether those Hawaiian Mustangs that were delivered from the factory without heaters had hoses to the carb spacer.

 

[addo]

If you look back to the first generation of Ford OHV sixes, they were designed and installed where space was not really at a premium. So, ambient-air cooling of all parts, was one of the assumptions.

Then we compunded heat issues by a bit of economy in patternmaking (the integral log), lower panel lines, lesser ground clearance and smaller engine bays.

So that leaves us with a motor that's almost too hot, in an engine bay that traps heat, and now we've more volatile modern fuels thrown in for good measure. Look how frequent posts are that expose issues with float level, hot carbs, hard starting and mysterious percolation in summer.

Ever wet your hat in summer and put it back on? Same deal as coolant in the carb spacer.

 

[ludwig]

Yeah, but when I put a carb spacer under my hat it didn't change the ambient fuel consumption characteristics of my energy converter. I still didn't want to work very hard in the sun.

 

[Bort62]

The only real benefit of the carb spacer in a warm climate is the increased plenum volume. On the 6, this is rather secondary.

The coolant is much warmer than that part of the engine would be otherwise, so it's a lot more likely to heat the carb up than cool it down.

It's solely there to prevent carb icing and other cold related atomization problems.

I've always run without one.

 

[ludwig]

So there, Addo. Pllll. Pllll. Pllll. (sound lips flapping loosely around the extended tongue tip)

 

[Harte3]

A spacer might increase A/F velocity and aid in atomization that might (or might not) be noticeable in a + in MPG.

 

[Bort62]

The increase in plenum volume by adding a spacer on these engines is a very small %.

Besides, increase in volume tends to lower the velocity in the intake.

 

[Anonymous]

lagrasta..the colder your fuel mixture the better the performance across the board. rainy,high altitude loc. the exception. look at the manifolds on prostock or almost any racing engine. do away with the hoses except in the coldest snowy cond. prob. good for 2-4 hp too depending on your carb set up you will increase volume. the harley air cleaner looks great but at wot is probably too small

 

[LaGrasta]

thanks superheat, I'll take your advice.