OK! I have a 1979 winnebago with a 440 in it! Gets 5-6mpg Trying to boost the mileage. I put headers and a new edelbrock 750 on it!
Have been told that the cam is retarded and these are very low compression was looking at maybe a new cam and timing set maybe an edelbrock manifold. Could rebuild if power would come up. Wondering about putting a hei conversion in it! What do you guys think? I know hotrodding motorhomes is weird but any suggestions would be great! What about aluminum heads?

 

Not weird.. Not at all. Im all for Hot Rodding anything!!

You are on the right track. I would keep in mind some of the things the OE guys do to get better mileage.

Make sure you are getting your dollars out of what you have. Add a wide band meter and tune your carb and timing. Then consider the other stuff...

1. on the engine side reduce internal friction: Lighter piston, less ring resistance, skirt coatings, roller lifters, plastic intakes, aluminum heads / blocks... etc..

2. Proper AFR though out the entire range and proper timing.

3. Gearing: keep it in meat of the band. The spread between peak torque and peak HP. If your highway speed doesnt have you in the sweet spot change the gearing.

4. Elimate external friction. Make sure wheel bearings are free, brakes dont drag, tires are correct pressures, etc..

 

holy cow.. 6mpg LOL!

when is the last time the carb was rebuilt and a tune up done?

 

Actually the carb is brand new! Edelbrock 750 calibrated for mileage! New plugs wires all of it! Actually 6 is pretty common for these older motor homes!
Thanks for the inputs

 

Does that 440 have the reverse cooling, meaning the water pump flows threw the heads. I would really becarefull with e-brock 750. You might run lean. That 440 in that camper really gets worked under load. Like pulling plows with a tractor. I pulled a 413 out of a bago last year. It had reverse cooling

 

HEI would give a hotter spark /possible better mileage. A slight raise in compression could help too.. maybe surface the heads .030-.050 (intake side too...) and a thin Head gasket .Intake may help Did it have a thermoquad carb ? Make sure the vacuum advance is working. I have heard of using a Gear Vendors overdrive to help with mileage It comes down to that big heavy box / home on wheels is not going to get a whole lot of gas mileage without loosing a 1000 lbs

 

Not sure about the reverse water flow! I do know that when I put the headers on the bolts go into water jackets. The gear vender is big bucks was going to work on doing the engine stuff first! What about the cam being retarded for smog reasons?

 

If the cam was installed that way, we would have to know its specs to see if its worth moving. A new cam similar in spec would make a difference but I don't know if the cost benefit would be there.

If she needs a refresh and is coming out then sure. It can be made better and more efficient for sure. And for not much cost.

As for the carb. Its a good unit. The "tuned for mileage" thing would cause me some pause however.. There are many folks on here that tuned with a magnifying glass reading plugs, ETs, etc.. BUT I was very very humbled once at a demo for data logging. Part throttle tuning, transitions, down shift fuel trims, cruise, wot etc...

Innovative wide bands have come way down on their LM units and their LC units are even cheaper. Zetronix make a good unit. I have one of those too and would recommend them. I would stick one in the cabin and see what she is doing as far as AFR goes.