Building a redneck spray truck

7879fordman · Mar 10, 2014

Ok using a 1977 f150 4x4 . Going to use a 150-200 gallon tank . And a 6.5 predator engine and a roller pump . Going to probley rig it boom and boomless . Got the bed off the truck today . Bought the engine yesterday. And have pump . Just got to decide the tank size . And figure out the pulley size to gear the motor down .

Any and all help on the pulley sizes is much needed .

A before the bed removal

Sent from my iPhone 5 using TractorByNet

NS Gearhead · Mar 10, 2014

Cool project! What is it that you're spraying? The old truck looks to be in good shape!... although i know looks can be deceiving.

cgood · Mar 10, 2014

If you Google "pulley calculator" I'm sure you can find something to help figure out what size pulley you need.

7879fordman · Mar 10, 2014

NS Gearhead said:
Cool project! What is it that you're spraying? The old truck looks to be in good shape!... although i know looks can be deceiving.

Pastures for weeds/trees . And ya its a pretty clean old truck but I have a title issue that I can't seem to get straight . So I can't tag it . Plus I have 4 other 78-79 ford short bed 4x4's that are streetable . And I only have $200 in the truck .

Sent from my iPhone 5 using TractorByNet

NS Gearhead · Mar 10, 2014

Wow... where I live it's rare to find a 98 with that little rust.

7879fordman · Mar 10, 2014

NS Gearhead said:
Wow... where I live it's rare to find a 98 with that little rust.

It pretty much rust free .

Sent from my iPhone 5 using TractorByNet

7879fordman · Mar 10, 2014

I'm thinking maybe wrong but a 1" pulley on the motor and a 6.5" on the pump . And thoughts on that .

Sent from my iPhone 5 using TractorByNet

cgood · Mar 10, 2014

7879fordman said:
I'm thinking maybe wrong but a 1" pulley on the motor and a 6.5" on the pump . And thoughts on that .

Sent from my iPhone 5 using TractorByNet

The pulley calculator I found Pulley size and RPM says with those pulleys the pump will turn about 554 rpm with the motor turning 3600 rpm.

7879fordman · Mar 10, 2014

cgood said:
The pulley calculator I found Pulley size and RPM says with those pulleys the pump will turn about 554 rpm with the motor turning 3600 rpm.

That would be about right then . The motors 3600 . And 540-1000 max is the pump rpm .

So now the fun trying to find pulleys to fit the shafts of the motor and pump . Figure the pump will be the hardest it's 15/16" and motors is 3/4" .

Sent from my iPhone 5 using TractorByNet

7879fordman · Mar 11, 2014

Well it looks like I'm going to have to run a 1.75 pulley on the motor since that's the smallest I can find to fit the 3/4" shaft .

And then a 7.75 on the pump . But my problem is the pump shaft is 15/16" and I can only find 7/8" or 1" bore for this pulley . Should I buy the 7/8" bore and bore it out or turn the pump shaft down a 1/16 . Or buy it for a 1" bore and have it a 1/16th loose .

The rpm will be at 800 with that ratio of pulleys . So under the max 1000 rpm of the pump .

Sent from my iPhone 5 using TractorByNet