Given the recent spotty quality control on offshore made fuel pumps, water pumps, and other accessories, wouldn't it be a good idea to think outside the box a little where vacuum booster fuel pumps are concerned? Fortunately, there's another option. During the rapid gain in popularity of Diesel powered cars back in the 1980s, GM installed a belt driven vacuum pump on those engines to make up for the lack of intake manifold vacuum to operate brake boosters, air conditioner blend motors, and other vacuum operated equipment. Like this:
It would be simple to adapt one of these belt driven pumps to a stovebolt engine, and install a vacuum reservoir canister somewhere out of sight, such as a small refrigerant gas canister, maybe inside a frame rail under the cab. Plumb the reservoir to the intake manifold and the boost pump, using one way check valves to keep the reservoir charged. The pump could be mounted somewhere like on top of a generator, driven by a short belt from a double sheave pulley on the generator or alternator. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
The style of vacuum pump in your link is a diaphragm vac pump, I owned a 2000 Chevrolet K3500 that was the last model year of the Detroit/Peninsular/Gm V8 diesel in pickup trucks. It had that style of vac pump and its sole duty was to provide vacuum for the turbo waste gate. The pump had a history of failure and many owners opted for a mechanical waste gate control in order to reduce the spending on vac pumps. I don't remember the specs for that pump but it may not have enough volume or depth of vacuum for wipers and brakes, but along with manifold vacuum, your idea could be viable. If someone needs more vacuum, a 12 volt electric pump may be the answer. With my '57 2 ton truck, I added a refrigeration disposable cylinder just as you describe, plumbed into the factory vacuum system which has a check valve, my truck does not incorporate vacuum wipers but for the brakes and 2 speed rear, it works great.
Last edited by 78buckshot; 04/09/202412:25 PM.
1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy
Vacuum wipers - add a manual crank inside the cab like the WWII vehicles.
Vacuum brake booster - I solved this issue on a non-Stovebolt that didn't have enough engine vacuum to run the booster by changing to manual brakes.
And a more viable solution: on the above vehicle, I installed an electric fuel pump (it needed it) and then a camshaft-driven vacuum pump to replace the normal fuel pump, before I decided I didn't need power brakes.
Jon
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes! The Carburetor Shop
The dual action fuel pump also uses a diaphragm- - - - -the only difference I can see is how it's being driven. The dual diaphragm fuel pump is also plumbed in series with manifold vacvuum, but that system usually doesn't include a reservoir tank. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
On my 51 Chev PU, I plumbed in an air tank for a semi-trailer with check valve coming off the manifold. The vacuum end went to the hydrovac, wipers and AC vacuum actuators and for a while to the manifold side of the fuel pump vacuum booster. This worked fine until the wiper motor wore out and I didn't have enough good parts to fix it. The fuel pump eventually began sucking prodigious amounts of oil and so did it's replacement only a short while later. I gave up on mechanical fuel pumps and went electric -- wipers and fuel pump. Only trouble since has been a failed electric fuel pump that cost me a tow off the freeway. Wipers work well. Get the delay switch. It's worth the price.
I long ago had a 50 Stude with vacuum wipers. It came to me with a vacuum tank screwed under the floor and a check valve. It worked tolerably well on short hills in town but on the road I would have to lift my foot off the gas pedal to recharge the tank every so often. Eventually I found a vacuum boost fuel pump and took the other stuff off. I drove it daily for ten years in rainy Seattle. Wipers worked fine when I sold the car years later. I still have the check valve.
1951 3800 1-ton "Earning its keep from the get-go" In the DITY Gallery 1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971.
I worked on an isuzu box truck last week with a 6.0 liter v8 gas engine. 2014 year model It had an electric vacuum pump to work with brakes if the engine died or an emergency situation. Also some f250 fords had electric vacuum pumps on them to work the a/c controls for Diesel applications.
A pump that was designed to run everything can be found on the Oldsmobile diesel engines in Chevy trucks. It goes in the distributor hole and is a pain to fab up mounting and a belt drive pulley. We have one driven by an electric motor for testing that has been in use for at least 30 years.
Here is the NOS vacuum/fuel pump on one of my 292's. On my 53 292 I'm running a scroll vacuum pump that is quiet and requires no reservoir because of my blower. Electric fuel pump, electric wipers. I'll probably put a reservoir on it anyway.
