More Vacuum Pump Questions

mikester

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Mar 10, 2010
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Small town NY
This is the second brake post of the night.
The 406 in my 81 is putting out 12 in of vacuum at an idle. The guage actually bounces around but thats the average. Honestly Im not sure why since the cam is 510 lift and 296 duration. Maybe thats normal but the guy at Comp Cams said I could still run power brakes. Needless to say that hasnt worked out. Anything else that might cause low vacuum ?
Im shopping for an elelctric vacuum pump. Dont want to even bother with a canister. The local speedshop sells CVR pumps. Im looking at the vane pump that they have. Ive also thought about buying a Leeds brand. Theyre both around the same cost. Reviews online are similar. I'll probably mount it on the inner fender close to the booster if theres room. The CVR looks like a better fit but I wont know until I get one.
Anyone have one or a different one thats been working ? Looking at the vane pumps because theyre quiet.
 
After seeing an article in car magazine about these, I bought this pulley driven vacuum pump from a junkyard 30+ years ago off of a Ford Diesel truck that I believe had about 53,000 miles on it.
I made brackets and mounted it off of my power steering pump and I spin the BBC to mid 7000 RPM
This vacuum pump pulls 28 lbs. at idle even when the brakes are applied and it self regulates itself and also does not require a vacuum source. It's quiet and doesn't need any electrical or maintenance.
It obviously takes some fabrication to get it mounted but it pulls vacuum instantly and 8 more lbs than most electric pumps.
IMG_1479.JPG
 
so i was in in a similar position with my last 3 motors(3,reallly!) and I'm running this Hella pump along side of a can it's pulls well.just an FYI those larger pumps like summit branded/cvr are quite loud,they're air brush compressor loud.if i can recommend anything it would be to look at this https://www.summitracing.com/parts/leb-vp001b?rrec=true.-it has the one way check valve and pressure switch assembled all in one package. The way i did mine i had to plumb and wire everything piecemeal.
 
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After seeing an article in car magazine about these, I bought this pulley driven vacuum pump from a junkyard 30+ years ago off of a Ford Diesel truck that I believe had about 53,000 miles on it.
I made brackets and mounted it off of my power steering pump and I spin the BBC to mid 7000 RPM
This vacuum pump pulls 28 lbs. at idle even when the brakes are applied and it self regulates itself and also does not require a vacuum source. It's quiet and doesn't need any electrical or maintenance.
It obviously takes some fabrication to get it mounted but it pulls vacuum instantly and 8 more lbs than most electric pumps.
View attachment 255432
You responded to a question I posted a while ago. Only issue is Im looking for an easy fix. Im sure I could get a pump from a yard but I dont want to go through the hassle of making a bracket or getting a different pully since I have all March stuff already. I do like your setup though !
 
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so i was in in a similar position with my last 3 motors(3,reallly!) and I'm running this Hella pump along side of a can it's pulls well.just an FYI those larger pumps like summit branded/cvr are quite loud,they're air brush compressor loud.if i can recommend anything it would be to look at this https://www.summitracing.com/parts/leb-vp001b?rrec=true.-it has the one way check valve and pressure switch assembled all in one package. The way i did mine i had to plumb and wire everything piecemeal.
I think the louder pumps are diaphragm style. Im looking at vane pumps which are a lot more quiet. Installation looks pretty simple. I already changed up some of the wires under the hood thinking that would be the only good option.
The only hot with ignition wire I had coming out of the bulkhead connector was for the electric choke thats been deleted. The Holley HP doesnt have one. I was using that wire for the electric kickdown on the TH400. I rerouted that wire to the inner fender in split loom and ran a second wire from there to the kickdown switch. Picked up one of the Delco junction blocks with the single post and cover. These pumps draw 6 amps and pump up to over 20 in. They shut off when the requirements met.
 
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