billet-boy
New Member
- Joined
- Sep 6, 2008
Ok im new to vacuum pumps, I have just instaled a belt drive pump and would like a little guidence on how much vacuum i should run?
crank case vacuum
- Thread starter billet-boy
- Start date
- Joined
- May 26, 2001
About 10-12 inches of vacuum seems to be generally the best range. This is where local racers, both boosted and not, are set to run.
The max recommended is 18.
The max recommended is 18.
On the speedtalk forums (Speed Talk: Interviews - Racing Books - Racing Forum) several engine builders/racers have commented that more than 15" of vacuum will lead to oiling problems, especially on the piston pins. Like Nick said, 10-12" is popular.
- Joined
- Jun 18, 2001
I've just gone rounds with my mechanical pump, I have a Moroso 3 vane pump. If you run more than 10" on a Buick and a duttwieller or stock style pump you will have oil pressure issues. At 15" I had almost no oil pressure. Seal the motor as tight as possible and put the relief valve after the motor on the vacuum pump, NOT ON THE MOTOR. Take the pickup from the front of the VC if possible. These two changes eliminated filling the breather tank every pass and still being able to maintain 10" vacuum. Pay close attention to pulley sizes and pump speed. I ran the car on a chassis dyno to set the relief and crankcase vacuum and check oil pressure under full boost. I would suggest the same. BTW the pump isn't worth much if anything in HP.
- Joined
- May 26, 2001
Chris, we set our systems up like you said and especially the regulator at the pump. I have almost no oil in the accumulator after many runs.:smile:
I have run my vac up to 14" and not seen any difference in oil pressure? It is a Dut pump and RPM is less than 7000.
It was a big job to get the pulleys sized to keep the pump speed at 1/2 engine RPM.
There is a difference in performance in my car without the pump, about 0.1 sec. and 1-2 MPH.
- Joined
- Jun 18, 2001
Chris, we set our systems up like you said and especially the regulator at the pump. I have almost no oil in the accumulator after many runs.:smile:
I have run my vac up to 14" and not seen any difference in oil pressure? It is a Dut pump and RPM is less than 7000.
It was a big job to get the pulleys sized to keep the pump speed at 1/2 engine RPM.
There is a difference in performance in my car without the pump, about 0.1 sec. and 1-2 MPH.
What pump are you running to get 14" at 3000 rpm? That's pretty good. With 10-12" vacuum I will see maybe a 5psi dip in oil pressure with 15" I can watch the oil pressure fall as fast as the tach rises! Some of it has to do with the pump speed also, I reverse mounted the vac pump on the frame above the steering box. I used the IC fan adpater from my alum lower pulley and mounted a 3.5" v groove pulley to it to drive the pump. I have 5" pulley on the vac pump so my pump speed is much higher as a result and I can't easily change it without re fabricating stuff so I have to bleed off a lot of vacuum which is why I had such a mess until I switched the reg and VC pickup.
I didn't see any increase in power on the dyno or track BUT the dyno isn't real accurate with my car due to the amount of tq it makes and it being a load sensitive turbo motor. I am sure the pump is helping some but I'm just not going to see the difference on my car. I do know it helps with crankcase pressure which on my motor making 225hp+/cyl it wants to push anything and everything out where ever it can!
- Joined
- May 26, 2001
Chris, I worked with Steve at Star Machine in Baltimore to come up with the right pump and pulleys. We use a cog belt that is driven off the water pump shaft.
He was very adamant about getting the right speed of the pump, and he helped me by providing the proper pulleys.
Took a month or so between the mounting and parts to get it right.
We are building a new web site, and this is one of the items that will be featured with lots of pics. Am now developing a kit for the pump with no AC and no power steering.
The current kit uses the Champion AC delete bracket with another bracket we have made by CNC.
He was very adamant about getting the right speed of the pump, and he helped me by providing the proper pulleys.
Took a month or so between the mounting and parts to get it right.
We are building a new web site, and this is one of the items that will be featured with lots of pics. Am now developing a kit for the pump with no AC and no power steering.
The current kit uses the Champion AC delete bracket with another bracket we have made by CNC.
Again from speedtalk, posters there say that with an engine set up with normal rings they see maybe 1-5 hp on a 600-800 hp engine with a vacuum pump. Set up with low tension rings the vacuum pump is worth up to 50-60 hp on an 800-1000 hp engine. I think these are mostly high compression n/a motors, not turbo or nitrous. There is a page on vacuum pumps on Reher-Morrison's web site that I think says about the same thing (which makes sense because Darin Morgan, who was the chief engine builder at r-m, posts on speedtalk ). Even if there is no hp gain, it seems like it would be definitely worth it just to eliminate all the oil drips.
). Even if there is no hp gain, it seems like it would be definitely worth it just to eliminate all the oil drips.
- Joined
- Jun 18, 2001
Chris, I worked with Steve at Star Machine in Baltimore to come up with the right pump and pulleys. We use a cog belt that is driven off the water pump shaft.
He was very adamant about getting the right speed of the pump, and he helped me by providing the proper pulleys.
Took a month or so between the mounting and parts to get it right.
We are building a new web site, and this is one of the items that will be featured with lots of pics. Am now developing a kit for the pump with no AC and no power steering.
The current kit uses the Champion AC delete bracket with another bracket we have made by CNC.
They are good people and definitely the some of the best stuff you can get. Steve helped me out on YB.com with the vacuum pump and was the one who told me to move the regulator, nice guy. Excellent products I would like to see pics of the pump set up when done.
- Joined
- Jun 18, 2001
Again from speedtalk, posters there say that with an engine set up with normal rings they see maybe 1-5 hp on a 600-800 hp engine with a vacuum pump. Set up with low tension rings the vacuum pump is worth up to 50-60 hp on an 800-1000 hp engine. I think these are mostly high compression n/a motors, not turbo or nitrous. There is a page on vacuum pumps on Reher-Morrison's web site that I think says about the same thing (which makes sense because Darin Morgan, who was the chief engine builder at r-m, posts on speedtalk
That's probably accurate. I will run the same # with or without the pump hooked up. I run standard tension rings and personally don't feel low tension rngs would work well in the environment I would be running them in. I do like it though and it does keep the oil in the motor where it belongs:biggrin:
billet-boy
New Member
- Joined
- Sep 6, 2008
thanks for all the good help I need to change some plumbing now
billet-boy
New Member
- Joined
- Sep 6, 2008
Chris, I worked with Steve at Star Machine in Baltimore to come up with the right pump and pulleys. We use a cog belt that is driven off the water pump shaft.
He was very adamant about getting the right speed of the pump, and he helped me by providing the proper pulleys.
Took a month or so between the mounting and parts to get it right.
We are building a new web site, and this is one of the items that will be featured with lots of pics. Am now developing a kit for the pump with no AC and no power steering.
The current kit uses the Champion AC delete bracket with another bracket we have made by CNC.
That is what i did Champion bracket and GZ Motorsports chevy bracket and then to our cnc machining center
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