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Discussion Starter #1
Is there any value besides the obvious of hp gain at higher rpm to running a vacumm pump on a non race application.

Here is my scenario

21' daytona.
509 11 to 1 compression
conventional heads
around 750 - 800 hp on motor
pump gas
200 shot of n20.

spend most of its life at idle to 3500 rpm with occasional kilo passes.:D

I'm I going to gain enough to make it worth the $1000. Or are there any benefits besides at full throttle?
 

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It's going to make better power throughout the entire rpm range due to increased ring seal. Second your chances of blowing out gaskets such as oil pan, timing chain cover, valve cover, and intake will be greatly reduced because you are taking the inside of your motor from a pressurized state to that of a vacuum. Oil leaks are greatly reduced as well. If you can afford it, it's worth the investment in my opinion. F1~
 

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Red Blooded American
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It can help suck the oil off your cylinder walls and wear out rings faster so you can rebuild it as often as a race boat.
Hope that helps :D
 

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Discussion Starter #6
It's going to make better power throught the entire rpm range due to increased ring seal. Second your chances of blowing out gaskets such as oil pan, timing chain cover, valve cover, and intake will be greatly reduced because you are taking the inside of your motor from a pressurized state to that of a vacuum. Oil leaks are greatly reduced as well. If you can afford it, it's worth the investment in my opinion. F1~
Okay cool this is what I was looking for. Thank You.
 

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fwiw. I was thinking of running 12 to 14 inches vacumm
I've been told that 18" of vacuum is where you will have problems with the motor losing wristpins. Unless you are running a drysump, 4 vane pump, and low tension total seal gapless rings, I doubt you have to worry about it....
 

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Discussion Starter #9
I've been told that 18" of vacuum is where you will have problems with the motor losing wristpins. Unless you are running a drysump, 4 vane pump, and low tension total seal rings, I doubt you have to worry about it....
I've heard the same. We run 16 to 17 in the big chief dry sump motor. But that motor is a max effort drag race only motor.
 

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We all fail from time to time, just gotta dust ourselves off and keep trying!:D

It will also stop the blowbye at high rpm from pushing that nice oily mist out of your breathers and dirtying up your boat.
 

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Red Blooded American
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We all fail from time to time, just gotta dust ourselves off and keep trying!:D

It will also stop the blowbye at high rpm from pushing that nice oily mist out of your breathers and dirtying up your boat.
Isn't that what evac tubes into the headers are for? :D
 

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I've been told that 18" of vacuum is where you will have problems with the motor losing wristpins. Unless you are running a drysump, 4 vane pump, and low tension total seal rings, I doubt you have to worry about it....
I galled a set of wrist pins in one season w/ 14in of vacuum. We opened the pin tolerances up a couple of ten thousandths and went to a DLC coated pin and everything has been great since.
 

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You can lose wrist pins without a vacuum pump at all if they didn't have enough clearance to begin with. From everything I know, 14" should not be a problem, however I will dig deeper and research this better as there is a Product Engineering pump under my work bench right now waiting for me to install it. F1~

BTW I spoke with James today at So Cal. Upholstry, very nice gentleman, I thought the prices were very reasonable, we'll be hooking up, Thanks again Jordan~
 

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Precision Craft Marine
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You can lose wrist pins without a vacuum pump at all if they didn't have enough clearance to begin with. From everything I know, 14" should not be a problem, however I will dig deeper and research this better as there is a Product Engineering pump under my work bench right now waiting for me to install it. F1~

BTW I spoke with James today at So Cal. Upholstry, very nice gentleman, I thought the prices were very reasonable, we'll be hooking up, Thanks again Jordan~
I love product engineering equipment. that is well built stuff. This is a good topic. I am curious about this too. I would like to run a pump on my cruiser, if I can find a unit that will pull 10-12 inches, and get a boating season from it. On our hydro, we would have to get after the vac pump every 30- 35 passes. Maybe someone on here has done this with sucess?
 

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I think it's beneficial in many ways as long as you monitor/limit the amount of depression. I think you should be able to pull 6-8in all day long without any problems. Any higher than this and you may need to go to coated pins and open up the pin clearance a little. As JShelfo mentioned durability of the pump may be suspect but I would imagine a nicely made piece should live forever but...........
This is all a guess though as I don't have any wet-sump/crank case depression experience........I'm a dry sump type of guy! ;)
 

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Too much depression over an extended perod can also lead to seal failure. Something else to consider.
 

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Shelfo, I had a problem with my vacume pump having to be cleaned often. Seems that the oil mist would stick the vanes in the rotor. Cured the problem by running the pump to a canister before running to the valve cover. It stops the oil from getting to the vanes, works great:(:(
 

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mo balls than $cents$
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good thread kjell! i was wondering the same about my lil ls motor, i had a smog pump i was thinking bout runnin on it but to hell with it, i'll just give the motor as much windage control as i can and hope for the best.
 
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