to vacuum pump, or not to vacuum pump, that is the question?

BIZMANRACING · 09-22-2007, 10:48 AM

ALL THE PIECES ARE BACK IN PLACE AND I?M READY TO GO RACING AGAIN.

My question concerns the use of alcohol and vacuum pumps. As of this writing I was not planning on using a vacuum pump since I didn?t have one on they?re before. A little background. My 383 was originally build't to run on gas. But, after running it for 2 years I got tired of trying to figure out my ?dial in? if the weather changed dramatically. So, I decided to switch to alcohol. Which took care of the problem.

But,

The motor did not live long. I heard and got a lot of advice. You need to get a vacuum pump or if not you?ll need to change your oil after ever use .

So my question is, for those that use alcohol or have experienced the wows that I?m going through what do you recommend?

Carlos Mendes
S/street 1739

Mike Hedger · 09-23-2007, 10:53 PM

Put one on it, that throwup looking stuff (water and oil mixed) under your valve covers will be gone. I also get the motor hot 200 or so before I shut it down in the trailer and remove the oil filler caps so it can boil and any extra moisture out of it. I would not want any more than 10-12" of vacuum at the finishline or you will have lower end problems. (wrist pins and bearings) Put a gauge on it and make sure you are not going over, allot of engine builders have had comebacks since vacuum pumps because of people trying to run to much vacuum or running the car without a gauge. Hope this helps, Mike

BIZMANRACING · 09-27-2007, 07:57 PM

mike thanks alot for your responce. i was hoping to get more input to confirm your position since frankly i don't know........ before the motor let go i tried to "heat it up" by making the motor run as lean as i could before she shut down. but, i could never get the motor that hot. in any case i did the best i could and then i fogged the motor with wd-40.

as for the pump. thanks for the info. i plan on putting one on. i already have a gauge which i never used from the old gas days. where did you pump the gauge into?

thanks once again.

carlos mendes
s/st 1739

Mike Hedger · 09-28-2007, 08:42 AM

I have always put the fitting for the gauge in the oppisite valve cover the pump inlet is. If you shut the water pump and fan off you should be able to get it to 200 or so.

Mike Pearson · 09-28-2007, 04:03 PM

unless you are using a ring combination with very low pressure you will be wasting your money. get away from the alchohol it creates alot of wear in the top of the cylinders. Your motors will last much longer on gasoline. Run the car on the lean side and you will not get as much ET variation. If your car has a hood scoop block it off and pull the air from around the engine this will lessen the change in et due to temp change. in the .90 classes you are not looking for every last HP as we are in Super Stock

Bryan Gillespie · 09-28-2007, 09:15 PM

I ran alcohal carb for 2yrs and injection for 6 yrs and never had a vacum pump,if your milking the oil ,your fat,oil changes every 25 passes,taking the breathers out at the end of night will help with condensation,like the other dude said unless you have low tension rings your pissing in the wind with a vacum pump.

09-22-2007, 10:48 AM	#1
BIZMANRACING Junior Member Join Date: Oct 2004 Location: east brunswick, new jersey Posts: 62 Likes: 0 Liked 0 Times in 0 Posts	to vacuum pump, or not to vacuum pump, that is the question? ALL THE PIECES ARE BACK IN PLACE AND I?M READY TO GO RACING AGAIN. My question concerns the use of alcohol and vacuum pumps. As of this writing I was not planning on using a vacuum pump since I didn?t have one on they?re before. A little background. My 383 was originally build't to run on gas. But, after running it for 2 years I got tired of trying to figure out my ?dial in? if the weather changed dramatically. So, I decided to switch to alcohol. Which took care of the problem. But, The motor did not live long. I heard and got a lot of advice. You need to get a vacuum pump or if not you?ll need to change your oil after ever use . So my question is, for those that use alcohol or have experienced the wows that I?m going through what do you recommend? Carlos Mendes S/street 1739

09-23-2007, 10:53 PM	#2
Mike Hedger Junior Member Join Date: Jul 2007 Location: Kemah TX Posts: 93 Likes: 0 Liked 1 Time in 1 Post	Re: to vacuum pump, or not to vacuum pump, that is the question? Put one on it, that throwup looking stuff (water and oil mixed) under your valve covers will be gone. I also get the motor hot 200 or so before I shut it down in the trailer and remove the oil filler caps so it can boil and any extra moisture out of it. I would not want any more than 10-12" of vacuum at the finishline or you will have lower end problems. (wrist pins and bearings) Put a gauge on it and make sure you are not going over, allot of engine builders have had comebacks since vacuum pumps because of people trying to run to much vacuum or running the car without a gauge. Hope this helps, Mike __________________ Mike Hedger S/C 4646 MPH Racing and Fabrication

09-27-2007, 07:57 PM	#3
BIZMANRACING Junior Member Join Date: Oct 2004 Location: east brunswick, new jersey Posts: 62 Likes: 0 Liked 0 Times in 0 Posts	Re: to vacuum pump, or not to vacuum pump, that is the question? mike thanks alot for your responce. i was hoping to get more input to confirm your position since frankly i don't know........ before the motor let go i tried to "heat it up" by making the motor run as lean as i could before she shut down. but, i could never get the motor that hot. in any case i did the best i could and then i fogged the motor with wd-40. as for the pump. thanks for the info. i plan on putting one on. i already have a gauge which i never used from the old gas days. where did you pump the gauge into? thanks once again. carlos mendes s/st 1739

09-28-2007, 08:42 AM	#4
Mike Hedger Junior Member Join Date: Jul 2007 Location: Kemah TX Posts: 93 Likes: 0 Liked 1 Time in 1 Post	Re: to vacuum pump, or not to vacuum pump, that is the question? I have always put the fitting for the gauge in the oppisite valve cover the pump inlet is. If you shut the water pump and fan off you should be able to get it to 200 or so. __________________ Mike Hedger S/C 4646 MPH Racing and Fabrication

09-28-2007, 04:03 PM	#5
Mike Pearson VIP Member Join Date: Mar 2007 Posts: 2,447 Likes: 615 Liked 1,924 Times in 578 Posts	Re: to vacuum pump, or not to vacuum pump, that is the question? unless you are using a ring combination with very low pressure you will be wasting your money. get away from the alchohol it creates alot of wear in the top of the cylinders. Your motors will last much longer on gasoline. Run the car on the lean side and you will not get as much ET variation. If your car has a hood scoop block it off and pull the air from around the engine this will lessen the change in et due to temp change. in the .90 classes you are not looking for every last HP as we are in Super Stock __________________ Mike Pearson 2485 SS

09-28-2007, 09:15 PM	#6
Bryan Gillespie Banned Join Date: Dec 2006 Location: Maryland Posts: 456 Likes: 0 Liked 0 Times in 0 Posts	Re: to vacuum pump, or not to vacuum pump, that is the question? I ran alcohal carb for 2yrs and injection for 6 yrs and never had a vacum pump,if your milking the oil ,your fat,oil changes every 25 passes,taking the breathers out at the end of night will help with condensation,like the other dude said unless you have low tension rings your pissing in the wind with a vacum pump.