Took the car out for a drive and it ran better than it ever has. Tried to get into boost in second gear and all it would do is break the rear tires loose. Even in high all it would do is :3gears: on the street. Even drove over to the next town. The only thing now is it will not build any vacumm inside the engine. Thought it was the guage so I took it off and tested it. Do you need to seal up the engine really tight to get it to build vacumm?
I would think that it would need to be sealed up. No breathers etc. Otherwise it will stay at zero. ---------- Post added at 04:24 PM ---------- Previous post was at 04:22 PM ---------- In the next few weeks going to seal mine up and put a bung in to check the crank vacuum. Will let you know what the results are.
Michael, isn't the objective to keep the crankcase from pressurizing? You need a compound guage on the crankcase. Keep in mind that it is impossible to pull a vacuum unless it is sealed. That is not your primary objective. If you are building significant blowby or boost pressure in the crankcase, you need to relieve it. If the system is sealed, you cannot remove it beyond the capacity of the "vacuum pump" system. If you have additional vents, it will aid in dumping off pressure if it exceeds capacity of your system. HAVING SAID ALL THAT, REMEMBER THAT I PERSONALLY HAVE NO INTIMATE KNOWLEDGE OR EXPERIENCE WITH THAT SYSTEM. So why am I posting? just to keep you thinking. TexasJohn
Hi Michael, I can understand why you were asking about my pump now. What I did with my vacuum pump even before I started the engine for the first time, is I put a battery drill(you will need a good one) on the shaft of your vacuum pump and slowly bring it up to full speed watching the vacuum gauge. What tis does, is once you have say 5-10" vacuum you can stop the drill and listen for leaks. Your engine needs to be sealed up really good for you to maintain vacuum. I had leaks in the valley at the ends where the manifold mates to the block. I have about 1/4" gap there and I had vacuum leaks right in the corners by the heads. I kept doing this with the battery drill till it maintained good vacuum and I could hear no more apparent leaks. I could maintain 10" vacuum just running it off the drill which turns at 2700rpm on high speed. I also run an aeromotive adjustable vacuum regulator so I can dial in what I want. Hope this helps somewhat. Cheers
I need to do what you did to find out where my leaks are. I also have an adjustable regular for the vacumm. Maybe I need a stiffer spring in it. It looks like rain here this weekend.
Michael, Here is a pic showing my vacuum pump setup if it helps. You can see where I mounted the vacuum gauge. The vacuum reg has a 1/8"NPT port on the side of it, and thats where I mounted the gauge, so I can easily read it while adjusting the reg. Cheers
Rayden, Your post got me thinking. How much resistance does the pump give when being turned? I am at the limit on the belt adjustment, so it is possible that the belt is slipping. Have a 27 3/8 inch long belt on there now, will look for a shorter one. In sealing up the engine, I removed the valve covers to glue the gasket to them to find they were leaking some. What a pain that was. I have to remove the blower to get the driver's side valve cover off. After glueing them on and then I could not get all five bolts started all the same time. It was that I could only get three started at any one time only. I took the covers back off and took a 1/4 inch drill bit to match the gaskets to the tubes that are in the sheet metal valve covers. ---------- Post added at 04:18 PM ---------- Previous post was at 03:49 PM ---------- What size drive pulley do you have at the crank? The directions states that you should not turn the pump faster than 6000 RPM. So, with you four-inch pulley on your pump you should a crank pulley no bigger than 2 inches to give you room to Rev the engine with the safety of Not over speeding the pump.
Thanks for that Michael, I wasnt aware of the max rpm being only 6000rpm. I bought it of a race car and didnt even think of asking the pulley sizes or max rpm. I am running the stock crank pulley which is roughly 7" which is way to big and now I have to find a way of reducing this considerably. More bloody issues It did spit the belt off, but I thought that was due to the alternator bracket I made flexing to much, which I have since addressed by triangulating it (3 bolt fixings, instead of 2). Any ideas of how I can run the vacuum pump at a safe speed. I doubt I will see in excess of 8000rpm. I currently run a 4" pulley on the vacuum pump. Sorry for hijacking your thread here Michael, I got a little carried away Cheers
Michael, You need to go back to the source, and see if your vacuum pump is working. Simply deadhead it, and attach the gauge. I didn't catch what system you have, but if it is a belt driven engine system, then I would be wary of that type of vacuum pump in a street application. It's been my understanding that that type of pump is not ideal for that usage, due to longevity concerns. Ditto with you Royden, I would call the manufacturer and see what they say. Most of those systems are meant for light duty use.. translation, in a drag race situation, where the engine is only running for a few minutes at a time. One trip with your street car to the cruise spot, is about the same amount of run time that a drag motor sees in a whole season. In the systems I have used in the past, some amount of oil is required for the pump to function. Depending on where the fitting is, you may or may not have to remove the inlet hose once in a while, and shoot a couple oil can shots of engine oil down the inlet. You noted that there was no oil in your catch can, and that is probably because the pump is not functioning. I think that those folks who have pioneered the external electrical vacuum pumps on these engines are on the right track here. That's what my next race car will have, maybe even will test it out on the TSP test car, when that gets going on the street. JW
Thanks Jim for the insight. I will do just as you said I have not thought of that. It is helping as it is not putting oil out the seals like it was. Now it is putting some oil into the catch can. The blow-by from the super charger was to much on the 1/4 mile for the open-element. Set up that was fine on the 1/8 mile and the street. I bought the pump/system from a board member off this board and it looks like it has been serviced and well maintined. It is a three-vane Moroso pump. I put the engine back together last night and thought with the sealing up and changes I did, it would be better, but it was the same. Need to find a #12 to #4 union fitting or a 3/4 to 1/8 nipple. Roydon, You need a crank drive something like this but made up for the buick 455. http://www.ebay.com/itm/Moroso-Oil-...819?hash=item19dcd43f8b&vxp=mtr#ht_1529wt_808 Not sure of the pulley diameters (would have to do the math) to figure the RPM. I would think you will need to get in touch the the maker of the pump you have and let them tell you the max RPM.
Roydan, There are cheaper ways of getting this done like: http://www.summitracing.com/parts/aaf-all31031 Get this kit and have the bolt pattern changed to the buick six-bolt type. You will of course need to make a new mount for the pump. Picures of my setup.
another view of the pulleys. It shows that have a two-inch drive pulley and a five-inch pump pulley. uploading a video to U-tube of the car in the garage running. It has to do it's thing. My vacuum pump directions: http://www.jegs.com/InstallationInstructions/700/710/710-22640.pdf
Made the fitting and did the test that Jim suggested and the pump went to 20 HG with a stab of the thottle. So I would take it that the vacuum pump is working fine. Looked on E-bay and the cheepest union fitting I could fine on there was $13.49. Since I only needed the fitting for five minuets, I just dug though my fittings and made something that would get the job done. Need to sale my Auto meter 3471 guage and get an Auto meter 3401 guage to monitor it to see if the pump is keeping it at zero. Maybe it is best that it does not draw any vacuum so the pump will live longer. Just wonder where it is leaking. At least it is not spitting oil out of the valve covers.
