OK, I'm running a MOROSO 4 vane pump, and with the new motor I haven't seen it pull vac. on the gage in the car, I know that the rings need to seal, but you guys running this, or a similar set up, have you checked your motor for leaks?? I was talking to Peterson Fluids Systems, I run there external oil pump, they mentioned pressurizing the motor to 10psi w/shop air, and check it for what would be vacuum leaks, soapy water, OK, I'll do this, they mentioned that cork gaskets are prone to leak, I have a cork Pan Gasket, and a rear pan gasket seal leak, (from my other Thread). Are you guys not using a pan gasket?? Just silicone??Something other than cork?? With my leaking, popped out seal, others mentioned putting it in dry, and silicone the "corners", but will that actually seal regarding pulling vacuum?? Old motor would pull vac. going down the track, and I do have an adjustable vac. regulator on the valve cover. I'm reading vac. for the gage from a fitting screwed into the old fuel pump area, now blocked off. I just figure if I'm dropping the pan to fix the seal, and the cork is no good, just bust out the tube of silicone and lay it on. What do you think??? Gary G.
Gary, Which 4 vane pump are you using??? The old style or new style? Here are some things to consider when running a vacuum pump. 1. What rings are you using? 1/16, 1/16, 3/16?.... .043, .043, 3mm???? With standard rings you will probably get enough blow by to show no vacuum. With the 1/16 package you should pull vacuum. With the .043 ring package I would really watch the vacuum. Especially if you have the new style pump. 2. Which valve cover are you running? My Unique Products leaks around the welded areas of the bolts. I had then rewelded and still have to put a sealer over the bolts. 3. The vacuum pump has to be properly situated or your going to suck out to much oil. I will post a pic of how mine is mounted. If the exit hose is in the 6 oclock position it will pull oil. The exit must be up. 4. You WILL lose oil presure with a vacuum pump. There are different theories about why. I say just dont try to run to much vacuum and you will be fine. I keep mine around 6 to 7" at wide open throttle. 5. The vacuum pump will not pull much vacuum at an idle. Maybe 1 to 2" inches. You will not see any vacuum until it pulls a slight amount of oil to seal the internal fins. But if you rev the engine to 3000-3500 you should see it on your gauge. Testing for leaks..... Make up a device to pump compressed air into your engine. I made mine at the relief valve. You do not need much pressure (maybe 10 lbs of air pressure) to find the leaks. I might be stating the obvious here but do not use any breathers. I hope this helps. Later
Here is a shot of my relief valve. Its tucked away in the back with a #12 male fitting welded into the intake. Then I added a #12 female to the relief valve. If I try to run to much vacuum I can just loosen up this relief valve and I will gain 20 psi of oil pressure at an idle. So its best to keep it low. Also..... There are issues on deceleration. Remember you have just made a pass at 7000 rpms with 80 lbs of oil pressure and 8" of vacuum. Then you let off of the gas. What happens next????? Your oil pressure goes back down to 20-30 psi.... BUT... (if your engine is sealed properly) you will still have 8" of vacuum. Soooooo... . your oil pressure guage will show a BIG 0. We put our car into nuetral and shut off the engine. We also run a powerglide that NOW has a reverse lockout. (We put our car into the wall this year because we didn't have this) Some say dont ever nuetral a car. I say you have to if your running light weight parts. A lightweight connecting rod cap cannot handle the stresses when using the engine to slow the car down. I have heard there is a Turbo 400 double neutral trans brake now so the above proceedure can take place.
I would like add one thing here.You may have to put a baffle in the valve cover where you pull vacuum from.We had problems with push rods running dry.The vacuum pump pulled the oil from the pushrod tips and ended up killing the pushrods. If you were to have installed the pick up in John's motor 1 inch toward the intake you may have problems.A simple baffle around the fitting fixed everything.
John what about pulling from the back of the intake where that fitting goes for say the pcv valve would that be a good place for the vacuum pump to pull from?
Hope you are not using a dip stick and have that hole in the block plugged. Also if you have too much clearance in the front and rear seals, since they are a modification to the factory setup with the neoprene units sold, this is another area to look at. You may not see vacum on the gauge but if it reads o then you are pulling at least all the pressure out of the crankcase. Too much vacum can be harmful, watch for piston pins scuffing.
Adam, This was originally designed to be pulled from the intake but we were pulling to much oil from thre. Even at an idle. So I moved it to the valve cover and it still pulled to much oil. Then I did as Kevin suggests and added a baffle which cured the problem. Kevin, Are you saying because of the vacuum you wore out the tips of the pushrods? As in.. the ball of the push rod and the socket area of the rocker arm? If yes, this is an area I havn't bothered checking ou: Gary, Another issue I had, which I believe the vacuum pump was partially to blame, was the bottom of the oil pan was actually sucked up to the bottom of the oil pickup. This could be a serious problem!!! Install an oil pressure kill switch in the electrical system. If you lose oil pressure anywhere during the run your engine will shut off. Later
Are you saying because of the vacuum you wore out the tips of the pushrods? As in.. the ball of the push rod and the socket area of the rocker arm? If yes, this is an area I havn't bothered checking ou: Yes this is what I am saying.We were running a peterson vet vac pulling the vacuum from the front corners of the valve covers.The tips of the front 2 pushrods on both banks were burned up all others where fine.We where pulling 12inhg at 7800.A simple baffle over the fittings cured the problems. John I don't think you will have a problem as your fitting is farther down on valve cover.Ours where more in the corner.
OK, John, I run the older style (only 2 years old), MOROSO 4 vane pump, and it is mounted almost the same as yours, my breather tank is not as low, or as far forward, but basically the same. I pull vac. from the drivers side valve cover, middle, front end, and on the last motor it did pull alot of oil, so like Kevin said, I baffeled it. I run the SRE fab. valve covers, and I have the Aeromotive relief valve on the pass. valve cover. It was funny, vac. gage read "0" running in the staging lanes, but just before my burnout, I saw it start to read vac. like 5. Like I said this is a new motor, I know that the rings are not the as thin and light as the last ones, and that may be one of the reasons not to see vacuum, like someone else mentioned in there responses. I'm going to pressurize the motor to 10 psi, even if the rings are not ideal, pulling vac. down the track will help. I'm also taking the cork oil pan gasket off and the stock rear pan seal, and using silicone, like the last motor used around the girdle spacer. Looking over the push rods prior to build up, I didn't see any burned areas, so that shouldn't be an issue. I've also been told that it's hard to pull vac. on a nitrous motor, I figured since I had it, it didn't do any good just hanging off the old cracked block, so I put it to good use. The pum has about 30 passes on it, I haven't taken it apart, I figure it should go for at least 100 before it would need attention. Regarding the pick up sucking to the pan bottom, that will not happen, pan bottom is thicker, and the Peterson pick up kit is a good design, plus the way it's installed, It's all good. I did install a big red oil press. warning light, not set up as a kill switch, I'd rather have me kill it if the light comes on, less stuff to affect the basics. John you mentioned "neutraling" the trans. at the end of a pass, the trans.shop said do NOT do this when I got it from them, I'm not running synthetic oil this time, so from what I know so far, but haven't gone down the track yet, is that it has 45 psi at idle (1100 rpm) and was still there with engine temp. at 190 deg. so when I do get to run it down the track, I'll see what I've got on the big end. Thanks for the advice, hope to make this setup last until I can afford, and it becomes available, and it's everything it's cracked up to be, buy a New Block. I still have my brand new Moldex crank, JE nitrous flat tops, and GRP 7in aluminum rods, just sitting on the shelf, I see a 470 ci w/ 400+ shot fogger unit, and maybe even the 300 shot plate, in the future, that's gotta be close to 1400 horses!! Gary G.
