I’m curious what some of you came up with regarding a budget friendly evacuation or vacuum pump setup? I run a full exhaust system and the Summit/Moroso type header evacuation system didn’t seem to work well enough at high RPM. I’ve been told that those don’t work well with full exhaust/mufflers due to back pressure, which makes sense. Are there any other inexpensive systems without having to go with a complete vacuum pump setup? The motor is a 464 Stage 2, KB Kool Runner intake, 308s cam, 1050 Dominator. Feel free to add pictures or suggestions if you’ve had the same problem and found a good solution. Thanks.
I kinda remember some discussion about full exhaust + the usual header evac system, there was talk about fouling mufflers with oil, but for some reason I also remember someone or some folks having a workaround, too. Will do a search after work hours. Any symptoms you're having for not enough crankcase scavenging? Devon
Thanks Devon. No significant symptoms, other than when I watch a video of the car going down the track. It seems to smoke slightly (not out the exhaust, but from underneath on the drivers side), so I’m assuming it’s pushing oil out the dipstick tube and burning on the header as the header tubes have burnt oil on them. I’m currently building another car with this drivetrain and will be installing a new exhaust system, so I am trying to come up with a different evacuation system or breather system while the car is apart.
You're right about the header evac and mufflers. Doesn't really work very well with mufflers imo. We used to run it that way and it does introduce oil into the mufflers which causes smoking. We switched to a belt driven pump and it was better. There are guys out there running electric pumps with some success. They tend to pull less vacuum on 12 volts but I've seen some guys power them at the track with 18 or 20 volt drill batteries with success. More voltage spins the pump faster. If it is a track only necessity might be worth a look.
we played around some with electric pumps like the one from the Corvette and the Mustang one. Best we got from those pumps was 4 inches of vacuum, we even hooked 2 on a motor. One from each bank and was able to reach about 7 inches plus or minus. But the problem with the electric pump was, they CANNOT have any oil get into them or they will fry. Oil was the killer unless you mount them way in the trunk with filters etc but that killed more inches of vacuum. So when it was time to do my car, I just bit the bullet and went with the GZ Motorsports pump. This pumps actually needs oil to lubricate and so far I have had good luck on the street. I get 3 - 4 inches cruising around and wide open is regulated for 11 inches, but not cheap. I have yet seen any mist of oil or leaks from my motor! Fernando
I believe the newer cobra mustangs actually used an electric pump as a crankcase evac so I would assume they could handle the oil but I have no experience personally. Fernando is right about vacuum being only about 4 inches although I have seen guys pull 8 with a 20volt battery.
Todd, I have to believe that they do, but I don't know how the factory does it. I've never have seen or studied the factory set up on either cars but they got to have some kind of filtering. I'm not familiar with the late model stuff, but I do know the pumps crap out with direct oil to them. Now you got me interested on what they use. It would be great to find one in a scrap yard and rob all the parts that hooks to the pumps. Then order what ever they use new and try it. You would also have to hook up a vacuum gauge to monitor the outcome. I don't think the Vette or the Mustang has a vacuum gauge do they? Never been inside one or driven anything that new. Fernando
as a matter of fact, I just remember 2 years ago we had Mike Nussell big inch motor in Bowling Green and the car he had bought, the blue 70 that was Getner's old car had 2 of those electric pumps in the trunk and at the end of the track a big cloud of smoke came out. I thought it blew up but it turned out to be the pumps suck oil. Again another one that I was not familiar with how they ran the hoses or if any filtration before the pumps were used. But he ended up removing all that stuff and went back to the old way to pull from the scavange in the headers. I don't think he had a gauge in the car to verify, but everyone I know that has tried it with a full exhaust system knows that doesn't work very well. Did the pumps worked that good or did that motor had some blow by. It's not the first time I've heard or know that those big motors can create so much blow by. I also remember other members having so much that it would spit oil out the dipstick onto the firewall and the headers, and make a mess under the hood. Good God! good thing it didn't get under the slicks! Fernando
Something not right with that much blowby regardless of cubic inches..... I've tried some electric pumps over the years but now just run PCV with a catch can. Doesn't help at full throttle and not worth any HP tho.....
following. Been doing drag n drive events and cruising I have little issue until I push the motor, but making passes I'm having similar issue above 3800rpm but only in 3rd gear. Oil pan bolts keep losining up even though I've used loctite. not a lot but enough that gasket let's blow out onto headers. I'm assuming it's due to crankcase pressure. planning on SRE or TA deep sump pan and using stud kit instead of bolts to see if this will help. Still makes no sense to me why no blow by or issues in 1st or 2nd. If that doesn't work I'll need a pump to aleviate it hopefully.
Sounds like detonation in 3rd gear rattling the pistons/rings and causing blowby (more load, more heat by then). What octane?
Jan - I would love to run one of those vacuum pumps, but this project is a “budget“ build using a free Skylark a friend donated and using mostly spare parts laying around my shop. I’m trying to keep it under $10k, and that GZ Motorsports pump would no doubt be nice but it would eat up 10% of the budget! lol Has anyone ever tried one of these breather catch cans with the evacuators in each valve cover? I’m just curious if these work at all? I know there will be no HP gain, but I’m just trying to find a low cost alternative to the header evacuation system since I’m running full exhaust.
Adding the can would just give the oil a place to pool which is fine but there would be no advantage other than that. The breather right on the vc would work to vent but would collect oil pretty quickly and would have to be cleaned quite often.
James, Run 4 breathers in the valve covers.. and it's not a bad idea to run just -12 fittings (or 5/8 barbed hose fittings on a budget) in the covers, and hook them to a catch can like pictured. Two fittings in each cover... All we are trying to accomplish here is a fully ventilated crankcase, with no pressure. If you have more blowby than this, then the motor is hurt, or poorly sealed, and needs attention. Those of you running vacuum pumps on the street.. be wary of too many miles with one, piston pin galling due to lack of lubrication is a often reported side effect of a full on vacuum pump setup on the street. Most of you won't drive enough miles to have this be an issue, but be aware of it. Not a bad idea to take the belt off it now and then, and let the pins get some oil. JW
James, I just run the Moroso can,plumbed out of the front driver’s side cover. Yes,a vac pump would be a little better,and I would have picked up a few HP,but I just didn’t want to run one. I haven’t had any issues with smoke. Some of that can come down to ring seal. I’ve got cnc bores with .043/.043/3mm Hellfire rings. I like to drive plenty,which was another reason for not going with a pump. Exhaust is 3.5” all the way back to the bumper with race bullets.
