|
Dry sump venting open or closed.
Running a 3 stage Peterson dry sump pump, I am seeking information to see if its worth running a closed vacuum system with no engine venting or some valve cover venting, due to the pump only having 2 scavenge sections. I have valve covers that have a pop off pressure valve in one cover, the only venting is from the scavenge line through the oil tank which has two fittings for breathers to a puke can.
I was considering removing the pop off valve and fitting a vent so air can flow through engine for more road use than race, as one issue with a closed system is condensation build up causing rust? |
I run a system with an Aviaid Dry Sump system on a stroked alloy 427. Used to have several small leaks, one probably was the rear main side seals and one at the distributor. These engines can develop quite a lot of crankcase pressure.
I sealed the engine and used a calibrated vacuum leak on the manifold, so that at idle I get around 2-3 inches of vacuum. I still vent the dry sump tank. I used a regulator from Peterson: http://www.petersonfluidsys.com/engine_breath.html No more leaks! Love it. |
you can vent with no problems, if you run a closed crankcase you should put some type of regulator in, or provide for it, or the possibility of pulling too much vacuum which the consensus is anything above about 12" can be detrimental to the engine. the size of the pump sections also has an effect on how much vacuum you will pull. with my 3 scavenge sections i can pull around 5" running at 2000 rpm, so i do run a vacuum regulator. i have also owned a race car from a knowledgeable individual that used an open system, with a breather, so either way imo, whatever works.
|
Vacuum or vent?
Thanks for the info. I am running an alloy engine, Peterson pump has a large pressure section and std 2 stage scavenge, in hindsight maybe I should have gone with a 3 scavenge section pump if I wanted to increase HP. This engine isnt running over 7200rpm.
I assume the regulator allows air in (as it has a filter) to reduce vacuum. |
from what i understand with vacuum you could estimating increase hp 10-20, it also helps the oil drop out of the crankcase because the vacuum doesn't hold liquid as well.
the regulator does have a filter. you can also experiment with putting a hole in the blowoff valve piece below the spring. if that doesn't work then put a piece of aluminum between the spring and valve to block it and put a regulator in. if you are pulling 2-3" at idle which is what mine does, you will need something. the 2 scavenge stages are probably enough, they just have to be in the right places. sounds like you have a good handle on it. |
The regulator is adjustable for the maximum vacuum that be generated in the crankcase.
Why it adjustable up to 29 inches (near perfect vacuum) is anybody's guess. Here's another type: http://www.gzmotorsports.com/VCV102B...rol-Valve.html |
btw i have read you don't want to run any vacuum til the engine is broken in as the rings won't seal properly.
|
Dry sump venting
Quote:
I have read that running a non vented engine on the street can promote condensation/rust in the engine, this car will see some road miles for testing etc. As you mention there maybe some benefit to run the regulator, I thought closed at the track and vent for the street. I will try and rig up a system where I can alternate the plumbing between the regulator or the puke tank. |
Ant
We use 3 scavenge sections......2 each in the oil pan.....and 1 in the back of the intake manifold.......with a tube mounted in the valley.... Vent with blue thunder valve covers and -12 vent hoses to a catch can......also -12 line off of dry sump tank.....to another catch can.... That was the only way we could stop oil puking out of the motor.....BTW....we run the motor hard 2800-7000 PS....unless a engine and it seals are built to run a vacuum ....might not be a good idea....seals need to be reversed.... |
Dry Sump venting
Quote:
|
reversing the seals is one way, the other is to use double lipped seals.
|
Quote:
|
2 Attachment(s)
Ant
Here's a couple of Photo's of the valve covers and catch can and tank and catch can vent..... Hope it helps out... |
Quote:
|
1 Attachment(s)
Quote:
Vacuum is for short drag racing type of motors....... not extended time on a track.... like a Cobra is made for... Look at the 3 Scavenge section hose on the back of the intake.... |
Quote:
|
Quote:
|
Dry Sump
Quote:
Dry Sump with #16 lines to and from the tank. My valve covers are sealed and the only vent is on the Stef's dry sump tank in the trunk. I have not really had any problems with this system and don't seem to have an oil vapor problem in the trunk. We tried it on the dyno with vented vs unvented valve covers and there was a difference of about 20 HP. What I really like is the engine compartment stays really clean compared to the times I had remote valve cover breathers with baffles etc. The only time oil gets out of this thing is when it is not running, then it leaks like an old Harley. |
Quote:
We tried sealing up the motor before and it never worked....and I did it like you did, by closing up everything but the dry sump tank....should of looked at a different pump......Thanks again and will get on it.... |
Morris i have the same Dry Sump setup on a small block as Cobra 3170. Tank in trunk (Patterson), -16 lines to and from a 5 stage Aviaid S2 pump, one remote breather off of tank. I have not run the engine yet, but planning on about 10 to 12Hg. and hopping for a cleaner engine bay as well.
They will fit, but you my have to make up your own brackets. |
| All times are GMT -7. The time now is 10:06 PM. |
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: