I've heard a lot about the breather cap and even have a nice chrome one with a billet adapter. I have never put it on because I never had a problem with oil in the intake. In fact when I recently removed the supercharger after 15K miles there was no oil on the rotor pack and no oil on the heat exchanger. I have a 2001.

Question
Should I use a breather cap? Why?

 

Dammitboy! Don't change or add a thing--you're 'golden' .

Dan

 

Or maybe that clean intake was a sign of things to come...

 

High Roller, Gregg S,

What was/were your A/F without the Cap? I am thinking that the A/F
was closer to ideal without the Cap?

Thanks, Jim

 

Yesterday, at the dyno, I did the same experiment. I lost only .8 rwhp and 2.33 lbs/ft of torque with the Ford Motorsports screw in breather cap I bought from LFP. The air/fuel ratio, for the breather cap run, stayed leaner until about 4000 rpms, where the two runs merged into an almost identical mixture. They remained the same until I got out of it at 5700 rpms.

_RPM___________Breather______________Oil cap_
3300....................15.09..................... ....12.96
3400....................14.49..................... ....12.80
3500....................13.46..................... ....12.28
3600....................12.47..................... ....11.79
3700....................11.81..................... ....11.46
3800....................11.48..................... ....11.28
3900....................11.20..................... ....11.16
4000....................11.10..................... ....11.13
4100....................11.04..................... ....11.12
4200....................11.11..................... ....11.17
4300....................11.22..................... ....11.28
4400....................11.33..................... ....11.39
4500....................11.41..................... ....11.44
4600....................11.50..................... ....11.57
4700....................11.58..................... ....11.63
4800....................11.65..................... ....11.65
4900....................11.69..................... ....11.65
5000....................11.67..................... ....11.61
5100....................11.66..................... ....11.66
5200....................11.68..................... ....11.71
5300....................11.72..................... ....11.79
5400....................11.78..................... ....11.89
5500....................11.89..................... ....11.98
5600....................12.05..................... ....12.07
5700....................12.10..................... ....12.10
____________________________________

 

Can I just say something here without everyone getting upset? Here goes...The engine WILL produce more horsepower when crankcase pressure is pulled or vacuumed from the engine as opposed to letting it vent under it's own pressure. The less pressure inside the crankcase during engine operation, the more power the engine will yield. Even with a chip programmed to compensate just for the installation of a breather, all other things being equal, our engines will make more power with the vacuume line hooked up drawing crankcase pressure out. Some of the highest performance race engines use dedicated hi-volume vacuume pumps plumbed into their crankcases to remove as much horsepower robbing pressure as possible. So...it makes sense that removing the cap in allowing pressure to vent more freely will create more h.p. than having the cap on. Better yet...create negitive pressure in the crankcase and power will increase even further.

 

I bought my breather cap from JLP, he told me via e-mail that i didnt need a re-burn for this mod. Is he right?

 

Rich B, I have run vacuum pumps on the street for a few years now. They do make a few more Hp that way, but the big gains come with low tension oil rings.

I have had a ring seal problems putting moly rings in an old thinwall 289 block. That solved the problem, so it does work.

 

Extremly Interesting Post,

I've done much work on our "TWO DIFFERANT" Oil Sucking Problems. I had every Mod You could think about and pretty much stopped all the oil problems. ""BUT"" to my surprise when I recently decided to take all of it off and see what a difference it made at the track, the SOB ran it's best 1/8 yet, best 1/4 yet, highest MPH yet, and a dam good 60ft. I should also mention it ran faster with the 4lb Pulley minus the Oil Mods, than it did with 6lbs of Pulley and all the Oil Mods. Can't wait to go back with 6lbs of Pulley "minus all oil Mods" and get a mid 12 run in

"Your Dyno numbers" just explained why that happen.

THANKS EVERYONE, EXCELLENT POST
I'll live with the oil problems for now on in, "IT'S FASTER"
The numbers don't lie...

 

Rob_02Lightning,
Just curious if you ever tried the oil seperator mod without a breather cap? So what are your new times?

 

Rob,

Did you eliminate the entire factory crankcase ventilation system which includes the line from the intake tube to the d/s valve cover, the PCV valve and line to the top of the s/c,and the vac line to the lower manifold from the PCV line??? Did you disconnect or plug any other lines or valves? Also, I am sure you vented both valve covers but what vents or filters did you use? Are you running the stock oil cap or are you still running the one way valve. Last...any engine codes?

Thanks much,
Rich B.