pauldana

Any one use a vacuum system for their pcv? I've been doing some reading and I have seen where people are showing like a 20hp+ gain in using them...... Any input?

bluedawg

I've thought about it, but ponied up the money yet. There also the header evacuation system that uses the scavenging effect from the headers to keep a slight vacuum on the crank case. Is a whole lot cheaper and seems to do the job well but I don't know if it adds any power.

DannyBlake10

when i did this exhaust it did clear the floor pan. i know you cant see in the picutres he posted but way up at the collecter, i actually extended it with a curve right off the bat and put my first flange about 8" past factory collecter. this piece i added does have a slight downward angle for clearance (also used v-bands for the lower profile and other benefits). but i kept it wrapped becasue it is SO close to the floor pan or id worry about scrapping due to the 3 inch exhasut and how low he has the car. the only clearance issues I had on this exhaust is those stupid 1 7/8" primary tubes. one of them was hitting the steering set up. granted this car has hydroboost and has a different steering shaft and a pretty beefy u-joint in it. and thats right where it hit. I had to shave it down, and replace the set screw with a dowel pin. havent had an issue yet but what a pain in the butt

KJL

Thanks for the info, hopefully he may be able to snap a couple if pictures at some point. I wish we had some talented custom shops in the Atlanta area. You would think in an area that has a many cars as we do we would be flooded with them. The ones that do exist mostly cater to the fast and furious crowd and have never laid eyes on an eight cylinder engine.

hugie82

this is the route I would go as long as your exhaust doesn't have cats on it. The oil residue will ruin a converter.

pauldana

Danny meant he had to clearance for the rack-n-pinion's steering linkage from the steering wheel...

I have done some research, and so far this is what I found......
The scavenging system only pulls 2-3 lbs of vacuum which is not enough... You need about 6-8" of vacuum to be efferent... People are using the electric vacuum pumps off the Cadillac's and showing a 25+ hp gain on the dyno,

This is done by removing the gas pressure behind the pistons and also creating a better ring seal

bluedawg

Theres also belt driven but just the pump is expensive.

76Rat

This will only work with open headers
The full exhaust will create back pressure and dump exhaust into your crankcase.

76Rat

[QUOTE]Originally Posted by bluedawg View Post
%2

bluedawg

I got a friend that runs them on his 383" with full exhaust. From what he says you just need free flowing exhaust. You'd also think that like the pvc system you'd need a one way check to prevent issues from a back fire which you'd think would also keep exhaust gas out of the crank case. I've not ran one so lm definently no expert on them.

pauldana

ok... going to get back tot the vacuum PCV system.... flywheel pilot bearing...

STUCK!! ugh!

the ring gear slipped off... like wtf... so we pull the TKP-600 today to put the ring gear back on and add a few small tacks....

had to put the flywheel on the freezer, and the ring gear under the heat lamp for 30 min to get it on... so it does fit correctly...

but when we start to put it all back together, I check the pilot bearing,,,,and its toast.... get out the pilot bearing removal hammer tool and we took turns pounding until our arms were ready to fall off...ugh! then i tried to take the jig saw and cut a notch out on each side,,,, the bearing race is some sort of case hardened steel... took out the teeth on 3 blades faster than you can sing dixey! put on some solvent and quit for the night out of frustration.

Jig saw cut a small notch, but only big enough to make the back pressure oil method not able to work:-(

Some sort of case steel so don't think i can thread it????

Ideas???



Pilot bearing race:




flywheel steel billet 22lbs






why the heat marks all the way around????


our tack's




when off, in car..

TheSkunkWorks

Dang, I was going to suggest the hydraulic method before I saw your comment about having already notched the pilot bearing. If you can find some carbide blades I'd give that a try, but it won't take much of a slip to mess up the crank bore. Anyway, I don't envy your predicament. Good luck!

You might want to have a clutch shop re-check the flywheel's balance since you've added material. Or, is there a chance I could convince you that it's a good time to go ahead and try a 15# one?

69427

I'd be interested in hearing more about that.

Edit: This topic has me more curious the more I think about it. I think I'm going to hook up a vacuum/pressure gauge to the dipstick tube at the next track day to get some sort of idea on what's happening in the crankcase at WOT conditions.

hugie82

The kit I saw had a one way check valve that would stop exhaust from pushing up but exhaust pulse and scavenging will pull the crank case fumes out. Maybe not as well as a pcv at idle.

KJL

Paul-

Try carefully heating the around the perimeter with a torch and then using a can of compressed air upside-down, freeze that little SOB then try to extract with your puller.

Another trick I used when my puller could not get enough bite against the race is I used a very thick washer and ground it into an oval shape. Slid it over a bolt and angled the oval washer so it would slip into through the hole with the head of the bolt. The long dimension of the washer was equal to the outside diameter of the bearing. Takes a little trial and error getting the shape but I eventually got it in and pulled up snug against the back of the bearing. Then I found a socket to slide over the threads of the bolt that was larger in diameter on the bearing, put a couple of heavy washers on it, oiled them to reduce friction, then screwed a nut on and pulled it out. Worked like a dream. As long as you have enough clearance behind the bearing race for the head of the bolt and to manipulate the washer, this should work. Need a good washer.

KJL

Paul-
I am considering upgrading my headers to KooKs but I have some clearance issues with my Hookers. Could you snap a couple of pictures from the drivers side so I can see where the collector is located relative to the floor pan? I am also interested in how you connected them to the exhaust. That would be a huge help. See the attached pic. That is what I have now.

Thanks!!

cv67

Tried thatgrease trick I just made a huge mess.

Had to take a carbide on a drill and butcher itdidnt hurt the crank

Thinking these aftermarket cranks may not be sized perfectly. This crank (rpm) was real tight probably too much so used a GM pilot too, last 2 CAT and SCAT were just about right. This one will be a mother to get out lol

Unless you really need the vac system dont waste $ on it in hopes of any noticeable power.

pauldana

ok... trans back in.. lets switch topics back to PCV vacuum:-)

my exhaust thread with pics:-)

http://forums.corvetteforum.com/c3-t...-pictures.html


i used V clamps, and the headman ball clamps as well





ok... got the fracken pilot bearing out!!!!! WWWOOOOOHHHOOOO!!!

got a tungsten bit for my Drimal and that thing cut through that race like butter... wow... was i impressed!!! i stopped about 1/16" inch from crank, got the bearing puller out again, ... a few good locks of the hammer and ,,,,,OUT!!!!

KJL

Thanks Paul regarding the header info!!!! Looks like the trick is to cut the collector a little further back which gives more room to fit the exhaust past the floor pan. Mine are Hookers are ceramic coated with flanges already welded on..... I love the V-Band connectors. A least I know it can be done.

Congrats on getting the pilot bearing our.

DucatiDon

Paul, did you replace the throwout bearing with another roller or the bronze fatory style?