96speed

What did you do with the pass side PCV tube?

Reroute somewhere?
Ditch it?

Ryan

Alvin@pcmforless.com

You better get used to having a aux return spring..

Just got mine and I'm highly dissappointed they coudln't put a strong enough spring to close the throttle back after a blip at idle.

96speed

Alvin: I haven't had that problem. This TB probably has 15k miles on it.

My intake has been coated with oil since day one. I need to figure out what could help control the oil . My builder told me just to cap off the pass side pcv port and run a breather. Its not doing a very good job, IMO.

Ryan

OBE1 95Z28

Your oil coating in the TB might be produced by blow by; if you remove your oil fill cap with the engine idling, does it puff smoke?

Deutsch makes an oil separator (P/N BF412) that plugs directly into the valve cover where the stock TB line goes, and then you connect the TB line to the oil separator. This might help.

96speed

OBE: I used to run that part from Autozone, but the Monoblade does not have a fitting to connect that line to the TB. I asked my builder about this and he said to cap it and slap on a breather.

I probably should just run a Moroso vacuum pump, but there are some setup costs to that, well, setup .

Here's a pic of the intake ports of the heads :-/



Ryan

OBE1 95Z28

The port in the valve cover provides air to the PCV system; it's taken from the TB as that's a source of metered air. You can tap into you intake tubing anywhere between the MAF and the TB to feed air to the valve cover. The vortech supercharger kit has you reconnect the tube right after the MAF.

turbo_Z

Hard to tell but it looks like your motor is sucking oil from the lifter valley. My buddy recently rebuilt his motor.. going back in tomorrow or Sunday we hope and had intake runners that looked exactly like yours but his motor was burning a quart of oil every 500 miles give or take. His intake was never matched to his motor that had a decked block and milled heads. I decided to pull my intake after seeing his and noticing my motors oil level kept falling(which it never did before the head install) only to discover it was also sucking oil from the lifter valley. My intake bottomed out on the block leaving about a .045" gap to the heads... thankfully the angle was the same so I got it all sealed up now I hope. Unfortunately had to use the messy RTV method because I couldnt find any gasket thicker than 1/16". Only time will tell if it holds.

1racerdude

That's a good sign of reversion from overlap.
Put a breather on the cover or put an inline fuel filter in the line and let it lay by the valve cover.
At WOT if the valve cover line is hooked to the air intake it causes a suction on the line and pulls oil from the cover into the intake from all the air rushing by the hose. If it is just filtered it will operate like a conventional PCV system. It shouldn't hurt a thing.

Edit:The reversion could be caused by the headers not being correct for the application.

Honda Hunter

If youre looking for good oil seperators you should do a search on the Mustang and Lightning boards. It's a common problem for the svt blower vehicles and a common mod for them. Lots of great kits for good prices. I'm going to get this http://www.accmachtech.com/pcvcatchcans.htm for my Lightning motor and for my Camaro.

96speed

OBE: You're saying that air is PULLED from the TB to the valve cover? I thought the TB put a vacuum on the valve cover. The filter going in the valve cover prevent oil getting into the TB.

Brad/Turbo: That is a possibility. The intake was moderately ported by myself - no machine work/milling. The heads were lightly milled (not sure how much) and the block was decked (not sure how much). I'm not sure if I want to chance RTV'ing the intake gaskets. I'm about to pull the heads off anyway for some valve pocket machining.

A/G: I made it a point to give all info to my builder so he could earn his money and set it up properly. To his credit, it would have been easier if he had taken care of everything, but I'd think he'd cover all of the potential hazards. Anyway...

LR: "reversion from overlap" meaning that this problem is from having a large cam running around at low rpm? I'm assuming this wouldn't be a problem at high rpm. The cam is 25xº+

The headers are Heddman 1 7/8 (Although I'm about to start calling them Ryan 1 7/8s after all the welding I've done ) and the heads are LT1. I believe they are a bit too large, but it is all I have right now. Not to be a smart$#@, but how could headers cause reversion? Too small, too large? Walk me through it if you have a minute .

Thanks guys. I'm going to address each theory, and I welcome more of them.

Ryan

OBE1 95Z28

The PCV valve is connected to your intake and it's pulling a vacuum. The port in the side of the TB supplies air from the air entering the TB, routes it through the tube to the valve cover, allows the air to flow through the top portion of the engine (inside the valve covers and lifter valley) to gather oil fumes and gets sucked into the intake via the PCV to be burned during combustion.

1racerdude

If the headers are too large or the wrong length the exhaust pulses will go back through the cyl and into the intake runner. They should keep pulling on the cyl . The bottom of the header should hang below the bottom of the port as a barrier to these pulses that reverse at the wrong time or don't get pushed all the way out. My 1-7/8 have an adaptor plate and I am using these as a barrier, The TOP of the exhaust port are even with the header and the bottom of the pipes hang down below the port making a barrier.
It's like intake wave tuning but on the exhaust side.
For formulas for this ya need to get into wave tuning and the math is horrendous.

When ya go to WOT the hose from the valve cover get's a suction put on it from the air in the intake side rushing by it's hole and no vacuum. This allows oil to be sucked into the TB from the valve cover and goes everywhere in the intake.

The reversion at RPM is not as bad cause it has more speed in the intake flow and more on the exhaust side to get it out.

Yea cam overlap.

96speed

The adapter plates I have were previously used on a head with much larger ports. I have a feeling that the owner might have gasket matched them.

Thanks for the help .

Ryan

1racerdude

New adaptor plates maybe?

96speed

Not really another option .

The header tubes are smaller than the adapter plates (exhaust residue on header flange). Let me ask, does this barrier need to be immediately before the header? I know the adapter plates are larger than the ports, so the adapter plates in their current size are "using" the exhaust port itself as a barrier.

Does this have a different effect than we are after?

Edit: I think I answered my own question:

If exhaust is having to hit the flange of the header before it escapes, our system isn't as efficient as it could be.

Always something!