My 85 RX7 has white sludge and water under the oil cap, and in the oil fill neck. It is also producing large amounts of BLUE smoke on startup and especially after being run at high RPMs. What kind of problem am I looking at and what needs to be done to correct it. Any advice would be greatly appreciated.

 

search lung butter

 

This is a common problem. seach Lung Butter.

 

I personally believe that you will find better information searching for "lung mustard" instead of "lung butter." But, other than telling you to search, here is what's going on. You aren't venting the oil pan properly so it's building up condensation in there. You need to vent your oil filler neck properly by either using a PCV valve, or verifying that the stock setup is working correctly. Personally, I think that a PCV valve from your local parts store is the only way to go.

Put a piece of correctly sized vacuum hose on the nipple of the oil filler neck. Now examine the PCV valve you bought at your local parts store. The PCV valve is just a check valve that lets air go one way. Put your PCV valve on the hose so that it will only allow air to come out of the filler neck, NOT GO BACK IN. Put another piece of hose on the other nipple of your PCV valve. Connect it to a nipple on the carburetor or manifold that is pulling vaccum.

Let me know if you need more help.
Jamie

 

Thanks I'll try that and let you know how it gos

 

I've used a Fram FV333 PCV valve on an Edelbrock with good results. It has a 3/8" nipple one one end that matches the size of the nipple on the carb and an NPT threaded section on the other which will accept a 5/16" hose and run it over to the nipple on the oil filler tube. Vent the other nipple at the top of the intermediate plate to the air cleaner, or the interior of the vehicle, or anywhere where it won't suck up dust and debris.

I recently picked up an FV266 to try on a Nikki manifold hooked to the automatic trans modulator source nipple. This PCV valve has a 1/4" straight nipple with BSP threads (little smaller diameter than the NPT threaded one mentioned above) I'll run this to the modulator nipple because they are very close in size. The other end has a 5/16" nipple that will work perfectly with the nipple on the oil filler tube.

Note that these PCV valves mentioned here flow one direction and, using an air compressor to test flow, have determined that this is the way to hook them up in an aftermarket arrangement.

Also note that the FV333 has the nipple pointed to the carb while the FV266 has it pointed away from the carb and toward the oil filler tube, for proper flow direction. They must have been manufactured this way to work correctly in their intended engines. Just a heads up if you plan to try one of these.

 

^ Good advice from a smart man. Jeff said everything there that I was too lazy to look up. The best part is that he probably did it all from memory.

 

I did.

I just purchased another FV333 for another SC project and I come to find out the new ones have a smaller nipple (5/16" now). Hmm, if that's changed, I wonder if the flow direction is still the same. It probably doesn't matter too much because I'll make it work with the nipple on the Edelbrock regardless of direction.

 

Here you can see a PCV valve inline. It is the FV333 on the Edelbrock mentioned earlier. Look kinda in the center of the picture. You'll see it.

 

Brand new FV333 on the left and a FV266 on the right.



FV333 - 5/16" nipple (was 3/8" nipple) and 1/8" NPT. Unsure of flow direction since it's still in the package. Old version with 3/8" nipple was backwards, but worked out fine with an Edelbrock pictured above.

FV266 - 5/16" nipple and 1/8" BSP (slightly smaller) and a 1/4" straight nipple. Flow direction is in to the 5/16" nipple and out from the BSP threaded end. This will work fine on the automatic modulator nipple on one of my Nikki manifolds.

I'll use the new FV333 on my next SC Edelbrock project. I'll know the flow direction when I test it.

 

why couldnt you just put a venting cap on the filler neck

 

Because the air won't move. Why not just run a long tube? Again because the air won't move. You need a controlled vacuum source.

 

So is this something that should be done on a 13B fuel injected engine?

 

I dunno. Do you have an emulsified sludge problem?

 

Just thought I would throw this out there for the parts pack rats like myself with aftermarket carbs... I have a leftover fuel line check valve for the nikki and was wondering if this would work as well. I know the PCV valves are very cheap, but in theory, wouldn't this work too?
Justin

 

To a certain degree I think I do. I've kinda wondered what the rust-colored stuff was near the top of the oil filler tube.

 

Roundabout, I don't know. I only tried to use a check valve once and it seemed to work, but it was a while ago so I don't remember how it was hooked up.

I checked flow direction of the new FV333 and it also flows from threaded end to nipple end. It's going on the SC project with my special 3/8 and 5/16 adaptor hose. Should work out perfectly.

 

^ Very nice! Thanks for the insight

 

ive noticed a bit of 'butter' in mine (no blue smoke) i have a 45 DCOE soon to go 48IDA i just removed my oil line and left it with out a pipe so it could breath is this what other aftermarket carb guys are doing? if not how are you hooking up the vacum?

thanks
Mark

 

I don't know how I'm going to run a PCV system on the 45DCOE I'm working on.

 

Here is a closeup of the FV333 on an Edelbrock.



Loosly fitted. As you can kind of see in the photo, it is facing the correct direction for proper flow into the carb.

 

^^ Hey Jeff, where'd you get the Oetiker style clamps at?

Jamie

 

I didn't build the SC. Ask Atkins.

 

Another Edelbrock guy! WOOT!