skpyle

Hello Gentlemen,

I am on a roll of questions. Shortly after I install the water bridge on the Red Witch, I am installing the oil filler neck.

I have the stock cast aluminum? filler neck, an old Devek baffle, a new Greg Brown baffle, and a new old style gasket.

I had to slightly tweak one of the louvers on the Devek baffle to fit the recess in the Greg Brown baffle. A couple of well placed love taps with a mallet, and all fits nicely.










Had to tweak the left louver fin down a bit so it would fit in the recess of the Greg Brown baffle.











Holes line up, fits good. Work good, last long time...



So...question number 1): Where do I put the gasket in this sandwich? Between the filler neck and the Devek baffle? Between the Devek baffle and the Greg Brown baffle? Between the Greg Brown baffle and the block?
I have DreiBond 1209 to seal all else.

Question 2): Are the stock bolts long enough? Stock bolts are 55mm under the bolt head. With the thick gasket and both baffles, I have approximately 8.5mm of thread engagement. Is that enough? Torque for an M6 fastener is 71-89 in/lbs.

Question 3): Should I even use the thick gasket? If I leave the gasket out, there is approximately 10.5mm of thread engagement. Would that be better and just seal each part of the sandwich with a thin layer of DreiBond?





Thick gasket on top of Devek baffle.





Stock filler neck mouting bolts.





Mounting surface of filler neck cleaned.





Approximately 8.5mm thread engagement with gasket and both baffles.





Approximately 10.5mm thread engagement with just both baffles.




I have tried searching, but to no avail. I know there is a thread out there, as I read something from Greg Brown in the past about installing his baffle. Of course I can't find it again...


Thanks for any and all advice!

Tom in Austin

I overkilled mine a little ... spread one of those 'make-a-gasket' products on either side of my Greg Brown baffle and then (arbitrarily) put the new gasket between the baffle and the block.

GT6ixer

Hey Seth. I also overkilled mine. I don't have the Devek baffle but I did install a GB one. I actually had Roger send me two gaskets and put one between the filler neck and the GB baffle and the other between the baffle and the block. I also applied Drei bond to both sides of both gaskets. I had to buy longer bolts since like you I had lest than 10 mm of engagement.

928NOOBIE

OK stupid question time...and yes I know I should know this but I really don't....so here goes...

The baffle we are speaking of...is this to help alleviate the breather system limitations and help prevent oil in our intakes? I have an S3 and as everyone knows they have loads of oil in them all the time...thanks.

FredR

Seth,

Are you sure Greg intended his baffle to be used with the Devek one? I have a feeling it was intended to be one or the other but not both.

Similarly, is there a reason you felt you needed to install addtional baffling on your model year? I have the impression that your MY is good on oil separation but...?

Rgds

Fred

NoVector

I tried the same thing although I think I had a 928 motor sport baffle (which looks a little thicker). I had to give up on using both though as it was too tall and I think it was hitting the water bridge/t-stat housing. But it may be different on your MY. Anyway, I would try and dry fit it on the engine before applying the dreibond. In the end, I just used Greg's.

Mrmerlin

Seth I would get longer bolts you have to space them / trim them you will have to fit check the bolts to verify how far they go into the hole.
I would use the baffle plate and the GB part,
leave the gasket out,

NOTE use the Dreibond on every surface,

if you put too many spacers under the fill tube it may hit the intake so it would be wise to fitcheck this assembly,

if it does hit then remove the flat plate and use the GB part make sure to get longer bolts and trim them to fit having a long bolt thats only 4 to 6 threads in is not the best for this assembly

KenRudd

Installation order is important with regards to the water bridge:

polcan

Everything looks great but I don't see a check valve on your oil filler.
Your intake is going to be sucking oil thru 1/2 " open hose. That subject was discussed here many times.

GT6ixer

Interesting. On my 84 I was able to install the GB baffle after installing the water bridge. Obviously differing geometries, but something Seth should look out for.

GT6ixer

In my case I opted to to add a couple of additional washers under the bolt head in lieu to trimming the bolt in order to wind up with the same thread engagement. Not the Cadilliac way but I admit I was being lazy that night.

Eplebnista

Stan is correct to point out that as you put more stuff in between the oil filler and the block, interference between the filler and the intake manifold becomes more likely. I have a paper gasket, GB baffle and stock baffle plate between my filler and the block and there is definitely contact between the intake and oil filler when I dry fit the intake.

GregBBRD

The "ideal" situation is if you can find the '85/'86 stock baffle....which looks a lot like the Devek Baffle (I never knew, until now, that Devek made a baffle.) I know the stock baffles are NLA....I'm working on making something like this, for the people with "early cars".

No big surprise, I don't understand what Carl's baffle is supposed to do, without integral "drip rails" for the collected oil to drop off of. I'd call that a restriction, not a baffle.....

My baffle is designed for the stock '85/'86 baffle to drop into my baffle. In the case of the later plastic filler necks, this baffle is an integral part of the filler neck.

I never use the thick gasket. I use Drei Bond between each layer. On the plastic filler necks, I use the stock O-ring, plus Drei Bond.

I haven't had to ever use longer hardware, but I can see if the "stack" of pieces gets high enough, one might need a couple 5mm longer bolts.

GregBBRD

Yes. The "check valve" is a requirement for this filler neck. Must be present in the rearmost hose or you will ingest copious amount of oil into the intake.

skpyle

Wow! Thanks for all the responses!

Here is what I am taking away from all your ideas and advice:

-leave the thick gasket out
-dry fit the filler neck/baffle sandwich with the water bridge and front intake pipes
-get longer bolts if necessary, trim as required
-ensure the bottom of the metal filler neck is flat
-use Drei Bond to seal all the pieces
-install Greg Brown's baffle BEFORE I install the water bridge
-install the Devek baffle and filler neck AFTER I install the water bridge


I do have the check valve, it is still in the old hose removed from the filler neck. I will transfer it to the new hose to go back on the filler neck.



928NOOBIE: You are correct, these baffles are an attempt to arrest the oil from being whipped up into the oil filler neck and picked up by the intake hoses, then onto the outer plenums. The S3's are especially bad about that.



KenRudd: Thanks for that video, it clarified things!



FredR: Greg did not intend for his baffle to be used specifically with the Devek baffle. He intended it to be used with the factory baffle on 85-86, and S4. I think I will be able to get away with using it. I hope.

I must disagree with you, S3's are abysmal at oil control. The outer plenums usually have pools of oil in them.



Greg: This Devek baffle has been on the Red Witch for almost 20 years. I initially mistook it for a factory baffle. Until I found a photo of the factory baffle. Not it.

OK, to be blunt, are you saying I should NOT use the Devek baffle and I should search for the NLA 85-86 factory baffle?

Whichever one I use, should I drill a hole in it to match the drain hole opposite the rectangular opening on the top of your baffle?


Thanks again for all your help guys!