347 and/or high HP engine guys (PCV?)

[Duke Mk1a]

What have you done for the PCV system on the engine if anything?

On my recent 2000 mile trip I had quite an issue with oil being blown out the oil filler cap (had to clean it every gas stop). I also found out Sunday that my bell housing is full of oil again , getting past the rear main I think.

So I start the engine and zip tie a rubber glove over the oil fill tube to see if any air is entering the engine. Not only is it not entering but the glove gets blown up like a balloon. I pull the PCV valve out of the VC and the glove immediately deflates. I them pull off the PCV and stick the tube from the manifold straight into the VC....the glove is then just about sucked into he VC.

So, I must have the wrong PCV valve. I get a 1992 5.0 Mustang PCV and install it. Now at idle, the oil fill tube has a vacuum that increases with throttle.

I hope this solves my rear main leak now that the crank case has vacuum and not pressure pushing oil past the RM.

Here are some more thoughts. I have one vacuum fitting on the intake manifold and none on the carb. The PCV line is T-ed off for the brake booster and cruise control. The line is 1/2". I am wondering if a dedicated 1/2" fitting should be installed into the manifold just for the PCV. I could then run a 5/8" line vs. the 1/2".

 

[Moondoggie]

Duke,

You have too much stuff running off that single manifold hose....in fact you probably don't have brakes with the PCV hooked up to the brake booster.
Run a dedicated line for the pcv to the carb like this one on my motor........

Moondoggie

 

[Duke Mk1a]

Looking at at carb spacer with port right now.

 

[at the beach]

Hi Duke,

I agree with Moondoggie about you needing more vacuum port capacity.

The plate is a good way to go and I've had some custom built ones that are thin but have a port made out of a stainless tube that starts oval at the plate and then transitions to round for the hose. This way the ID of the tube keeps the same cross section and the thinner plate is more friendly to the Tiger's air cleaner.

PCVs are calibrated to the size of the engine. You may want/need to think about trying to find one for a 351, which would be more in your ball park.

bt

 

[venice532]

carb spacer plate

Duke, I found a guy on the boss 302 forum that makes a really skinny plate (5/16" thick I think) out of aluminum.
The boss plate was also thin but it was phenolic and people complained that they eventually had problems.
I have one of the aluminum plates on my car and an extra, I'll try to dig out the contact info for the guy that was making them and post a picture of the plate.
Bob J.

 

[venice532]

aluminum carb spacer

I have one of these under my 1848 carb and the stock air cleaner housing clears the hood by about 1/4".
Bob J.

 

[hottigr]

I've been running the brake booster off the rear of the intake manifold and the pcv valve off the base of a Carter AFB competition carb for years and no problems with either. The breather runs off the base of the air cleaner. No pressure/buildup/blowby issues anywhere.

 

[Duke Mk1a]

Problem solved. I have a bung on the left rear of the manifold (#4 runner) that I will install a tap for the brake booster and CC. I will then use the 3/8" fitting on the rear of the manifold carb tower for the PCV only.

Thanks for the input guys.

 

[cadreamn67]

Hi Duke,




PCVs are calibrated to the size of the engine. You may want/need to think about trying to find one for a 351, which would be more in your ball park.

bt

FWIW, I just bought a PCV valve based on Buck's recommendation. It is ACDelco part CV899C. It has a 90 degree elbow at the top for a 3/8 inch hose that matches the diameter of my carb port for the pcv valve. It is listed as being for a Chevy high performance 350 CI. motor. Should match up to use on a 347 nicely.

A very interesting feature is that the bottom has a nipple that extends the opening intake 5/8 inch deeper than the one for a 351, which does not have the 90 degree elbow. I can see that nipple and its additional length as possibly being helpful in reducing oil burning when the valve cover does not have a baffle. It also opens up to some possibilities of adding even a longer tube for oil control purposes. Such a tube could be pop riveted onto the nipple to ensure it does not fall into the valve train with dire consequences.

In another thread opened by Duke, there was a suggestion of using some VC grommets that have a sort of baffle built in. When I checked at the local speed shop they all seemed to be by Moroso and were for its valve covers with a larger than stock PCV valve grommet hole. Did anyone actually find one that fit a stock hole? I thought about enlarging the hole in my LAT valve covers, but it looks like one of the roller rocker arms is very close to the side of the stock hole as it is.

Sorry for crossing two separate threads with this, but thought that they are rather interconnected.

Gene

 

[Duke Mk1a]

Gene,

Look up Mr. Gasket Baffled Breather Grommets. I have one that is inserted into the oil fill tube then a oil breather into the grommet. Will be able to give a better report on its performance once the PCV system is worked out.

I don't think there is rocker clearance for one on the PCV VC.

 

[cadreamn67]

Thanks Duke, I will check it out. And maybe the pcv valve I described can help out, or be modified to help out, on the PCV VC side.

Gene

 

[Duke Mk1a]

FWIW, I just bought a PCV valve based on Buck's recommendation. It is ACDelco part CV899C.

Found the PCV valve here for $8.88 including shipping -
http://www.ebay.com/itm/NOS-OEM-GENUINE-GM-AC-DELCO-PCV-VALVE-CV899C-/180818061523

 

[cadreamn67]

Well this is embarrassing.

Duke thanks for posting a source for part I identified. I just looked at the application shown in the ebay listing. It's for a bunch of 3.3 or 3.8 V6's!

I just called my parts guy and told him the problem. He is checking and will call me back. We were looking at several yesterday and one was supposedly for the 350 Chevy and one for a V6. Hopefully I just left with the wrong one.

Please standby!

Gene

PS my parts guy owns the company and has an E-type Jag and a Pantera. He normally does not make mistakes like this...

 

[Duke Mk1a]

How about this one -

http://www.ebay.com/itm/FRAM-FV112-...Parts_Accessories&hash=item5ae811506a&vxp=mtr

 

[cadreamn67]

Duke,

That definitely has the longer reach that got me all interested, and looks like it well fits with engine size to make it compatible with the 347's. Lot better than what I was erroneously passing along.

My parts guy just called and apologized. He has ordered a couple of others, different brands, that should be at the store tomorrow morning after 9am. I will go by and check them out. Only thing I can think of that might make them possibly any better than what you have already found is perhaps a 90 degree elbow at the top for cleaner line run. And that is more a personal preference thing.

Stay tuned all,

Gene

 

[Moondoggie]

How about this one -

http://www.ebay.com/itm/FRAM-FV112-...Parts_Accessories&hash=item5ae811506a&vxp=mtr

Duke...

You would put a buck forty three part on your tweleve thousand dollar motor
and expect it to protect it !!!!! Surely BMW or Mercedes has something much
more robust and trick looking for around tewenty five bucks.....

Moondoggie

 

[Duke Mk1a]

Only thing I can think of that might make them possibly any better than what you have already found is perhaps a 90 degree elbow at the top for cleaner line run. And that is more a personal preference thing.

Going with this PCV line -

Will make for a nice install with a vintage feel.

You would put a buck forty three part on your tweleve thousand dollar motor and expect it to protect it !!!!!

How about this one?
http://www.ebay.com/itm/FRAM-FV112-...es&hash=item3378698c1f&vxp=mtr#ht_1246wt_1270

I am actually getting it at AutoZone that has it in stock for $2.99

 

[Moondoggie]

Duke.................

Come on now you have a very nice Tiger that you have put allot of effort
into making first class...it's the details that matter so how about this one

http://www.jegs.com/p/Billet-Specialties/Billet-Specialties-Aluminum-PCV-Valve/744140/10002/-1

Also let's not forget about sticking in an oil seperator inline after the PCV
and your best bet is putting a plate under the carb for the pcv as it won't scew up the flow in the back half of the manifold.........Think effient and smooth you want that 11 second timeing slip and you can taste it. You know my 302 just might make more horsepower than your 347...it's in the details
Dyno on Friday !!!!

Moondoggie

 

[Duke Mk1a]

Come on now you have a very nice Tiger that you have put allot of effort into making first class...it's the details that matter so how about this one

http://www.jegs.com/p/Billet-Specialties/Billet-Specialties-Aluminum-PCV-Valve/744140/10002/-1

Also let's not forget about sticking in an oil seperator inline after the PCV
and your best bet is putting a plate under the carb for the pcv as it won't scew up the flow in the back half of the manifold.........Think effient and smooth you want that 11 second timeing slip and you can taste it. You know my 302 just might make more horsepower than your 347...it's in the details
Dyno on Friday !!!!

I don't agree that a blinged out billet aluminum PCV will work any better than a part designed for and used on tens of thousands of large displacement V8 engines. The manifold bung will only be used for the brake booster. The brake booster vacuum flow is static unless the brakes are being used. The engine throttle is closed when the brakes are being used. Don't see an issue with flow. The PCV signal will come from a 3/8 fitting on the manifold carb tower.

Looking at your engine, there is a tap on the #4 runner, are you using that for your brake booster?

More than 454 HP from a 302! That would be awesome, post numbers ASAP!

 

[michael-king]

I don't agree that a blinged out billet aluminum PCV will work any better than a part designed and used on tens of thousands of large displacement engines. The manifold bung will only be used for the brake booster. The brake booster vacuum flow is static unless the brakes are being used. The engine throttle is closed when the brakes are being used. Don't see an issue with flow. The PCV signal will come from the carb tower.

More than 454 HP from a 302! That would be awesome, post numbers ASAP!

I was looking through the AFR website.. the dyno numbers for the motors using their heads are certainly impressive.. there were some interesting comparisons with their heads and various cams, manifolds and carb/ignition setups.. and displacements... i just wonder how streetable the motors are,