327 Not Breathing Right?!?!

[Slick67]

Originally Posted by cdowns

valve covers cool?

without a proper PVC system the old school result was SLUDGE heavy thick and grimey NOT COOL

I will cut them if needed to avoid the sludge issue. If I do this, it has to be exactly what the engine needs. Holes in the vc's is a major step that I do not want to make a mistake on.

[fleetsidelarry]

I had another thought. If the PCV valve you have (had) is made to function opposite how it was installed it would explain why the cap blew off in the first place and why the current set up runs better.

I ran into this when trying to fit a system to my tri-power intake.

[LONGHAIR]

The real issue here is that you are not allowing "incoming" air. You have the oil filler tube connected to vacuum, which will produce a vacuum inside the crank case. If you do not have some kind of filtered way to let air in, it will suck in a gasket somewhere. Must likely it will be one of the intake end seals or valve cover gaskets.
The whole point of the PVC system is that it does indeed draw out fumes, but it has another tube connected to the air cleaner to allow air in from the other side. That's the bigger heater hose sized tube that goes to the stock air cleaner housing. Most times when the stock unit is removed, a simple vent is installed in place of that tube.

If you want to keep the valve covers un-touched, you are going to have to find an alternative way to let air in. You could drill and tap a hole near the back of the intake manifold, behind the runners, that would get to the lifter valley. This would allow you to put a hose on it, allowing a "remote" breather. It's not an ideal thing because the intake air and PVC draw would both be in the lifter valley. It probably wouldn't pull fumes from the valve covers as well as the "correct" set-up, but it will eliminate the gasket sucking problem.

[fleetsidelarry]

Originally Posted by LONGHAIR

The real issue here is that you are not allowing "incoming" air. If you want to keep the valve covers un-touched, you are going to have to find an alternative way to let air in. You could drill and tap a hole near the back of the intake manifold, behind the runners, that would get to the lifter valley. This would allow you to put a hose on it, allowing a "remote" breather. It's not an ideal thing because the intake air and PVC draw would both be in the lifter valley. It probably wouldn't pull fumes from the valve covers as well as the "correct" set-up, but it will eliminate the gasket sucking problem.

Yes, and just drilling a hole in the valve cover for the PCV valve is not enough since there won't be a baffle present. There is a baffled gromment you can get to take care of that issue. If you want to go that route I'll find the link for the gromment (I saw one not long ago)

[Slick67]

Originally Posted by LONGHAIR

The real issue here is that you are not allowing "incoming" air. You have the oil filler tube connected to vacuum, which will produce a vacuum inside the crank case. If you do not have some kind of filtered way to let air in, it will suck in a gasket somewhere. Must likely it will be one of the intake end seals or valve cover gaskets.
The whole point of the PVC system is that it does indeed draw out fumes, but it has another tube connected to the air cleaner to allow air in from the other side. That's the bigger heater hose sized tube that goes to the stock air cleaner housing. Most times when the stock unit is removed, a simple vent is installed in place of that tube.

If you want to keep the valve covers un-touched, you are going to have to find an alternative way to let air in. You could drill and tap a hole near the back of the intake manifold, behind the runners, that would get to the lifter valley. This would allow you to put a hose on it, allowing a "remote" breather. It's not an ideal thing because the intake air and PVC draw would both be in the lifter valley. It probably wouldn't pull fumes from the valve covers as well as the "correct" set-up, but it will eliminate the gasket sucking problem.

That sounds like a good alternative, would it still allow the engine to breath properly enough to eliminate the sludge issue? Also, with the PCV valve on the same runner would it still have enough vacuum?

Originally Posted by fleetsidelarry

Yes, and just drilling a hole in the valve cover for the PCV valve is not enough since there won't be a baffle present. There is a baffled gromment you can get to take care of that issue. If you want to go that route I'll find the link for the gromment (I saw one not long ago)

I have purchased the baffled grommets that can be installed on the rear of the valve cover, but that is a last resort. Although it seems that it would be easier and more effective than drilling into the intake at this point. This is what I purchased.
http://www.summitracing.com/parts/SUM-440332/

[fleetsidelarry]

Originally Posted by Slick67

That sounds like a good alternative, would it still allow the engine to breath properly enough to eliminate the sludge issue? Also, with the PCV valve on the same runner would it still have enough vacuum?


I have purchased the baffled grommets that can be installed on the rear of the valve cover, but that is a last resort. Although it seems that it would be easier and more effective than drilling into the intake at this point. This is what I purchased.
http://www.summitracing.com/parts/SUM-440332/
Attachment 802246

Slick67, you may have misunderstood Longhair, the hole he's talking about would not go into the intake runner, it would go into a place on the manifold that goes into the lifter valley. that's what I did on the tri-power.

[Slick67]

Originally Posted by fleetsidelarry

Slick67, you may have misunderstood Longhair, the hole he's talking about would not go into the intake runner, it would go into a place on the manifold that goes into the lifter valley. that's what I did on the tri-power.

Understood. Do you have a pic of where you drilled? Did you istall a PCV or some other attachment?

[67cheby]

Originally Posted by Slick67

That sounds like a good alternative, would it still allow the engine to breath properly enough to eliminate the sludge issue? Also, with the PCV valve on the same runner would it still have enough vacuum?



I have purchased the baffled grommets that can be installed on the rear of the valve cover, but that is a last resort. Although it seems that it would be easier and more effective than drilling into the intake at this point. This is what I purchased.
http://www.summitracing.com/parts/SUM-440332/
Attachment 802246

these are exactly what i was looking at in JEGS to use on mine, and just put them at the very back , run one of the square breathers turned sideways ?? just what i was thinking of doing

[n2billet]

Originally Posted by Slick67

That sounds like a good alternative, would it still allow the engine to breath properly enough to eliminate the sludge issue? Also, with the PCV valve on the same runner would it still have enough vacuum?



I have purchased the baffled grommets that can be installed on the rear of the valve cover, but that is a last resort. Although it seems that it would be easier and more effective than drilling into the intake at this point. This is what I purchased.
http://www.summitracing.com/parts/SUM-440332/
Attachment 802246

Originally Posted by 67cheby

these are exactly what i was looking at in JEGS to use on mine, and just put them at the very back , run one of the square breathers turned sideways ?? just what i was thinking of doing

When you drill into the back of the v/c's make sure these don't stick to far in and hit the rocker arms or lifters. I had to make mine shorter than I wanted to because of this issue. When I made my tubes (for the v/c's) I built two baffler in each to try and keep the oil from slinging up into the tube but still allow air movement. I also built a "catch can" type box to house the pcv and the breather. In theory my motor should pull in air from the old oil filler tube (it's been modified) and from the breather and the pcv "should" pull the fumes....should. I've only had it running for a little while and I'm still working the bugs out (other issuse not related) so I will report back after I get some miles under her. Here's some pics of what I did....

[fleetsidelarry]

Originally Posted by Slick67

Understood. Do you have a pic of where you drilled? Did you istall a PCV or some other attachment?

Slick67, yes I installed an inline PCV valve. I'm seriously thinking that the valve you were using is designed to thread into the oil galley something like the fitting I have below threaded into my manifold. if so, the manifold vacuum it was hooked to was actually pulling the valve closed and your system was building pressure. Am I making any sense? if that's what was happening, then you could use that valve (in the proper location), plumbed to the carb vacuum source and a regular breather on the oil fill.

Here's the inline PCV valve


here's the manifold location (this is just a fitting, not a PCV valve)


and the "vacuum source"


drawing from the oil galley has the drawback of not being baffled. I don't know if that's a problem as it would be with valve covers. and, as Longhair mentioned, in your case if you use the oil fill for the breather, you won't be drawing from the valve covers. it would still be better than no crankcase ventilation or the situation you may have now where manifold vacuum is apparently creating a low pressure situation.

[Slick67]

Originally Posted by 67cheby

these are exactly what i was looking at in JEGS to use on mine, and just put them at the very back , run one of the square breathers turned sideways ?? just what i was thinking of doing

I picked mine up from Wild West Rods on eBay for $15 bucks each. So if you are still thinking this direction is right for you here is a way to save a few bucks!

Originally Posted by n2billet

When you drill into the back of the v/c's make sure these don't stick to far in and hit the rocker arms or lifters. I had to make mine shorter than I wanted to because of this issue. When I made my tubes (for the v/c's) I built two baffler in each to try and keep the oil from slinging up into the tube but still allow air movement. I also built a "catch can" type box to house the pcv and the breather. In theory my motor should pull in air from the old oil filler tube (it's been modified) and from the breather and the pcv "should" pull the fumes....should. I've only had it running for a little while and I'm still working the bugs out (other issuse not related) so I will report back after I get some miles under her. Here's some pics of what I did....

I am going to measure to make sure before any cutting happens. That is a really cool settup you have there! This is starting to sound like I may have cured the problem with the vacuum by rerouting the hoses, but now I need fresh air. Eventually this will all be clear to me and correctly done.

Originally Posted by fleetsidelarry

Slick67, yes I installed an inline PCV valve. I'm seriously thinking that the valve you were using is designed to thread into the oil galley something like the fitting I have below threaded into my manifold. if so, the manifold vacuum it was hooked to was actually pulling the valve closed and your system was building pressure. Am I making any sense? if that's what was happening, then you could use that valve (in the proper location), plumbed to the carb vacuum source and a regular breather on the oil fill.

Here's the inline PCV valve


here's the manifold location (this is just a fitting, not a PCV valve)


and the "vacuum source"


drawing from the oil galley has the drawback of not being baffled. I don't know if that's a problem as it would be with valve covers. and, as Longhair mentioned, in your case if you use the oil fill for the breather, you won't be drawing from the valve covers. it would still be better than no crankcase ventilation or the situation you may have now where manifold vacuum is apparently creating a low pressure situation.

I think the settup you have is essentially what I have. The engine does not seem to be building up any pressure since I rerouted the the oil filler hose to the carb and it seems to run better. But I have to see what is happening with my settup first.

[67cheby]

i was looking at my speedway catalog this morning and i noticed , Offeanuser (sure i didnt spell that right) has a breather that mount to the side of your valve covers and comes up looks pretty cool i think but $75 bucks apiece

[Slick67]

Originally Posted by 67cheby

i was looking at my speedway catalog this morning and i noticed , Offeanuser (sure i didnt spell that right) has a breather that mount to the side of your valve covers and comes up looks pretty cool i think but $75 bucks apiece

Ouch. That is a little TOO pricey. This is just another opportunity to be creative and come up with something cool that noone else has. I am not seeing any signs of leakage since I rerouted my vacuum from the oil filler to the front of the carb. This seems to have resolved the issue, maybe not for good but I will be keeping a close eye on all of my gaskets and running it very little for now.

[lil hoodlum]

I understand you don't have the hole for the road draft provision anymore but here is a pic I found off of the web that someone had done for their 283 with stock valve covers. I wish I had more information.

Keith

[Slick67]

Still have not cut the valve covers and waited to see what happened with the re-routing of the vacuum lines. It looks like I will have to cut the vc's to avoid drilling into the intake since it is still not acting right when it runs. Also noticed a little oil around the #5 spark plug which is a sure sign of oil getting through the rings because of the built up pressure in the engine. Is that a correct assumption???

[oldblue1968chevy]

I saw a truck today at a show

They had the PCV port from the carb going to a port on the oil filler (that went into the lifter valley thru the intake manifold)

[Slick67]

Originally Posted by oldblue1968chevy

I saw a truck today at a show

They had the PCV port from the carb going to a port on the oil filler (that went into the lifter valley thru the intake manifold)

I have seen those, but I don't know if that will pull enough pressure. It seems like a hit and miss thing going on with each new way of doing it. If anyone has this settup, please let me know more about it!!!!

[oldblue1968chevy]

ive seen it more than anything

CUT THE VALVE COVERS AS A LAST RESORT! Keep trying!!!

[Slick67]

Originally Posted by oldblue1968chevy

ive seen it more than anything

CUT THE VALVE COVERS AS A LAST RESORT! Keep trying!!!

I don't get it. I have an oil filler cap hooked directly to my carb and it still isn't enough. Maybe a oil filler tube with the pvc hookup and run that to the back of the carb while still running the cap to the front? That is double the suction and may work.

[Slick67]

Tried everything. I also put my old Edelbrock vc's on yesterday and covered the hole with a peice of cloth......it works perfectly. The vc breathers I have decided to go with are the So Cal 90 degree side mounts....thanks 67cheby. They look the best. After all the research it seems that this is the only real solution and the install can be reversed with a little welding if someone wanted to remove them and fill the holes on the vc's. They will be mounted at the end of the vc's closest to the firewall. So now I need to get rid of the baffled air breather inserts in pic 2.

[67cheby]

i hope it works so i can do the same thing !!

[Slick67]

Originally Posted by 67cheby

i hope it works so i can do the same thing !!

It will. The other baffled insert called for a 1 3/8 hole to be cut and that really didn't work for me since I am putting them on the ends. If they were on top of the vc it woulda been done already. I'll keep ya informed on how everything works out.

[Slick67]

Gotta update this thread. This is how I tested to see if I was getting enough pcv. It seems to do ok. I have not had the truck above 25 miles per hour, but I didn't see any oil coming from anywhere. Hopefully it will continue to operate this way under regular driving conditions. The breathers come in tomorrow so I will have to do the last thing I wanted to........drill holes in the valve covers. The holes are small and can be patched so I don't feel too bad about it.

[Hubscrub]

i hear ya on cutting them but if it will make it "more right" its worth it to enjoy it.

[fleetsidelarry]

slick67, what is under the yellow tape on the valve cover closest to the firewall?

it looks like a hole in the valve cover. or are these just temporary valve covers?