327 Not Breathing Right?!?!

[fleetsidelarry]

Originally Posted by Slick67

Routed the oil filler to the carb, the power booster to the manifold and the trans to the front of the carb on the small tube. It seems to be fine now, we'll see after I run it a little bit.

Slick67, love that engine, it is sharp!

I'm a little confused, unless I'm reading the above wrong, you ran the filler tube cap to one of the large carb "vacuum" sources and swapped the booster to the manifold source. also you're now running the tranny off one of the smaller carb sources.

If that's the case, as far as your crankcase ventilation goes, I don't see where you changed anything. And if you now have the tranny hooked to the passenger side port on the front of the carb it is no longer getting a vacuum signal at idle.

it appears to me you are still pulling a low pressure on the crankcase with no cross ventilation.

Sorry, I may be missing something

[Slick67]

Originally Posted by fleetsidelarry

Slick67, love that engine, it is sharp!

I'm a little confused, unless I'm reading the above wrong, you ran the filler tube cap to one of the large carb "vacuum" sources and swapped the booster to the manifold source. also you're now running the tranny off one of the smaller carb sources.

If that's the case, as far as your crankcase ventilation goes, I don't see where you changed anything. And if you now have the tranny hooked to the passenger side port on the front of the carb it is no longer getting a vacuum signal at idle.

it appears to me you are still pulling a low pressure on the crankcase with no cross ventilation.

Sorry, I may be missing something

Thanks! The trans is going to be hooked to the small driver side tube on the front of the carb. The booster is hooked to the manifold, which is correct according to other vehicles. But I am still questioning the ventilation also. There should be a entrance for fresh air, correct?

[cdowns]

valve covers cool?

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

[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.

[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]

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.