Valve cover breathers and steam ports?

I know this is probably a dumb question... But, I don't have any breather ports on my valve covers. Do I need them? I'm running a SBC. I also don't know where/how to plumb the steam ports either? I've never worked on a SBC before so I'm really trying to understand the basics. Sorry for asking such rudimentary questions.
 

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Bill Kearley

GT40s Supporter
You will have to vent the crankcase somehow. Are there any knock outs on the valve covers to fit a PCV system? If not you will have to create one. An old style PCV tied into the intake works just fine with a vented oil fill cap.
 

Neil

Supporter
Steve;

My Dart cast aluminum valve covers had no vents (breathers) either so I cut holes with a hole saw and installed three surplus screens (filters?) from an unidentified something and one oil filler cap. I added oil splash shields under each vent as well.
 

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You will have to vent the crankcase somehow. Are there any knock outs on the valve covers to fit a PCV system? If not you will have to create one. An old style PCV tied into the intake works just fine with a vented oil fill cap.
Thank you! Why do they come without anything?
 
Steve;

My Dart cast aluminum valve covers had no vents (breathers) either so I cut holes with a hole saw and installed three surplus screens (filters?) from an unidentified something and one oil filler cap. I added oil splash shields under each vent as well.
Thank you! I'm on it! What about steam ports for the intake?
 

Bill Kearley

GT40s Supporter
An air bleed/ steam port? I hope it's just an air bleed so you get a complete fill of your cooling system. I have one at the top of the rad and at the highest point on the engine, the top of the thermostat housing. fill once and be done.
 
An air bleed/ steam port? I hope it's just an air bleed so you get a complete fill of your cooling system. I have one at the top of the rad and at the highest point on the engine, the top of the thermostat housing. fill once and be done.
I just figured that out. Ugh! Sorry!
 
It may depend on your engine, but my LS3 crate motor had 4 steam ports from the factory, 2 of which were already plugged. I tied the two remaining together then teed those into a bleed line I'd routed from the top of my radiator, then all 3 into the top of my surge tank. The ports are all open and there's active communication between all ports and the surge tank at all times.

I added a ton of information about cooling as well as a few links to other helpful sites. In particular the "Pirate4x4" site I linked, and which is referred to in the SLC wiki, has a ton of great information on cooling an LS motor - highly recommend you read my blog post and the Pirate4x4 site for details.



Here's a quote from the 4x4 site:

Special LS-specific "steam tubes" or "engine vent lines" are installed on top of the cylinder heads. As vapour or steam will always seek the highest point, any steam pockets created by local hot spots, particularly in the cylinder head exhaust valve area, will migrate up and into the steam tubes which will carry them and a small amount of coolant away and either into a port located at the top of the rad (as shown here) and from there to the surge tank, or directly to the surge tank (depending on application) where the steam is separated from the coolant.

Steve - it looks like you've got quite the motor going there - I'd highly recommend you speak with your engine builder (or a builder familiar with your engine setup) and ask them about how PCV should be routed and setup for your particular engine.

I have a post about PCV and catch cans; there's been some debate about my setup but at the end of the day a properly configured PCV system is important to having a healthy motor. I'm also now a big believer in installing a catch can on LS motors.

 
This would have been valuable information (proper air pocket prevention design of a coolant system) to a certain kid building his slope nosed, IMSA fendered, SBC powered 914 back in the day. It was fast but, he (I) had to bleed the cooling circuit constantly to keep it from overheating.

A little knowledge would have gone a long way.
 
It may depend on your engine, but my LS3 crate motor had 4 steam ports from the factory, 2 of which were already plugged. I tied the two remaining together then teed those into a bleed line I'd routed from the top of my radiator, then all 3 into the top of my surge tank. The ports are all open and there's active communication between all ports and the surge tank at all times.

I added a ton of information about cooling as well as a few links to other helpful sites. In particular the "Pirate4x4" site I linked, and which is referred to in the SLC wiki, has a ton of great information on cooling an LS motor - highly recommend you read my blog post and the Pirate4x4 site for details.



Here's a quote from the 4x4 site:

Special LS-specific "steam tubes" or "engine vent lines" are installed on top of the cylinder heads. As vapour or steam will always seek the highest point, any steam pockets created by local hot spots, particularly in the cylinder head exhaust valve area, will migrate up and into the steam tubes which will carry them and a small amount of coolant away and either into a port located at the top of the rad (as shown here) and from there to the surge tank, or directly to the surge tank (depending on application) where the steam is separated from the coolant.

Steve - it looks like you've got quite the motor going there - I'd highly recommend you speak with your engine builder (or a builder familiar with your engine setup) and ask them about how PCV should be routed and setup for your particular engine.

I have a post about PCV and catch cans; there's been some debate about my setup but at the end of the day a properly configured PCV system is important to having a healthy motor. I'm also now a big believer in installing a catch can on LS motors.

Hi Cam, Thank you so much for the response. I actually am running a custom SBC with an alien intake. I'm learning that I need to do a lot more research before taking any action. I never imagined I would have to drill my own valve covers for breathers (catch cans) or PCV's. I thought when the engine came back from the builder that things like breathers and oil lines for the dry sump would have been worked out.

As far as steam ports, I think I understand what they are and what they do (based on my findings on youtube that is). Now I have to determine if I even have them on my engine. I had heard about them on LS engines and assumed I would have them too. I'm going to have to call my engine builder and see what he says. UGH! I always feel like such a PIA when I call him.

I've read your build log twice now and seen all your videos. You definitely have been a great source of inspiration and information!

Thanks for the help!!!
 
This would have been valuable information (proper air pocket prevention design of a coolant system) to a certain kid building his slope nosed, IMSA fendered, SBC powered 914 back in the day. It was fast but, he (I) had to bleed the cooling circuit constantly to keep it from overheating.

A little knowledge would have gone a long way.
I have owned about 1(0) 914'6's Several that I converted from 4's and a couple factory. I even owned a 7000 original mile 914/6gt It was a BLAST! I owned two that had SBC's also. It was amazing how well the engine fit back there and that the car actually felt well balanced. They (sbc powered) were a little too crazy for me. I definitely preferred the 6's. 914's are still one of my favorite cars! A blast to drive, fantastic configuration! I owned a Lotus Elise simultaneously and it was amazing how similar they were to drive. Even though my 914/6 gt was a 1970 and the Lotus was a 2005.
 
I have owned about ten 914'6's Several that I converted from 4's and a couple factory. I even owned a 7000 original mile 914/6gt It was a BLAST! I owned two that had SBC's also. It was amazing how well the engine fit back there and that the car actually felt well balanced. They (sbc powered) were a little too crazy for me. I definitely preferred the 6's. 914's are still one of my favorite cars! A blast to drive, fantastic configuration! I owned a Lotus Elise simultaneously and it was amazing how similar they were to drive. Even though my 914/6 gt was a 1970 and the Lotus was a 2005.
 
Ha!
I had a 914/6 too, although the webers were too complicated for my early 20's experience level ! Loved my V8, still one of my favorite cars to have driven. Built my SLC as a 'replacement' for that car decades later. Still, that 914 holds a dear place.
 
Ha!
I had a 914/6 too, although the webers were too complicated for my early 20's experience level ! Loved my V8, still one of my favorite cars to have driven. Built my SLC as a 'replacement' for that car decades later. Still, that 914 holds a dear place.
I knew a mechanic about 45 minutes from my house who lived for these cars. A real old school Porsche mechanic. He was able to tune mine better than new. The cars were screamers! So fun to drive! Easy to work on too! I remember dropping the engine in about 45 minutes.
 
Here's how I did mine. I didn't want any hardware inside the valve cover that is just waiting to come loose and jam itself in a valve spring and break the motor.
Wow, I see you ran a carb too! How does it run compared to FI? My valve covers are already black anodized. I was thinking about drilling them and using an -8an fitting for a fuel tank that has teflon washers rather than weld. Do I really need a baffle?

Thanks for your help by the way!

Steve
 

Bill Kearley

GT40s Supporter
I think you could look at another set of valve covers that have provisions for an inlet filter and a PVC port. A good set will come with baffle.
 
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