EFI Valve Cover question

[Izzy]

I have the Bronco Script Valve Covers that were on my Carb'd engine. Since I am now switching to EFI, I understand that I need to plug up the ports on the covers. How have you guys accomplished this?

 

[EricLar80]

I have the Bronco Script Valve Covers that were on my Carb'd engine. Since I am now switching to EFI, I understand that I need to plug up the ports on the covers. How have you guys accomplished this?

You should only really need to do this if you plan to run the emissions system on the EFI, such as the PCV valve and tube running from the oil fill neck to the throttle body. No harm in running this equipment, since it wont hurt power, but you may prefer to keep the valvecovers the way they are.

If you decide to do this, just make sure the only place air can escape through the valvecovers is the tube going to the throttle body. Then, you also want to run the PCV valve.

Eric

 

[mattt]

I thought you had to run non vented valve covers with EFI so that all air entering the engine is metered by the MAF sensor? With open breathers there is a source of un-metered air that could enter the engine and throw off the EEC calculations???? I'm not 100% certain on my assertion, but it seems like that is logical and one thing I read during the EFI learning curve.

 

[Rox Crusher]

Yes, they need to be sealed up so that all air entering the engine is metered by the MAF sensor.

I am planning to use those same valve covers and was worried about clearance to the upper air intake. I test fit them last night and while it is close, they will fit.

I am going to graft the oil filler tube from my Explorer cover onto the one and just find a plug for the other.

 

[Izzy]

My understanding is we need to plug the two holes one. I'm just curious what others have used to plug them. using the oil filler from a explorer cover is a good idea, I'll have to look at how those mount and see if I can do that.

Any other ideas or pictures?

 

[Viperwolf1]

You should only really need to do this if you plan to run the emissions system on the EFI, such as the PCV valve and tube running from the oil fill neck to the throttle body. No harm in running this equipment, since it wont hurt power, but you may prefer to keep the valvecovers the way they are.

If you decide to do this, just make sure the only place air can escape through the valvecovers is the tube going to the throttle body. Then, you also want to run the PCV valve.

Eric

The PCV valve may have been considered emissions equipment when it was introduced in the early '60s. But it has so many good benefits for the motor it should be considered as a necessary system. It eliminates water vapor, fuel and combustion gases from the crankcase, all of which can contaminate the oil. It also eliminates pressure from the crankcase which can cause oil leaks.

 

[Izzy]

Viper,

On the Explorer intake, the PCV valve goes in the back, are you sugegsting to run it from the back of the intake to the valve cover? I thought it was best to run to the vacuum line on the plenum?

Should I run a second PCV valve in the valve cover?

 

[Viperwolf1]

Viper,

On the Explorer intake, the PCV valve goes in the back, are you sugegsting to run it from the back of the intake to the valve cover? I thought it was best to run to the vacuum line on the plenum?

Should I run a second PCV valve in the valve cover?

No, I'm just suggesting it be used. Run it the way it is already setup. PCV valve at the back of the intake, vacuum hose to the upper plenum, vent hose from valve cover (filler tube on explorer) to filtered and metered air source.

 

[Izzy]

vent hose from valve cover (filler tube on explorer) to filtered and metered air source.

Sorry to sound dumb but can you elaborate on this part? I have the Bronco Script valve covers that each have a hole in them. On the carb setup, one goes to PCV and the other is just capped with the Oil filter.

The one that is for the PCV, are you saying to run it to the air intake tube? What about the other?

 

[Viperwolf1]

Sorry to sound dumb but can you elaborate on this part? I have the Bronco Script valve covers that each have a hole in them. On the carb setup, one goes to PCV and the other is just capped with the Oil filter.

The one that is for the PCV, are you saying to run it to the air intake tube? What about the other?

Some explorers had the vent tube going to the throttle body, some went to the rubber intake hose. Both are filtered (air goes through air filter first) and metered (air goes through MAF).

You'll need a filler cap so you can leave that side as is. Just make sure the filler cap isn't open on the bottom. On the other side, where the PCV valve was, you can use to run the vent tube into. You'll need to fabricate a little.

 

[Izzy]

Ok, that makes more sense now. Thanks Viper

 

[EricLar80]

The PCV valve may have been considered emissions equipment when it was introduced in the early '60s. But it has so many good benefits for the motor it should be considered as a necessary system. It eliminates water vapor, fuel and combustion gases from the crankcase, all of which can contaminate the oil. It also eliminates pressure from the crankcase which can cause oil leaks.

Agreed. My point was about unmetered air entering the intake.

Eric