Holley Tall LS Valve Covers

[diddies]

I am going to be installing the Holley Tall LS Valve Covers and have a quick question. It mentions on step 12 as you can see that an external PCV valve may be needed. Is this needed on the ZL1 and if so where would I put this?

[HDRDTD]

I see many valve covers advertised to fit the LS series engines, but so far none of them state they will fit the LSA that comes in the ZL1 ??

[diddies]

Originally Posted by HDRDTD

I see many valve covers advertised to fit the LS series engines, but so far none of them state they will fit the LSA that comes in the ZL1 ??

It says on their site that it fits a ZL1

[HDRDTD]

Originally Posted by diddies

It says on their site that it fits a ZL1Attachment 1056540

Interesting.

In the main description it lists pretty much all the LS series except the LSA.
It's only when you look for parts to fit a 2013 Camaro ZL1, does it state it does fir the ZL1.

Hmmmm

[larry_g]

I have these, the vent had to be seriously restricted otherwise it would fill my catch can in a matter of minutes. Just adding a PCV valve didn't work for me. They also made the plug wires a snug fit. That said, they do look good.

Sent from my Pixel XL using Tapatalk

[diddies]

Originally Posted by larry_g

I have these, the vent had to be seriously restricted otherwise it would fill my catch can in a matter of minutes. Just adding a PCV valve didn't work for me. They also made the plug wires a snug fit. That said, they do look good.

Sent from my Pixel XL using Tapatalk

Do you have pictures of what you did or how you restricted it?

[larry_g]

So when I went through this, my research indicated that the hose from the valve cover required a restriction. I first tried the recommended PCV valve which didn't work so then I ordered a fancy aluminum restrictor and it too wasn't enough.

I already had a T fitting in the hose because I needed to split the vacuum between the catch can and my NPP (due to the Whipple). So I had a huge brain fart and decided to try a stepped T fitting like this

https://www.autozone.com/fittings-an...tor/373175_0_0

I left the side facing the valve cover at the smallest opening and then trimmed the other two so they weren't restricted. So far it has worked perfectly for me, I now get just a small amount of oil in the catch can.

If you don't need a T, you can cap it or I'm pretty sure they make the same thing in a straight connector as well.

[diddies]

Originally Posted by larry_g

So when I went through this, my research indicated that the hose from the valve cover required a restriction. I first tried the recommended PCV valve which didn't work so then I ordered a fancy aluminum restrictor and it too wasn't enough.

I already had a T fitting in the hose because I needed to split the vacuum between the catch can and my NPP (due to the Whipple). So I had a huge brain fart and decided to try a stepped T fitting like this

https://www.autozone.com/fittings-an...tor/373175_0_0

I left the side facing the valve cover at the smallest opening and then trimmed the other two so they weren't restricted. So far it has worked perfectly for me, I now get just a small amount of oil in the catch can.

If you don't need a T, you can cap it or I'm pretty sure they make the same thing in a straight connector as well.

My catch can is currently in tied to my valley cover and supercharger vacuum return. How would you tie this into the valve covers?

[larry_g]

Originally Posted by diddies

My catch can is currently in tied to my valley cover and supercharger vacuum return. How would you tie this into the valve covers?

With the Whipple, the valley cover port is capped.

Any of the three ports (valley and 2 valve covers) will allow you to pull air from the crankcase.

[SiC ZL1]

I have the tall holley valve covers on my 12 ZL1 and no issues what so ever. I have a JLT catch can ran to the valley port and supercharger port. I cut the ends off of the breather tubes and used a little 3/8 hose to adapt them to the valvecovers. Supercharger is nice and clean inside and catch can works exacyly as it should.

[JimCT_9C1]

Sub'd. - Thanks for real world experience from SiC ZL1 w/ factory PCV, and larry_g's w/ Whipple too!

SiC ZL1 crossed my response but since I already wrote this up, figure I'd post it anyway ...


I have been looking into LSA valve cover and PCV compatibility as I build toward the future of my Caprice.

From wading through experiences of others here and with Caprice/G8s, it seems the Holley valve covers have minimal flow restriction. Without some sort of PCV valve or flow orifice, a PCV dirty side (outlet from crankcase) connection from an unrestricted valve cover creates an open draw from crankcase to catch can / intake leading to high oil carryover. The factory valve covers with a PCV dirty side connection have built-in flow restrictors and baffling to control this. With a factory valley cover PCV outlet, the dirty side restriction and baffling are in the valley cover.

OP - check your factory valve covers or someone can chime in on any flow restrictors in the LSA factory valve covers. The Holleys may work as-is with your setup.

Hope this helps,

Jim

[diddies]

Originally Posted by SiC ZL1

I have the tall holley valve covers on my 12 ZL1 and no issues what so ever. I have a JLT catch can ran to the valley port and supercharger port. I cut the ends off of the breather tubes and used a little 3/8 hose to adapt them to the valvecovers. Supercharger is nice and clean inside and catch can works exacyly as it should.

Do you have a picture of your breather tube or how you attached these?

[SiC ZL1]

Originally Posted by diddies

Do you have a picture of your breather tube or how you attached these?

If my car wasn't in storage at the moment, I'd get you better pics. But hopefully this helps.

[diddies]

Originally Posted by SiC ZL1

If my car wasn't in storage at the moment, I'd get you better pics. But hopefully this helps.

That helps a ton. Do you have any problems with it giving way from the OEM hose? I will be doing this tomorrow.