[Z OH 6]

Originally Posted by KingLT1

Yea I agree which is why I run the Metco breathers on my engines. But the MM wild does work well if you increase the breather line(s) diameter to -10 as I mentioned prior.

That is one nice thing about Whipple's. Is they upgrade the factory vent lines with their kits. It definitely becomes an important thing to address as you turn the boost up and make more power.

And I still believe catch cans are important to keep oil from being ingested. That will cause detonation and power loss. Stock LT4's get quite a bit of oil blow by through the PCV system. I have seen oil pooling inside the supercharger lid.

I agree here and if JSH didn't upgrade the breather line as his power and boost level increased this was bound to happen eventually.

[LiqTenExp]

Originally Posted by KingLT1

Yea I agree which is why I run the Metco breathers on my engines. But the MM wild does work well if you increase the breather line(s) diameter to -10 as I mentioned prior.

That is one nice thing about Whipple's. Is they upgrade the factory vent lines with their kits. It definitely becomes an important thing to address as you turn the boost up and make more power.

And I still believe catch cans are important to keep oil from being ingested. That will cause detonation and power loss. Stock LT4's get quite a bit of oil blow by through the PCV system. I have seen oil pooling inside the supercharger lid.

I avoid the catch can and just use a gently spray of water/meth to keep the whole upper engine clean

[JSH]

Originally Posted by jlaudio11

I understand you have the race can but what size lines and where are you running them from? We're similar power levels and I have actually too loose of ring gap so I get some blow by, but I'm just going to a generic catch can with 5/8 lines off the stock valve covers. I did put an ls3 front seal in when I had my engine apart. I think I actually reused my stock rear main seal. Cant remember right now.

The -10an lines come off the back of the valve covers. MM has suggested a few things including -12an lines

[JSH]

Originally Posted by KingLT1

I run metco breathers on my engines. That being said the MM wild catch can has a breather so it should do the same thing, but you might try adding the Metco breather on the Valve cover.

I had a rear main go out on a new 5.3 LS(mild build) that was less than 1k miles old. Replaced seal added Metco breather, no issues since.

If you don't want to try the Metco breather, One thing you will want to make sure is that your breather lines are all upgraded to -10 and routed correctly for the MM wild can to vent crank case pressure efficiently.

MM says:

you can hook the valley plate adapter or spare valve cover port(s) to one or both of the outer ports on the stock black box, since it appears the exit of it is still connected to the cold air intake

you can also unhook the lines at the valve cover and blow toward the can
this should be very easy to blow, and may find a restriction somewhere perhaps also double check the fittings in the valve covers for not necking down on the hose size

if the valve cover fittings are -10 port, we can go up to full flow -12 with our parts

[JSH]

What if I start by putting a nipple in the oil fill opening and attaching a breather cap to it and see if the leak responds

[KingLT1]

I wouldn't do that because then it's just open to atmosphere. The metco breathers have a check valve disk that closes under vacuum.

[JSH]

Originally Posted by KingLT1

I wouldn't do that because then it's just open to atmosphere. The metco breathers have a check valve disk that closes under vacuum.

I now see both valve covers have bungs I can use for breathers

[RobZL1]

I'm still betting on a loose filter, loose cooler bolt, or loose pan bolt

[Joshinator99]

Originally Posted by KingLT1

Yea I agree which is why I run the Metco breathers on my engines. But the MM wild does work well if you increase the breather line(s) diameter to -10 as I mentioned prior.

That is one nice thing about Whipple's. Is they upgrade the factory vent lines with their kits. It definitely becomes an important thing to address as you turn the boost up and make more power.

And I still believe catch cans are important to keep oil from being ingested. That will cause detonation and power loss. Stock LT4's get quite a bit of oil blow by through the PCV system. I have seen oil pooling inside the supercharger lid.

Yep, I’ve been running the -12AN line with my MM Wild from day one. We’ve had LOTS of “learning experiences” in regards to boost and fueling lol… still using an LT1 front seal and OEM rear main with no issues at all… We definitely would have popped one if we didn’t have this setup. <furiously knocking on wood>

[JSH]

Originally Posted by KingLT1

I run metco breathers on my engines. That being said the MM wild catch can has a breather so it should do the same thing, but you might try adding the Metco breather on the Valve cover.

I had a rear main go out on a new 5.3 LS(mild build) that was less than 1k miles old. Replaced seal added Metco breather, no issues since.

If you don't want to try the Metco breather, One thing you will want to make sure is that your breather lines are all upgraded to -10 and routed correctly for the MM wild can to vent crank case pressure efficiently.

I'm going to put a metco on it

[KingLT1]

Originally Posted by Joshinator99

Yep, I’ve been running the -12AN line with my MM Wild from day one. We’ve had LOTS of “learning experiences” in regards to boost and fueling lol… still using an LT1 front seal and OEM rear main with no issues at all… We definitely would have popped one if we didn’t have this setup. <furiously knocking on wood>

Yeah I meant -12 just to clarify.

Originally Posted by JSH

I'm going to put a metco on it

It should work.

[JSH]

Originally Posted by KingLT1

Yeah I meant -12 just to clarify.

It should work. Or swap all your lines to -12.

As you see here, each valve cover has two -10an breather provisions front & rear on the valve covers. The CC is connected to the rears, and LME says to use the fronts for crankcase breather caps. LME used a complete LT rear cover with seal.

[CamOnlyJabroni]

Looks to me like you need to upgrade the line that goes from the intake to the PCV junction box. This will help evacuate crankcase pressure with vacuum. I went with the JRE kit he sells that comes with a 5/8 hose and fitting.

Edit: The Big Gulp should have came with 3-4 fittings total with the intake. You end up using the one with a 5/8 barb. That will be one six pack of Three Floyd’s Zombie Dust.

[JSH]

Originally Posted by CamOnlyJabroni

Looks to me like you need to upgrade the line that goes from the intake to the PCV junction box. This will help evacuate crankcase pressure with vacuum. I went with the JRE kit he sells that comes with a 5/8 hose and fitting.

Edit: The Big Gulp should have came with 3-4 fittings total with the intake. You end up using the one with a 5/8 barb. That will be one six pack of Three Floyd’s Zombie Dust.

This line? https://jannettyracing.com/products/...40696118116375