LSA Head Coolant Leak

[Flavorwrench]

I have a coolant leak that I thought was probably coming from the water pump. I pressurized the system to about 20 psi and started searching. It looked like there was some moisture around the front of the drivers side head gasket but I was more focused on trying to get an angle on the well known
Coolant Leak From Oil Cooler Hose Fitting On Left Side Of Engine Block - SB-10045062-6854, but I just couldn't see completely around that fitting. Anyway, from underneath a steady drip drip developed and of course I spent a while looked for the leak. I was concerned that 20 psi might be too much pressure to test with, but regardless, there shouldn't be a steady flow coming from the side of the head at the head gasket. I finally saw where it was coming from and got a video of it leaking (link below)

Pardon the video, if you forward to about 28 seconds you can spare yourself my fumbling and Darth Vader breathing.

https://1drv.ms/v/s!Aiay8kud3SFI01tRbwEf1iY4zuCJ

This has to be a bad head gasket... what a bitch to tear everything back down. Motor has 5000 miles on it and I guess I'm wondering if it was bad from the factory or too much boost. My combo with the 2" headers I believe is in the 15 -17 psi range and I have a hard time believing the stock gasket couldn't handle it.

Well I guess if I'm tearing it back down I'll be studding it and getting the heads ported...

Anyone seen this before?

[Flavorwrench]

Lots of views, no comments? Someone​ has to have seen this before... Well, I will provide info and pictures after I pull the heads. I have a feeling the gasket failed on the outside of the water jacket which would explain the coolant only leak... Motor runs fine.

[ZO6 Bryan]

Not much to say. Yes, blown head gasket. Tear it down.
Wonder why it happened? Is it tuned well? Proper AFR and no KR? Too much boost? 2.55 plus 9.55 pulleys is a lot. Detonation/KR will lift a head and blow the gasket. Ever miss a shift and over rev? That will do it too. Otherwise, just bum luck.

[Dutchman427]

I know some CTV-V guys are in that PSI range and more, but I did read that you could start pushing water when running anything over 15lbs of boost.

[Flavorwrench]

Hey Bryan, been a while... Yeah I regretted going from the 9.1 to the 9.55.. Im always logging so I've got data... I'll go back and look closer I'll forward anything that needs better eyes. I haven't spent much time with the car since completing my build... Pretty much just sat in the garage... Kind of a waste.. Anyway I'll get back on it and post pictures. Thanks Bryan.

[Flavorwrench]

Originally Posted by Dutchman427

I know some CTV-V guys are in that PSI range and more, but I did read that you could start pushing water when running anything over 15lbs of boost.

Yeah I will say I was more concerned of over-spinning the Supercharger before over boosting the motor.. The 2" headers gave me some head room... No pun intended.. I was thinking about posting over at CTS-V as well but like Bryan said, gotta tear it down.. I'll post what I find. Thx for the input.

[ZO6 Bryan]

Originally Posted by Flavorwrench

Hey Bryan, been a while... Yeah I regretted going from the 9.1 to the 9.55.. Im always logging so I've got data... I'll go back and look closer I'll forward anything that needs better eyes. I haven't spent much time with the car since completing my build... Pretty much just sat in the garage... Kind of a waste.. Anyway I'll get back on it and post pictures. Thanks Bryan.

Never overheated did it? That also could result in a blown head gasket. Pull the heads, get some good Cometic MLS gaskets and put it right back together. Just put a straight edge on that head and make sure it's not warped. If it is, it pretty cheap to mill the head to fix it. You don't even have to pull both heads. Unless you mill the head, then I would do both to keep them equal.

[Flavorwrench]

Originally Posted by ZO6 Bryan

Never overheated did it? That also could result in a blown head gasket. Pull the heads, get some good Cometic MLS gaskets and put it right back together. Just put a straight edge on that head and make sure it's not warped. If it is, it pretty cheap to mill the head to fix it. You don't even have to pull both heads. Unless you mill the head, then I would do both to keep them equal.

Nope car has never run hot or overheated, not even close. Too cold up here in Washington State most of the time to even drive it.

Yeah I've been away from the forum for a couple years. All the ZL1 chatter when we first got our cars had me glued to the screen, I see there is tons of new stuff around for these cars now. I haven't heard of the Cometic MLS gaskets, I just started to research my options and this advice is great timing.

If I'm gonna tear down I will definitely do head studs as well this time around, I've always had better luck on my other boosted motors.

So whats the word on Heads... Port the LSA heads? WCCH? MAST? someone else... love to hear your thoughts on that too. may just go for it and replace my BTR2 cam with something we can really push air with.

Thanks Brian

[Dutchman427]

I am looking at going with an aftermarket head. The Trick Flow GenX 255's either ported by Tony Mamo or CFM seems to be the ticket. I thought my car made good power though with the Formato ported LSA's. He prefers hand ported over CNC.

[Dutchman427]

Richard @ WCCH is a great guy to deal with as well. At the time, Formato was really making some good power with the cts-v crowd, that is why I went with him. He still is.

[DrkPhx]

The TFS 255 is a good head out of the box and even better if it's in your budget to have them ported. The 12 degree valve angle and thicker deck definitely help. There's also the Brodix and MAST LS3 heads, but they're more expensive.

[Flavorwrench]

Thanks everyone for the input.. Hand porting Vs CNC, yeah I'd probably argue both together may be the best, but I definitely don't have access to a CNC and at this point I think I'll save myself the hassle and just pay to get what I need, if you know what I mean. Jeremy and Tony I too have heard do great work, just over the years reading the forums.

At the end of the day the question will be what cam to use with what heads/headwork.

I remember a forum build on here back in 2012....??? I think the first guy to use MAST heads... I don't remember that build getting that good of results with the MAST setup... One of the first guys to tear into a new ZL1... lots of money on that build if I recall... I need to catch back up.

Well the tear down started yesterday and some decent progress. I was telling a friend the first time through that car it took me a couple of slow methodical days to get the front clip off the car... documenting everything... pictures.. taping the gaps, you know. This time it was off and in the living room in about 25 minutes... Kind of funny!

[Dutchman427]

Mike @ Rapid is gonna spec a different Cam as well for my second phase build. Mast is a lot of money.

[Flavorwrench]

Ok... as promised, here are some pictures.

I will start off by saying that I was surprised by what I saw during the first half of this tear down and it is obvious to me my Tune is headed for the trash and I'll start over from square one.

I am really pissed at myself for not checking the torque on the head bolts during my first tear down and as easy as it would be to blame Chevrolet for a lackluster head assembly, I'm not gonna go there.

I know by the way the head bolts came off.... they weren't torqued correctly... or loosened... not good, this thing was pushing coolant.

The drivers side head gasket was full of moisture and I just don't have enough experience with these 7-layer gaskets to come up with an opinion on how or exactly where it failed other than where my video shows it coming out.

What concerns me the most is Piston #7... really black on top... Could be where it was leaking... maybe from the pictures we can figure it out.

Keep in mind this motor has about 5,500 miles on it.

One thing I will add is that I have a feeling something was up with the head gasket from early on... (That mysterious light smell of coolant that followed me around.)