Mustang Tech

Spray them with spray on Hylomar, both side 3 coats just use the printo seal Felpros,

OK I'll give the Hylomar a go, I do feel like the definition of insanity though. Also saw on a video someone was using plastic razor blades to clean alloy heads so I have ordered a set of those as well.

Didn't know such a thing existed.

Did the head guy say why he wanted you to spray the heads and try again? I wonder if the heads are a touch warped? should check the deck of the block while you are at it. Wouldn't expect it to have warp but its a process of elimination and little on the head side plus a little on the block can be enough to cause you an issue.

5 thou a felpro gasket will take up,
5-10 thou you are in the might as well have a go zone,
over 10thou and you are likely to need decking

lukep6470 wrote:OK I'll give the Hylomar a go, I do feel like the definition of insanity though. Also saw on a video someone was using plastic razor blades to clean alloy heads so I have ordered a set of those as well.

Didn't know such a thing existed.

Wipe down the block and heads with thinner first so there there are no contaminants. My expectation would be if the heads were not flat they would have faced them.

I'm just struggling the the previous post being made at 4:32am.

I'm pretty sure the next startup will be a fail as well but I just want to avoid yet another engine out at all costs so am willing to try.

I would be very, very surprised if anything is warped as this motor has never been overheated in any way.

So the head have been vacuum tested right?

Little guy got us up at 4am for his feed, no point goi g back to sleep as i get up at 5 normally...

Its shouldnt be warped but just worth checking is all incase it is a dud block. It all should have been checked last build though.

I like checking for myself then and only then can i remove things from my mind.

Hope you are pleasantly surprised next start up

Just a thought. Have you checked the head locator bushes aren't too long or twisted not allowing the head to compress the gasket?

I did look at them when I did the gasket last time. They looked ok to me

I will post pics of my head and block cleanup before installing the heads again.

Hi,

Just posting to get some noise going on the forum again.

So I am cleaning up the heads to have yet another go. When I first pulled the heads I noticed there are small, I want to call "bite marks" all over the head surface where the head gasket has dug into the head. Has anyone seen this before with Felpro gaskets on alloy heads?

I think this is another good reason to hit the gaskets with hylomar before assembly.

I check the heads with a .1mm gauge (3.9thou) and straight edge and it was fine. One thing I did notice is some of the water passages are so close to the bore it looks like the compression ring overlaps a little bit. Do other alloy heads come so close?

https://photos.app.goo.gl/dAwWFLomXhihmfC37

That's the mark left by the head gasket, I assume there is a steel ring inside where the marks have been left from the old gasket. If you lay the gasket over the head what does it look like.

So if the head gasket was letting coolant to pass into the cylinder there, would that explain the symptoms?

Dwayne wrote:So if the head gasket was letting coolant to pass into the cylinder there, would that explain the symptoms?

Yes, have you had the heads faced? What brand heads they must be soft. An engine shop can check the brinel hardness. The Wynnum engine boys would check them for free for me. Takes like 30 seconds to check them. If you want to drop them down I'll get it done.

some good advice and offers of assistance here. Nice work fellas!