Engine Replacing the gasket on a gt40 head need some advice

Steel1

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Aug 18, 2017
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Those appear to be cork v/c gaskets ?
If they are I would change them out to the blue reusable Felpros, cork will eventually leak.
Looks like that may be the fuel line kinked pretty good (last pic left side) if so hopefully you
can remedy that with no leaks. Looking at the pic again I think it's the cross over line, so worst
case scenario you would need to replace that section.
 
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Ukturf

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Mar 20, 2020
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I pulled it last night prior to calling it quits.
im starting the cleaning process and found a crack in on of the threads. On the outside. If you have the ability zoom in and you shall see!
So thoughts???

Keep in mind That I’m not asking this motor to last another 20k miles as I will swap into my 351. Down the road.
 

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Ukturf

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Cleaned prepped and ready for test figment!
need to order gaskets tomorrow but she’s ready for success or failure.

i used a razor blade on everything to get the majority of the gasket off and then went after my cordless Drexel with their brown light duty pad. It worked like a champion!!

Still not sure on the the crack in one of the head studs so really looking forward to “hey place Jb weld around it and bolt her down to spec” comment. Let’s hear it folks.
 

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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
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Stick a small screw driver in the hole to see how far the threads go into the head, someone may have used a short bolt at one time that didn't grab enough threads.
 

Ukturf

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Good thinking. Plenty of threads left past the cracked area. im assuming that last the best scenario here?
 
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Ukturf

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Gaskets have arrived Fel-pro along with bolts for the lower intake that I will be cutting for alignment purposes. Per recommendations I will be ditching the blue rubber gaskets that belong at the end of the intake and going with straight permatex grey.

After I apply the the gasket maker how long do I need to let it set up before placing the intake down? Seconds, Minutes, Hours?

After placement snug the bolts hand tight? or simply follow the torque specs. wait 24 hours for a total cure time and then go for it?
 

Steel1

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I've always used "Right Stuff" rtv on the end rails, smear of it around water ports, let it sit 10-15 min. then plopped the intake on.
Snug all bolts evenly using torque sequence then again to torque spec.
Just the way I've done them and it's worked out good for me.
 
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90sickfox

Wasn't a pretty sight...and I've got big hands
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I also use Permatex " Right Stuff " and don't have any issues. I'm going through the same process with an engine I didn't put together. Seepage at the rear lower intake. The joy's of project cars.
 

Ukturf

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Well life is good so far. I put everything back together and fired it up no leaks and it seems all is good so far.
I’ve still got to bleed the coolant system but it fired up right away and after 30 seconds of rough idle it ran as it did before! I didn’t have a timing light but marked the distributor throughly and placed it back. Finger crossed and it all seems to be good. Tomorrow a test drive and then business as usual.
Thanks a lot for the advice and help. Couldn’t have completed this without it!!
 
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Ukturf

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Epic fail gents. First drive was a short one. The car ran great. I get back and I’ve still got a leak. It seems to be right below the pvc valve area ( just changed both filter and valve.
So I believe I may have done something incorrect!
 

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Ukturf

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I did not use the rubber gasket.
what is that round thing?
I applied ample amounts of rtv so I am a bit lost on what went wrong to be honest.
My process was. Apply place the intake down, hand tightened the bolts and after an hour torqued to spec 3 times like instructed.
Let sit for 24 hours and go.
I’m not really upset because this wa Amy first experience at doing anything like this and it was only 40 bucks total invested.

so should I use the rubber gasket method this time or do the same process over again?
 

90sickfox

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Over the years I've tried several different way to seal lower intakes. These are the instructions from felpro for a 1250 3s gasket set. Usually, I use just right stuff at the front and rear valley seals. The instructions show how to see how large the gap is between the upper and the block. I've seen some engines sit down almost on the rails and others that have had up to 1/4 gap. I've even seen a couple where the angle of the intake didn't match the angle of the block.

This is the one area where you could fail any way you do it. This time around I used the cork gaskets that came with my gasket set. I trimmed them to fit the valley and then stuck them down ( they come with adhesive on one side ). After that I put a 1/4 bead of right stuff in the corners and I put a small 1/16th bead of right stuff on top of the cork gasket.

I've tried soaking the cork gaskets and using shellac....held for about a month ( the cork has changed now so that isn't done anymore ). Tried just right stuff. Lasted usually a few months to a year. The blue rubber has never worked for me on the valley. They always find a way to leak no matter what I do. The trick to all silicone is that it has to be thick. It has to be able to resist the pressure from the engine pushing on it.

20200410_182358.jpg
 
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