FelPro PN 9333PT1.

Don't waste your money on anything else.

 

+1
and no gasket it going to get you to 10.0

I'll also like to hear more about the dye trick. Where was the dye showing up?

 

I'll also like to hear more about the dye trick. Where was the dye showing up?

It's not a trick. It's a diagnostic tool. A little pricey, but if you're unsure of a blown head gasket it's a money/time saver.

A solution (dye) is added to your coolant. The engine is run for a few minutes to circulate the solution throughout the engines coolant passageways. The "tester" extracts a sample of the coolant and tests it. I've forgotten the exact means, but the tester determines if the head gasket is blown.

It's similar to the old "anti-freeze percentage" tool that can tell you what percentage of your coolant mixture is anti-freeze, but a little more high-tech.

I think the kit is around $40.

 

Could this not also be a cracked block or cracked head?

 

If a solution was added to the cooling system it was a dye to be used with a UV light to check for external leakage.

What you described sounds like a tool designed to take a sample of the gases coming from the cooling system. The fluid in the tester will react with hydrocarbons (combustion chamber gases) and change color.

If no hydrocarbons are present the test fluid will not change color and the car is ok at that point.

 

Yes, that sounds like what he described to me as far as the dye turning color based on some chemical reaction. Pretty cool.

He also said it could be a cracked head but I wonder what would have cause an iron head crack. They were full inspected and all components replaced in these GT40 iron heads to the tune of $500 before I installed them.

Anyways, I am not looking forward to the process of tearing it apart but I am happy to finally have an answer on this problem after months...

Thanks alot for the recommendation on that gasket.

-Nick

 

Tearing it apart? It's a couple hour job, especially if you're carbed. I had to do it twice, one after another, after a wrench broke off and went down the plug hole on my car. I'm sure a search will turn it up.

Of course, I think we're all anal and clean our bolt threads to perfection, etc, so the hours stretch onwards.

 

I would take off both heads and have them milled slightly to make sure they are true and not warped, then I would use good old trusted Felpro gaskets. The milling will also get your compression closer to the 10:1 you are looking for.

 

I'd get the heads milled like Vinnie suggested and use an .039" gasket. Get those things down to 55-56cc and 10:1 is no sweat.

 

Believe it or not they have been milled down so much that they measured 53cc before I put them on. I am not sure how much more they can be cut. Originally Iron gt40 heads are 62cc or so. Maybe they will need to be milled more though after overheating...

 

You are describing these heads as GT-40's so I'm assuming that is what they are, not P's right? If they are OEM GT-40's then they have already been cut WAY too far to get 53cc out of them. The stock deck won't handle that and will crack, likely the overheating problem. GT-40's will take about 57-58cc's and live without power adders. Since the engine has been running really hot a few times I would expect that the heads may have cracked.
There are a bunch of SBF iron heads out there on the aftermarket that are very affordable. If you are being cost-concious then look at something like the WP Windsor JR. They can be cut to 53-54cc and maybe more.

 

Sometimes a normal compression test will not show a problem. I would suggest a leak-down test. I know that you already determined that you have a head gasket or cracked head problem but it would help you find it if you could determine what cylinder it is on before you pull it apart. I've pulled heads off a car before chasing a head gasket and couldn't see where the problem was. I was sweating it putting it back together because I didn't actally "find" a problem.

 

Yes they are the non p heads. I thought taking 10cc off of them was alot. I guess we will find out soon. I think however, that if they are cracked I will be looking into something like used twisted wedge heads or something else. I already have about $700 into these heads and I could have had some more modern design aluminum heads.

I'll keep everyone posted as I plan to take it apart Sunday. Thanks!


OH and I also have a trans leak at the linkage on the side of the trans and the speedo gear...Ugh does it ever end? This c4 was rebuild 2 years ago. I think they are just meant to leak. Not to mention my new water pump leaking...

 

Good crap, that means they milled off .070" and something like .040" is usually the recommended limit.

Don't bet the farm on my SWAG, but I wonder if you have enough deck left to seal the headgaskets? OEM Ford heads don't seem to have the thickest decks in the world and it seems like they milled the snot out of them,

 

At least pulling the heads is an easy job on a SBF vintage Mustang, especially if they have been off in the last decade......

Did you get to it on Sunday? If so then what did you find?

 

I too recommend a leakdown test if it is available. This would narrow it down to a cylinder or two, so that you know where to look for cracking or blown gasket

 

gasket

The trouble with leakdown is unless the crack is huge, it may not show up unless the engine is at operating temperature. If you do it cold, the crack may be "shut" with carbon and or just the metal itself. Many cracks don't open and start leaking unless the metal is hot. I'd yank the heads if compression in the cooling has been confirmed and then either scrap the heads in favor of aftermarket heads or plan on having a teardown with full magnaflux (mag particle) testing to located possible cracks. We had a tank back when I was at Caterpillar that was heated up to 180ish degrees that cylinder heads were dipped into for testing. The heads would have deck plates bolted to them to block off coolant passages and any other coolant passages were capped off with a block off plate. One plate had a QD for compressed air that would be pumped into the casting during it's soaking in the hot water tank. If the headgasket has simply blown, the head surface will need to be checked (along with the block) for a true straight sealing surface. If both are flat and no cracks present, you might get away with new gaskets. Id so, you may consider swapping to head studs instead of bolts for better clamping force.