Lot of people recommend the Ford intake gaskets but what about head gasket for a 95 4.0 OHV. Felpro is offering 2, and improved design and then a SD or severe Duty . I always like severe duty when offered but don't want something thick enough to drop compression ratio. What are you guys using and getting good sealing with?

 

Which ever is cheaper, but Felpro for sure

 

considering the magnitude of the job the issue isn't 10 dollars it's which ones have good results, sealing and longevity. Which ones work best.

 

Longevity is a relative thing when it comes to head gaskets.
Head gaskets don't fail on their own, they fail because the engine was over heated, it was installed wrong or the block/heads are not flat any more (usually because the engine was overheated).
One isn't thicker then the other so the compression issue isn't the concern.
After some reading, the severe use one will with-stand higher compression ratio's.

It almost doesn't matter since the engine isn't turbo charged anyway.
If it was, I wouldn't even go with a composite gasket, you would need a MLS one for that.

 

The cheaper ones are the ones I have always used from Felpro, never had one fail.

4.0l OHV or any cast iron block with cast iron heads don't have head gasket issues.

Aluminum heads with cast iron blocks do.
Thats why MLS(multi-layer steel) gaskets are used, well have to be used, lol.

Head gaskets fail when an engine over heats, over heating is caused, or causes, the loss of coolant, and the heads being at the top of engine lose the coolant first so gets very hot.
Metal expands when heated, heads are held in place by the head bolts, so expanding metal head pushes down on the block, head gasket starts to get crushed.
If one the the metal rings sealing a cylinder gets crushed then the 900+ psi pressure from a cylinder firing can breach that ring, and you have a head gasket leak.

But 4.0l OHV heads would be cracked by this time, they have a weak casting between valve seats so as the hot metal expands it cracks there.

Aluminum expands 5 to 7 times faster than cast iron, which causes a problem when they are used together.

As engine warms up the aluminum head will expand faster than the iron block, this RUBS the head gasket material, then when it cools down, same thing happens, head gasket gets RUBBED.
So after awhile a composite head gasket will fail.
Usually 20-40k miles, lol.

MLS gaskets allowed SLIDING instead of RUBBING, but they had a hard time sealing cooling system in cold weather.
As temp dropped aluminum shrank too much and coolant started to leak out.
Eventually they found the right combination.

Anyway point is head gasket isn't what fails, ever, either driver allows overheating or engineer goofed on original design.

Cheap head gasket :)

 

There's a guy over at the Rolls Royce forums with a Bentley Turbo "R" with a blown head gasket.
Apparently it was a common issue after 50,000 miles for them to go, they were just composite head gaskets.
He had the top end totally redone by an authorized mechanic and had original Bentley gaskets installed, unfortunately they were just new old stock _ it looked exactly like the failed original.
I gave the guy an address where he could have some custom MLS gaskets made, but he insisted on genuine parts...

That engine is all aluminum with steel liners so at least the two metals will expand and contract together, but with just a composite head gasket in there, I'm sure it will fail again with the turbo building up all that pressure in the combustion chamber.
But with both bottom and top end expanding greater then cast iron, I'm guessing the composite head gaskets will have even a shorter life on top of the higher pressure in the combustion chamber.
It's a wonder it lasted as long as it did ???

 

OK good explanation, guess I can see where more pressure builds from a turbo. As for overheating, with a guage and some maintenance no excuse for running an engine hot enough to do damage. I bought my truck used 116,000 miles but not well cared for. Got it cheap and have run it 2 yrs now with minor misfire, passed emissions twice, ???. Starts well all weather and never runs hot.
finally got to a compression check and found low across the board with 1 cyl in the 20 psi range, ut oh. So decided to do heads. Got a core engine and pulled heads , off to machine shop for works. Found core motor push rods and rockers in poor shape at 155K so I have ordered new push rods and rocker arms.
In the end I ordered the Felpro SD gaskets and as soon as my parts arrive I'll get into this. will also give the cam and lifters a good look, as well as clean/test all the injectors. Just a daily driver so it should be better than it is now and surprisingly it isn't that bad. Does buck on the interstate hills if I pull my motorcycle on a trailer, probably 1500 lbs total. other than that runs OK. Nice little truck just needs some attention.
Should have noted, 95 4x4 automatic.