Best head gasket kit ?

[joey]

Sorry about that wolf... not sure what happened, but I fixed it.... should take you to platnium motor sports now... Nathans Site.

 

[armandjones82]

This information about the Cylinder Head Gasket Set is not bad at all. It maybe is a long read, but it was sure of full read of information to all of us. Keep it up and hope to continue us newbies helping out here!

 

[vandev]

hey chongo

Engine

The engine in the disco 2 is the old buick 215 v-8, with no roller cam, and no rotators on the exhaust valves like US engines. The dry cylinder sleeves, “ these are not wet sleeved engines”, are straight, un - flanged and made of steel, while your block is made of aluminum. This creates a thermal condition of dissimilar materials. Many mechanics blame a blown head gasket on this thermal condition as a, “dropped liner”, but in reality at about 210 degrees operating temperature the cylinder liner actually moves around .004” of an inch away from the head gasket ring , this releases the tension on the head gasket between the liner and the head. This also releases the tension between the head and the head gasket between the liner and the head, and reduces the heat sink value on the head gasket steel ring, {this is why when you remove the old head gaskets on a land rover the steel ring on the head gasket is usually yellowish or has a burnished color}, causing premature head gasket failure. Now note what I said, the head to liner distance is getting larger by .004” not the head separating from the block, but the liner actually grows 50% shorter than the aluminum block walls. And since the stock land rover liners seat at the bottom of the bore, and on the main bearing saddles the expansion ratio starts at where it seats, at the bottom of the bore, not the top.
Expansion ratio of steel is 6 parts per million per degree
Expansion ratio of aluminum is 12 parts per million per degree.
No real such thing as a dropped liner according to popular belief, it is a thermal problem with dissimilar materials. And there is only one bullet proof cure, Top flanged liners, sometimes called top hat liners in the British market.
There just isn’t any other long term substitute for this issue. Different head gaskets are only a myth, not the cure, production short cuts caused this problem, Buick when they had built these engines cast the liners in place, Rover bored them out and pressed them in with polished side walls. Perfect ingredients for cylinder bore walking........Which is what happens.

Cracked blocks

A rare issue

Land Rover Bosch engine blocks, or the old buick 215 block usually cracks on the main bear saddle bulkheads, just below the liner. This is caused by the straight walled liner. Since the straight walled liner has no lip or flange at the top of the bore to seat against, it must seat against the bottom of the bore. Where the crankshafts main bearing saddle bulkheads hold all the tension from the tightening of the cylinder head bolts. As you tighten the head bolts, the head is pushed towards the block, pushing the steal ring head gasket towards the cylinder liner, forcing the liner to push hard against the bottom of the bore in the block, which is the main bearing saddle bulkhead. Switching to top flanged liners eliminates this issue. This is a rare issue, but I have seen this
several in my lifetime with this engine.

Head Bolts

Head bolts must be replaced every time you remove the head, they are not regular bolts, but a special designed stretch bolt. There is a tightening sequence principle that must be followed although contrary to popular belief, and the service manual, as long as the principle is adhered to the sequence can be changed. The principle is uniformly and incrementally tightening the head down. The actual order doesn’t matter.
Take a good look
how the head gasket is designed and it comes with a sticky adhesive on the
composite part of the gasket. This will work beautiful if both surfaces are left
perfectly dry, and free of oil, i.e. lacquer thinner. Use NO OIL PERIOD on the head bolts, You’ll regret it if you do. You see the oil you put on the threads, like the book tells us to, will push off the threads as you thread it into the threads of the block and it
gets between the block and head pushing into the gasket areas ruining the effects of
the adhesive on the gasket, Oil and adheasive isn't usually a good combination......

What I did and this works well, I put only 2 layers of Teflon Tape on the threads of the new head bolts and a small amount of grease just under The bolt head. What this does is not let the bolt head gall into the heads and lubes The threads into the block without any oil. I believe this is an area where a lot of people have got themselves into trouble, and they followed the book. This would probably cause gasket failure in a few thousand Miles or so, and would probably be blamed on the mechanic or machinist, when it is A procedure problem. Use the Teflon tape on the bolts, it runs in nicely and life Is good.

In testing the book vs. torque standards I found the service manual, “again” in error as it says to tighten all bolts to 15 ft. lbs. then 90 degrees more in sequence, then a additional 90 degrees for final torque. This is bogus, and utter nonsense. My findings after doing this left the 3 long head bolts at 50 - 58 foot pounds of torque, while the short head bolts read 68 - 72 foot pounds of torque. I found that almost an additional 90 degrees was required on the long bolts for a total of 245 - 270 degrees before the long bolts achieved the 68 - 72 foot pound equivalent to the short bolts. This makes the tension and torque on all bolts even. If the tension on all bolts is not the same, I couldn't care less what you think, or what the manual says, un even head bolt pressure is one of the best ways to blow a head gasket.
Due to the dissimilar materials of the steel bolts and aluminum heads it needs a stretch bolt design. Don’t go buying studs for this engine, you won’t be happy with the long term effects.

Best wishes……..Chongo

This is a great article. would like to repost on landroverforums if you dont mind. I would also like to know what torqing sequence you would recommend as i have my heads off right now. Let me know.

Thanks Chris