39 replies to this topic

[Leonrjohnson]

The point of dry decking isn't to stop the head gasket failing, it's to reduce risk through coolant losses or hydraulically locking the engine and to better control cooling the head. The amount of the oil going through the head and the viscosity means it won't bother the engine during a head gasket failure.

Dry decking stops combustion gases leaking into the cooling system in the event of blown head gasket, and also stops coolant leaking into the bores and then into the gearbox(sump). The only oil flowing through the head is that which feeds the rockers, and that hole isnt blocked off. The chances of this oil leaking into a cylinder is unheard of. Dry decking offers constant  coolant temperature throughout the head and block, thus eliminating local area overheating. If a head gasket blows, it will only allow combustion gases to escape either between cylinders, or out of the engine itself.No mess when changing gasket!!!!!!!!!!! Works great for me on my 970!   

[Captain Mainwaring]

The point of dry decking isn't to stop the head gasket failing, it's to reduce risk through coolant losses or hydraulically locking the engine and to better control cooling the head. The amount of the oil going through the head and the viscosity means it won't bother the engine during a head gasket failure.

 

Are you telling me the head has no water in it then?  The head water ways still face the gasket and the now blind block face - why can't they leak to an oilway or a bore?

[Captain Mainwaring]

 

The point of dry decking isn't to stop the head gasket failing, it's to reduce risk through coolant losses or hydraulically locking the engine and to better control cooling the head. The amount of the oil going through the head and the viscosity means it won't bother the engine during a head gasket failure.

Dry decking stops combustion gases leaking into the cooling system in the event of blown head gasket, and also stops coolant leaking into the bores and then into the gearbox(sump). The only oil flowing through the head is that which feeds the rockers, and that hole isnt blocked off. The chances of this oil leaking into a cylinder is unheard of. Dry decking offers constant  coolant temperature throughout the head and block, thus eliminating local area overheating. If a head gasket blows, it will only allow combustion gases to escape either between cylinders, or out of the engine itself.No mess when changing gasket!!!!!!!!!!! Works great for me on my 970!   

 

 

 

I'd say coolant temp may be better regulated, but as for constant? Maybe not

[Leonrjohnson]

 

The point of dry decking isn't to stop the head gasket failing, it's to reduce risk through coolant losses or hydraulically locking the engine and to better control cooling the head. The amount of the oil going through the head and the viscosity means it won't bother the engine during a head gasket failure.

 

Are you telling me the head has no water in it then?  The head water ways still face the gasket and the now blind block face - why can't they leak to an oilway or a bore?

 

Of course the head has water in it. The water holes in both head and block are plugged, and the water goes through the block, out the rear outlet, into the rear inlet on the back of the head, then out the thermostat housing back into the radiator.The oil feed hole  from the block to the head for the rockers ISNT BLOCKED! Have a look at my photos and you will see all the water holes are plugged .

[Captain Mainwaring]

 

Should have checked age of thread. Had been up all night working and was a bit dazed when I responded. All my plugs are just threaded bar, screwed in tight and sealed with high temp epoxy.
I've only sealed the block.

 

 

Would that not be a bit of a wasted effort? Surely the gasket can still fail between head waterways and an oilway or a bore?

 

 

^^^^^^^

 

Sorry, I thought he said he only sealed the block.

 

There are also pictures in this thread showing air bleed holes - if the head is sealed, just where do these air bleed holes vent to?

[Captain Mainwaring]

 

 

The point of dry decking isn't to stop the head gasket failing, it's to reduce risk through coolant losses or hydraulically locking the engine and to better control cooling the head. The amount of the oil going through the head and the viscosity means it won't bother the engine during a head gasket failure.

 

Are you telling me the head has no water in it then?  The head water ways still face the gasket and the now blind block face - why can't they leak to an oilway or a bore?

 

Of course the head has water in it. The water holes in both head and block are plugged, and the water goes through the block, out the rear outlet, into the rear inlet on the back of the head, then out the thermostat housing back into the radiator.The oil feed hole  from the block to the head for the rockers ISNT BLOCKED! Have a look at my photos and you will see all the water holes are plugged .

 

 

 

Yours may well be, but not everyone is drydecking in the same way, thus my question.

 

I can understand a full dry deck, but unless the head is blocked and there are no airvent holes, I can't see what benefit it would give.

[jakejakejake1]

The benefits aren't limited to preventing head gasket failures, or water mixing after a failure, its to help keep all the cylinders the same temperature by forcing the water to flow past number 4, which is notorious for getting quite hot if the cooling system isn't up to scratch.

The fact that it also stops you leaking coolant in the event of a head gasket failure is the icing on the cake, but not the reason you do it.

[HUBBA.HUBBA]

the idea isnt to pass fluid equaly between cylinder (of a sort) its because all the take off's for the cooling system are at one end of the block..as you know. its not a flow problem its that at the end of the block the water stays more stagnent, giving the water remaining around that cylinder will have more time to heat up. and of course more chance of hot spot in the cylinder...the dry deck for those who doesnt know just means water HAS to flow along the block past 4, into the pipe, into the head at 4 and out the outlet past 1
its not a mahoosive job, for piece of mind i would go ahead and dry deck it. im not convinced that restricting would be the way to go

Out of interest when you say 'out the out let past 1', what outlet?

[HUBBA.HUBBA]

I have dry decked an AEG163 as well as a 12G940 with no trouble. Fitted a blanking sleeve in place of a thermostat in both of them, and blanked off the bypass in both head and water pump. Works a treat.

How does the water 'flow' with it like that?

[JimmyB]

http://www.minispare...ing sleeve.aspx