Do you mean the gasoline engine does not have a head gasket but rather
rubber seals to hold in combustion? I guess I am way too ignorant about this
engine, but I thought all engines need a head gasket.

Entity Walter E Stephens spoke thus:

>> It is not your nut that is leaking but the head gasket. No pressure should
>> be coming up through the head bolt holes.
>
> What gasket do you refer to when you say head gasket?  The aluminum head
> sealing rings are not the problem.  The cylinder bores are still dry.  The
> formed rubber gasket is at least 1/2 inch from the problem area, and was
> just replaced.  The coolant is definetly coming out from under the #3
> cylinder upper rear nut.  I can watch the coolant drip out, at about 2
> oz/min with no pressure on the cooling system other than 2-4 inches of head
> at most from the expansion tank cap open and the engine not runing.  It
> amazes me that it can leak so much and I can not find the reason.