Radiators and cooling

[billwill]

I'm just in the process of doing a head-off de-coke, prompted by the fact that water is somehow getting into my oil!

But looking at the new head gasket, I observer that, just like all former ones that I recall, the waterflow is restricted by the gasket having only tiny holes over 4 of the water transfer holes (from block to head) I notice too that these are restricting flow, just where I would have expected MORE water flow to be required, i.e on the exhaust side of the block.

Does any one know WHY this is done? should we open up these holes to give more water flow?

[rgh0]

This gasket with the restricted holes is the orginal Lotus design compared to the Ford gaskets which had larger holes in the same location.

The intention of the Lotus design is to ensure that the flow is across the head from the inlet to exhaust side and then out the thermostat housing. Lotus were obviously concerned that without the restriction flow could bypass the inlet side of the head leading to overheating in that area.

The small holes ensure you still get some flow around the exhaust side of the cylinder bores and that this area is not totally bypassed with the flow mainly entering the head via the inlet side

However lots of people have run the Ford gasket over the years without apparent problems so it does not appear to be all that critical in normal use.

regards
Rohan

[chequeredflagracingjoe]

Hi All I have made for me Alloy radiators for the Spitfires. We have been using them in our race cars with great results. They are 2 rows of 1 inch tube that is fully welded. It would be easy to adapt for the Lotus as they are custom made for me. The inlet and outlet pipes are 1 1/4 they can be made much cheaper than others I have seen approx 395.00 + shipping. I will ship anywhere.
Thanks Joe

[billwill]

Pah! it looks as if all my effort changing the head gasket has not fixed the water leak problem. So I guess I have either got:

1. A warped head
2. A crack in the head or block, that I did not spot.

Any one else got any other ideas?

Symptoms:
a)Water vanishes
b)The water system seems to get a positive pressure, shortly after starting, long before the water is hot.
c)Water was getting in the oil, but I might have fixed that.
d) white smoke from the exhaust (possibly steam)
e) Piston 2 had remarkably little carbon on it and a few drops of water, but that water might have been minor spillage as I lifted the head.



Someone mentioned a head gasket of a new material not Copper/Tin & asbestos(?).

What material is it and where can I get one?

[steveww]

I got a composite head gasket from QED.

[rgh0]

Bill
I think your diagnosis of possible problems is correct.

When you pull the head next time get it pressure tested to verify whther it has any leaks or not. I find the modern composite gaskets that I use seal better. Measure the head for flatness, ideally it should have less than 2 thou out of flat but I find up to 5 thou can be accomodated by the gasket OK.

What bore block do you have and has it been linered. You could have a split bore low down in no2 that is hard to see as it is mainly below the piston crown even when the piston is at bottom dead centre.


good luck finding the leak

cheers
Rohan

[billwill]

Today, I definitely confirmed that water is still getting into Cyl 2 and still getting into the oil. Bang goes the cost of a whole can of oil, that I put in the other day. The Cam box now has WHITE oil in it.

I did a compression test & got 165 psi in cyls 1,3,4 and 160 psi in cyl 2. so you may be right about a crack low down. There are liners, though. I've not got enough bits together to do a leakage test (which of course with effort one can do twice, with the piston at top and at bottom of the stroke).

I think the most likely thing is that the head has warped slightly as a result of the water pump seal failing late last year and me not realising where the water was dripping out (see my other topic) This sometimes resulted in me not realising that I was losing coolant until the heater went COLD, a dangerously low condition. I fixed the water pump, but it looks as if I was too late to prevent head warp.

SO FOLKS be aware that leaking water pumps can do LOTS of damage.

Though I could try a composite head gasket, there's no guarantee that would work, so... This kind of repair is beyond my personal resources, I think, so I'll most likely get Vegantune to do a complete engine over haul, again... When I can get enough money together.