Correct AF880 head gasket

[miked]

I have two head gaskets with the same AF880 part number but they are different. One is what I am used to and the other is different. The oil way/head bolt hole near the front sticks out into the letter box cork gasket area in an elongated shape. Also there are missing water way holes and ones reduced in size. Can any one shed any light. Have Payen put the wrong gasket in the packet? Last photo is the odd ball one. The other one shows a conventional one. I don't want to use it. Do we recognise from another engine block? Any help appreciated.

Mike

[promotor]

Hi Mike,

Some late Xflow blocks are designed without as many holes on the face (including the hole that you show in the picture) even though there are relevant cooling holes in the head. The cooling is blocked off by the block not being machined so the head gasket doesn't need it. However, there are also some xflow blocks that do have that hole among other extra ones.

All Lotus and pre xflow blocks have the extra holes in the block. I believe less holes were machined to aid cooling in the crossflow blocks by making the water circulate better to certain areas - by having less choice where it could go - as cylinder number three could overheat due to cooling not being sufficient due to it simply passing-by certain areas. Cooling holes in some head gaskets were also made smaller.

Obviously a T/C head wants to be cooled through this part due to it having all the holes and as far as I know wasn't ever re-designed without it at any time so as you say fit the extra-holed one.

[promotor]

Is the gasket without the hole definitely a Payen one as it could be a re-production?

The copper gasket I have is in a Payen package and has the hole. The gasket is stamped with AF880 on the non-copper side.

[Hawksfield]

Mike

Use the first photographed one that is the normal one for a twincam

How did you purchase these gaskets that may give clue to what the oddball one is for?

Have a look on ebay at head gaskets for a twincam that will show a normal gasket

[rgh0]

The cooling flow in the twin cam head is from the inlet side to the exhaust side where the thermostat outlet is located. In the Ford heads its is from the rear to the front where the thermostat is located. I would expect the twin cam gaskets versus the ford gaskets to be different to achieve that different flow pattern.

Can you post a photo of all the holes in the two gaskets you have and i can comment further

regards
Rohan

[miked]

Guys, I am out at present. Thanks for replies. Both gaskets show proper manufacturer markings and are from 2 of my favourite and reputable suppliers. I had two of the good ones so was able to carry on with my job and not use the suspect one. I am in dialog with the supplier of the wrong one. They have acknowledged this is wrong and are sending out a fresh one. They are also in communication with the main supplier as all packaging and numbers are showing correct. I will update when I get an answer but would be aware even with the correct numbers.
Rohan I will photo when I get home. Thanks Mike