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| Joined: | 05-01-2005 |
| Location: | Minneapolis, Minnesota USA |
| Posts: | 575 |
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On top of the cylinder head, where the cam carriers go, at the front, there are two roll pin/ dowels sticking up. One per cam carrier. They are both the oil transfer tubes, and dowel pins that locate the cam carriers.
When the gaskets are eliminated, a rubber O-ring is installed over each of those roll pin/ dowels. But the top of the head is flat, so the O-ring just sits on top. It would get crushed if an 'old' flat-bottom cam carrier was bolted on.
A 31/64" diameter counterbore needs to be cut 0.050" deep into the bottom of each cam carrier, concentric with the oil passage that mates with the head's roll pin/ dowels.
That gives the O-rings someplace to go. But it's a snug 'squish' fit in order to form a good seal with the O-ring.
O-rings should not be installed dry. In this case, instead of oil, I prefer to rub on a thin smear of Hylomar AF (Advanced Forumla). Plain old Hylomar Universal Blue will work. AF just has a longer working time, so it's easier to use.
As I told Tim in a PM, when installing the cam carriers, do NOT use the torque spec given in the J-H Workshop Manual... it's too high, and you risk stripping the aluminum threads in the head (ie, pulling the studs out). Instead, use the Lotus torque spec: 14-16 Lbs-ft with clean dry threads.
Regards,
Tim Engel