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| Joined: | 09-17-2007 |
| Location: | San Francisco, California USA |
| Posts: | 221 |
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Turns out, after calling Barry Spencer, that it has a Dave Bean Cam called a DB3. It has 420 lift, 290 duration, and 104 MOP. Somewhat hotter than a actual Lotus 104 grind.
I called Dave Bean and they couldn't give me the opening and closing degrees, which was a little odd. They did seem to suggest I could use a 104's timing info from Lotus. Tim Engel generously provided much of the information on that.
The head looks great, dead flat, head gasket was ok (I came to the conclusion there was water in the oil reading the dipstick, but it turned out to be just a little water in the actual dipstick tube.
The head seems to have had some nice porting work, nothing crazy but well done. Valve guides seem fine but I do have to measure a bit more. It's .018" clearance right, both intake and exhaust?
Valve seats look ok but worn, looks like a 3 angle valve job that has a deep throat on both ends. Valves themselves look good, one intake had a little roughness. Plan is to lap and then vacuum check it. If it passes I will put it together, if it fails I will have to cut some new seats. A friend has some Newall stuff and I think I can borrow it.
Question: I usually always skim the deck just to have a nice surface, even if it's just a .001" cut. I noticed how close my valve seats are the edge of the deck, almost zero clearance.
I think this head was decked very close to the chamber in order to get some of the compression lost back when using the thicker newer head gaskets. Does anyone think decking this thing one more time might get into the valve seats? Is that bad for the head gasket? I feel like just a .001-..002" cut would probably have the edge of the seat at the deck height.
Last edited on 04-19-2020 12:53 pm by discogodfather