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| Joined: | 05-01-2005 |
| Location: | Minneapolis, Minnesota USA |
| Posts: | 575 |
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Valve guides seem fine but I do have to measure a bit more. It's .018" clearance right, both intake and exhaust?You're missing a zero in that clearance dimension... it should be 0.0003"-0.0018" (0.008-0.046 mm), both intake & exhaust.
The stem diameter spec is 0.2805"-0.2810" (7.125-7.137 mm), both intake & exhaust.
Do you have a copy of Tech Data Section A (TDA) from the 1983-87 Lotus Esprit manual? IMHO, all 907 owners should have a copy.
discogodfather wrote:
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 prefer to never cut the head unless you need to in order to flatten a warp. Even then, first straighten/ flatten the head as much as possible, and then take only the lightest cut possible, as necessary to flatten the bottom.
(Snip)... Does anyone think decking this thing one more time might get into the valve seats?
Taking the maximum cut for any other purpose (ie, compensating for head gasket thickness) just takes away all future options for dealing with a slightly warped head.
But done is done, and it looks to me like all your 'cut options' were previously used up. Times like this are why I resist ever taking a cut that is not required at the time, or taking a deeper cut than is necessary at any time. Always leave as much thickness available for future use as you can.
I understand wanting to scuff the surface to give it a little tooth (maybe a swipe with a Scotchbrite pad), but I wouldn't acutally "cut" any further.
Regards,
Tim Engel
Last edited on 04-22-2020 03:46 pm by Esprit2