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| Joined: | 03-14-2005 |
| Location: | Atlanta, Georgia USA |
| Posts: | 406 |
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Garry Kemp is THE man when it comes to developing high HP 9xx series Lotus engines. About 10 years ago Garry showed me a 907 dry-sump casting he had developed, and I've been sold on his wisdom ever since.
If I understand correctly, oil starvation to the mains is the problem and you are running a wet-sump oiling system with all the usual modifications?
One possible cause of your problems could be presurization of the crankcase, and pooling of oil in the head at those higher RPMs. Also, your oil pump could be cavitating at the higher revs. A dry-sump system may be the solution.
For a strapping plate, consider milling off roughly 10mm from the lower bearing panel and replacing it with a one-piece steel section. A medium carbon Cold-Rolled-Steel should be sufficient or you could use 304 Stainless Steel.
The key is to use a grade of steel that is fairly rigid but easy to machine. The lower panel itself would make a great template for your machinist.
There is a firm here in the States that makes the 'top plates' or 'block protector plates'. Their process is to loosely fit the plate between the liners and block, then tig-weld it into place. The block is then 'decked' and the liners are honed.
Whatever you decide to do, please let us know and post some pictures.