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| Joined: | 06-11-2009 |
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Why I hear you ask. Because I just want to know due to my crank girdle strengthening plate/ sump pan that I am designing for my 907 race engine. ( it's a dry sump conversion). It's a 2.2 stroker with cross drilled crank running fully dowled main girdle align honed and running tri metal bearings from Gary Kemp. But I am about to undertake an upgrade of the bottom end to convert it to 318 Chrysler main bearings as this gives me much greater selection of main bearing brands and thicknesses. What I have found is that there are two year groups of 318 bearings. Pre 74 and Post 74. For those who have undertaken the 318 bearing conversion which era bearing did you use? Also did anyone open or close up the tolerances of the main bearings to that of the original lotus spec to account for the block expansion that takes place in a race engine. Did anyone change to a different oil grade as a result.
For information 75 model block. My lotus engine has been designed to rev. With a very expensive new CNC ported big valve head to be installed as part of this gen 2 upgrade.
At gen 1 upgrade it got the fully dowled block, new liners, a talbot sunbeam works ported head with 1mm oversize inlets and exhaust valves. All head parts by Gary Kemp. Pistons by Gary, light weight rods by Gary. high lift Gary special 104 cams. Match ported inlet, and Tony Law tuned sand formed exhaust headers. Mechanical belt tensioner on HTD belt with vernier Cam pulleys. Stage two is all about the bottom end strengthening as well as the new CNC big port/ valve head. Oh and the three stage dry sump system. Why? Accusump worked fine everywhere with trapped doored wet sump with windage trays.......except at Philip Island on the Southern Loop! Did I mention the spun bearing and new crank as a result!