Last summer I dropped an HEI that I had, in place of the old points distributor in my motorhome, BBC 402. Seemed to run great but ran significantly hotter than before. I had 14 degrees of initial adn about another 16-18 of mechanical for 30-32, total. So out of curiosity before I left for this weekend I dropped the old points distributor back in set a 14 initial. Took it out, cool as a cucumber. Oops, forgot to check advance, pulled the engine cover..... zero, mechanical advance. So why is it running hot with 30-ish degrees of total with the HEI and cool with 14 degrees total with the points. Bass ackwards of the way I had always though..

Inquiring minds want to know....

Cam

Usually will run hotter retarded.

MmmHmm.. and that is what I have heard and expected. Now tell me why it runs cooler with 14 degrees of initial and zero mecanical advance (stuck weights) than it does with the HEI with 14 initial and another 16 mechanical. Is it because, do you suppose, that at cruise, the vacuum advance is providing the advance needed to get it to 30 something???

Does this look like a motorhome forum? J/K. The vacuum advance thing was what I was thinking but you would think that lugging a motorhome around you'd have your foot in it a lot and negate the vacuum advance. Unless it does cruise easily and thats when it heats up.