I have a '79 RX7 that has been abused pretty bad. Usually a little puff of smoke when it started, then cleared up an ran good.
Changed oil and filter, and since it's summer, used 20W50 (Havoline, the cheapest...) Now it smokes BAD whenever accelerating over 3500 rpm.
Is this just the oil, or is the engine ready to die?

Any help is appreciated.

 

Sounds like the rotor seals are biting the dust, the oil control rings on the side of the rotors im refering to. Is it oil smoke , what color is it?

 

It's grey (smells like burned oil). Will lighter oil help at all?

 

I would ATF or MMO your engine as soon as possible, to see if it might help clean any carbon that might be causing your seals to not perform right. Hopefully, it will make a noticeable difference as it has in mine. Do a search to find out how, if you are unfamiliar with what I am talking about. As far as oil choices, I believe I am running 20W50 Valvoline Maxlife oil in my '80 and am having no problems with leaking, puffing smoke, or other such errata.

Remember.... Search ATF.

Good luck,
James

 

Lighter oil will make it worse probally... See lighter it is, the easier it is to pass trhrough the bad seals from the rotors to the combustion chamber

 

true, but its odd that it happened after he changed.