I purchased a '66 Electra in June. It has a 401 nailhead. Does anyone know what is the recommended, tried, and proven modern day engine oil to use with this engine? I've heard 10W-40 and 15W-40 Rotella amongst others. I'm CORN-fused!! Also I'm wondering about what spark plugs to use. It appears that the car now has AC Delco R33S plugs. I have a friend with a '65 Electra who has used R34S plugs and was told he could also safely use a "hotter" R35S plug, which he has been doing without any problem. I wonder if the '65 and '66 nailheads are different engines and require different plugs. One a side note: Strange, but I could only remove one plug of four on the driver's side of the engine (didn't even try the other four plugs on passenger's side). Somehow the deep socket wouldn't fit around three of the four plugs, only one of them. A larger socket didn't work either because it was too big in diameter and it hit the wall of the engine when trying to get it around the plug. Never experienced this before. Any help on the above is greatly appreciated.
Hi Bill, Any motor oil will work fine, and since the engine is well broke in, you may not need to throw in some ZDDP. (I would anyway, just because it's cheap insurance) I'd try and avoid heavier oils like 15w-40, or 20w-50, unless you're going to be running the car in a very hot environment. 10W-30 works just fine. Spark plugs; the 65 and the 66 were essentially the same motor. I've used whatever the current number is for the original AC Delco 42 with no problems. And yes, the plug to wall clearance is a bit tight, and you'll need to go and buy a thin-wall socket in order to get them. Cheap sockets won't fit. Been there, done that...
For what it's worth I'm running Royal Purple 10W-40 full synthetic. I had been running regular 10W-30 oil, decided to swtich to synthetic (partly for the added zinc/mineral content) and go to a slightly heavier oil (pressure was too low at hot idle for my liking). Also, I'm running standard NGK plugs. You can look up a multitude of available plugs on the sparkplugs.com website. There's many choices available!
I would use Rotella 10W30. It is hard to find, but my local speed shop orders it for me. 10W40 will do no harm, but it will lower fuel economy a little. Unless you regularly drive the car on long trips in hot (I mean Las Vegas hot) weather, the 10W40 is overkill. I use Rotella 10W30 in my '66 425.
John, et al. I switched to Rotella T6. It's Shell's fully synthetic oil. Must say, I'm very impressed with it.
My favorite is casterol with a dose of zddp.... straight 30 wt.... sparkers--- autolite in the appropriate number....
After lots of oil evaluation on my Ram Air IV GTO I standardized on Castrol SynTEch BLEND (partial synthetic). The engine was rebuilt and I talked to my mechanic about what oil to use in the high winding RA IV...he said to use the syn blend as it was still petroleum based but used the syn to grab and suspend any dirt or contaminants in the new engine. On other engines that are broken in with petroleum based oils, I would be concerned that the syn oil would cause leaks due to the internal cleaning capabilities of the syn oils. By the way...my 84 BMW 733i has 430K miles and I use the Castrol 20W50 syn blend...the engine has never been apart! My 65 Jeep Wagoneer with its OHC 6 cylinder uses Brad Penn oil (green oil) and the solid lifters seem to like that ($$$$) oil. I'll be running Brad Penn 10W30 ZDDP oil in my 65 Riv 425. Plugs? The RA IV Pontiac motor favored the Autolite plugs and didnt like Champions. I dont run import plugs in domestic engines). Same for my 65 Jeep...champions seem to be finicky for my applications. AC Delco plugs are right up there with the Autolites and are usually Made in USA but they tend to cost a bit more...some Autolites are made in China and some are made in Mexico...depending on where you buy them and what plug you purchase. Has anyone here on the thread replaced their old school petroleum based oil with full synthetic? Any leaks? smoother running? results? please advise thanks
Finally decided upon the following: 1. Oil-Rotella T6 100% synthetic....No leaks discovered as of this writing. Happy with it thus far. 2. Plugs- AC Delco R43S if I recall correctly. 3. Filter-Fram....yeah I blew it on this one....gotta get a WIC or whatever it is called. I read the concerns on the blown out Frams. 4. Currently battling timing issues. Car shakes a bit too much at idle and feels like it is off time as I approach 60 MPH. Will play with it this weekend Lord willing. Gotta re-check vacuum and centrifugal advances and mess with carb idle screws...there are two of 'em....I suppose one for fine tuning...other for to get it in the ballpark.
