Conventional or Synthetic on my rebuilt 63 225? I'm planning on using Comp Cams moly break-in additive to get her going. I had purchased a 5qt. Pennzoil 5W30, then started thinking maybe I should take the opportunity to go Synthetic....maybe?

Are there any real pros to Synthetic beyond a longer OCI and possibly fewer deposits in the engine over time?

I've already pored over the countless posts about it, but even after reading all of that, I don't know the pros of Conv. v Syn.

My 63 will become my 'daily', but 'daily' might actually be a bit of an overstatement, considering I work from home.

Thanks!

Some more thoughts to consider.....

Your going to get lots of opinions.....and more reading. I will keep it short.

I learned about synthetic oil while going to college. It has a longer chain molecule (bigger blob) and does not easily break down thus providing protection over a longer period of time. I have used it for the last 40 years and my engines all last much longer than most. I run Mobile 1, 15-50W since it has extra high zinc content in my old shot stock SL6 engine with over 275,000 miles. Since you have a new rebuild you can go much lighter weight as long as there is enough zinc for your flat tappet cam. That is a problem with either oil (Dino or syn)......lower zinc content. That is the only thing I would look for....I did run as low as 800 ppm zinc, but the cam did wear in my good engine...It would be nice to stay above 1200 ppm.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Grey bottle Rotella 10-30 semi synthetic diesel oil. $16 a gallon, lots of clean, plenty zinc.

If it was an everyday driver? Maybe full synthetic diesel oil of any brand. Wallyworld coast to coast!

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

http://board.moparts.org/ubbthreads/sho ... age=0&vc=1

The latest oil thread at Moparts.

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

Mobil Super High Mileage 10W-30

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1964 Dart GT

Whatever 10-30 is on sale. Unless you are running an agressive cam, and high spring pressures, combined with above average RPM, why spend the money on exotic oils. Once the engine is broken in, I don't think they are necessary. The cam that is in my Barracuda has been run since 1978, but it is a mild cam.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Initial break-in (assuming you have new rings, cam/lifters) just run a straight 30w with a break-in additive (lucas,comp cams, or equivilant) or a good quality break-in oil.

After about 3000 miles or so after you know everything is broke in and seated up nice then you can switch to synthetics... Personally running Royal Purple HPS 10/40 now, was running Valvoline VR1 40wt for the break-in. I am beyond 100% satisfied with my results, have great compression, engine runs extremely quiet and cool, no oil burning, and havent had to touch the valve lash since the rebuild...

Synthetics are the way to go IMO, I have tested conv vs synth on a previous car I owned, (had an in-dash read out that showed coolant temp, oil temp, and oil pressure) and I noticed huge improvements in oil life, oil temps, and over-all performance. My cars get driven VERY HARD and using a high quality oil be it synthetic or conventional is worth the investment... Keep in mind while our slants are not considered high-revving or high-performance we still run mechanical cam and lifters that require the extra protection from performance oils... You never be too protected

I switched the oil in my Lincoln from some unknown dino oil to 5W-30 synthetic and picked up a solid 2 MPG. Whatever you run, start with 5W-30 and go lighter (make sure whatever oil you buy has the API starburst logo). I like synthetic oils but they are pricy. Just as important is the oil filter you run. Run Wix, Purolator PureOne, or Napa Gold if possible.

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Casually looking for a Clifford hyperpak intake for cheap.

That is something I didnt even think to add in there was the importance of the filter, thanks Reed. It is probably a little more important to use a good quality filter than a pricey synthestic oil, I have seen some unbelievable damage done to an engine because a cheap filter was used and had failed...

Interestingly I ran a mild 245 Hemi engine on a dyno years ago. We tried a variety of manifolds,carbs and pipes,including a lynx ( hyperpac) style intake with a plenum divider. The engine was around 220 hp,mild hyd cam,daily driver. Just for kicks we then ran it with synthetic oil. Same day,same combo,same temps........the power difference? 2 hp A one percent gain.I wouldn't go synthetic expecting a noticeable performance gain as such,as for added protection? Go with your own feelings,really you can't go wrong. Personally,with a carb engine and oil dilution and combustion by products I go conventional oils and change the oil and filters regularly.