Synthetic oil in 200?

[67chrrybucket]

Im sure this question has been asked a dozen times but i hear conflicting stories i wanted to run royal purple hps in my SC 200ci royal purple says its fine but my oil reps (from valvoline) say you cant use synthetic oil in older than 81 engines so if anybody knows for sure i would like to know also if i cant use synthetic whats a good break in oil? And whats a good viscosity to run in a SC engine?

 

[wsa111]

Need more information on your engine.
Has it freshly bored?? If so what type of rings are you using. Cast iron, plasma moly?
What grit did the machine shop hone your cylinder walls.
I run Brad Penn racing oil, its a synthetic blend 10w-30 & has all the necessary additives for flat lifter cams.The regular royal purple i don't believe has all the anti scuffing additives. Now royal purple racing oil does.
To run full synthetic you need to tighten up on all your bearing clearances & only use after a 3000-5000 mile breakin. Bill

 

[67chrrybucket]

it is going to be bored soon .020 over plasma moly rings hopefully forged pistons hydraulic cam and a eaton m90 supercharger

 

[JackFish]

I would not use synthetic for break-in, but certainly after a couple hundred or thousand miles.
I am running Redline. I expect to run this out to 10,000km.

 

[Route--66--]

Hi 67
I've read a bit on this topic and the main reasons against synthetic are that they contain detergents, which, if you've got an engine that's been running for years on non detergent oils, would cause loads of gunk to get dislodged and plug up oil-ways.
If you're rebuilding tho this won't be an issue.
Another issue was synth tends to find any weaknesses in old gaskets, again, assume you'll have all new so no probs.
Last main thing, as WSA says, for flat lifters you're supposed to have ZDDP in the oil, which modern synths don't, otherwise it wears cams / lifters..
.. but I'm certainly no expert - but there are a few articles on zddp and cam break-in try this
http://forums.vintage-mustang.com/general-discussion-non-vintage-mustang/627152-todays-oil-zddp.html

I run 20/50 (n the temperate UK) with zddp

CHeers!
D

 

[rbohm]

8) still some disinformation in these posts. here is the reality. you can run synthetic oil in ANY engine. there can be issues though;

1: while synthetic oil contains no more detergents than mineral oil does, synthetic oil is more agressive at cleaning out deposit build up in an engine which can lead to oil leaks. however if you have an issue with oil leaks, it is because the leak was already there, but was plugged with deposits.

2: there is no need to tighten up bearing or ring clearances to run a synthetic oil. the manufacturers have done this in modern engines to run a lighter oil for better fuel economy and longer engine life before an overhaul is needed.

3: a synthetic oil will run cooler than a mineral oil, about 10-20 degrees cooler

4: you can interchange mineral oils and synthetic oils, and you can swap back and forth between the oils also. remember that a semi synthetic oil is just a blend of mineral and full synthetic oils.

i will say this, i would not use royal purple oil unless i was going racing, it is far too expensive to run on the street. pennzoil, valvoline, quaker state, and castrol all have excellent synthetic oils that you wont be paying an arm and a leg for each time you change your oil.

 

[67chrrybucket]

the biggest reason i was thinking royal purple was because of the supercharger and royal purples ability to prevent thermal breakdown

 

[thesameguy]

for flat lifters you're supposed to have ZDDP in the oil, which modern synths don't, otherwise it wears cams / lifters..

Many synthetic oils don't have or don't have enough zinc, but OTOH many of them do. There's a thread around here somewhere on that, but Mobil 1 High Mileage and Motul 6100 Synergie+ - both in 10w40 - have very high levels of zinc. You just have to do a little research in selecting your oil. I believe RP is one of the synthetics that uses relatively high levels of zinc, FWIW, but it may vary by weight and formula. IIRC their 10w-40 API-rated oil is one of the ones that does.

I did a lot of research on this, as I was trying to find one oil I could use in most everything I own. I have a lot of turbo cars and a lot of older cars and a lot of older turbo cars so high zinc is a requirement for me.