I have a 1968 camaro (non rs,ss, or z28) with a 1969 327 in it thats got a gillion miles on it (ok, maybe more like 170k but it feels like alot) and I use 10w-30 full synthetic as often asI can (only one out of 5 oil changes are not full synthetic). But my problem is that the oil is always filthy after about 1000 miles and the pressure starts to drop to about 40psi and when I'm at 3000 miles it wil drop to 20psi at red lights. When I start the motor and its cold, the pressure is at a strong 60psi but drops as it warms up.

Does this mean I should try to get soething like 10w-20?

What do you guys with the '69 327 use?

By the way, I dont know if this helps but I have a 625 edelbrock carb and headers and a non-stock cam for more torqI believe.

 

10W20 is the wrong direction to go, for a high mileage car like yours 10W40 is more like it. The oil getting dirty just shows that the oil is doing its job (detergent) an collecting the dirt your engine is putting out. Your oil is getting dirty fast and the pressure dropping after 3000 miles is probablybecause a lot of blow by due to worn rings or/and raw fuel getting into the crankcase.

 

Thanks for the help. I was afraid ther there was too much blowby but didnt want to face the reality of changing the rings. Ill check and see if there is a decent 10w-40 synthetic out since I'm going to change my oil this weekend.

Does anyone have any specific oil preference or do most synthetics act the same? I know mine is high-mileage but quite a few oil makers have "high-mileage" oil. What do you guys use and have had success (and failure) with?

 

I use 15W40 Rotella oil in my '69 Big Block. I was told by Compcams that it has special additivesand manganese( for diesel engines and engines with flat tappet cams) that has better lubrication properties and works great in gas engines. I also read somewhere that GM said that it will not warranty any engines that use 10W40 oils(something about that it breaks down too much when hot). There are some special oils out for higher mileage engines you might want to check out. But in any case you need a thicker viscosity oil and not thinner (the higher the number the thicker the oil). I alsohave a '68 Camaro SS350 with a lot of miles on it and I have had good luck with 20W50 in it.

 

also, royal purple products are very good from my experience

 

Thanks for the help guys! I got some fully synthetic high mileage 10w-40 for my last oil change last weekend. Of course, my old oil was blacker than black but at leastI got it changed. I'll try to keep away from the lower numbers as much as possible and is fully synthetic any better or shouldI stick with the basics? I want to give it the best because its all i have to drive for a good while and don't want it breaking on me or seizing up.

 

there really is no "best" oil. there are "better" oils, but best is all preference. the one thing I suggest is that if your car runs kind of rich, or if you smell gas in your oil when you change it, I would suggest staying away from synthetics.

why?

if your oil smells like gas, then you cylinders are getting washed down and you need your changes more frequently because you will cause more damage leaving it in there. if you have this problem and go to a conventional oil, you will save lots of money and you will also be better off in the longrun because you will always have fresher oil and won't be reluctant to change it because of the synthetic's cost.

this might sound a little strange to you but it is a pretty common occurence. I have had many people stay away from synthetic for just this reason. I actually stay away from synthetics in carbed engines.synthetic isn't going to help better if you end up with gas in your oil

 

I don't smell gas in the oil, its just pitch black from the blowby and I just dont have the money to tear the engine down. =(