Mopar Muscle Association UK

is it ok to use synthetic oil in our type of engine?
the grade i am considering using is 15/50 and has a jaso/ ma rating, or is it the kiss of death in these motors, i have seen some motorcycle engines glaze the bores cos of using it, an dont want this to happen to me, thanks trev.

I never use synth in them, just good quality 15/40 changed regular works fine for me never had a problem or sludging to this day.

I use semi synthetic Castrol Magnatec for basic engines and have had no problems.

gonna go to halfords tomorrow an see whats on offer, i can get oil from work for nowt, but it's all 10/40 except the fully synth, i like the sound of the magnatec it's supposed to stick to the motor parts or something is that right kev?
alex what brand do you use?

Paul Worrow was chasing a Cossie in his Charger and lost his sump bolt. He swears the Magnatec saved his lump.

Shell......

I used semi synthetic in the 360 motor in the Sox, but that was a brand new lump - I do not think I would have done so in an older engine.

Magnatec.
But the heavier of the two versions you can get.

I lost all oil pressure on the strip at the Nats. No sign of damage yet but I have yet to inspect the main bearings.

Valvolene 15/40 mineral oil. Have used 20/50 before but not for long periods (the lifters don't seem to like it).

Either should be OK, just don't break in a new engine on synthetic if you want to go that route - start with mineral oil, get the rings seated and cam broken in, and then change to synthetic.

Frequent oil changes seem to be a key ingredient of making oil work for you. It would be an interesting question, for the SAME amount of money, which is better (i.e cheaper mineral but more frequent changes, more expensive syntehtic but less frequent changes). Don't know the answer.....

With synthetic can't you just filter it and re-use it?

I know synthetic is definately the oil of choice on the 4s as it stays on the parts when not running (much better for the Turbo).

well, went for the 15/40 magnatec, bloomin pricey though! still, havent paid for oil in ages so can't complain really, got me filta from local shop, fram job cost less than a fiver, when i think of how much they pay for bike filters at work, ?9.50 an there tiny also put in me new hot u denso plugs, just need dave robson to come round an dial in the timing tweek the carb and that's me happy in the motor dept for now

Nothing wrong with the good old traditional oil in our age and technology engines, alot cheaper aswel. Your free stuff would probably work fine if the correct grade. I find changing at the right intervals is the important bit.

Well I had a quick look at Trevs engine this morning. BTW the car is looking very sexy with it's new wider meats on the wheels. 8)

I checked the timing. 12 degrees initial and 35 total all in under 3000rpm. Not worth touching it.

The idle mixture I set for max vacuum in gear. While doing this I came to the conclusion that the 383 has a longer than stock duration cam installed.

Max manifold vacuum is 15" in gear. With the throttle blades closed not quite enough (still a tiny amount of vacuum on the dizzy port) the neutral idle speed was only 750rpm. This suggests that it needs more air in it at idle (it needs to be at least 800rpm) which is typical of longer duration cams.

Also when you put it into "Drive" the idle speed drops down to around 600rpm. Again suggesting to me that the cam is a longer than stock duration and the car could do with a slightly higher than stock stall speed torque converter.

Trev could easily live with the car like this. It is close enough unless you are a fanny like me.

It looks and sounds lovely.

hi dave, thanks for giving up your saturday morning, i am pleased that evrything is in order with the igniton timing, and the carb idle settings, it was interesting to see where the vacuum guage came into play, while trimming the air screws, i can live with the slightly lower idle setting no problem, roll on the better weather eh!
also dave i am going to try and get in touch with the previous owner states side, and try to find out more info about the specs of motor internals.