Pennzoil, straight 30 weight in cold months, straight 40 in summer.

Probably as important, if not more important, the frequency in which you change, and if you change the filter. I've been using the above combo and Fram, yes Fram oil filters (hold the flames please) but change both oil and filter every 40 hours maximum. :D

Keith, any reason on those weights? Also why straight? I use Quicksliver(Merc) 25w40, but its a stock 502mpi. Would you use those weights with higher horsepower applications?

Speaking of Fram. All the hype I have seen has been about the other models Fram has, I have never seen an article on Fram racing filters(HP4 and the rest). Also I believe the editor(i think) from Fam. and Perf mag said that only Merc and Fram filters dont have any flow back, meaning that their is oil trapped in the filter(good when you start up;) ) He is supposed to have a article published soon on oil filters, I guess we will find an answer then.

Over the years where I lived on Lake Michigan, I have usually seen guys run straight weight oils (usually Valvoline) in many these offshore boat engines. One in particular in 1985 a close friend of mine had a 30' Welcraft with a pair of 330's that we modified with larger valves w/bronze guides, roller rocker arms, bigger cams and headers. I usually maintained the engines for him. They probably made about 450-475hp each. We did NOT have any oil coolers on the engines---again, NO OIL COOLERS!....and at the time and we ran that straight 40wt Valvoline mineral based oil and we must have put close to 600 hours on those engines until he sold the boat in 1993. We usually had at least 3-4 people aboard and constantly cruised the boat at about 3700-4200rpm. We should have been using oil coolers, but we were young and dumb then, they were more of a luxury item at the time, and were extremely expensive. We just always made sure we stayed on top of oil changes and we never had any problems with the engines. That oil had to be running pretty HOT without any coolers-----not a bad testamonial. I think that's why I have always used a straight weight mineral based oil and that I'm not too quick to change to synthetics or multi-weight/viscosity oils and not that they don't work well or maybe even better than a straight weight----but I know by experience what a straight weight oil has done for me and my friend over the years.

These days, because I have oil thermostats and very large oil coolers, I will start using the straight 30wt mineral based oil as long as the air/water temps are cold as well in my 540 cubic inch engines from the time I start water testing the boat (end of April/begining of May) until about mid/end of June or when it really starts getting hot/humid out and the switch to a straight 40wt as "Keith" says he does. Only difference is that I use/prefer Valvoline. I was acutally thinking of doing this starting in the spring prior to this thread/conversation anyway. I think it's a good idea for the area/climate I live in. I prefer not to use a multi wt/viscosity oil----probably because of what I have seen work and I have experienced in the past.

I'm sure there are others here who perhaps have a testamonial about the oil they use when it comes to synthetics or multil-weight/viscosity oils that have worked well for them over the years too. I just know what has worked well for me in my climate.

????
 

Myself, and almost everyone else I know runs Roller lifters with synthetic oil. If you run a solid roller, the only time the wheel could slip is on the base of the cam (when you have valve lash). I've run solid rollers in my SBC with almost 400 hrs & synthetic........Not a single issue. Everything looked really good at the freshen up. In fact, I sold the used lifters to a marine mechanic to use in a street truck.

I would suggest this though.....with any solid roller, run a rev kit (springs set up between the head & the lifter) if there is one avaialble for your set up. This ensure's that the roller will aways be contacting the lobe.

Just my experience / opinion

Reading Kaama's post I forgot to mention that I had no engine oil coolers either, and used to run 5800-6200 RPMs. Anyone I've been with knows I ran them either on, or off all the time.

In fact, the upper halves of the drived would even turn white (even with drive showers).

A pro of synthetic oil most don't realize is that it has a much wider operating temperature range than mineral. We all know about the high end, but synthetic also flows better at lower temperatures than straight mineral oil. As for the roller lifters sliding I think Ratchet has hit the nail on the head, probably happens mainly on the heel of the cam during valve lash or zero lift. If the lifters are slightly sliding what is it going to hurt? The slippery oil is between the cam lobe and the roller which means very little friction, and heat. I would guess if the roller slides on the cam, it is only slipping a very small percentage which shouldn't hurt anything on hydraulic or solid lifters. Like stated earlier GM recommends synthetic oil in their roller cammed LS1 motors, so it must not be that big of an issue. :) I run synthetic oil because it is supposed to be the best as far as handling high bearing loads that may occur if detonation sets in. It may be the difference between a holed piston which is easy or a spun bearing or broken rod. Lets hope that never happens, but the price of synthetic makes me feel there is a little more of a chance if it does. Just my opinion as usual.;)

Seems like I have often wondered about that as well. I wouldn't think it would make a difference in a boat engine either, but Dave Crower even told a local engine builder here not to use synthetic oils with an engine using roller lifters.

Ratchet, I hear what you're saying, but isn't it pretty much a known fact that small block chevy's don't seem to have the problems with solid roller cams that the BBC's do? I've been told that solid roller cams in the SBC don't have near the problems because of design as compared to a BBC. Just a thought.

Wette Vette, how often do you change your synthetic oil in your boat engine?

I change the oil in my motor every spring. Same with the drive. Has anyone heard of a motor failing because of the oil being of the incorrect type or weight? (assuming motor oil is being used) I haven't. As long as the motor is built right it really is like splitting hairs when it comes to the motor oil. I think it comes down to doing what you feel is right.:cool: Another one of those opinion things. Did Crower say what would happen to the cam or lifter if it does slide? Just curious.

Craig,

Apparently it causes premature lifter failure. Supposedly the roller bearings don't wear properly when using the synthetics. You're right sometimes it's like splitting hairs. I would probably use a synthetic, but fact or myth, that lifter issue has me concerned. I also usually like to change my oil more like 3 times or so per year. I seemed to get a little gas in my oil and condesation builds up too. It probably shouldn't do this because I have 212* oil thermostats. Perhaps I may go to a lighter weight oil---like straight 30wt. I have some pretty large oil coolers. I'm running about 160* water temps and about 190-200* oil temps at cruising speeds and about 220-230* temps @4000+rpm.

lately, ive been using kendal straight 40,
a guy i know claimed he was using amsoil
in a hp500efi, and gained 150 rpm top end,
so i called amsoil, told them the application,
they advised 25w40 marine/diesel, so i
order 5 gallons, next day i get my, i believe,
july 2002 PBM, and i read about the above
mentioned lifter sliding.
if the lifters are indeed sliding, due to the
superior lubrication properties of synthetic's
is that a problem ?, flat tappets slide on the
cam.
i would be more worried about the lifter
not "wheeling" up the cam lobe, which, i
would think, would cause high sideloading
on the lifters, due to the more aggressive
cam profile.
needless to say, the amsoil is still in the
garage.
i want to hear from more "guiena pigs"
before i am tempted to put this stuff in,
next oil change.
just a thought,
j.t.

p.s. ran amsoil in the drives this vear,
less chalk build up on the drives,
and, at least around here, it was cheaper
than the merc. hi perf. ''green sh-t ".