restrictive oil system?
 

Is this a restrictive system at all?
lines are 5/8" and running about 450 hp, is this a bad setup? I figured merc used it on a ton of boats, my engine builder thinks the fittings and block adaptor are crappy...opinions??

http://i36.photobucket.com/albums/e4...108_5450-1.jpg

I'm not familiar with the adapter set up so no comment.

I'd say 5/8 ID lines on 450 hp are ok. Your builder has a point about the fittings though. Those 90's are not a good way to go. Also, the ID of the fittings might not be full 5/8".

my .02

Do some reading on this board. Smitty has post a really good tread n marine oiling. It is all about how much hp you are running. I personaly have melted thebearing out of a 700 hp 540 with the wrong fittings/lines.

Looks fine to me !

I run that on my raceboat , the only diff. is i have 2 coolers.
If your oilpress is around 50-70 ? ,its fine .


I would change out that oilfilter thoe .LOL

A couple of thoughts-

- not all block adapters are equal. If yours is restrictive, it's a problem.

- not all hose is the same. High-pressure hydraulic hose is a terrible choice for automotive oiling systems. The guy at the hose distributor probably doesn't know this. He knows diameter and pressure. 5,000 psi hose is much smaller in ID.

- ditto on the 90's. Replace them with sweeping elbows.

This is the definitive guide to BBC marine oiling-

http://www.offshoreonly.com/forums/s...3&page=1&pp=20

Read smitty's post. It's on this page now.

Smittys is more about the smaller 1/2 stuff, I can see how that is an issue to, mine is factory merc stuff, just was wondering what issues there was.

Even in larger diameters, the 90's are flow killers.

we have had this discussion before. first i will say that everything smitty says in correct. period. end of that discussion...

however..

there are a couple of things that i suggest are factual:

1) the simple mathematics that define pipe sizes and flow rates in hydraulic systems are 100 yeras old and speak for themselves

2) the engineers that define these configurations at merc know this math and don't design this stuff on bar napkins over cocktails.

3) these motors... like mine , in box stock trim run forever with no oil system failures, thus validating those engineered solutions.

now... i would suggest that the vast majority of oil system packages you see on these motors that are running -12 and -16 lines are done with the notion that " bigger is better" . that simply isn't the case. the pump is a positive displacement device... it pushes x volume per revolution. assuming that volume is sufficient to supply the clearance losses inside the motor with the oil at temp and with pressure sufficient for the call out for that design, all the piping has to do is accomodate that flow rate plus , maybe 20 or 30 % .

for just about every motor in the galaxy except for those drag motors making 7000 hp and CERTAINLY any non dry sump motor, a -10 line is sufficient 99.999 % of the time. I haven't seen a winston cup motor in some years but when i was seeing them pretty routinely, they were all -10 pressure and -12 scavenge...

i think this notion of "flow restriction" centers around one of two issues: the simple notion that the factories don't know what they are doing.... which i don't agree with...

and the desire to put lots of whizzy stainless line and anodized fittings where your buddies can see them and be envious.

i suggest a quick browse online for the topic " flow rates and fluid mechanics" to separate the myth from the truth.

I have a simpler explanation-

-10 line and fittings costs pennies more than -8. Sweeping elbows- a bit more, but the flow rates are substantially better.

Keep in mind, many oiling systems are more complex than the one shown. If you have double bellhousing coolers, a thermostat, the adapter, the remote filter pad and a fine particualte filter, all these fittings add substantial flow disruptions. Even the straight unions and adapters. But I will agree with you, someone like Merc uses engineering principles where the average rigger uses Amish engineering- build it the way we know for sure it isn't going to fail, ever.