Sorry guys if this question is stupid, but I cant wrap my head around my real world PSI results and the oil rating numbers.

Basically I have a fresh sohc D16 motor that I am breaking in, less than 350 miles on it since complete rebuild (2 oil changes of 5W-30 Supertech dino oil so far) but I am having a problem

I am up north and the temps are very cold this time of year. -10C for the next month atleast. I get very high oil pressure on startup 80+ psi and the car leaks oil passed the valve seals and smokes for the first 5 minutes until pressure at idle goes below 60psi. But when the engine is fully warmed, it idles at a perfect 12-15 psi.

This is while running 5W-30 oil. What weight numbers should I switch to on my next fill to lower the cold start oil pressure, but not lower the warm oil psi.

In my head a 0W-30 or 0W-40 oil is what i want, and they do make that in synthetic, but my motor is to new for synthetic I believe, and there are literally no dino oil by any brand made in that weight.

What would you guys do?

 

My car's oil pressure reads 100+ at startup with no issues whatsoever and the engine is pushing some miles but with new seals. Don't know what your issue could possibly be.

 

Thats great news for you. But in my case, it smokes. And I want to get the cold start oil pressure down, but not affect the warm idle pressure

What oil weight could I try to help if 5W-30 is giving me the results that I have

 

I guess I'm trying to tell you that I don't think it's an oil issue. Your seals should not be allowing anything to smoke at anytime.

 

Its an oil pressure "issue". As I said Im not sure its seals, the engine isnt broken in yet so Im not worried about it. I just want to create a lower oil pressure on cold starts. Im not looking to diagnose anything here, just try a different oil weight in the current weather conditions

Just need to know what weight oil would help me out, and maybe why, the direction I should go with the weight numbers I dont understand

 

Jeez. Always overcomplicating things when you don't need to. If you need to know what oil weights mean then Google it.
http://www.upmpg.com/tech_articles/motoroil_viscosity/

I wonder then. How my tired engine running 5W-30 with higher oil pressures is having no issues whatsoever with seals or smoking.

 

My engine is broken in yet. Im not to worried about it until I get some more miles on the rebuild. Id like to try a different weight first to see what happens. There shouldnt be a problem having 60psi at startup.

Does your car see temps of -15Celcius? Thats what mine is seeing right now

Just asking what weight oil will lower my cold start pressure, but not affect my warm idle pressure, I cant find an answer to that when searching.

What weight should I try running

 

Understand what the oil weights mean and you could probably answer your own question. Read the info at the link I gave you.

BTW. I have never seen anyone report anything resembling your issue. It is not normal. Whether you're breaking in the engine or not it should not be smoking when it's cold then stop as it warms up; temperatures outside not being a factor, ever. Trying to mask that issue by working oil viscosity magic is not wise. Even when temps manage to drop below zero and cars are covered in a sheet of ice I have never had such an issue.

 

Thats great Marc, I want to try and get a lower pressure at startup to see what happens. 60 psi wont hurt anything, wont starve anything.

I did read that article, but I dont understand how to use that info to get an oil weight for the psi ratings Im experiencing, and where i want to be.

I just want under 70psi at startup

 

Oh. You want it handed to you instead of figuring it out on your own. Like "run xWxx will lower your starting PSI by 10PSI"? Sorry. I can only furnish links that you have to read. Like this one.
http://www.drivenracingoil.com/dro/viscosity

Hope someone else can help you. Good luck.

 

In my head I want a 0W-30, but Im not positive Im going the right way.

Or possibly there is an additive that will lower the psi since I dont see any NON synthetic 0W-30 weights for sale at all

But Im not sure if Im right on that number

 

Last one. http://wiki.answers.com/Q/What_is_th...n_cold_weather

 

They dont sell a non synthetic 0W oil that I can see though, and after 350 miles I doubt my engine is ready for a synthetic oil

Would a 0W actually lower my cold start pressure that much?

 

Just ask whoever rebuilt your engine what they would recommend... simple.

 

that would be myself, and Im obviously unsure which weight to run to lower starting oil pressure

 

There's even a less than zero weight oil but if it isn't available in regular oil then you're screwed. I've also read incorrect tolerances will cause problems with oil pressures.

 

Ya I definetely need a dino oil, I cant find anything even 0 weight

If Im running 5 weight now, would switching to 0 weight signifigantly recude pressure or just slightly?

I went to the 2 auto stores in town today, neither have much for oil stocked, but I can order most anything, but I cant even find a proper suited option online

 

Why not break in the motor tuning?

you should be ready for an oil change anyway right now.

 

Ive changed the oil twice already

Im not liking my cold start pressure, and would like to lower it if possible b choosing a different oil weight

Hence this thread....

 

Use a coolant and oil heater. The coolant heater will keep the coolant temp above freezing and decrease the high idle rpm. The oil heater will decrease the oil thickness.

 

Neither my apartment nor my work would have a plugin for those heaters, but good idea

 

Not sure if you have figured out the oil weight system yet, but if you haven't I'll spoon feed you on it because it took me a little while to find an explanation that made sense. Hell, what I'm about to say may not help at all.

The first number in a multi grade oil ie 5w-30 is the viscosity of the oil at room temp. The higher the number the thicker it will be. The 2nd number is the viscosity of the oil at opperating temp. So 0w-30, 5w-30, and 10w-30 will all have the same viscosity at opperating temp, but they will get thicker as you go from 0w to 10w at room temp.

In your case since you are wanting a thinner oil at room temp, find a 0w-30. Oil is something that really should be adjusted based on oil pressure which as a general rule of thumb should be 10psi per every 1000rpm. You may also be able to run a 0w-20. You just need to verify that you have adequate oil pressue with 0w-20, don't just throw it in and hope. Apply the above rule and see if you have 10psi per 1000rpm with 0w-20. If you don't then change it out and go to 0w-30.

You said you built the engine? What clearences did you spec all the bearings out at? Tight side of factory spec, loose side of factory spec, middle of factory spec?

In my experience oil is probably the most misunderstood thing among car people. If I had a nickle for every time I heard someone say that they were changing from 5w-30 to 10w-30 to help an oil burning problem I'd have quite a few nickles.

I'm of the opinion that people need to fend for themselves and do the research on their own, but on the other hand I could write "search" as a response to damn near every thread I see. That being the case, we might as well close down the forums because they are no longer needed. It annoys me when people just reply with "search." They'd be better to just not respond at all. I'll admit that I've done it before, but I try my best not to.

 

I built the engine on the loose side of honda factory specs with acl race bearings. But I still have sky high oil pressure with 5W30. Even when fully warmed up, i get about 10psi at idle, 30psi @ 2000rpm and 65+ at 4500 rpm

So Im definetely looking to switch to a 0W-30, but the problem is they dont make that it seems in conventional oil, only synthetic, and since my motor is brand new rebuild, i cant switch to synthetic for quite some time. Hell with the little ammount i drive the car I probly wont even have enough miles on the engine to switch it this year!!

Why dont they make a 0W30 conventional darnit

 

Did you actually measure anything or did you just throw the bearings in? ACL race bearings are the last thing I would want in a street car. I won't go into great detail because I have in several threads previously. Look around a bit as they were semi-recent. Just change your oil every 1000ish miles and you'll be fine.

With that kind of oil pressure on a 30, I'd give 0w-20 a shot. How many miles do you have on the build now? Controversial subject, but you can run synthetic after about 350 miles and be just fine. Even more controversial subject, you can actually break an engine in on synthetic.

 

No I didnt just order bearings and throw it together, it was mic'd and plastigauges. Rod clearance was about .0015 and main clearance was .0023" I belive going from memory.

My first fill was 10W40, and the idle pressure was high after full warm (25psi @1000rpm), so after the first change I went to 5W-30 and my warm idle is about 12-14psi@1000rpm.

So I think if I went to a 0W-20 it would help my cold start pressure, but also drop my warm idle pressure to low

I dont believe they make 0W-20 in conventional either.

If Im just going to switch to synthetic, I can get 0W40 which I think is my ideal number

But switching to synthetic after less than 500 miles kind of scares me....

Should I?