I have a b16a2 that is stroked with cp pistons. I have heard either from this site or from another that i shouldn't use 5w-30 anymore and that i should use 10w-30 or 10w-40 can't remember which one. Could someone please explain to me why. Thank You....

 

bump it up please

 

I didn't think new pistons really had any factor for the weight of oil you use. I was always under the assumption that bearing clearances and operating temps were the major factor when considering oil weight. Therefore, unless you changed your bearing clearances, I would figure using the same weight oil you were using before would be good. I could be wrong though.......

 

^^^ that was gonna be my answer. depends on your bering clearances and p2w

 

some one had made that comment. So i was wondering if it was true. I did ruun my car for a month and did notice that it did burn oil a little quicker than normal. That is why i made this thread to see if i could get a definate answer before i start buying royal purple on my new build.

 

I would prefer using synthetic.

 

if you know your clearances that would help alot. If they are on the looser side try some 10w-30 and see if the smoking clears up but i would expect smoking if your still breaking in

 

no smoking. its a tight fit. i will try to find the piston sheet i have in the garage.

 

No smoke but you stated above that you noticed it was burning oil at a quicker rate than normal? Where is it burning if there is no smoke? Do you have an oil leak somewhere?

As for the clearances, the piston sheet will only tell you the suggested clearance. Only the person who installed the pistons and measured the installed clearances will know the exact measurements.

Did you get a spec sheet from the engine builder? or Did you install the pistons blind with no installed measurements taken?

 

i run 5w-30 torco sr-1

 

builder installed them. so i don't no. It just seems that i am changing my oil more frequently than normal. No oil leaks anymore. Last oil leak was the dizzy.

 

how much oil loss are you talking about? Not sure how accurate this info is, but I did read it somewhere that had some authority (can't remember where though): If your using forged pistons, they usually run a little loose on the clearances (or a little tighter, depending on silicon content) at startup so they can expand with heat and wind up with proper clearances. Therefore, it may have looser tolerances at startup, so the oil is being lost at startup until the piston gets to operating temperature.

 

Wouldn't proper piston ring end gap & ring seating also come into play when it comes to oil consumption? I'm not 100% but I don't think the piston ring clearances are as loose as the pistons at start up.

 

that is what i heard. Not sure how accurate. But in my case that might be my issue... But i remember something to the effect of using a different weight of oil to deal with the issue. Not sure if that is true or not????

 

According to this write-up you should be using 10w40

Here is a link to the rest of the write up. Which oil do I use?"

 

Yea, I'd say try 5w40 (if they make it), or just jump to 10w40, might solve the problem. Cheap attempt anyway, so if it doesn't work, you won't be out big money. Hope it works out for ya.

 

[QUOTE=GhostAccord;39120589]According to this write-up you should be using 10w40



Here is a link to the rest of the write up. Which oil do I use?"[/QUOTE


I have a motor built from the ground up. everything is new. its been bored and honed. So i quess i am still at a lost....

 

head rebuilt too? maybe seals in there? How did you break the engine in?

 

So what is your question here? Are you trying to figure out what weight oil to use or why a newly built motor is burning oil?

One of your questions was why do you need to use it. The answer might be one of the following;
1. Improper piston ring end gaps
2. Improper positioning of the ring gaps (inline)
3. Leaking valve seal(s)
4. Engine not fully broken in / Piston rings not sealing against the cylinder wall.

How many miles on this engine? Have you done any sort of engine break in procedure?

 

engine has 1000 miles on motor. was properly broken in. Just trying ti figure out what would cause the situation and have a sense of idea of what motor oil i should run...

Head is totally rebuuilt as well only thing stock are the rocker arms..