Whats up HT?

Just a quick question, I fully built a GSR motor the other year (forged with upgraded eveything, stage 2 turbo cams etc) Only when I came to the running-in of the motor I did it with fully synthetic 5w-30 motor oil.

I know this is a mistake (didn't know at the time to use mineral)

I ran the engine in NA with no problems, no blowing of oil out the rear muffler or anything.

Came to boost it 4k miles later and ever since it has been blowing little parts of oil out the rear end, I have spoke to a few garages with different verdicts and suggestions.

The motor has done 4k NA and 3k boosted, i'm running CP 9.5;1 pistons on an open block at 340WHP, compression is 165 across all four pots.

The question I have is;

Can I get away with just a set of new rings and a re-hone of the bores or do I need to go to next oversize (82mm)

I really think that I would get away with just a rehone and a new set of rings but as always it would be nice to hear from some of you guys with far greater experience than me.

I will be running it in on mineral oil this time dunna worry lol

 

Maybe it's just soot? Running rich...
Anyway, there's a lot of old threads about this if you search back.
Cant remember the general consensus, but some cars come from factory with Mobil synthetic, the arguments to that statement are what u can find in search.
If it's consuming oil excessively, and not just leaking it out, maybe it's a problem.
Is that normal compression for that combo? If so no problem.
But Hey, re ring it and let us know. Yeah, just a hone tho.

https://mobiloil.com/en/faq/product-faqs/product-faqs

• Is it true that new engines need break-in periods using conventional motor oil?

  That is a myth. In the past, engine break-in was necessary to remove metal flashing or any other abrasive material left inside the engine after machining, as well as to allow the valves and rings to "seat" properly. Today's engines are built with much tighter tolerances and much improved machining, and under much cleaner conditions compared to the engines of 10 or 20 years ago. Current engine manufacturing technology does not require a break-in period using petroleum-based motor oils.

 

I am unsure if 165 is normal or not, I tested it within first 100 miles and then again after 5k and its always been 165. The AFR does read rich upon idle which threw my tuner out a bit, he then clicked on that oil is getting into the exhaust and is throwing the reading off, it goes up 13 odd when you touch the throttle but stays rich when TB is closed. A few spatters of oil are being found around the exhaust manifold as if it's leaking out threw the gasket, it does not blow air just the odd spat of oil. Its nothing major and it runs fine it's just if a hone could sort it and run in on proper oil then I would be willing to give it a try

 

Did you actually see the oil around manifold?
It's kinda hard to pinpoint with a sorta vague symptom you describe.
Oil moves around a lot of places in our engines, with potential to escape.
I have ZERO tuning experience, sadly, as far as your afr concerns,
...but if you could post a pic of the residue maybe a guru might see it and chime in.
Good to have another Brit around since Rich777 evaporated or whatever happened to him, hope nothing bad, he was fun.
What are you using for engine management? Hondata?
Btw..the fact that the oil situation didn't manifest during the all motor phase has to be relevant, in my opinion.

 

165 seems low for gsr but...keep in mind just because *new* engines might not need it due to better tolerances, that doesn't mean your local machine shop is that good/clean..just a thought

 

Is it low for 9.5:1 comp. tho?

 

Depends..comp gauges measure dynamic pressure, so cams, cam offset and other factors can change it.. if your valves aren't seating 100%, etc..

GSR stock, new, is 270psi.. last time I checked my b18b1 (9.2:1 IIRC) it was around 170 across though I realized after my intake cam was a tooth off.. haven't done one since..

Do a leak down?

​​​​​gen 3
94-01 b18b1
nominal: 199 psi
minimum: 135 psi
max var: 28 psi

94-01 b18c1
nominal: 270 psi
minimum: 135 psi
max var: 28 psi

97-01 b18c5
nominal: 270 psi
minimum: 135 psi
max var: 28 psi

 

B16a2 here with 265 miles on a new build and running 5w30 fully synthetic with no leaks what so ever, if any problems I seem to be spitting more oil through my valve cover breather and oil catch can set up. My tuner even said that was too thin oil for our temps here, once hit 500 miles I'm going for 5w40 or 10w40 fully synthetic.

 

Yeah, your tuner is wrong. "Too thin?" That doesn't matter at operating temp.

So where is "Up here?"

 

what weight oil do you recommend for summer temps I.E never sees anything below 80 F.

 

Depends on your bearing clearances.

 

Bingo.. Yes, your climate makes a difference also, but the bearing clearance is the best determining factor, ESPECIALLY at cold start.

 

damn that I dont know I had the block built several years ago, I no longer have any paper work for it.

 

If nothing bad has happened at this point now, you're good to go with the oil you're using now.

 

Get an oil pressure gauge then.

 

I have an pressure gauge everything seems normal there, 80 psi at cold start... never below 20 once warmed up forget exact numbers but never goes very low.

I was more wondering about the thickness on cold start i.e the 10w portion since im not dealing with cold ambient temps. Was thinking something on the lines of 15W-40 may work better given the environment

 

The closer the numbers together, the more stability it has. If you never see below freezing, 10-30 would be better then 5-30.

 

gotcha everyone arround here runs 10w-30 for as long as I can remember its what I have always used in all my cars

thanks

 

Up here is UK. Fresh 5w30 oil 5 litres (mobile 3000 fully synthetic) pressure gauge reads 4.5 bar (65 psi) on cold start up and running oil cooler with thermostat. Once warmed up pressure drops to a 1.2 - 1.0 bar (17-14psi). Overtime though oil pressure seemed to drop, now done 260 miles and oil pressure from cold 4.1 bar (59 psi) and once warmed up goes to down to 1.0 - 0.9 bar (14 - 13 psi).

Checked oil and is clean with no metals or anything, only thing as said seem to be putting a lot of oil through the cam cover rear breather and oil catch can, don't know if the SK2 Pro 1 cams has anything to do with this!

While driving oil pressure goes up to 4.4 - 5.0 bar just before hitting 5K RPM, limiter set to 5162 RPM until engine is run in.

 

Being around 17-20psi is about optimal. Try a slightly higher weight at operating temp, like about 10w 40 or 5w-40 (The second number is the important one. ) Otherwise, oil pressure seems pretty normal. Just only a tiny bit lower. not by much.
Your bearings should be a little on the loose side to account for heat expansion.

 

Mine runs around 22psi according to my gauge, usually run 5w30, gets cold here, sometimes as low as -40°c, though thats rare..

 

​​​​​​​Try a leak down test to see if its getting past the piston rings. You could try a proper catch can setup.

 

Thanks for the replies guys, managed to get a photo or two of the manifold for you.

Like I said before it doesn't leak air not one bit.




I keep cleaning the manifold with de-greasant and a rag so I know it's ongoing as it keeps coming back




I took some videos but photobucket is being a pain in the *** about them so I cant share the footage of the AFR gauge and the back end of car with black stuff coming from the exhaust.

This is my build anyway

 

Can't really see a lot on the rear but this is the usual spot in my garage where the car sits, it often gets started up in here and left for 5 minutes so the black stuff you may be able to see is a gathering of many weeks worth of soot and oil

Also there is a video of the AFR gauge changing from 10 up 12 odd upon revving it which it has always done since fitting it

<iframe width="560" height="315" src=" " frameborder="0" allowfullscreen></iframe>

<iframe width="560" height="315" src=" " frameborder="0" allowfullscreen></iframe>

 

That's a pretty neat looking engine bay. Sorry that's all I have to add :p