So got a forged engine and it recently completed 2000 miles. Last 1000 miles used nearly a litre of oil. Is this about right? Sounds like a lot. Hoping it will improve as the engine loosens up a little.

Also I'm using a 5w40 fully synthetic oil, wonder if moving to a 10w50 would help the oil consumption. Any advice?

 

Sounds like a lot to me. What oil did you run it in on? 5/40 is too thin & 10/50 would be a better choice.

 

I was told to use a 10w50 once run in on my forged rebuild. I think they use a little oil but if run in on some boost that is minimized.

 

It was run in on valvoline 10w40. Had a oil change after 1000 miles, now running a 5w40 fully synthetic oil and as a result has used 1litre of oil in the last 1000 miles. I will replace the oil with a 10w50 fully synthetic and see what the results are like. I was told by a engine builder that forged pistons do tend to burn more oil. Maybe the 5w is just too thin hence the heavy consumption.

 

I don't know mate. What i do know is 1L per 1000 miles is excessive regardless of Subaru's guidelines. I also know if a 2.5 is not run in with at least 0.5 bar of boost after a re-build they will become oil burners.

 

Simon from JGM set it to 5psi boost so was certainly run in correctly. I will give the 10w50 millers CFS a go and see what it is like. Also in case you didn't know just seen Opieoils has a 20% discount on the go until end of bank holiday.

 

Who did the rebuild ??maybe worth asking them!

 

Yeah, just missed out on that deal when i bought my diff oil. Story of my life !

 

Yeah I did. They said it will use more then average at first but to be honest they did say to use a 10w so having 5w at the moment is clearly not helping the situation. Ill get it taken out and replaced as per my previous comment. Hopefully then it will improve.

 

Never had a problem with millers 10w/60 on my forged engine build.

 

I'm not convinced a change from 5w40 to 10w50 will make any difference but interested to see your results.

 

Thanks for the feedback. Just ordered the 10w/50 so if this works then happy days if not ill give the 60 a go. Part the problem is getting an accurate reading from the dipstick. Such a pain in the ****..

 

Front of the dip stick , full to the lines of the F. Simples.

 

Yeah but is that cold or hot or left after its got warm for a few minutes as mine varies depending on those circumstances. I generally let it run till warm and then let it sit for say 30 minutes without the dipstick in and then do a test ... And a second and a third for good measure lol

 

Did you run it in on synthetic or mineral oil?

 

The oil was put in by the builder and was just told it was valvoline run in oil..

 

I think your being to **** and making life hard for yourself. Go for a drive, upto temp. Flat surface and upto the F line. Any other senario wont make that much of a difference. There's like at lest 1/2 liter between the min and max line. I doubt anyone has topped up that much.

 

Simple check it when warmed up

 

Oh right.

Whenever i build an engine (which has been about 3lol) i run it on adsa 10w50 oil for 50 miles then change that and the filter and go for a half decent mineral oil and give it a bit of stick.

If you just fanny about and run them gently it wont bed the rings in. All this talk about going easy for 1-2000 miles is a misconception imo as you need cylinder pressure to force the rings to seal against the cylinder wall.

There was a thing on the net ages ago about a pair of brand new gixxers, one was run in as per the usual, one was given grief from the first turn of the key.

The latter went on to make a good bit more power and torque, and use bugger all oil.
The other wasnt as powerful and used more oil lol

But after spending a few k on an engine build, i guess you will be a bit reluctant to start pushing it with only 50-100 miles on it.

 

My advice from my engine builder who is very respected and worked on F1 engines for many years told me :- Semi synth for 1000-15000 miles. Use about 0;.5 bar of boost regally. Drive like a fanny and you will end up with an oil burner. Then drain out, put fully synth in and drive.
I'm a bike mechanic and its the same advice i would of given after a re-build. If quality parts were used and the builder got his tolerances right there will be no problem.

 

Matter of personal choice then lol.

I personally would not use a semi synth to run in on either as its too slippery.

You want a bit of friction to bed the rings.

But at the end of the day my job is electronics, not engine building!

 

Do as you engine builder tells you, but ive built race bikes and raced after 10 mins of bedding in and on fully synth. Put in mineral and take it easy... put in synth and hammer it !.

 

Lol fair enough. As said i build my own engines lol.

Only got yourself to blame when they pop then pmsl

 

OR you could do what I did, which was put rebuilt engine in with mineral oil, drive gently for 20 miles, stop check all is well, then give it beans, BIG time for 50 miles drop the oil and stick some fully synth in and jobs a good un, drive it like you stole it, a la motorcross bikes.

Still won't die no matter what I to it.

All this pussying about is a waste of time, if it's going to **** up it will do it in the first 10 miles.

 

+1. never had a bike engine let go. Quality parts and exact tolerances and all's good.

 

Thats kinda what i was trying to get at lol.

 

People who build engines for a business will always air on the side of caution. Thats just good business, but the quality of their work for the most part will withstand anything you're liable to subject it too on the road.

 

Doing 1000 miles on mineral then 2000 on semi synth and after 3000 going onto full synth.

Been using boost (upto 0.5 bar) and 4.5k rev limit since I was given the keys back to it.

Hasnt used a drop of oil yet, although only upto 800 miles now. Once the semi synth is in. Ill raise the revs slowly until it gets mapped.

2.5 forged.

 

It wont use any on 0.5 bar. Once you turn up the boost it may use a little. Most of that being vented into the intake or catch tank (what ever way you're plumbed).

 

mines has 1500 on forged engine not a drop of oil used, do you have a catch can set-up? as my builder installed one due to the standard system pulling oil from crankcase etc into intake