Hi,
Thought I'd start a discussion on running in a rebuilt G40 engine - I did a search,but believe it or not, there doesn't appear to be a massive amount of running in advice on this forum.
My engine has had all new gaskets, and new shells and piston rings - supercharger has also been rebuilt. So will be run in together.
The engine shop are saying drive it gently for 1,000, and keep an eye on oil levels (it will use some), it will be filled with running in oil. Then at 1,000 miles oil should be changed to regular synta 10-40w.
What did you do? When you ran your engine in.
Cheers
Joe
When I finished my full engine rebuild. I drove it pretty normally. Took it up through the gears fairly often making sure I increased the rpm I took it to. Initially just to 2k. Then after a few hundred miles I took it to 2.5 and so on. Bearing in mind I didn't have a charger to think about. I guess you just want to make sure the rings beds in, so don't go too easy.
I did a couple of 100 miles doing laps of the M60 trying to vary the revs etc...
then did a couple of track days :D
the car still works
Did any of you use 'running in oil'?
Did you experience any oil level drops - before tolerances close up?
(http://static1.squarespace.com/static/51d98778e4b0fc2d0dfa3cfd/t/566a1ce9d8af109f6011d5cc/1449794794085/)
There's 2 trains of thought generally for running in:
1. Take it steady and don't rev too high, etc.
2. Load the engine and allow it to rev up.
1. Is for "old" (poor tolerance) engines where there would be a lot of slop, so you would have to let it run gently to enable interferance parts to wear into each other nicely, making a good seal.
2. Is for "modern" (high tolerance) engines, where the manufacturing processes for the parts are much better controlled, therefore the parts fit together nicely as the tolerances are much smaller. Therefore there is less material to "wear in" to each other.
Running in oil is for number 1. I believe. I don't want to comment either way as I don't have enough engine building experience and don't want to advise you poorly. I'm not sure where 90's VW parts lie, I would imagine more towards higher tolerance, better parts (no.2) but that's just anectodal evidence! I know when I rebuilt my KTM 640 engine I was being told no.2, but that was manufactured in 2002 and low volume. A high volume product made circa 1991 may be a different story! I'd go by the advice of the person that built it, as they will be more experienced and you may find doing the opposite voids any form of warranty due to "abuse".
I justuaed normal 10w40 semi synth oil and changed it after 100 miles and again after a couple of hundred more.
I rebuild my engine a couple of years ago. Did 2000km, with normal oil, under 2000rpm, then gradually went higher and changed the oil at 5.000km! Worked fine for me!
Yer the engine shop said go with option 1, which is what i'm doing.
Running in oil and free reving up to 3k but no more (advised to not go above 4k), and no flat out acceleration or excessive lugging. Basically 'normal' person driving.
So far have done 250miles and oil level has dropped from max to 1/3 of dipstick.
@physicsfool - you did well driving at just 2k & 2.5k I need to get to 3k to not annoy drivers behind me!