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Hey all. I'm currently looking at purchasing an R34 GT-R and found one in Sydney that looks like a good deal. It's had a forged bottom end rebuild in the last 10,000 kms.

So I rang up the well known northern Sydney workshop to ask about parts used and to get a bit more info about the car. I was glad to find out all the components used were all top grade, however when I asked what boost the motor is running while in it's run in period I was told it was run for an hour then boosted straight to 23 PSI. I was always under the impression an engine had to be gently broken in so the piston rings can mate properly with the cylinder walls.

What are your opinions on this? Should an engine be broken in for a few thousand km's before it's run on high boost and dyno tuned?

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personally, I would gently drive the car, keeping the revs moderate and gradually introduce inclines and engine load over the first 2000kms or so

BUT

Some engine builders seem to swear by straight harsh driving conditions to bed the rings and burn off all the coatings.

Going by all the episodes of megafactories: ferrari, bmw, lamborghini; they all put the engine on a dyno and run at varying revs for ages, even at redline

Then they take the car out on their tracks and give them a good thrashing.

I seem to recall lamborghini running their engines @ redline for 7minutes

my new twin cam rb30 is going to be run in on dyno,

then a street tune at 18psi for around 1000klms while i learn to drive the thing!

i would say 99% of all track only cars would be run in on the dyno as they have no where to clock up 1000s of klms.

so running it in on the dyno should be fine.

if anything from the build is not right it will break on the dyno not 5000 or 10000klms later

Hey all. I'm currently looking at purchasing an R34 GT-R and found one in Sydney that looks like a good deal. It's had a forged bottom end rebuild in the last 10,000 kms.

So I rang up the well known northern Sydney workshop to ask about parts used and to get a bit more info about the car. I was glad to find out all the components used were all top grade, however when I asked what boost the motor is running while in it's run in period I was told it was run for an hour then boosted straight to 23 PSI. I was always under the impression an engine had to be gently broken in so the piston rings can mate properly with the cylinder walls.

What are your opinions on this? Should an engine be broken in for a few thousand km's before it's run on high boost and dyno tuned?

This is the correct way. Should be run in before it leaves the dyno. If you run it in gently it will never bed in properly and always use oil. Not to say you should be holding it to the limiter the minute you get out the door!

This is the correct way. Should be run in before it leaves the dyno. If you run it in gently it will never bed in properly and always use oil. Not to say you should be holding it to the limiter the minute you get out the door!

+1

Once the rings are bed in, which occurs in the first few mins anyway...

Tune it up.

3 motors I've had built were all done that way. Current one has over 10,000kms on it, doesn't breathe one iota of oil.

Breaking in slowly is a urban myth these days with tight clearances etc.

Hey all. I'm currently looking at purchasing an R34 GT-R and found one in Sydney that looks like a good deal. It's had a forged bottom end rebuild in the last 10,000 kms.

So I rang up the well known northern Sydney workshop to ask about parts used and to get a bit more info about the car. I was glad to find out all the components used were all top grade, however when I asked what boost the motor is running while in it's run in period I was told it was run for an hour then boosted straight to 23 PSI. I was always under the impression an engine had to be gently broken in so the piston rings can mate properly with the cylinder walls.

What are your opinions on this? Should an engine be broken in for a few thousand km's before it's run on high boost and dyno tuned?

been doing it that way for years, its the best way to run them in.

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