Running in a built engine

[Owen:s]

I've always heard the first 20 miles is the most important, my dilemma for the weekend is, how do u make the best of this time window whilst needing too blead the rad off and get up too temp to check fans?? Will leaving it too idle for too long glaze the bores? Or do u just put water in and go for it?

 

[Fred@BTM]

Remove thermostat, fill up with bleed screw out - done, start engine GO

 

[Chip-mk1]

Definitely don't want it idling for too long before it sees some moderate load.

 

[Owen:s]

Champion cheers been wondering how too get around this, how long would u leave the thermostat out for

 

[Andyman]

Going back to the oil. What should the cycle of oil changes be ?

Edited to say, On a new build.

Is it running in oil then change to normal oil job done or should you do a couple of close running in oil changes prior to the final oil change

 

[Martin.]

Very interesting thread.

I've never bought a new car and I dought I ever will. But was always under the impression they needed to be driven very carefully and slowly to run in!!!!!

 

[Chip-mk1]

Going back to the oil. What should the cycle of oil changes be ?

My preferred method is do the first half an hour of running on mineral oil and a new filter, and then pull the oil just so any of the running in swarf particles (of whick 90% percent will be present within half an hour, showing how much running in is done in this time!) are gone and out the way.

Then a new filter and oil for rest of the run in period, mineral again.


Its not essential to do this extra change after half an hour, you could do it all on one lot of oil and I sometimes do, but if you are really being fussy I think its a nice to have.



Then change to a decent oil and treat it like you nicked it.

 

[bozothenutter]

once had to run in the engine on an alfa 156 challenge car...
Dealer put it in a roadcar and gave me the keys "drive it to paris and back, and cane it on the way back"

turns out a few other teams had the same idea

 

[Jeffers_S13]

A good hone is important and a parallel and round bore, leave it to a decent machine shop is my advice, it's only £10 per bore at Chesman in Cov, done all mine. It's all about the rings. You want high pressure above the piston to force rings against bore wall, then a vacuum to draw cool oil onto the bores. I bought a book by A. Graham Bell years ago when I first started tinkering, 'Forced Induction Performance Tuning' worth buying. No magical methods or internetz pseudo engineering, just read this: