lisa 23

hi hope someone can help,recently bought a saph cosworth that has had a engine rebuild and am in need of advice on how long you have to run it in????? it has a new 200 block and new low comp pistons, new bearings gaskets etc.. the head has not been rebuilt just the bottom end the car has currently been set to 10 psi of boost, but how many miles before it can be tuned up? and what is the best oil to use when its run in???? hope you can help many thanks

Derek Burleigh

Who rebuilt the engine is a good starting point?

You run them in for as long as necessary, it varies depending on the fit of the parts. You need to get it looked at and compression tested by a professional tuner and listen to their advice regarding running in.

You'll get as many different answers as there are users on here!!

Rhys

I run mind in for about 750 miles ish

safflad

750-1000 miles then swap run in oil for appropiate grade fully synthetic oil

The Gravedigger

Generally you'll hear that you use cheap mineral oil for the first bit, driving carefully, then put decent oil in say 500 miles later, but as has been said above you'll get a lot of opinions in this thread

lisa 23

well thanks to all above for advice so far the car has done 1000 miles since rebuild and has been run on castrol gtx mineral 15/40 grade..

so should i change the oil and get it tuned up now?? and can it be driven faster now?? as its boring only going up to 3'000 revs and having 10 psi of boost

what is the best oil to use ?? mobil 1 15/50 or castrol rs 10/60??
thanks again

safflad

I'd say either would be fine

Billabong

If the motor's done 1000 miles then you should have been using more than 3,000rpm by now, imo.

Oilman on here can give you some good recommendations on oil, and bust a few myths....

Snowy_Astra

Thats what i always heard, was to use a cheap low grade mineral oil to help the parts bed in better as its generally a lot thicker.

I'll be running my rebuilt engine in like that, for a minimum of 1000 miles, then drain all the fluids and flush it out and fill it with semi

lisa 23

thanks again i forgot to ask anyone if the car can be driven hard on the run in oil??

this has just been changed to the same oil gtx 15/40 mineral and a filter to clean out the old stuff!! or should it only be driven hard once the oil has been changed to the usual quality grade spec oil???? thanks again to all above for the great advice so far

MK5RST

llisa 23, Why is it boring with 10 PSI ??? If you havent been over 3000 RPM this shouldnt affect you and if the turbo is coming in before 3000 RPM must be one hell of a small turbo

DazC

iTrader: (1)

Don't thrash it while running it in. You will only polish the bores and it will end up smoking....