Running in re-build engine
Discussion
Get my Cerbera 4.2 back next weekend after it's re-build. Found this on the net, any other comments? or should I follow what they say below? Also any comments on start up procedure after a re-build?
What are the rules for running the car in?
Opinions differ, but there is a general consensus that it is worth being careful, as it makes the engine smoother and actually more powerful in the long-run. However this is not unanimous, and some people claim that you can thrash the engine from the word go. You should be warned however that TVR have been known to refuse warranty claims on engine problems if they find out that the car has, for instance, been taken on a track day when less than 2000 miles old.
A sensible scheme is the following:
Mileage Behaviour
0-200 miles 3000rpm
200-1000 miles 4000rpm
1000-1500 4500rpm, occasionally more
1500-2000 Start opening it up more and using high revs once in a while
2000 Let rip..
During the first 1000 miles never use full throttle, never strain the engine, and avoid prolonged periods at constant revs. During the second 1000 miles start breaking these rules very gradually, but only really start using the car freely after 1500 miles, and even then, show restraint.
It should be noted that the factory's official line is that the engine is not fully run-in until it has done 6000 miles, which is why at this mileage it is "converted" to fully-synthetic oil (i.e. some bloke in overalls pours Mobil One into it).
Thanks
What are the rules for running the car in?
Opinions differ, but there is a general consensus that it is worth being careful, as it makes the engine smoother and actually more powerful in the long-run. However this is not unanimous, and some people claim that you can thrash the engine from the word go. You should be warned however that TVR have been known to refuse warranty claims on engine problems if they find out that the car has, for instance, been taken on a track day when less than 2000 miles old.
A sensible scheme is the following:
Mileage Behaviour
0-200 miles 3000rpm
200-1000 miles 4000rpm
1000-1500 4500rpm, occasionally more
1500-2000 Start opening it up more and using high revs once in a while
2000 Let rip..
During the first 1000 miles never use full throttle, never strain the engine, and avoid prolonged periods at constant revs. During the second 1000 miles start breaking these rules very gradually, but only really start using the car freely after 1500 miles, and even then, show restraint.
It should be noted that the factory's official line is that the engine is not fully run-in until it has done 6000 miles, which is why at this mileage it is "converted" to fully-synthetic oil (i.e. some bloke in overalls pours Mobil One into it).
Thanks
Thames Vally Racetech are doing the work other than TVR.
It had a loose Valve guide and so needed new guide, liners and rings. Glazing was also a problem. They have put new cams in it too. Unfortunately the loose guide caused some damage to the Head and a new one is required!! (£1,000)
Total of about £4,500 (plus £17,000 purchase price = £21,500.. Still not as much as dealer prices) and I get a 12 month warranty!
It had a loose Valve guide and so needed new guide, liners and rings. Glazing was also a problem. They have put new cams in it too. Unfortunately the loose guide caused some damage to the Head and a new one is required!! (£1,000)
Total of about £4,500 (plus £17,000 purchase price = £21,500.. Still not as much as dealer prices) and I get a 12 month warranty!
Don't forget that even after the running in period/mileage you must not thrash the engine when cold. There was a recent post from John McKenzie about running the car for at least 10 miles before the noil was warm enough –good advice I'd say. No good of course if you're only going two minutes down the road tho'!
I would be ultra-careful and adhere to the rev limits without exception. You do not want to have any more touble with it!
I would be ultra-careful and adhere to the rev limits without exception. You do not want to have any more touble with it!
Bandit - only taking it to 5k from 4k from 1000 to 1500 miles means you only have 500 miles to go from 5k to max revs - you probably want to increase the revs more proportionally rather than start going a lot harder right at the end.
The most important bit is the first 500 or so miles anyway. Important not to be *too* gentle because you can glaze the bores - quite common apparently.
danny
The most important bit is the first 500 or so miles anyway. Important not to be *too* gentle because you can glaze the bores - quite common apparently.
danny
quote:
Is it a full run in after a rebuild?
Not sure that the start up process is any different during a run in?
Depends what sort of rebuild. If there are new piston rings, then yes, should run in from scratch. If the same rings and liners have been used it can be a lot shorter - go on the advice they give you when you pay the AJP dept bill!
quote:
quote:
Don't forget that even after the running in period/mileage you must not thrash the engine when cold.
Doesn't this apply to any kind of car? I have never heard of a car which begs for being thrashed from cold...
Yeah, but Thom, all my rep mates are doing 90 in their Euroboxes five minutes after starting off – I've been with them – traffic light Grand Prix, the lot.
This is all IMHO!
Talk to your dealer/factory about running in, but I would have thought 3000 rpm till 1000 miles was too gentle. Work it up slowly so that you reach 7000+ at 2000 miles.
If you drive at constant speed, or don't work the engine at all, a glaze of baked-on oil forms between the bores and the rings, preventing a proper seal from ever developing, and the engine will use oil. It may affect compression & power too - not sure. Anyway, the only cure is to re-hone the bores, i.e. scrape it all off again, i.e. rebuild.
This DOESN'T mean thrashing it - always let it warm up completely (10 minutes or so MORE after the coolant thermostat opens (drops back to 80 from 90)) and don't "lug" it - wide throttle, low revs in wrong gear. Much better to work the gears and change throttle position, i.e. A & B roads instead of motorways.
I did my first track day at 2000 miles, and my engine hardly used any oil at all up to 15k miles, and was the most powerful 4.5 cerb on a dyno that I've seen.
Talk to your dealer/factory about running in, but I would have thought 3000 rpm till 1000 miles was too gentle. Work it up slowly so that you reach 7000+ at 2000 miles.
If you drive at constant speed, or don't work the engine at all, a glaze of baked-on oil forms between the bores and the rings, preventing a proper seal from ever developing, and the engine will use oil. It may affect compression & power too - not sure. Anyway, the only cure is to re-hone the bores, i.e. scrape it all off again, i.e. rebuild.
This DOESN'T mean thrashing it - always let it warm up completely (10 minutes or so MORE after the coolant thermostat opens (drops back to 80 from 90)) and don't "lug" it - wide throttle, low revs in wrong gear. Much better to work the gears and change throttle position, i.e. A & B roads instead of motorways.
I did my first track day at 2000 miles, and my engine hardly used any oil at all up to 15k miles, and was the most powerful 4.5 cerb on a dyno that I've seen.
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