How many miles to run in a full engine rebiuld??

[M3Jimbo]

As above!! Ive just had a full engine rebuild!!

What sort of miles do ya think i should do to run it in???

Most of my mates have said the usual 1000
Phil Crouch who built it said 500 - 600
And a lot of over mechanics ive spooke to have said the 5 6 700
sort of range??

What do you boys think???

[Andy335Touring]

I'd do as your engine builder says

[player6]

bexley who did my 2.7 said 1000 and oil cange ever 250 coz it set up to over fual untill its run in

[M3Jimbo]

Hmm dont if i i'll go to that extent??

1000 miles will be so hard!! ive done 130miles in it today!
It so annoying gets up to 3500 revs and even at half throtle it just wants to take off but by 4000 ive got to change gear!! Argh want to play!!!

[player6]

mines not even maped fully yet its a cow to drive but soon back to bexley for TB's and mbe

[Adammcf]

Im rebuilding the head on mine but not touching the bottem end. Will it need any run in once put back together?

[smithy318i]

Im rebuilding the head on mine but not touching the bottem end. Will it need any run in once put back together?

You will need to re torque the head bolts after about 600 miles

[TVRTASMIN]

Don't forget to use mineral grade basic oil, NOT PART OR FULL SYNTH.
Oil change at 250 miles is a good idea as much of the initial bedding in metal particles, cam lube etc will be in the oil.

Keep the revs happy, no labouring and you will soon see 1000 miles clock up.

I ran in a 5.2 litre TVR in a week (1000 miles). Went up to the Lakes and back the long way round nearly every evening.

[Simon]

Im rebuilding the head on mine but not touching the bottem end. Will it need any run in once put back together?

You will need to re torque the head bolts after about 600 miles

Not with the torq bolts, which most replacements are, I think it's only the hex bolts that have to be re-torqued.

[Simon]

Im rebuilding the head on mine but not touching the bottem end. Will it need any run in once put back together?

Adam, are you replacing the cam/rockers?? I'd advise on a new oil spray bar too, cheap from the dealers. Take it easy for the first few miles, but you wont need to wait for 1000 miles though.

[Adammcf]

I wasnt planning on doing the rockers or cam as the engine was pretty quiet before the head/gasket went. Was only going to put in new stem seals etc and give everything a good clean up and make sure its all adjusted properly.

[medway]

Trust mate, run her in for at least 600 miles, keeping rev's below 4000rpm, change oil and filter before and after coz there will be loads of crap floating about (use the good stuff). After the first 20 miles check all fluid levels and for any oil leaks. I do this in my line of work all the time and have always had happy customers, so trust what i say!

[Jimbob]

After going the full hog of 1000 miles it made it all the more sweeter when I did the final oil and filter change and really found out what the engine could do!

[andyp]

i would have said 1,000 with an oil and filter change after a few hundred.

[rickk]

This is how I did it:

0-50 miles - drove like a pussy just to make sure no bits will fall off
50-200 miles - kept revs under 4k
200 miles - oil+filter change
200-800 miles - revved until 6k rpm occasionally
800 miles - oil+filter change, valve adjustment
800+ miles - drove it like I stole it

The key issue seems to be however not to stress the engine for prolonged periods, and to avoid driving at constant rpms.

The former avoids overheating of not fully ran in components (due to the extra friction), the latter helps the rings create a better seal agains the walls (due to the pressure differences when accelerating/decellerating). Babying it too much is said to create a sub-optimal ring seal, and so a lazy and oil burning engine in the long run.

So, highway driving, towing, burnouts, etc. are bad, twisties and the occasional 0-60 are fine, just give it some time to cool down in between.

I did it this way on mine (rebuilt m20b25) and now, 10k later it pulls very strong and no blowby or oil consumption..

My 5p,
Rick

[M3Jimbo]

Cheers for the input lads done 290miles now will give her an oil change
and then do what ive been doing might give it the ocasianl prod up to
5500rpm but dont wanna go past that cause thats when the cams are gonna start having there say, and i'll save that for when i can realy find
out what there upto think i'll do the 800miles sound good to me!