First startup of a rebuilt v8 engine. bedding in?

I can't speak for Rover V8's but with a Chev V8 I'd be running it for about 20 mins at 1800-2000RPM with the odd rev to 3000. Id also be making sure I'd used the magic cam lube stuff that is normally supplied with a new cam.

Well done that man. What oil have you used?

I havent got any magic cam lube. New one didnt come with any. Didnt know that existed! It got doused in normal engine oil. I didnt even know you had to bed the bugger in till last night.

I followed the 'refit cam' instructions in the book and ive never seen it mentioned before when doing normal landrover/car cams?

mineral 20/50 IIRC.

1. New cam followers always with new cams
2. Coat cams and followers generously with Piper cam lube (thick red stuff)
3. Check entire valve train for interferences (e.g. coil binding or rocker striking valve guide)
4. Do NOT remove black 'phosphate' coating from cam lobes (though wash of the rust inhibitor with paraffin before installing)

1. Do NOT idle the engine during the first 20 minutes of operation, rpm should be 2500rpm or more. DO NOT IDLE blah blah

Although cam gloop comes with new cams I dare say you can buy it specially. Just google for Kent cams or Piper cams you will find it I am sure.

V8s can eat cams - my old P6 had swallowed an entire lobe before I found the cause of the misfire (it was down to about 30thou of being perfectly circular), so it is good to give them the best start in life

Steve

I did some reading up and googleing on why it should be bedded in as such, and now see why. all the car engines i have done have been OHC with hat style followers/tappits which is why i havent encountered it before.

There were some people on google saying they used just engine oil generously, or even engine oil mixed with grease so i went with it- the proper cam lube just appears to be 'stickier' oil from what i can find.

Dont have the time or the tuits to take it all apart again (i need to get it back on the road asap!) so it has ended up being done without the proper oil - but i used lots of engine oil during assembly!

I did:

Followers were submerged in a big pot of new engine oil for about 9 days before fitting with occasional rotatings.

new (std) Cam was cleaned and dipped in oil before fitting in engine

after cam, followers and pushrods were fitted a litre or so of engine oil was poured over it all.

ran the oil pump in the engine with a drill for about 5-10mins getting about 20psi on the pressure gauge.

its so far had about 6 minutes at 2000-2500rpm. had to stop as it was getting hot in there and i was dying from smoke inhalation (oil on the exhaust manifolds!) will give it another 15 mins or so tommorrow and hope the cam is alright with that..

Casting my mind back ( I do a bit of beachcasting so I can get quite a way) the recommendation we had for new trucks ( yes I know we are talking V8 car) was not to exceed 3000 rpm until the first oil change (1000km) not to allow the engine to labour and not to run at a very constant speed (to easy to hit the m6 and nail it at 60mph for an hour) but to vary it periodically seemed to work my engine was still sweet after 250,000 though I did have a turbo go titsup at 50,000+. Derek

there seems to be so many different approaches for breaking in new engines depending who you ask or what you read!

After i've given this cam another 10-15 minutes or so im hoping i can just get out and drive the truck normally. I'm not gonna deliberately thrash, but im not going to take it easy - just drive it normally. . Shall change the oil and filter at 1000km or so.

Tom Woods uttered summat worrerz funny about:

I wouldn't beat yourself up too much over it.

What ever you do it's still going to be metal rubbing against metal with oil to lubricate it.

The rest is just common sense. I'm certain all our old V8 Police vans were run in..... like hell they were, they were thraped to within an inch of there life and proably the only bit worth pulling out and transplanting in to another vehicle in the end.

Lee D

It should be fine. You've done everything that's reasonable and then some. I feel the magic goop is only really necessary on high-performance engines with outrageous valve spring pressures.

Sounds good to me - not only the correct oil for the engine but not anything too special so it's unlikely to glaze the bores either.

With regard to "taking it easy" I'd not bother too much. The major thing to avoid is letting the engine labour - it's far better to change down early and let it rev a bit and run freely whilst it beds in. I'd definitely be changing the oil & filter after the first 600 miles or so, and then changing just the oil after another 2000 miles or so. The mineral 20W/50 will be just fine.

One last thought - you have fitted a new thermostat haven't you? Having it run either to hot or too cool during the initial miles will do it a major disservice.

Yeah. im on a stock new cam which is the correct one for the engine and used plenty of oil. Since ive now rebuilt it once I can actually get the cam out if i wanted to do it again (my socket is still wedged in the centre of the crank pulley so its very easy!)

Its in a 101! its gonna be using a lot of its revs just to get it to move! (as a consequence of the weight and low gearing you have to use all of gears - especially 3rd!) in a 101. 1st and 2nd are for pulling off. 3rd is for driving and 4th is for cruising...

no - no new stat but i know the existing one is good as i have a proper temperature gauge and it always runs fine. It runs a tad cooler than it perhaps should (I drilled a small hole in the stat as mentioned in a previous thread and went a mm bigger than i should have done) - but in a 101 that is good since they run notoriously hot! Sits at about 85C as normal and rising when i thrape it up a hill. Will even cope with sitting in stationary traffic!

Ran it for a minute or so at revs with a rocker cover off (what a bastard to do!). There is loads of oil splashing about (much of which is sprayed over the gearbox and LPG kit now) so the cam should be well lubricated! Cant do a lot else.

I've got a mate who has had a couple of new cars and he reckons the one he thrashed when it was brand new was loads faster than the one broken in gently.

I used to race motorcycles and sidecars, and new ones we used to 'run in' by keeping revs to 1/4 of the redline for maybe 50 miles, then up to maybe half their redline for another 50 then occasional blats to full throttle for the next 50/100. Always varying the throttle and load, use the gears a lot, with very light loading for the first 50.

Never blew a racing engine and always had decent, oil-tight, reliable kit. ;)

Always changed oils after this 'run in' (which we always did in a day) and filters, then oil and filter after another 100 miles, then normal service ... which with a our racing engines was oil and filter changes every four races.

The business of running in engines is a bit of a mystery - after all they don't run in race car engines do they ? I certainly haven't seen them with "running in please pass" on the back ! Thought they always warm them up before driving.

On the other hand some very tuned engines, such as a Ducati (120bhp out of 750cc is fairly tuned), are run in just like the good old days

- and they have running in oil for the first 600 miles, and progressively increasing rev limit as you clock up the miles.Most modern cars don't seem to have much in the way of running in, and I think this early first service seems to have disappeared - so its all rather a mystery.

There are no doubt a lot of different factors, and I am pretty sure that bedding-in the cylinder bore used to be a big concern - maybe oils have advanced so this is less of a worry, or maybe they use different materials, or maybe they are able to machine to closer tolerances. If its the oils that have improved (and I think this might be the main thing), then even though the Rover engine is a 50 year old design, there will be no need to follow 50 year old running in practices. I certainly didn't go to any great lengths with mine - though I didn't really start to work it hard until it had some miles on it.

Steve

I've been following this thread with a certain amount of interest, & the main reason for running in seems to have changed in the last 20 years or so. It used to be that running in involved knocking the roughness off the newly installed components, but with the advance of machining techniques, this became less important. The running in oil typically has a lower viscosity, but an increased HP additive, like the one used in hypoy axles, to accomodate the small unevennesses in the bearing surfaces.

Race engines seem to be built to much tighter tolerances than road engines, and don't need to last as long, so don't need running in as such. They also get a fair amount of testing after they're built but before they get installed, so they're pretty much run in before the race. A Formula 1 engine only has to last a few hundred miles & a few hours, not half a million miles over 20 years.

With modern techniques, the bearing surfaces can be made smoother and to a finer tolerance, so the rough edges aren't there to be knocked off, but the materials used for big ends & the like still need to gradually work harden, so while speed isn't so much of an issue, the pressure on the bearing is. If too much pressure is put on the bearing too soon, the material will initially wear relatively rapidly, so slogging the engine early on will reduce the life of the bearings, as the clearances will increase. The same applies to piston rings & bores, the finish you can get now is better controlled, so again, high speeds aren't a major problem, but high power is.

I could, of course, be totally wrong here, but that's my understanding of it. It's one reason you don't see Running in, please pass stickers on the back of new cars any more. They don't need to drive that much slower for the first few hundred miles, but they do need to be treated gently as far as acceleration goes.

With 50 year old engine designs, the running in would depend on the standard of the components used in the rebuild. A crank ground to modern standards, with bearing shells to modern standards will need modern running in techniques, ground to old standards, with bearings made the old way, it would need old running in methods. Just my 2 penn'orth:-)

They are run in on the dyno. I have a run-in programme on the dyno for the race engines I build. 30 minutes or so of lightly loaded running, then I can get down to the business of tuning them for maximum horsepower.

That sounds perfectly reasonable - lovely to hear from someone who really knows. If it is not giving away a trade secret, is a new engine on your dyno lightly loaded at near to full revs or at reduced revs ? I get the feeling that all the old-fashioned limits on revs when running in an engine are to prevent it getting too hot - and I suspect heat is related more to power output (or dyno load) than to revs. If this is the case then running in instructions could be more like "use it freely but don't make it work too hard". Some old fashioned engine running in instructions used to say vary the revs and do not hold it at constant speed.

Steve

Lightly loaded, running fairly freely from 1800 to approx 2/3 of redline. IME constant revs are not good and letting the motor lug under high loadings is a sure way to glaze the bores.

Overheating isn't ever a problem for me - I'm only building sub-600HP engines and the dyno I have use of is set up to keep 1000HP cool.

bastard :)

I pay thru the nose to use it. :-(

I was thinking more in the terms of 'GIT' ;-)