The V8 Owners Forum -

About to start my 3.9 efi 1990 engine soon, was wandering what procedure to do about running it in holding it at a certain rpm for a certain amount of time, plus how to drive once out on the road It has new pistons,rings,rods big/main bearing, cam, followers .Will prime the oil pump up via a drill attachment so thats sorted. Also what oil have others used and when do you do the first change, my last engine rebuild I did at 50miles - is this right?

Thanks

Leigh

I am assuming you have got plenty of cam lube on the cam and followers. best oil, ant 25/50, most people like to use a cheapie as they drain the engine down after 50 or 100 miles, What you most NOT run rhe engine on for a good few thousand miles is any form of synthetic oil, as the syns better oiling abilities will not allow the rings to bed in and possibly glaze the bores,
once started, its reccomended you run the engine for about 20 mins at about 2k to bed the cam in, after that assuming there are no odd noises and the engine is dry externally. drive it, Not hard, just pootle around, no more than 3k for the first 250m, then increase the rev limit by 500 every 100m dont cruse about on a motorway at fixed revs untill the engine has probably about 1k on it,

I always smile when the 'run the cam in at 2000rpm for 20 miuntes' is mentioned. I'm not having a go or even advising anything different (the cam manufacturers advise it after all) but how many of the factory built million RV8s ever got that? how about the 50-60-70 million Chevys or Fords built over the years - not a single one. In fact, in a car plant they get started and stopped for as little as seconds at a go, using 'the utmost of care' from new while the cars are shunted around the factory. They then go to first careful owner who religeously run them in (but without the 20 minutes advice) - fortunately most go on to do 100K miles, in some cases with barely even an oil change, before the cams wear out.

Anyway, recommendationi s 20 minutes cam break in, followed by a few hundred miles of no low speed high load running as already said by Ian.

Russ

I've always found this:

http://www.mototuneusa.com/break_in_secrets.htm

Very intriguing......And a few people who I've know to follow it have had very good success with the engines feeling much more flexible than similar 'normally' bedded in ones

I know it's for bikes but the logic applies...

The honed crosshatch pattern in the cylinder bore acts like a file to allow the rings to wear. The rings quickly wear down the "peaks" of this roughness, regardless of how hard the engine is run.

There's a very small window of opportunity to get the rings to seal really well ... the first 20 miles !!

If the rings aren't forced against the walls soon enough, they'll use up the roughness before they fully seat. Once that happens there is no solution but to re hone the cylinders, install new rings and start over again.

Fortunately, most new sportbike owners can't resist the urge to "open it up" once or twice, which is why more engines don't have this problem !!

An additional factor that you may not have realized, is that the person at the dealership who set up your bike probably blasted your brand new bike pretty hard on the "test run". So, without realizing it, that adrenaline crazed set - up mechanic actually did you a huge favor !!

Thanks for replies, really helpful

cheers

Leigh

Lewis wrote:I've always found this:

http://www.mototuneusa.com/break_in_secrets.htm

Very intriguing......And a few people who I've know to follow it have had very good success with the engines feeling much more flexible than similar 'normally' bedded in ones

Have heard that before- is quite tempting to give it a go...! Whats there to loose!!!

This is something that has been worrying me, as the advice for running the cam ie 20mins at approx 2000 RPM on a relatively light throttle is completely the opposite of what you need to do to bed the rings in properly.

Des Hamills book recommends putting some load on the engine asap at say 2000/2500RPM which would mean finding a long steepish hill and driving up it in third gear, turning round at the top switching off coasting down and repeating several times to ensure the rings have bedded in properly. You could of course do it on a rolling road or have the engine run in on a dyno where a proper load could be placed on the engine.

Of coarse you still have to get the car to where you want to run it in without starting the engine and running it on a light load.

Comments?

Kevin.

I ran my new 4.6 lump using advice on the following websiite:-

http://www.pumaracing.co.uk/runin.htm

I ran the cam in first then did the 10 hard blasts to pump the rings into the bores. After that I just drove the car normally but did not keep the rev constant or under very light load/hi-ish revs so that the bores did not glaze too quickly.

Use valoline VR 20-50 or something reasonable but like others have said not a sythetic.

When running the cam in have someone ready to blast the rad with cold water from a hose pipe, if the motor starts to over heat kill it without letting it tickover at all. Its a bit tricky to get all the air out of the system at first so you might have to run it with the cap off for about one minute with the revs up at 2k whilst someone tops up the system. As soon as no more coolant can be added stick the rad cap back on.

I found that having three people around helps!

Pete

Didn't realise there was more information on the motortuneusa web site

Have now read the whole thing and it makes a lot of sense so think i'll use this method which is still a slight compromise.

Do the initial start up and run the engine at say 1500RPM to warm the oil and check for problems then as sdon as it's warm enough get the car on the road and run it through the accleration and decelleration cycles as recommended and run it for sbout 50 miles, provided thst the engine isn't aloowed to idle below say 1500RPM there should not be any detrimental effect on the the new cam and the rings should have been bedded in.

Sounds simple but it's not going to be a fun drive!

Kevin.

Kevin,

I agree that it would be better for the rings if you did not have to run the cam in but with regards to Des Hammills comments, he is talking about the bores being plateau honed which is not quite the same as a normal hone.

One thing is for sure which is that nursing the engine for a 1000 miles will do it no good at all!

Pete

Its obviously up to any single person to run an engine in they way they think is best. There probably isn't any single completely right way to do it. Having read some of the link here though I would warn on one thing though. On any Rover engine whether it be a P5 up to the last of the 4.6 engines you are not dealing with a modern engine with modern materials and modern engineering standards and practices. You are in effect dealing with an engine that was born in the 60s with everything that that implies. At the very best your dealing with materials and design from the early/mid 90's. Even if it is a freshly machined engine I would put money on it that the majority of machine shops work is far from completely accurate. There are always exceptions to this of course and the reality is that you will get what you pay for. Get a cheap rebore and you will be within tolerance but you wont be at an optimum blueprinting standard or even a modern mass production standard.
Anyway in short don't go thinking you can treat any Rover V8 like you can the latest greatest Audi or Lexus V8s or even something that appears to be old skool Chevy LSx.

Pete,

My bores were plateau honed so how differently should they be treated.

Kevin.

CastleMGBV8 wrote:Pete,

My bores were plateau honed so how differently should they be treated.

Kevin.

Well according to Des they do need to be put under load as soon as the motor is fired up. (But then you knew that as you've got his book!)

I guess it's due to the fact that the "peaks" of the ridges of the honing marks no longer have a sharp points, they now have a plateau due to the finer grade stone that has been passed down each bore after the rough grade. In effect the bores are already some way to being smoothed and glazed so the time frame to bed the rings in is less. This is my understanding of it and could be totally wrong (as usual!)


Pete

Pete,

Yes just re-read the section in Des Hamills book which does indicate how important to get the engine under load asap after start up.

I thinking it may be necessary to get the car onto a rolling road with no prior start up so that it can run under load straghtt away and run it at a min of 2000RPM for approx 20 minutes to ensure the rings bed in and the cam is properly run in, which means getting towed or transported to the rolling road.

The nearest rolling road to me is Sanspeed at Bexleyheath who I believe have a good reputation, anyone have any experience of them?

Having spent a lot of money on building this 4.35 engine I would hate to screw it up by not doing it properly.

Kevin.

CastleMGBV8 wrote:Pete,

My bores were plateau honed so how differently should they be treated.

Kevin.

You need to get the engine loaded straight away, I glazed the bores on my plateau honed Rover engine whilst running the cam in and it burnt oil from day one

Mark