The V8 Owners Forum -

According to A. G. Bell a plateau honed engine needs to be run in on a dyno, it need to be put under load within 30 seconds of it being fired up.

who's he?... and what happens if you don't?.....

I agree with pushing the rings out to bed in.. why you have to do this within 30 seconds of starting I have no idea?...

Have you got a gas sensor?? Or access to one- this should tell you if you are burning oil - you may have already said but what do your plugs look like?? I ran my engine in with a very Hal hazard initial stage but within an hour or two of running had it on the motorway and under load- good rings and a nice hash pattern stone hone - I actually run an extra thou clearance to reduce friction at temperature and burn no oil. The rate of consumption you are describing would give you evidence on your plugs and exhaust gas I believe- crank case pressure my lead to heavy consumption - but are you certain you don't have a leak around the filter or rocker gaskets or around the sump while running- I know you may think me cheeky for suggesting this but I have been caught out on stupider things:-)

hi.. no, I've checked for leaks and its bone dry.. I've even looked for fine jets spraying on the ground but nothing.. Plugs are fine.. not a lot of crank case pressure and the vent pipes are very clean with little evidance of oil... It passed the MOT fine but I do have a gas annalyser so will give it a go... But never any smoka at all even when my mate followes me and I overrun 500 meters and blast it.. nothing.....
TBH 1 ltr over 1200 miles is only 1 ML per mile so would you see this??

Mobil 1 5w50 peak life inc 1200ppm zinc, same as Valvoline 20w50 VR1..

When i build my 5.2l engine and wonder my oil consumption.. I ask it for V8 Developments.. They say it is quite normal for those big engines..
You have got short piston skirt and rod´s are short also? This will make more oil consumption..
Do you hear any piston lap noise? I think not if tolerances are ok..

A. G. Bell wrote a few books on tuning engines,

http://www.amazon.com/Four-Stroke-Performance-Tuning-Graham-Bell/dp/0857331256

With regards to plateau honing he stated something along the lines of plateau honing being a much finer hone that is sent down each bore after the main hone, this fine hone takes off the sharp peaks that the normal hone leaves behind, as a result each peak now has a flat plateau on it. I think that the sharp peaks normally bite into the rings and bed them in but in the process there is some wear on the rings, with a plateau hone there is much less wear on the rings but they must be forced out into the bores very quickly otherwise the bore will be too smooth to bed the rings in, once this has happened they won’t ever truly bed in.

When a pure race engine is built it can have the bores finished with a rough hone so that the rings bed in as soon as the engine is fired up, the down side is that the rings then do not last as long but this does not matter on an engine that is rebuilt frequently.

Another thing to bear in mind is that some engine shops use the words ‘plateau hone’ when in fact they just carry out a standard hone, plateau hone just sounds better!

The advantage of plateau honing when the engine is run in correctly over a standard hone is that the rings last longer and the blow by only after a couple of hours running can be down to zero, this is not something that a standard hone will usually achieve.

The above is just what I have read, I’m not saying that it is right or wrong!

hi, Yes.. may try the mobile 1 see if it works?.. when you think its using less than 1ml (size of a pea) per mile over the 8 pots and quite a few revs in that distance, it's not massive usage... I think it may be the hone still bedding in.. I also have very good oil pressure so this may be splashing more than normal on the walls? and no noise.. it all sounds good

It was just std honed. I think from what you describe the other honing method is for more modern engines that come as 'already run in' and not our V8's... I've had arguments both ways on this saying it's best not to have flats put on the peaks as it stops the rings bedding as well as peaked bores do...

Hi
if you are using 1 litre in a 1000 miles you are running about 200 to 225:1 petrol to oil, that would foul your plugs if it did it continuously I still think it is chucking most of it out when you refill then running normally either that or it is chucking out when it is cold and using less when warm, otherwise the plugs would show it. I also suspect that you rings have not bedded fully as I think the oil you filled up with to run in with is far too good, on older design petrol engines I like to fire up on straight 30 weight oil, with extra Zinc, get the cam bedded, set the rings (a good blast up a hill) and dump it out and put some cheapo 20/50, many of these modern oils are just too good for an engine designed in the 50s I certainly not put semi synthetic in a rover V8.
What cylinder bore are you running? 3.7" or something much bigger needing special liners? I'm not sure I would plateau hone a highly over bored rover engine where the cylinder bores can flex more.
Best regards
Mike

running in was done on cheap 10 w40 mineral oil so should have been okay.. I did 800 miles on this.
It does appear to put a bit more water / sutt out now when cold I've got to say.. maybe it is using it on start up? although I've moved it around the garage a few times without getting it warm.. and again removed a plug or two.. and can't see any issues??...

The only official maximum oil consumption figure I have ever seen published was in an old Rover workshop manual update for something or other and that quoted 450 miles per pint!!!
More modern variants of the engine ought to use less in all honesty, what with the improved valve stem seals etc, but your engine is still settling itself down, run it in on a 20W50 mineral oil for a few thousand miles more and see what it does. RV8 engines, in my experience, tend not to like or tolerate modern synthetic oils all that much, and they will eat a thinner oil than that which they were designed for. Dizzy and external oil pump, use 20W50. Internal oil pump (over nose of crank), use 10W40 or 15W40.
I have been rebuilding RV8 engines for over 25 years and the only one I ever came across where oil consumption didn't settle down within 3 or 4000 miles was traced to an incorrect breather routing on a 3.9 with a Webber 500 carb.

Thats interesting to note.. I guess I'd already made my mind up to run it next season and see what it does.. I'm on 20 w50 now so may drop back to 15 w40...

I have also talked with 'TVR Power' on this and they did come up with something that could explaine it... If my bores were to top limit when they were honed, the hone could throw up peaks a bit so they measure okay when checked, howevre running in could now take them oversize opening the ring gap up outside tolerance.. and in doing, letting more oil in to the conbustion chamber? it does sound plausable as you can't just keep re-honing a bore without making it bigger. how much gap youd need to use this amount of oil I don't know.. but it does answer why my CR is fine and no blow by pressurising the crank case as the rings are run in very nice.
I do have a lot of oil pressure (more than is required) so also wonder if the bore is getting splash fed with too much oil?.. it may be worth dropping the pressure a bit?....
had a scope down the bore tonight and nothing much to report.. the hone still looks in top condition with no glazing at all....

what do you think?.. could this be the answer?... file fits required??.