40 replies to this topic

[MiniLuke]

My rebuilt 998 engine is smokey (blueish) when the throttle is opened up and have been told by Peter Baldwin that I need to replace the oil back to running in oil and drive it hard for 500 miles or so to try to get the rings to bed in properly.

The engine has liners to STD size and "d" top cooper pistons. On running in I set up the twin carbs myself and as it happened the fuelling was very rich. During this time the engine was ran carefully rather than the "hard" running in method, and being overfuelled may have caused bore wash and prevented the rings bedding in.

Oddly the engine didnt smoke too badly for the first 500 miles, being run on cheap comma oil. At 500 miles I changed to Halfords Classic oil and then had it rolling road set up. On changing the oil it started to smoke on acceleration, and now the rolling road has been done and the power increased, the smoke has got worse.

Peter was quite confident that the rings could still bed in. I have replaced the oil with millers running in oil and driven it for about 40 miles or so with clouds of smoke at times, although it might be getting a little better (or running out of oil to burn!).

The question is, is it worth carrying on trying to bed them in, or give up now and conceed that the bores need re-honing new rings gapping etc. i.e engine out......

[oltonlad]

mmmmmm, well you have nothing to loose by doing what peter says to start with, drive it hard for another 500 miles and see how it is, vary the rev range between 2 and 5000 rpm (but no more than that)

its either going to go one way or the other, its either going to stop smoking or it will continue to smoke....were the bores honed properly before you put new rings in it?

[grumpy2]

Hi again luke, sorry to hijack but your pms seem not to be working.

Refund for the sub will be good for me, no sign of it being delivered. You should be able to get compensation if royal mail have lost it.

Look forward to receiving the refund

Cheers

[MiniLuke]

What are on about grumpy2, ive not sold you anything.......???

[grumpy2]

Sorry if I've made a mistake, will pm

[MiniLuke]

mmmmmm, well you have nothing to loose by doing what peter says to start with, drive it hard for another 500 miles and see how it is, vary the rev range between 2 and 5000 rpm (but no more than that)

its either going to go one way or the other, its either going to stop smoking or it will continue to smoke....were the bores honed properly before you put new rings in it?

I honed them. I am thinking that it was ok, but I don't know for sure. I am concerned i have glazed them by running rich.

The pistons were used D tops, and the block a NOS one with liners from the factory. I am learning that machine shops match the pistons to the bore. I did measure them and the ring gaps, but i am a little concerned now. Do you think new flat top pistons and a re hone/matching by a machine shop (usually use MED) and a skim of the head to raise compression is the safer route to acheiving success?

[Sam Walters]

Try as Peter says. Try a compression test on it, then try one wet with caps of oil down the bores. If everything comes out a-ok i would have the head off and put new valve stem oil seals on all 8 of the valves.

But get rid of the halfords oil and get a new filter on it.

this is based on experience rather then anything else. Been present in the teardown of a 1380cc 300 degree cammed that had been run on halfords oil.

[MiniLuke]

compression has been consistently 155 accross all 4.

could it really be valve stem seals, the symptoms point to rings to me?

also, is a know issue that halfords oil has this effect then?

[ACDodd]

I think you may have bore washed the engine. By all means try but I think you will be measuring the bores and re-honing/re-ringing as required. Engines need to be run lean during break-in.
This is all too common on new engine builds.

AC

Edited by ACDodd, 13 June 2012 - 09:54 PM.

[MiniLuke]

Sorry if I've made a mistake, will pm

just thinking, do you mean mini-luke another member...... I had the name first i'll have you know!

[MiniLuke]

I think you may have bore washed the engine. By all means try but I think you will be measuring the bores and re-honing/re-ringing as required. Engines need to be run lean during break-in.
This is all too common on new engine builds.

AC

Yes, I think I know in my heart this is correct..... I think I'll go down this route as I am impatient.. Peter said that now the fuelling was correct the cylinders would be burning dry now and might assist breaking in, but I think I know it's not going to happen really....

[grumpy2]

Could well be, please see pm

Sincere apologies

[Sam Walters]

Could have bore washed the engine. But you could also have honed too big and too uneven if you used one of those things that mounts in a drill.

Only one way to find out.

[MiniLuke]

Could have bore washed the engine. But you could also have honed too big and too uneven if you used one of those things that mounts in a drill.

Only one way to find out.

I must say I found it quite difficult to hone the linered bores with the drill thingy. I heard from someone that liners are harder than a straight bored block.

I doubt I over honed it as to get a cross hatching seemed quite difficult. Is the alternative to get it honed by the machine shop to be sure, is the drill honing tool not recommended then?

[Sam Walters]

Well.



Take a look at that video. Youll understand why. Measurement of bore ect ect. consistancy through bore, lube.

Edited by Sam Walters, 13 June 2012 - 10:56 PM.