Hello Everyone,
I'm looking for some advice about my smoky engine - I want to know if its the rings or the valve guides, or both.

When you start the car in the morning the exhaust is very smoky - fills the driveway up with smoke! The smoke dies down once you drive off and it warms up, but it still blows smoke when you floor it when driving. When I start it after leaving it at work for the day it is also very smoky, but otherwise it isn't particularly smoky when started warm.

I took it down Black mountain the other day, left it in third off throttle for most of the way down. When I got to the bottom and accelerated hard into traffic, it was very very smokey, like a two stroke!

Got it home today after work, backed it up the driveway, and lay on the throttle at a fast idle (2500rpm) and there didn't appear to be any smoke at all no matter how hard I tried.

The thing is I thought (and have been told) that generally valve guide wear doesn't produce smoke in the large amounts I am getting. Took the spark plugs out today and No1 was oil fouled. I had a temporary head on a while back, that one fouled No4 plug, No1 fine. We had put a exhaust valve in No4 due to the old one being cracked, so that was why it was smokey then. Maybe I have buggered a valve on No4 on this head, when I lapped the valves?

What do people think?
Anto.

If it only gives a puff on starting or at then bottom of a long hill it's probably just guides.
If it blows under load and is using heaps of oil, it's rings.
I wouldn't bother just re-ringing it (been there, done that..) as the bores will be worn- the cure is to rebore it and fit new pistons.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

1. white smoke when just startin up = water/condensation = not much of a problem

2. blue grey smoke = oil = rings/valves

3. black smoke = too much petrol

option number two would be your biggest enemy i would think

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Inconspicuously Conspicuous
Appreciation without Depreciation
forever chasing clearer skies...

Well it is definately oil smoke, and a couple of weeks ago I topped it up with 1.5L of oil, after only a week or two (can't remember exactly how long). Thicker oil hasn't helped much. Probably used 15 litres of oil topping it up between oil changes, looking at the amount of empty bottles lying around.

Weird thing is, the car still goes hard. On my last motor, with very blown rings, the engine ran like a dog with heaps of blow-by. Haven't got unusually high levels of blow-by at the moment.

I was under the impression that the reason you get smoke after deceleration through the guides (like going down hill off throttle) was higher vacuum pulling oil through the guides. Does this go for rings too? I think it must be a mix of both. Might do a compression test (leak-down) and see what I come up with.

Any chance of getting a another virgin block and boring it 20 thou and using my current pistons?

Last question 1st- if the pistons have been in there long enough to wear the rings & bores out, probably no. Skirts and ring grooves will be worn.

Downhill, the vacuum in the cylinders can pull oil up past the rings if they are stuffed.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Hmm in that case I might think about rebuilding a 1275, ready to go in *before* the current motor finally blows up. Any thoughts on using an A+ Metro motor as a basis? I may be able to source one, either full power unit or short block - I take it I must change to non A+ drop gears if I wanted to use my existing gearbox? Does the pulsar dizzy conversion work equally on an A+ motor?

Anto.

Metro A+ is OK I run one in Barney. Just need an A series 1275 primary gear. Otherwise bolts straight on.
Mine has A series timing cover, no breather to get in the way.
Make sure you open up the breather hole on the flywheel housing! 1275 needs it.

Pulsar dizzy fits, you need to use the A+ drive dog, and machine the Pulsar flange a little for the clamp plate.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Do you know if the A+ units came with duplex timing chains?

Ant...have you done a compression test? engines generally will continue to function till the death with increasingly low compression....have you considered getting a leak down test...to determine whether it is the guides or not??

BTW Stu will be calling you soon about Albury....is Chris coming (or WHAT!!!!)

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"Show me the Mini!"

Yeah I was planning a leak down test just to be certain. My motor definitely isn't in a hurry to die, just have to keep the oil topped up is all!

Albury is this weekend isn't it? Might put the HS2 carb on for the trip to improve the mileage And no, Chris has piked, it will just be me.

Pretty sure they had a single row, with a tensioner. But ours is a duplex..

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.