Hi everyone.

So it came time to start the old girl after the blown head gasket overheating affair. She didn't start without a fight - I was losing hope and then I heard a cough from within and finally got going.

The only problem is she's running on 3 cylinders. It is number 1 cylinder (closest to rad end). What are some possible causes be? I've changed to other leads and spark plugs to no avail. What else should I be checking?

I run an electronic dissy. The spark plug is wet with fuel and there is a spark from both sets of leads and plugs but clearly not firing.

Any help would be great.

Cheers
James

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Have you disconnected the fuel and tried grounding the plug to see if it still sparks?

Also, have you compression tested since the gasket has been changed?

Does it only run on three for all revs, or will it start firing if you give it more revs? Might just be running too rich.

Hi there

I didn't even think to do a compression test. I just had my comp gauge (I'm not sure HOW accurate it is, but here are the results

Cylinder 1 (not firing) - Didn't even register a number
Cylinder 2 - 150 psi
Cylinder 3 - 50 psi
Cylinder 4 - 130 psi

I think the engine is a boat anchor right?

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was about to say, just check the rockers on #1 before you get too upset, one might not be closing

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This. Afterwards, check compression - if it's still bad, put a little oil in your cyclinder and try again. If the pressure rises, it's your rings. If not, most likely a valve stem seal, or maybe a cracked head :/

Did you check your head for flatness and/or have it machined flat?

I'm not too sure what I'm looking for exactly. With the rocker cover off the springs seem to go up and down.. does that mean their closing correctly?

I should also note I got head work done once it overheated - it's definitely not cracked it got tested, I also got double valve springs put in cause a couple on mine broke. All new stem seals and valves serviced ect. It also had some porting a polish and was decked for flatness.

Would that mean my rockers would be all out of whack? Just chucked them back on how they came off cause I don't know how to adjust that stuff correctly

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Yeah im guessing you got a valve not clos8ng. Rockers need to be adjusted especially since you had the head skimmed.

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The best part of fixing your mini is the test drive

Minis..

1976 van daily drive
1975 van
1968 deluxe in the shed
1967 deluxe high strung 1310
1959 austin healey sprite

OK, so it's probably your rockers then, if you've had you head adjusted, they need to be adjusted too. If you jack up one side of the car and put it in gear, you can turn the wheel to turn the engine and watch the rockers open and shut.

Each rocker should open - the spring will fully depress, and there will be a gap between the rocker arm and the top of the rocker. If there is no gap, the valve will not go up high enough to create a seal with the head.

So going back to turning the wheel, watch the rockers and turn until one arm is as high as possible. At that point, get a feeler gauge and check the clearance between the rocker and the valve. If memory serves, it should be a 12-15 thou gap, but don't take my word for it. Some people also do different gaps for the exhaust and inlet. But anyway, once you have one valve done, keep tuning the wheel until the next rocker is at it's peak, and repeat. The engine will fire cylinders 1-3-4-2, so the valves will also follow this order. Do all the exhaust valves, then the inlet (or inlet then exhaust - if you want to do inlet and exhaust at the same time, you can, but the order isn't as simple to follow

just to add to Irish's post there...

You adjust the gap marked '2' in this photo :



Using feeler gauges and spanner and screwdriver as shown.

Then follow the "Rule of 9" as shown below to adjust them in sequence - stock cams are 12 thou gap...and happy days should follow




cheers,

Jacob

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'72 Clubman Van - 1022cc, 295 head, 731 cam - Daily Driver
'69 Morris 1100 S - Dinged by a bus, in shed under repair
'64 Morris 1100 - Early 1100, long term project

When I have done the rocker clearance I set the cylinder to TDC for for the firing stroke for #one cylinder so both valves should be closed and adjusted both inlet and exhaust.
Then wound the engine over 180 deg to the next cylinder #3 (see which one the rotor button is facing) and adjust both valves for this cylinder and on you go.
Is this OK

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Find a job you love and you will never have to go to work !

Yup that works phil

_________________
The best part of fixing your mini is the test drive

Minis..

1976 van daily drive
1975 van
1968 deluxe in the shed
1967 deluxe high strung 1310
1959 austin healey sprite

Haha, yep, sounds easier than my method with each cylinder separately.

Thanks everyone. It doesn't seem too bad to do then. Does anyone know the inlet/ exhaust clearance for a GR Re83 cam? It aas mentioned a stock cam is 12 thou

Cheers
James

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I wish I had some sort of witty quote in my signature

Most people run 15thou on mild to mid range cams.

According to the good doc here, the clearance for the RE83 cams is 0.016" for 1.3 rockers.