Hi everyone,
I brought this motor earlier in the year and was told it’s a "good runner". It’s an 1100cc and I got it for a good price, but its missing a carby. The guy I brought it off said that the guy he brought it off, was going to use it in the car and had no reason to believe it wasn't any good. I want to know, before I go to the trouble of trying to use it in the mini is. What is the best way to check if the motor is any good? I don’t really want to do a full rebuild on it (never done one and at the moment don't have the funds), just want to try and clean it up and get it running if it checks out ok. So where is the best place to start? So far I’ve got it on the engine stand and I gave it a good clean up.



Any help would be appreciated.

First thing I would do is an oil change checking condition of the oil and if there are any bits of metal or brass.

Then prime the main front oil gallery and oil filter pipe, put some oil on the rockers, down the pushrod holes and a squirt down each bore. Leave the plugs out and spin it over until you get oil at the rockers. Fitting an oil pressure gauge would be good so you can check the condition of the oil pump and bearing wear.

Then do a quick compression test on it. You will need to get it running and warm it up to do a proper compression test but a cold one will give you a starting point. A 5% variance between the cylinders is ok but anything over 10% could indicate an issue. Compression can vary a lot between different motors, anything between 150psi and 180 psi depending on the compression ratio.

I would rip the head off and check out things like carbon build up, piston slap , bore condition, check for a lip where the top ring stops, head gasket condition, valve recession, valve burning, visible cracks, rust etc.

Great thanks for the info gtogreen! That's sounds l like a good place to start. I'll get an oil pressure gauge, could probably do with one anyway. Do you know what size socket is required on the front of the motor to turn it over? I don't have on big enough. I don't need any special tools to take the head off do I? Should I take the head before coving it in oil? After that I'll probably need to check the gearbox too.

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The crank pulley bolt is 1-5/16" = 33mm approx.

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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.

Awesome thank you!

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Don't expect to do a compression test using the front pulley bolt. You will have to use the starter motor for that.

No special tools to pull the head off. 7/16" and 1/2" sockets will do you.

There are only 2 ways to know for sure if the powerplant is a good runner.
1. Stick it in a car and run it
2. Pull it all apart and check the clearances, replace worn parts. ( Rebuild)

The suggestions I made were just to get an idea of piston ring wear before you start to pull it down. A head gasket is cheap and pulling off the head is quite easy and tells you a lot about an engine. If you want to know what the gearbox is like then its either drive it or pull it apart.

Fair point! Thanks for the advice. That car is up at my parents place, so you've given me a good place to start. I'll start with your suggestions and see what that reveals. It might be stuffed?

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OK I hooked up a battery to the starter motor and got it to turn over after oiling it up. What's the best way to hook up the starter motor. It would turn the engine over for a moment and then stop. It seemed to be shorting the battery out and heating up the jumper lead which is not good.

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Make sure the plugs are left out and see if you can turn it by hand. It should be easy to turn over without the plugs.

Ok, well it didn't turn easily by hand so I figured I might as well take the head off. Once I got the head off I realised that the plate on the flywheel was rubbing on the engine stand, which may have been stopping it. Now with the head off it’s easy to turn over until the pistons are inline with each other, but I’m guessing this is normal? Well it doesn't look too bad to me, but to be honest I don't really know what I’m looking at . So I’ve attached some pic's, I know it not really easy to tell these sort of things from pic's but it’s worth a shot!

Its a shame you couldn't check the compression before the head came off. The problem now is you won't know if your rings are ok until you put it all back together. But a head gasket is only $20.

Here is just a few checks to start with.
1. Deep scratches in the sides of the bores. This could indicate a broken ring.
2. A large lip near the top of the bores. This indicates that the bore is worn and may need a re-bore.
3. The bores will wear an oval shape. With the pistons at TDC try rocking them back and forth with your thumbs.
4. You can clean the carbon off the tops of the pistons and combustion chambers. I like to leave the carbon at the top of the bores. Make sure you clean out all the loose the carbon particles from beside the pistons.
5. Clean the mating surfaces and check them for flatness.
6. It is worth pulling the head apart. You can check the wear in the valve guides, valve seat recession, burnt or worn or bent valves, cracks in the metal around the valve seats.
7. Wear in the rocker gear bushes and the contact pads.
8. Valve spring heights.

If it all looks ok then you could just lap the valves back in with some paste and put in some new inlet valve stem seals. Wack a new head gasket back on and start it up. Just get a VRS kit like this. http://minisport.com.au/mini-850a998a11 ... gasket-set

Yeah it was a shame, silly me. Oh well. I'll check through your list and go from there. Thanks again.

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Just out of interest, what is a rough cost to do a basic rebuild? Cheers

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FYI Your block has been pocketed for a 1275 head so valves dont hit. They are the dished cut out at the top of each eylinder. Non standard.

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Now with 2 extra ports!

What your looking at is the standard small bore gasket which is still in place.
The Block looks standard in that regard to me. (Not Pocketed)
The poor bloke is confused enough as it is, he really doesn't need to be given incorrect information.
Had to be said!!!
Dave

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