30 replies to this topic

[scoop-face]

As above, freshly built 998 engine bored out to 1030, 12g295, 266 cam, mega jolt ignition.
The engine turns over a little then sticks then then turns again then sticks..
It has a new battery, engine earth, fresh fuelthis is my first build so unsure if the engine should be so tight?
If not.. what are the possible causes?
I am fairly certain all bearings and washers are in correct.

[yeti21586]

How easily does it turn over by hand with the plugs out?

[scoop-face]

It turns better with plugs out but does stick/stop at times when using the starter.
It turned by hand when engine was out and being built.

[KRM_Simon]

So just for clarity:
When built and now if you turn it over by hand (plugs out) it turns freely with no tight spots or sticking?

The problem only occurs when using the starter motor? Are you trying to start the car for its first fire or just turning it over on the starter to get oil pressure?

[imack]

Starter and ring gear matched?

[scoop-face]

I have not tried to turn it over by hand since the engine was put back in the car. How would you suggest I do this?

I have only used the starter motor with plugs out (moves ok but sticks sometimes)
And plugs in (sticks every rotation/ every other rotation)

I have primed the engine and oil with plugs out, and looking to start with plugs in but no luck!

I will check the teeth on the flywheel and starter.

Edited by scoop-face, 26 May 2019 - 04:25 PM.

[Fast Ivan]

Did it turn freely during the build? All the clearances double checked?

[scoop-face]

Yes it would turn by hand when I was building it.
I know this because I did make a mistake with one con rod bearing/shell which tightened everything up. I started again and double checked all the bearings/shells on the con rods and crank.

[scoop-face]

I’m starting to think I might need to pull the engine out again and strip it..

[KRM_Simon]

I’m starting to think I might need to pull the engine out again and strip it..

Not yet, still some things you can check.

Haynes manual says you can turn the engine over pushing the fan round by hand while applying some pressure to the fan belt - I’ve never had much look with this I usually go for crank pulley bolt with the radiator out this is the best way for feeling what’s going on as you are directly on the crank. The other way to try is if the wheels are on stick it in gear jack one wheel off the floor and turn the wheel (unless you have and LSD) but then you are acting through the dif, gearbox, drop gears etc so feeling what is going on is a little more difficult. Do this with the plugs out so you aren’t fighting compression.

The starter motor, pre-engaged or inertia? Is the flywheel either pre-engaged or inertia? Should match the starter. Is the starter known to be a good one, is it potentially the starter itself that is sticking? If the engine turns freely by hand without the starter engaged it would point to the starter or ring gear issues.
If the sticking persist when turned over by hand and the starter not engaged where it span freely before, something has moved.

When it was turning fine by hand during the build, was this just crank and pistons or was the head cam valves etc all in place?

[scoop-face]

Definitely can’t turn it with the fan!
I think it’s pre engaged (1991 mini) it’s just the original starter and flywheel from the car, it always worked fine before. I feel the issue is with the engine not the starter.
It was just the crank and pistons that moved freely.
I will remove the radiator and get in to the crank.

[KRM_Simon]

That does make it sound less likely that it is the starter (although not impossible)
How did you time in the cam? Did you check that for free rotation as well?
Tappets set correctly on the rockers?

[greenwheels]

Are you sure your battery is fully charged.

[scoop-face]

I did the timing as per advice on the forum, finding TDC on cylinder one, protractor on crank then con rod in inlet 1 etc.. then added the mega jolt electronic ignition in relation to that.

[scoop-face]

I did the timing as per advice on the forum, finding TDC on cylinder one, protractor on crank then con rod in inlet 1 etc.. then added the mega jolt electronic ignition in relation to that.