timing help needed please

CharlesY said:

Just what "timing dot on the crank" are you talking about?

There is ONE reliable way to establish TDC in this engine and you have been told it half a dozen times now.

CharlesY

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The one I used was stamped into the side of the crank pulley, the one the cambelt runs on. I couldn't use the locking pin, as firstly i didn't have one, and also i couldn't actually get the plug out of the flywheel housing - i spent about an hour trying. However, I don't know if the dot stamped is TDC, but it worked for me, which I am glad about as I had only had my 90 for a week, and couldn't afford to do any seious engine rebuilding!!!

Surely also if the belt is off, and the cams are not moving, then the engine cannot be one turn out of snych? My father and i had a long discussion about this, and from what we could get our heads round, if you rotate the crank but not the cams or fuel pump, then you won't be able to get it just one turn out, surely?

GRUNT said:

Hee hee Uncle Charlseys gettin tetchy.

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Not me ... I'm the living embodiment of patience, kindness and virtue.
My niece Hybridgirl will tell you so herself.

CharlesY

boydy1989 said:

Surely also if the belt is off, and the cams are not moving, then the engine cannot be one turn out of snych? My father and i had a long discussion about this, and from what we could get our heads round, if you rotate the crank but not the cams or fuel pump, then you won't be able to get it just one turn out, surely?

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Oh My Gawd ......

First, if you rotate the crank but not the camshaft you will cause one or more pistons to hit valves.

Remember, in those engines, the valves go down deeper into the cylinders than the tops of the pistons come up when they are all the way up. If the timing is not right, pistons and valves WILL collide.

But I think you are missing the point .... this is a FOUR stroke engine, and the crankshaft turns TWICE for ONE turn of the camshaft and fuel injection pump.

That is why the valve timing and injection timing (or sparks) can be 180° out, because the crankshaft is exactly ONE FULL ROTATION out causing the cam and INJ pump to be HALF a turn wrong even though the crank appears to be set right.

In fact, it IS set right, but for firing on number 4 piston, not number one.

Keep thinking ... you will get there, but you may mangle a few valves on the way.

CharlesY

Nah I am aware of this, my cam belt snapped on me and i had to buy some new push rods, and i then spent hours setting all the valve clearances, i know how they work. However, I don't think I am missing the point, cos as long as the valves and the injection are in time with each other, then i don't see how the engine can be one turn out. I know that the cams the injection pump turn half the speed of the crank, i know how a 4 stroke engine works, and please don't get annoyed... My engine still works, im just suggesting ideas! If the pump and valves are half a turn out, then surely it won't matter because they are both that much out, and the pistons are then still at TDC (in this case 1 & 4)? Like i said, dnt get wound up by it i know how they work, at least im pretty sure i do, having rebuilt several engines petrol and one diesel... Hmm.

boydy1989 said:

Nah I am aware of this, my cam belt snapped on me and i had to buy some new push rods, and i then spent hours setting all the valve clearances, i know how they work. However, I don't think I am missing the point, cos as long as the valves and the injection are in time with each other, then i don't see how the engine can be one turn out. I know that the cams the injection pump turn half the speed of the crank, i know how a 4 stroke engine works, and please don't get annoyed... My engine still works, im just suggesting ideas! If the pump and valves are half a turn out, then surely it won't matter because they are both that much out, and the pistons are then still at TDC (in this case 1 & 4)? Like i said, dnt get wound up by it i know how they work, at least im pretty sure i do, having rebuilt several engines petrol and one diesel... Hmm.

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Oh Dear God .......

Tell him Slob .... I'm going to bed.

CharlesY

GRUNT said:

Hee hee Uncle Charlseys gettin tetchy.

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just abit

What your saying is not correct, when 1 and 4 are at tdc one is on a compression stroke and the other on an exhaust stroke, next revolution they are other way round so 1 should be on compression stroke for setting the timing

Rustyrus said:

What your saying is not correct, when 1 and 4 are at tdc one is on a compression stroke and the other on an exhaust stroke, next revolution they are other way round so 1 should be on compression stroke for setting the timing

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Whatever you say Mr Rusty, and give my regards to Florence, Dougall, and Mr Zebedee.

Stay clear of "dopey" Dillon by the way, he's a bad influence, and that Brian is a low-down creep.

CharlesY

CharlesY said:

Whatever you say Mr Rusty, and give my regards to Florence, Dougall, and Mr Zebedee.

Stay clear of "dopey" Dillon by the way, he's a bad influence, and that Brian is a low-down creep.

CharlesY

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boinggggggggg! charles wot a comic brilliant made me laugh anyway cheers

In much the same way that a petrol dizzy can be 180 out and require a full rotation of the crank to bring it to the correct point in the cycle and have the rotor pointing at the correct lead..

Cheers Steve