MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - setting engine timing - from scratch!

hi all

long story short - i need a procedure for setting the engine timing from scratch. found some instructions on dvapower but they make assumptions like cam wheels are fitted correctly etc.

so, if i have no crank or cam wheels fitted, i.e. want to set the timing from scratch - what do i do?

cheers
steven
steven

Buy a Repair Manual CD from B&G.

Geoff.F.
G. Farthing

Steven,

Dave Andrews has demonstrated this to me on my own car. There are two methods the complicated one for non-standard pulleys and an easy method:

First the difficult one:

You will need at least two dial gauges these can be bought for about 25quid each from the likes of machinemart.com or screwfix. For one of them you will need to extend the needle with a peice of welding rod typically.

The extended dial gauge is used to find TDC of the piston nearest the pulleys.

The other gauge is used to measure the lift on the Ex/In follower of the same piston. For this it is advisable to make a simple bracket to hold the gauge to the head and also use a piece of welding rod, bent to touch the follower. Now using the data from the workshop manual (so I don't have the data to hand) you can set the position of the first cam.

First rotate the crank to find TDC you will need to go slightly past TDC and back again to make sure you have the exact position (there is also a mark on the BACK of the crank pulley which can be aligned for TDC, but don't get this confused with the notch on the front of the pulley, this is why the dial gauge is useful).

You can now rotate the first pulley wheel with a 17mm(?) spanner to achieve the correct lift on the follower (from the workshop manual). the problem now is to fix this pulley so you can set the other pulley.

Now the easy method with standard pulleys. On the pulleys you will see two notches. These should align at their closest point, this position corresponds with a crank position (which I think is TDC but may be 90 degrees BTDC check this). With the cams and cranks on the correct place you can replace the cam belt.

Always check the settings before completing the job. It is an idea once assembled to turn the crank by hand to make sure nothing is touching, also double check the crank pulley positon and cam pulley positions, these can move when re-fitting the cam belt, (I know I've done this).

The job is not beyond DIY but it does need quite a bit of time and lots of cups of tea.

Unfortunately, although Geoff refers you to the Workshop manual you will not find the whole proceedure in there.

Good luck.

Tim

Where in the UK are you?
Tim

Standard cam timing:
there is a line cast thru the cam pullys, it's marked exahust on one side, line lines up, ensure exhaust is pointing at exhaust. Ensure crank is at 90BTDC (which is the notch on the drivebelt pully pointing directly upwards - if you haven't fitted the pully yet, there are two dots on the cambelt pully which mark the same thing. Note: take great care rotating the crank with the cambelt off, you may impact the valves (never force the crank or use the starter).

The cams will hold their position by friction- just.

Also note if the engine is installed then it sits at a slant, so the cam timing lines lining up is not compleatly obvious.

If you don't have the cam locking tool then move the cams ever so slightly in (exaust anticlock, inlet clock) - also remove the 8mm bolt from the tensioner as this will give you more slack.

http://www.brooke-kensington.co.uk/misc/Elise%20Service%20Manual%20-%20indexed.pdf

is the elise service manual which includes the k-series manual.
Will Munns

Hi,

Again, standard camshaft sprockets etc...

The camshaft sprockets are identical and are located on the cams by rather feeble roll pins. Fit the sprockets with the cast wording facing out. The inlet cam roll pin fits in the IN keyway in the centre of the sprocket: the exhaust cam roll pin fits into the EX keyway of the sprocket. Tighten the cam bolts and washers temporarily. Insert the camshaft sprocket locking tool (see below) and tighten the bolts fully. Remove the tool. Note that the roll pin keyway marks are now hidden. Ignore them, and align the sprockets using the marks cast in the spokes of the sprockets.

The crankshaft gear and pulley can only be fitted one way. Fit and tighten temporarily.

The camshaft sprockets are marked EXHAUST on one side, and IN and an alignment mark on the other. The way they line up is confusing and not (I believe) as Will has described. The markings should be aligned, reading from left to right, as:

EXHAUST o IN ---- EXHAUST o IN ----

so that the exhaust marks actually point to the rear inlet side of the engine. Don't ask me why. Align the IN --- mark on the inlet camshaft sprocket EXACTLY with the EXHAUST mark on the exhaust sprocket. A picture would be worth many words. The cams will tend to spring out of position so buy a simple sprocket locking tool from Halfords or some other motor factor. The markings must be in a perfectly straight line across the two sprockets, and in line with the cylinder head joint. Phew!

The crankshaft timing gear (as Rover calls it) and the crankshaft pulley are aligned exactly as Will says, vertical: the dots on the crankshaft timing gear or the mark on the pulley are aligned with the cast flange on the oil pump. The crankshaft can be aligned when the pulley is bolted up by turning the pulley bolt. If it's more than say 10 or 20 deg out then there's a danger of the pistons hitting the valves.

Fit the cambelt so that the run between the crankshaft gear and the exhaust camshaft is taut. Tension the belt approximately by hand and tighten temporarily. Rotate the engine a couple of times, check alignment again.

Then move onto adjusting the tension correctly. By this time I hope you have access to a manual.

Please don't sue if I have made a mistake. Regards, Kes.
Kes

Your're right - Page 5 of engine manual (link above) shows the wording 'exaust' the correct way up, and 'exhaust' indeed on the inlet side of the engine!
Will Munns

Now that IS strange... 8oO
Rob Bell

<the exhaust marks actually point to the inlet side of the engine>

There is, of course, a perfectly rational reason why this is so. I wonder what it is?
Kes

guys thanks,

i'll try and read through all this later
steven

This thread was discussed between 27/04/2004 and 29/04/2004

MG MGF Technical index

This thread is from the archives. Join the live MG MGF Technical BBS now