17 replies to this topic

[TOMMO0302]

Hi All,

Currently building a 1380 and have a few little questions if you don't mind - some of which more basic than others!

1. The oil delivery pipe...should there be a crush washer both between the bolt head and pipe AND the pipe and block, or just the former?
 18_06_07_1221.jpg   265.99K   3 downloads

2. the dreaded cam timing (i would like to point out that i have spent the morning searching, this is just for clarification)...anyway, so i have lightened duplex timing gear and a minisport cam which i wish to time in without having to buy any more toolage, dti etc. So its the dot to dot method for me.
---------So firstly i need to find the true tdc (head is off by the way), looking at the photo, we know the dots should line up with each other and the centre of the crank and cam, so if the crank dot is on this line i have true tdc? ignoring the cam side of things for know
 18_06_07_1219.jpg   335.85K   3 downloads

---------i appreciate you can't see the dots due to the angle of the photo, but at present i dont have a woodruff for the cam, but the slots are aligned, i would say the dot needs to come a few degrees clockwise to fully align, so this is where the offset woodruffs come in, but just to confirm a say 4 degree key will turn it clockwise right?

---------Are all woodruff's the same size indpendant of manufacturer?


can someone please mark out which parts i need to bash out on the below photo please and also tell me the thread size for the screws that i need to be countersunk, the ones by the crank.
 18_06_07_1220.jpg   289.91K   3 downloads

Many thanks...there may be more questions later. Also, i know TimS is after engine build photo's so let me know if you want any particular ones bearing in mind i only have a phone camera.

[Jupitus]

The timing cover - top part I dremelled the baffle off, bottom half take a hammer to this lumpy bit

[Jupitus]

For your timing, I would stronlgy recommend you get a copy of 'Mini Expert', a spin off of mini magazine with Keith Calver doing some great items on engine/gearbox work... it has a good guide to getting your TDC accurately and other tips to go on. Only costs about a fiver.

[TOMMO0302]

Cheers for that Jupitus...are there tips in there on finding it without the use of a dti? does my theory at least sound plausible to you?

[Jupitus]

I'm a bit rusty on the timing gear setup (about 20 years ago was last time! I'm building a 1310 right now though, hence reading up on stuff)... Mini Expert has an article showing how to find TDC using a block with a hole in it and a nut and bolt, and how to get your cam setup with either vernier stuff or offset keys.

To find TDC, basically do a dry build with your timing cover in situ and pulley in place. If you don't have clear timing marks on the case then make up a pointer to the pulley (I reckon you'll have a series of points on the case though, right?). Then, get to approximate TDC, wind engine back a bit, then make up a block or plate with holes so it fits over the stud holes in the block around cylinder 1, and a hole in it approximately over the centre of the piston. Put a bolt about 1.5 " or so through the centre hole and fasten it in place and secure the plate/holed block in position. Next, carefully wind the piston forward until it touches the bolt, and mark the pulley wheel adjacent to the markers. Next bit is to wind the engine backwards until the piston comes back round to touch the bolt from the other direction... N.B. !! not sure here, but you might need to remove the block/plate and go a full turn then the rest of the way (the mag is at home) !!! .... and mark the pulley again. Next, take a tape measure and carefully find the mid point on the pulley. This should be TDC!!

The basic principle is that because the vertical movement at TDC is much slower it is hard to be accurate just by looking at that point and guessing (the piston is virtually stationary for a few degrees of turn)... half way up the bore the piston is travelling up or down much more quickly, so just 1 degree of crank turn is far more measurable.

Hope that helps!

EDIT: I'd like to point out that this method is not mine, it is Keith Calver's, and I certainly recommend getting his fab book!!

Edited by Jupitus, 18 June 2007 - 12:21 PM.

[TOMMO0302]

Right, im pretty sure i do understand that after reading it a couple of times. One thing though, if my point of reference is the crank pulley and timing marks on the cover, when i remove to adjust the timing they will be lost - or is the point to make sure the crank doesnt move after its been found?


Edit: Just thought further about the offset key and of course you can put it in either way round to either advance or retard it.

Edited by TOMMO0302, 18 June 2007 - 12:42 PM.

[Jupitus]

Right, im pretty sure i do understand that after reading it a couple of times. One thing though, if my point of reference is the crank pulley and timing marks on the cover, when i remove to adjust the timing they will be lost - or is the point to make sure the crank doesnt move after its been found?

That, sir, is a very good point.... ummm... I dunno!!

I'll read it again when I get home

[GraemeC]

The descirbed article is also in this months Mini Magazine (might be easier to get hold of) along with numerous pictures.

Once you have accurately marked TDC on the pulley in reation to the teeth on the timing cover then obviously they will always be there whenver those componenets are built up. So use them to establish TDC then carefully remove the pulley and the cover to align the dots on the gears.

to be honest if you are only using dot-to-dot then following the Haynes description of putting No1 close to TDC on compression and then lining up the dots will be good enough anyway.

[Jupitus]

The descirbed article is also in this months Mini Magazine (might be easier to get hold of) along with numerous pictures.

Meep! That MIGHT be where I read it then... mind you, the expert book is still very good

[TOMMO0302]

That's what i was kind of hoping someone would say Graeme, but Haynes seems extremely vague about it even by Haynes's standards! However, it is amazing how much the crank moves even when the piston 'appears' to be at tdc. As you cannot alter the position of the dot on the crank sprocket other than by turning the crank or using an offset key....what do you think about my theory in true tdc being when the crank sprocket dot is aligned between the centre of cam and crank?

[GraemeC]

The problem with relying heavily on dots lining up with centre lines to give you absolute true TDC is that you are relying on the dots, keyways etc being accuratley machined - probably not always (if at all) the case.

If you are going to start using offset keys to correct the timing then you are almost certainly going to need a DTI etc as you will also need to measure the lift on No1 inlet lobe on the cam and reference that back to the crank.

The Calver article in Mini Mag does show you a method of setting accurate timing with nothing more than a set of feeler gauges, however I think it would be a oainfule process with offset keys, even more so if you don't already have a range of keys to experiment with. However it is well worth a read!

So either get a standard cam key and line up the dots as per haynes, being happy that it will be near enough to run within acceptable limits, or buy the equipment to measure up, calculate and correct the timing.

[Jupitus]

Ok guys - I checked and it IS in the latest mini magazine. Also, he uses a pattern to make a pointer that bolts somewhere other than the timing cover, so you can take off pulley and cover, replace pulley, and still have the accurate reference mark...

[TOMMO0302]

Cheers for confirming it Jupitus, i have a 3 hour train journey tomorrow so i know what i will be reading!

If it won't set me back too much time i will knock up that tool, then get a protractor and time the cam in properly....


i have sourced the countersunk's, bashed out and ground the timing cover so i think the only thing i need to know is about the oil delivery pipe number of washers.

Oh, and in my sump gasket set there is a rubber o-ring for the g'box and another larger thinner one, anyone any idea what thats for?

[GraemeC]

Copper washer either side of the oil pipe banjo.

Can't think at the moment what the other O ring is for - is it much larger/thinner?

[TOMMO0302]

Thanks,

Here's a pic of my unused items so far...as well as A series timing cover gasket etc..

 19_06_07_0841.jpg   123.36K   3 downloads

Edited by TOMMO0302, 19 June 2007 - 07:50 AM.