ned
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| posted on 27/4/06 at 09:53 PM |
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finding tdc..
a basic question you might think and one i feel a bit silly asking but..
the engine is in, has been timed up on the verniers and the crank pulley/front cover was marked with paint.
however the engine is now in and i want to replace a bolt i hadn't changed on the belt tensioner and swap another bit over. I now can't
find the mark on the crank pulley (it was a blob of yellow paint) so can only assume its been knocked or chipped off etc.
I know that the timing is correct and was going to mark the pulleys to the rocker cover so i could safely remove the belt, swap the bits i needed to
and refit the belt wihout having to retime the engine (which was done by a friend before the engine was fitted into the car)
Now I don't have a dial gauge etc myself and was wondering if there were any other ways of re-marking tdc accurately.
I have turned the engine over with no.1 plug out but can't find tdc accurately enough for the timing.
I'm sure the answer is that I need to either buy a dial gauge and timing disc or take the car back to my mate but thought it worth asking
anyway.
Along with the 4 attempt at painting my rocker cover and it turning out crap i'm getting pretty pissed off with the whole bloody thing now -
its just turned into a money pit and I have on numerous occassions thought about cutting my loses but I know I'd nver get back what I've
spent 
Any help appreciated..
Ned.
ps if i can sort this out i'm running of excuses for the engine not being run for the first time!
beware, I've got yellow skin
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Peter M
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| posted on 27/4/06 at 10:03 PM |
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Dial gauge is the most accurate, but you could mark all the pulleys (cam/crank etc) with paint to something near ie head/block etc before removing
belt as long as all these marks line up replacing belt then should not be a problem.
[Edited on 27/4/06 by Peter M]
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ned
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| posted on 27/4/06 at 10:11 PM |
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Peter,
This is what i want to do but seems pointless doing it at a random engine position, I want tdc as a reference point. I also plan to put small
drillings into the pulleys and rocker cover as a more permanent mark than just paint so want it to be right.
Ned.
beware, I've got yellow skin
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Surrey Dave
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| posted on 27/4/06 at 10:13 PM |
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I have a dial gauge and degree wheel which you are welcome to borrow at your convenience.
I dont know if you could get it right with a vernier caliper, some of them have like spike that protrudes from the end that you could use as a depth
gauge.
Do you mean you're getting p***ed off with the whole thing?
Hang loose man!!, the trouble is that you get to a stage where you think it 's nearly finished but all the little detail jobs just keep adding
up ,it can get a bit gutty. but know doubt you will get there, and no doubt will be quite fast beast when finished.........
[Edited on 27/4/06 by Surrey Dave]
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ned
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| posted on 27/4/06 at 10:20 PM |
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Dave,
If I don't get a better offer I'll take you up on your offer of the dial gauge loan.
Guess I'll have to take the rocker cover back off aswell to make sure which valves are open and which stroke its on
Ned.
beware, I've got yellow skin
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jonno
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| posted on 27/4/06 at 10:28 PM |
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Hi Ned, dunno if these will help ?
http://www.locostbuilders.co.uk/viewthread.php?tid=37774&page=1
http://www.locostbuilders.co.uk/viewthread.php?tid=38531
hope you get it sorted
Jonno
[Edited on 27/4/06 by jonno]
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mark chandler
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| posted on 27/4/06 at 10:33 PM |
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A dial gauge is not needed to do this.
All you need is something to block the piston before it reaches TDC in each direction, voila between the two points is TDC.
I welded a bolt into the end an old spark plug so that it fouled the piston on the up stroke (have a peak down the plug hole before you wind anything
down the hole, you do not want to be burrowing into a piston so ensure its halfway down before you start.
As for taking the rocker cover off, why ? if you mark up the pulleys accurately it does not matter which valve is open.
Regards Mark
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ned
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| posted on 27/4/06 at 10:38 PM |
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The engine was timed with no1 inlet full open iirc (was a while ago now).
Your suggestion is interesting Mark, but have ou tried it? I am concerned that the amount of movement when fouling may still not be acurate enough.
The cams are timed to within half a degree and are at about 105 degrees if memory serves correctly. think we run 103-104 on the race engines which is
even tighter on these cams.
Ned.
beware, I've got yellow skin
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mark chandler
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| posted on 27/4/06 at 10:50 PM |
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Yes I have tried it, and it works extremely well.
If you use a dial gauge then you do not look for maximum rise on the piston but take two readings either side of TDC and devide . the principle is the
same infact this is a prefered method by many. No counting how many times the needle has flown around you only have two positions so no choice, its
always correct.
When I last set up an engine I used this method to centre the crank and a dial guage on the cam.
Either way the precise timing is determined by the notches on the cam belt, you must get at 15 degrees advance or retard by being out one tooth on the
cam so as long as it goes back as it came apart you will be okay.
Regards Mark
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Surrey Dave
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| posted on 27/4/06 at 11:35 PM |
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Yeah, should work OK ,just dont smack a hole in your piston!!
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stevebubs
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| posted on 27/4/06 at 11:51 PM |
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Dude,
You're sooo close to a usable car...don't give up....
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millenniumtree
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| posted on 28/4/06 at 02:50 AM |
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When I was doing my head gasket, when I was SO CLOSE to being done, I heard the timing belt slip while I was trying to set up the tensioner! So both
timing covers had to come off and I knew it was going to take another hour or more to put the belt back in place...
I had no way of figuring out TDC, or so I thought. I accidentally stumbled upon a really easy way. Since I was only looking to match up the belt
teeth, I didn't have to be terribly accurate, just close enough for the teeth to fit together in the right slot. I already knew the cam was on
TDC because the cam pulley is clearly marked.
I had a thin brass rod laying around and I put it through the plug hole of cylinder 1. I just rotated the crank pulley until the rod was at
it's highest point. I went too far a few times, but rolled it back into the highest lift. I slipped the belt on, and it was dead on perfect.
A guage would be more perfect, and doing math may be as well, but this method is quick, easy, and cheap. Hell, a drinking straw would work just as
well as my brass rod. 
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dilley
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| posted on 28/4/06 at 05:41 AM |
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cam lobes 1and2 at 10and2 oclock, keyway on crank pully is normally straight up or down, stick a screwdriver down a plug hole to see, just remember to
allow for overrun on the crank, and allways turn an engin 2 revolutions at crank to make sure nothing hits,
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Danozeman
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| posted on 28/4/06 at 06:22 AM |
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Can you not tell tdc by the mark on the crank pulley?
I thought the alt belt pulley was keyed on to the crank and a notch on it to line up with a peg for tdc?
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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ned
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| posted on 28/4/06 at 06:28 AM |
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The alt pulley isn't keyed to teh crank, the crank (belt) pulley is but as said i can't find that mark and the alternator pulley is a
brand new one anyway so isn't marked at all.
Ned.
beware, I've got yellow skin
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Danozeman
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| posted on 28/4/06 at 06:32 AM |
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Try this
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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Danozeman
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| posted on 28/4/06 at 06:34 AM |
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Try this
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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Danozeman
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| posted on 28/4/06 at 06:38 AM |
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Or this
I may be completely wrong or you may have a different set up. Worth a try
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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ned
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| posted on 28/4/06 at 06:39 AM |
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Good diagram, not seen that one before.
It parts T and G that I need to take off to swap bits on.
On a standard engine that would be very helpful but seeing as I've completely rebuilt mine, have not refitted the marker by the crank, have
fitted new vernier pulleys and have cut the flange from the rocker cover which has the timing marks on and am running different cams its of no use
sadly
Ned.
def the first diagram, not the second.
[Edited on 28/4/06 by ned]
beware, I've got yellow skin
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02GF74
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| posted on 28/4/06 at 07:11 AM |
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dial guage is the most accurate or less accurate is the pencil dwon the spark plug.
not tired it but if both valves are closed, then filling the chamber with engine oil and watching the level rise and drop through the spark plug may
work - it may drain past the rings too quickly (you'd need to whizz the engine over to clear the oil later.
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BKLOCO
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| posted on 28/4/06 at 10:35 AM |
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locost method of finding TDC
Remove plugs
insert dowel same size as plug thread id into cyl1. place spirit level onto top of dowel and a convenient block of wood or similar so that bubble is
level. The closer the block is to the dowel the more accurate you will be able to set TDC.
Experience is what you get when you don't get what you want!!! 
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Danozeman
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| posted on 28/4/06 at 12:05 PM |
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would it be possible to remove the sump and look at when no 1 conrod is dead straight??
TBH id just go with the Dial gauge and be done with it. Much easier than pissing about trying to find other ways.
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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ned
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| posted on 28/4/06 at 12:27 PM |
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I thinik the dial gauge it will be. Whether I find one cheap at stoneleigh or borrow one she shall have to wait and see...
beware, I've got yellow skin
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stevebubs
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| posted on 28/4/06 at 12:28 PM |
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As you're just removing pulleys / tensioners, would it not be easier to somehow fix the belt in position on the critical pulleys (wrap laccy
bands round it?, change the bits and then "unfix" the belt.
I know it's probably easier said than done, but....
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ned
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| posted on 28/4/06 at 01:28 PM |
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yes i suppose i could just cable tie the verniers together and make sure teh box is out of gear and get on with it and mark it properly another time..
beware, I've got yellow skin
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