Fitting new camshaft without timing marks.

[SpitfireGeorge]

Hi Guys,

I have read the various posts on fitting a new cam using unmarked sprockets but I have read so many including non-tssc ones that I am confused.

Is this how it is done?

1/ Set engine to TDC on number one cylinder.

2/ With rocker gaps set at 40 thou on number 4 cylinder rotate the camshaft until the gaps on both cylinder 4 valves are equal (one opening the other closing).

3/ Connect the timing chain.

I have already installed the cam, months ago, but I want to check it as I am not too confident that it is correct.

Cheers.

[JohnD]

That'll do, George.

[Pete Lewis]

9 hours ago, SpitfireGeorge said:

set at 40 thou on number 4 cylinder

sorry my view is you  turn to get rocker 7 & 8 on the rock (in balance) and set rockers 1 and 2 to 0,040"  turn crank to no1 tdc compression stroke and the gaps on rockers 1 and 2 remain equal  adjust the cam sprocket hole pairs  till they are      

doesnt matter what the gap is so long as both are the same    reset the tappet to 0,010" when happy 

off the sprocket holes each pair gives 2 x  1/4 tooth increments turn sprocket over and you get  2 more   so there are 4 sets of 1/4tooth settings 

Pete

[Mjit]

The "equal lift on overlap" method's the best (and more often than not, easiest) to use.

http://sideways-technologies.co.uk/forums/index.php?/topic/7770-equal-lift-on-overlap-the-other-cam-timing-method/

That method makes it sound a lot more complicated that it is but I can't find a good, simple guide right now.

[SpitfireGeorge]

Hi Guys,

Been trying to find TDC using the homemade piston stopping tool in the no1 plug. Every time I try I find TDC is about 90 degrees different from the hole in the pulley! Before I take the cylinder head off and use my mercer gauge has anybody got any ideas why this is happening and what I am doing wrong.

Cheers

[Pete Lewis]

just to be clear on what you are doing   

 you have a piston stop in the plug hole  , so turn crank anti clock to make contact with the stop , and mark the pulley ,

then turn clockwise to the stop and mark the pulley

tdc is halfway between the two marks 

{Pete

[SpitfireGeorge]

Hi Pete,

That is exactly what I did. Put the stop in no 1 cylinder. Even tried to make it easier by putting the pulley at tdc with the rockers on no 4 cylinder rocking using the pulley timing mark but still got the same result. Quite odd!

Cheers

[Pete Lewis]

we know the timing marks on the 6 pot can move when the bonding fails but dont see it on a 4 pot pulley  

almost says the pulley/crank    keyway is in the wrong place  ????  or  missing ????   there's  an idea 

Pete

[thescrapman]

I would shine a torch in the plug hole and look for piston at the top, will sanity check your findings 

[Mjit]

On 17/04/2021 at 09:14, thescrapman said:

I would shine a torch in the plug hole and look for piston at the top, will sanity check your findings 

Poking a big screwdriver in the plug hole is easier.  Put the engine before TDC/pop in screwdriver and see how far it goes (keeping it as veritcal as possible through the hole)/remove.  Roll engine closer to TDC and repeat and it won't go in as far.  Roll past TDC and it will go in further again.  You'll get a little plateau around TDC with actualy TDC in the middle.

Not as accurate as the piston stop but a good way to confirm (and I can't say I've ever seen anything down a spark plug hole!

Or check if Lidl/Aldi are selling their little endoscopes at the moment?

[Pete Lewis]

to be 90deg off theres something basic missing here 

doesnt matter how you TDC the piston you have 1/4 of a turn error problem

please  check you have a pulley keyway fitted 

Pete

[SpitfireGeorge]

Hi Pete,

Yes keyway definitely fitted. Looked at piston down plug hole with a torch. The piston stop has dented the top of the piston, just hope it does not cause a hot spot. Anyway checked TDC as per Mjit post and then aligned with the standard timing mark. Set cam position on cylinder 4 valves rocking and hopefully it should be pretty well correct if pulley marking is correct.

Cheers.

[Pete Lewis]

you dented a piston!!!       what did you turn the engine with   ...big hands  ???

Pete

[dannyb]

My piston stop I can feel the piston just start to rock the bolt in the thread of the old sparkplug I made it from so I go very slow when turning the engine at that point. Also the end of the bolt is rounded to stop damage to the piston. 

Danny

[JohnD]

Here's my piston stop, like dannyb's (?)

 

[SpitfireGeorge]

My piston stop is a spark plug as per the photo above but has an allen bolt with the head at the piston end rather than the thread. Used a ratchet from a socket set. Did move it carefully and only pressed slightly when the engine stopped to make sure that it was touching the stop. Still got the dent though..

[DanMi]

Is it really a dent or just a bit of carbon mank knocked off? 

[Colin Lindsay]

Dented as in the little half-moon shape of the end of a bolt?

[SpitfireGeorge]

Half moon shape unfortunately. Not using that method again, only tried it as I couldn't be bothered to remove the manifolds and head and set up my clock gauge.

[JohnD]

PLASTIC piston stops, screw in place of a plug-type, are available for pennies on eBay.

[SpitfireGeorge]

Didn't know that. Thought they were all home made.