Timing chain tensioner fun

[jonbills]

Hi,
I think my timing chain tensioner has come out. Do they do that? what's involved in fixing it?

I was changing the head gasket, and as I was wiggling the sprocket into the right position in the chain, my wedge came out.
Now, I can't get the sprocket onto the cam nose - it's a couple of mm short of where it needs to be.
I've done this quite a few times before without much fuss, so pretty sure something is wrong

Is it engine out, or can I do it from the front with the radiator out?
do I need to take the head off again? etc.

thanks!

 

[Alphabettispaghetti]

http://www.rhdjapan.com/kameari-l-type-twin-idler-gear.html Now only £290

2 years ago with the exchange rates these were £400

 

[jonbills]

Mmm Pete was selling one of those... I might have to PM him to see if he's still got it.

 

[Rob Gaskin]

Jon, have you had a look to see if the tensioner is out?

I had one came almost out once and I got it back in with two long screwdrivers and 1 hour of patience!

In the worst case I'm sure you won't need the engine out.

 

[jonbills]

Thanks Rob - no, I had a look down there, but didn't see it, just saw chain and the bottom sprocket.
I'll take another look in the morning in daylight.

 

[racer]

If it's fallen down Jon then it's a front cover off job. Bit of a pain in the **** with the motor in situ.
Those Kameari tensioners are a fantastic piece of kit, cheap at £290.

 

[candy red]

Hi Jon I've got an l28 stripped with the front cover off so you can see the chain tensioner in place don't o if its the same as yours but your welcome to come have a look i kept the tensioner in place with a shaped piece of wood slid down in-between the chain if it is the same you will have to take the front cover off and the sump tray,oil pump, dizzy come see if you want

Derrick

 

[jonbills]

That sounds great Derrick - when is convenient? I'm on holiday this week, so I can come any time.

 

[jonbills]

So.. the timing chain was stuck out, and I couldn't get it back in. So I took it apart.
as you can see from the first photo, it definitely is possible to get the timing cover off with the engine in situ. Pretty easy actually. Didn't even need to remove the sump. Only pain was that I had to drop my new double ARB to get the oil pump out.


Photo 2 is the timing chain - there are definitely NO bright links, or any other distinguishing marks to identify where to line it up. I'm not sure it even matters, but does anyone know how many links there meant to be between the bright links?





Last picture is my cleaned timing cover. Just because


Next photo should be one of a certain Kameari twin idler tensioner in situ. I do have a photo of it on Derricks practice engine as a mock up from last night, but forgot to upload it.

 

[candy red]

Hi john just counted the links between the two bright links there are 20

Derrick

 

[jonbills]

Thanks Derrick - so : bright-link:20 other links:bright-link?

 

[SKiddell]

Didn't even need to remove the sump.

When you assemble it you will probably have to drop the sump a little otherwise when you re position the front cover dowles it fouls on the sump pan gasket and youll be forever chasing leaks.

Other wise the job is a relatively simple one, but the Kameari tensioner is one of the best mods out there.

They do another slightly cheaper option, its a re designed tensioner and has a slotted "keeper" bar fitted to limit the travel of the plunger so it cant pop out, its a neat solution but not as good as the full monti

BTW, after you've installed the tensioner you will notice it produces a particular "whine", proportional to engine speed, a bit like a supercharger, it doesnt bother me but some folks who arent used to performance cars (samuri owners) may not like it.

Regarding the "bright link" issue, its a bit of an idiots guide to make sure the cam and crank are about right, but if you have a performance cam installed, that normally goes hand in hand with and adustable sprocket so the "bright link" guide is useless as you set your timing off a degree wheel and dial gauge

 

[richiep]

it doesnt bother me but some folks who arent used to performance cars (samuri owners) may not like it.

Here, have a

This made for a genuine :lol:

 

[jonbills]

Thanks Steve. I almost think my subconscious deliberately let the chain slip so I'd 'have' to get the Kameari kit

I've got a timing disc and dial gauge now, so I guess I will just have to do it right this time. All I've got to do is persuade Kent to tell me what the timing should be.

Steve, what sort of tension do you put on the chain with the top wheel?

 

[SKiddell]

Very unscientific but push (medium thumb pressure) against the top sliding plate (slide towards left hand side of engine) then lock up, this should give you a good chain tension and limit side to side chain movement to a minimum. It doesnt warrant getting a pry bar out and leaning on it as that will just induce chain stretch and prematurely wear the needle bearings and sprocket teeth and then check this tension on a regular basis

Ive seen a threaded rod with two rod end bearings used to tension the tensioner but IMHO thats seems overkill.

All I've got to do is persuade Kent to tell me what the timing should be.

Their normally quiet good, they were very helpful in helping me design a profile

 

[candy red]

Thanks Derrick - so : bright-link:20 other links:bright-link?

That right John

Derrick

 

[jonbills]

Thanks Steve, Derrick.
Your comments on Mattbibey's thread also convinced me to skim my head 0.5mm while I'm at it.

 

[SKiddell]

Your comments on Mattbibey's thread also convinced me to skim my head 0.5mm while I'm at it.

cautionary notes

When skimming the head be mindful of the piston to quench zone clearance, dont let this go below 35 thou, any closer and rod stretch and piston float will mean that the two will contact each other, in the engineering world we have a technical term to describe this, FUBAR.

When skimming the head be mindful of the valve to piston clearance, dont let this fall below the min values of 80 thou intake and 100 thou exhaust otherwise the two will contact each other, in the engineering world we have a technical term to describe this, FUBAR.

Plasticine is your friend

 

[Alphabettispaghetti]

I like and use the following

Failed
under
continuous
testing

 

[SKiddell]

:lol: