16 replies to this topic

[dyshipfakta]

Not being experienced in these things but I think I am and I cant get my head around why.

Backstory is minispares stage one on 998. Essentially the same only difference is I have a metro inlet as I wanted a vac gauge.
Around town upto 30 its excellent no issues at all
Timing is set to 4 degrees at 1000rpm with vac d/c. And I think I am still pinging at 30-40-50 under any real load in top gear Mixture looks good plugs and colour tune is a nice blue and grabbing the choke while its doing it makes no difference so carb wise its not far off I dont think.

Im at a loss and wonder if i could be getting it confusing this noise with something else related to fitting a kit. I.e exhaust manifold leak etc( would this get worse with load I presume so)
Also any tests to rule out pinking? Can i retard ignition further without any worry?

Thanks in advance.
I know rolling road but I want to get it as close as pos myself and plus I need to get it there without knackering it.

[cal844]

What dizzy are you using? You might well have an inlet or exhaust leak. I wouldn't really rely on a colourtune(I don't know if you used one?) Anyway your much better setting it by ear at 2000 rpm. Our engines are all set up by my dad with no timing light, colourtune or rolling road.

Use a sharp chisel(or tipex) to mark a reference point on both the block and dizzy.

Set rpm to 2000
Disconnect and block the vac advance
Make slight rotation to dizzy, hold there and listen for pinking etc.

Then once your happy you tighten the bolt on the clamp and connect up vac advance, reset idle and test drive, take a spanner with you so you can make changes on the test route, always use the same route too!

Hope this is of some help.

Edited by cal844, 05 March 2018 - 05:48 PM.

[dyshipfakta]

Dizzy is whatever is standard in the late 80s 54? I have a strobe and colour tune used both but this noise is bugging me and not being 100% on what pinking sounds like or if thats even what its doing is pants

[carbon]

To rule out pinking run the petrol tank down to almost empty and then refill to brim with Shell 99 octane.

 

See if this makes a difference.

[Dusky]

I would not retard it any further. Could burn exhaust valves etc.
At 4° with good petrol I really can't see any pinking happening unless one of the advance springs broke. Could check that the dizzy advances its full timing by revving it at idle while looking with your timing light.
You didn't hook the dizzy to a manifold vacuum by any chance?
Exhaust manifold leaks can sound a lot like pinking. Drove me nuts on my mustang, it was the manifold to downpipe gasket ( wich you won't have on a stage 1 but still). Leaks at the Y pipe are very common. Talc powder and revving it in neutral is a good way to detect exhaust leaks.

Edited by Dusky, 05 March 2018 - 08:44 PM.

[dyshipfakta]

There was no such noise before the change so it has to be something i have done in fitting the kit. I dont think its the fuelling as choke makes no difference to the noise. (If that logic stands to reason). But it does only seem to happen at the kind of time you would expect pinking. On acceleration when working hard. When cruising you cant hear it at all.

[Retroman]

It sounds like your timing and carb is not far off.

 

Pinking can be just down to low octane fuel, one of mine only used to pink on Esso and not on BP. Nowadays its usually supermarket cheap crapy juice, made down to a price not up to a standard.

 

It does look like pinking from what you say...it comes most at lower revs under load in higher gears. Its quite a distinctive deep heavy pinging noise, rev related and regular, you can sort of tell its an internal noise.

An exhaust leak should be easy enough to hear and find at tick over.

 

Try filling up on a high octane fuel or add some octane booster, and see if that eliminates the noise.

[dyshipfakta]

Thanks chaps could be a coincidental bad batch of fuel I do use supermarket stuff and have only recently filled up coming to think of it.

[cal844]

If you are in the UK use either BP high Octane, or the Tesco 99 octane fuel(my cars run better on the 99 octane compared to Morrison's or Asda unleaded)

[dyshipfakta]

If you are in the UK use either BP high Octane, or the Tesco 99 octane fuel(my cars run better on the 99 octane compared to Morrison's or Asda unleaded)

Will try the Tesco stuff gonna replace manifold gasket too just to be sure

[cal844]

If you are in the UK use either BP high Octane, or the Tesco 99 octane fuel(my cars run better on the 99 octane compared to Morrison's or Asda unleaded)

Will try the Tesco stuff gonna replace manifold gasket too just to be sure

Sounds like a good idea

[carbon]

For info Tesco 99 has higher alcohol content. Used to run this, but now use Shell VPower 99 octane

Edited by carbon, 07 March 2018 - 09:49 PM.

[dyshipfakta]

Tried some Tesco 99 and its no different. So I replaced manifold gasket and reset the timing again. Still there checked the exhaust for leaks and found a bullet hole in the first silencer... I kinda ruled this out given its only done about 100 or so miles. No idea how it has happened but hopefully thats the issue so will get it off and welded up thanks for the input everyone.

On a side note seems to run much nicer on the premium stuff

Edited by dyshipfakta, 08 March 2018 - 11:48 AM.

[cal844]

Tried some Tesco 99 and its no different. So I replaced manifold gasket and reset the timing again. Still there checked the exhaust for leaks and found a bullet hole in the first silencer... I kinda ruled this out given its only done about 100 or so miles. No idea how it has happened but hopefully thats the issue so will get it off and welded up thanks for the input everyone.

On a side note seems to run much nicer on the premium stuff

If it's running alot better then you know you need to use it now

[Retroman]

Not seen a bullet hole in an exhaust...made a few in bodywork with a 303 rifle...

 

Not seen any holes in new Mini exhausts but occasionally seen them in the welds on other now exhausts. I think the problem comes from being robot welded.