Split: crank sensors in high revving 16Vs (internal and external)

what happenes when the abf one fails?

 

don't ford drill holes into the face of the flywheel for the pick up to, er, pick up? saw an article on this being done with a drill press for an efi conversion.

 

yep - seen that sort of thing also

 

they make a lot of mess inside the engine - mad20Vs engine let go and was detailed on a thread on here somewhere

 

Having had a look around, it's clear that the VW Golf Mk3 kitcars did not use the internal crank sensor


Of course they used different cranks (90.0mm instead of the standard ABF 92.8mm), but it's reasonable to suspect they deleted the crank timing wheel fittings at the bespoke crank design stage for a good reason.

The Group A engines had the sensor as standard:


.. due to Group A, rather than the kitcar regulations, with standard cranks, inlet manifolds etc, before the kitcar floodgates opened and we got steel bottom ends.

Max revs listed in VWMs catalogues:

Gr.A: 8,100rpm
Kitcar: 8,000rpm

.. but other evidence suggests 8,500rpm.

These engines were built by Lehmann, who of course built some of the Seat Ibiza 16V kitcar engines. Certainly some of these were revving to 9,000rpm and beyond.

I can't see any external cank sensors on any of the Golf or Ibiza engine information I have, and the only sensors (which are obviously far easier to see) are these:


Whatever function these sensors have... the design varies from a chunky aluminium fitting to a small plug sensor... but these are always on the works Mk3 Golf kitcars, same as the Ibizas.

 

I think these are cam phase sensors - necessary if you have sequential injection - but they could also be instead of a crank sensor

 

There's no sign of anything for a sensor on the works flywheels, so that's ruled out:

 

Drilling the flywheel must be the most accurate way of doing it, maybe most reliable as well?

Very good write up about this in PPC as previously said

But then again if you get external wheel bolted to crank pulley and align it perfectly to a sensor attached to solid chunky mount then that should be the end of it

 

I had a really interesting conversation at Autosport about the engines used in the Jonathan Palmer 1.8T single seaters.

They don't use the internal trigger wheel, because:

- they're not balanced, so if building a race engine, it's just a nuisance
- they're made of crappy tin
- at high revs (> 7,000) they end up explanding with the centrifugal forces, the crank sensor signal drops out, and lo and behold on strip down, the trigger wheel has hit the sensor.

On the specfic question of whether they ever had a 1.8T trigger wheel come off the crank, the answer was no.

They also tried the back of the flywheel, which should in theory work, but they had difficulty with it.

So they made a bespoke 36-toothed trigger wheel - integrated to pulley - on the cambelt end (no vibration damper in it) + crank sensor & bracket mounted off the back of the block.

Insert 'core plug' into the OEM sensor hole to close it off. Job done.

 

Good solid info there Chris, fit's with what I was told about another make of engine that's experiencing similar trigger problems under similar situations

 

S1600 polo engine (?) with crank sensor on the flywheel

 

Just looking at the 1.8T crank Chris Eyre has up for sale and notice the trigger wheel has slots in the outer rim where the crank sensor pickup reads.
I have seen ABF crank trigger wheels that are just pressed to create the low bits in the outer rim and wonder if this slot type is a modification to reduce the weight of the outer rim slightly and reduce the potential for them failing.

 

Some pics to help illustrate:

1.8T:

 

5 Pin external sensor on 9k high revving 16v of Bargates (3 single pins & 1 two pin signals) on webcon.

Doesn't look much but has worked well for years.

 

May more have to do with the Hall vs VR pick up.

 

Seat Ibiza Kitcar Evo 2

- crank sensor over PAS bracket (red oval)
- lightened steel OE? PAS bracket (green oval)

 

That looks like a std crank pulley. The alloy centre and the steel outer is very similar looking to the 2E and ABF engines ones.
Must be modded for crank trigger though.

 

Agree - OE & definitely a wide-belt pulley.

~90mm steel crank on those.

 

Is this where we were last discussing crank sensors in high revvers?

Putting this here for now, Prodrive Mondeo miniscule flywheel, 10 bolts...


And crank sensor:

 

Chris: Prob have some input on this, as knocked up a 36-2 crank pulley arranagement (ford pulley, bored out) for my luminition setup some years ago. Will try and get some pics to you.
Really its not that tricky, you just have to respace the V belts to suit. (mk1, 16V)
Oh, and to mention we did hav one DNF rally, as I used m4 bolts to hold it on. TOO SMALL...