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megajolt crank pulley question.
Thinking about it - 3/5/10 at 05:39 PM

Description
Description


Pic shows 1.8 CVH crank pulley.

I have a 1600 CVH FWD engine and am trying to use a crankshaft pully from the 1.8 RWD CVH engine

On the 1600 engine the TDC on the pulley sits in line with the woodruff key on the crank. On the 1.8 the woodruff key seems to be 55degrees off TDC

Am I right that the missing tooth has to be 90 degrees BTDC.

So to use this puulley what is my best option?

1. Machine a new locating groove in the pulley 90 degrees on from the missing tooth.

2. Remove the ring and move it 55 degrees. If so what is the best way to get it off and back on the pulley?

3.Set the ignition advance within the megajolt to compensate for the missing tooth being in the wrong place,(Add or subtract the 55 degrees whichever it is) or does megajolt not allow this?


prawnabie - 3/5/10 at 05:42 PM

Can you not move the sensor to compensate for the difference?


Thinking about it - 3/5/10 at 05:46 PM

I've considered that but the missing tooth needs to be 90 degrees before TDC. If I set the engine at TDC with that pulley it will be 55 degrees out. The white mark shows the TDC mark on that pulley 90 degrees on from the missing tooth but 55 degrees off what tDC would be.

Or have I got it all wrong?


prawnabie - 3/5/10 at 05:49 PM

May be miles out here but I thought it had to be 90 degrees from the sensor at TDC?


scudderfish - 3/5/10 at 05:52 PM

With the engine at TDC the sensor needs to be 90 degrees from the gap. Where the gap and the sensor are doesn't matter.


paulf - 3/5/10 at 05:53 PM

Thats correct the gap can be anywhere on the pulley as long as the sensor is positioned to be lined up at 90 degrees before TDC.
Paul

quote:
Originally posted by prawnabie
May be miles out here but I thought it had to be 90 degrees from the sensor at TDC?


wonderfulweasel - 3/5/10 at 05:55 PM

As above, gap between sensor and missing tooth is the 90deg you're looking for. Could you use the 1800/1600 mounting as appropriate to give you the required alignment?


Thinking about it - 3/5/10 at 05:58 PM

Oh its making sense now.

Thanks Guys


dhutch - 3/5/10 at 06:35 PM

quote:
Originally posted by scudderfish
With the engine at TDC the sensor needs to be 90 degrees from the gap. Where the gap and the sensor are doesn't matter.

This.

Although, depending on where that puts you sensor, you may still find moving the wheel to be advantageous!

I believe it also possible to compensate for miss-alignment within the map, although so far with mine i have not exploited this, and i think there might be a limit to how far you can compensate for. (like 10 deg)

Also, fwiw, i fitted a mejajolt to my cvh (1.9l 1600 block with dellorto 40's) about a year ago.


Daniel

[Edited on 3/5/2010 by dhutch]


whitestu - 3/5/10 at 08:19 PM

quote:

If so what is the best way to get it off and back on the pulley



Just warm it up with a blowtorch and it should come off and go back on easily enough.

Stu