ChevyLS1 engine and Megasquirt/jolt
Discussion
Has anyone got a solution to the trigger wheel issue with lS1s?
I really don't want to drop the Crankshaft just to change the triggerwheel- is there another way round this seeing as the nose of the crank doesn't have any sort of key to fix a new wheel to?
Hvae tried searching all over the place and just can't come up with anything yet.
thanks
James
I really don't want to drop the Crankshaft just to change the triggerwheel- is there another way round this seeing as the nose of the crank doesn't have any sort of key to fix a new wheel to?
Hvae tried searching all over the place and just can't come up with anything yet.
thanks
James
pugwash4x4 said:
Has anyone got a solution to the trigger wheel issue with lS1s?
I really don't want to drop the Crankshaft just to change the triggerwheel- is there another way round this seeing as the nose of the crank doesn't have any sort of key to fix a new wheel to?
Hvae tried searching all over the place and just can't come up with anything yet.
thanks
James
I really don't want to drop the Crankshaft just to change the triggerwheel- is there another way round this seeing as the nose of the crank doesn't have any sort of key to fix a new wheel to?
Hvae tried searching all over the place and just can't come up with anything yet.
thanks
James
You have 2 options. The crank will come out from underneath whilst the rods are in place. So you can change the wheel, uprate shells and rod bolts, oil pump etc at the same time.
Or, you can 'pin' the pulley to the crank axially.
Boosted.
pugwash4x4 said:
what's involved with pinning the trigger wheel to the crank.
I'll be honest it's not something i have ever heard of, or done. Being from a rover v8 background i haven't had to worry about this sort of things before!
I'll be honest it's not something i have ever heard of, or done. Being from a rover v8 background i haven't had to worry about this sort of things before!
You remove the pulley bolt and buy a pinning kit. It comes with a guide. Iirc the guide sits inside the pulley and will have an offset hole that you put your drill bit down into. You then drill down the hole. The hole you drill will be partly in the side of the crank and partly in the side of the pulley. It's a bit like inserting a woodruff key via the crank nose if you get what I mean.
Whatever you do make sure you use a new bolt and follow the correct torque procedure.
Boosted.
Instead of a square slot in crank and pulley....you end up with a round one.
So essentially a round keyway you drill yourself. Half in the crank, half in the pulley drilling axially along the length of the crank.
Of course, another more expensive option, is to use an ecu, that will work off all the factory triggers in the first place.
I have a funny feeling though, that I remember reading that some of the LS2 variants did in fact use a 36-1 from the factory ???
So essentially a round keyway you drill yourself. Half in the crank, half in the pulley drilling axially along the length of the crank.
Of course, another more expensive option, is to use an ecu, that will work off all the factory triggers in the first place.
I have a funny feeling though, that I remember reading that some of the LS2 variants did in fact use a 36-1 from the factory ???
Edited by stevieturbo on Friday 20th October 17:59
stevieturbo said:
Instead of a square slot in crank and pulley....you end up with a round one.
So essentially a round keyway you drill yourself. Half in the crank, half in the pulley drilling axially along the length of the crank.
Of course, another more expensive option, is to use an ecu, that will work off all the factory triggers in the first place.
I have a funny feeling though, that I remember reading that some of the LS2 variants did in fact use a 36-1 from the factory ???
So essentially a round keyway you drill yourself. Half in the crank, half in the pulley drilling axially along the length of the crank.
Of course, another more expensive option, is to use an ecu, that will work off all the factory triggers in the first place.
I have a funny feeling though, that I remember reading that some of the LS2 variants did in fact use a 36-1 from the factory ???
Edited by stevieturbo on Friday 20th October 17:59
What size hole did you drill?
In the Immortal words of Blue Peter...."Here's one I prepared earlier"
http://gallery112848.fotopic.net/p102
http://gallery112848.fotopic.net/p102
can i just check that i'm not being really really dense here- do you have the drill the crank in the right place so that the trigger wheel is 50degrees offset of TDBC? (obviously for a V8). You a bit buggered if you drill it in the wrong place aren't you?
how do you know that the trigger wheel is in the right rotation (in regards to a piston appearing to be at TDBC twice, but in reality one "TDBC" is on the exhaust stroke)? or is that why you have pinned both sides of the crank?
how do you know that the trigger wheel is in the right rotation (in regards to a piston appearing to be at TDBC twice, but in reality one "TDBC" is on the exhaust stroke)? or is that why you have pinned both sides of the crank?
Why pin one, when you can pin 2...
I am taking substantial drive loads off the crank pulley, so 2 makes sense.
As to where the missing tooth ends up...well that depends where you mount the sensor, how you mount it, and how you mount the trigger wheel.
Nothing is fixed until you want it to be, so there shouldnt be any issues getting it right, unless you are dense of course.
The trailing edge of my missing tooth, falls at 69deg BTDC. As this number is user configurable in my ecu's software, it really doesnt make any odds if its 69, 60, or indeed 50 deg BTDC.
The only limitation there is with mine, is the if you palce it at 40deg, the max advance you can ever run is 30 deg.
Similarly if you place it at 60 deg, max advance will be 50deg.
Not that I will ever run so much advance, but I could in theory run up to 59deg BTDC due to how I fitted my trigger.
I am taking substantial drive loads off the crank pulley, so 2 makes sense.
As to where the missing tooth ends up...well that depends where you mount the sensor, how you mount it, and how you mount the trigger wheel.
Nothing is fixed until you want it to be, so there shouldnt be any issues getting it right, unless you are dense of course.
The trailing edge of my missing tooth, falls at 69deg BTDC. As this number is user configurable in my ecu's software, it really doesnt make any odds if its 69, 60, or indeed 50 deg BTDC.
The only limitation there is with mine, is the if you palce it at 40deg, the max advance you can ever run is 30 deg.
Similarly if you place it at 60 deg, max advance will be 50deg.
Not that I will ever run so much advance, but I could in theory run up to 59deg BTDC due to how I fitted my trigger.
Ah well...good luck 
If you check my pinning pic...you can actually see my 36-1 trigger wheel mounted on the rear of my crank pulley.
My crank pulley will appear different to yours visually, as mine is an aftermarket item, to allow the blower drive to bolt on.
I just machined the rear of the pulley to accept my trigger wheel centrally, and put a couple of welds to hold it in place.
If you check my pinning pic...you can actually see my 36-1 trigger wheel mounted on the rear of my crank pulley.
My crank pulley will appear different to yours visually, as mine is an aftermarket item, to allow the blower drive to bolt on.
I just machined the rear of the pulley to accept my trigger wheel centrally, and put a couple of welds to hold it in place.
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