Crank triggers....dumb question.....

mrvette

mrvette

Phantom of the Opera
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Mar 24, 2008
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I have a stock batch fire computer, 1227730, and a L98 dizzy setup....it all running decent....have been curious if any improvement could be had via a crank trigger....so the ONE dumb question is....

assuming a get holes drilled in the crank pulley....how many holes is necessary???

remember the spark indexing still done via the dizzy up top.....

I say 4 holes.... every time crank turns 90* the next cyl fires....

so call it 0-90-180-270 degrees in which time the dizzy goes to the next index for the crank to repeat it's majic for the last 4 in the parade....NO???
still think I"m right....

so, working on a '94 Dodge PIA van 318, same essential setup...but the holes are done off the flexplate in the rear.....and the dizzy is in the same postion and does the spark distribution index per any other 318 I ever saw from the carb daze yet....

BUT the 318 mopar has EIGHT HOLES in that flex plate.....???? why??

:crap:

still think 4 holes is enough....so how many holes/sense points in a crank trigger???

anyone any clue what is on Chrysler's mind with 8 of them???
 
Four holes (or magnets in the case of MSD) is enough, but maybe they provide 8 so you can position the distributor in an optimum location or something similar... ?? Or maybe that same plate can be used for a 6 or 4 cyl. engine... ??

crank01.jpg
 
Since you have a newer roller block already and like to build stuff from junkyard parts why not use a Vortec crank sensor? Just rob the parts out of any Vortec 5.7 or 4.3. That would seem like the best option since it would be bolt on, use off the shelf parts, and is proven durable for a daily driver.
 
Fuelie74 said:
Since you have a newer roller block already and like to build stuff from junkyard parts why not use a Vortec crank sensor? Just rob the parts out of any Vortec 5.7 or 4.3. That would seem like the best option since it would be bolt on, use off the shelf parts, and is proven durable for a daily driver.
Click to expand...

UMM....well, good idea....4.3 is a 6 cyl...so not good there, but where is the crank trigger on a 5.7 Vortec?? is it up front and more or less accessible, or in back where Chrysler did theirs???

:flash:
 
The crank sensor on a Vortec is up front behind the balancer. It is very easy to replace if it goes bad.

I said 4.3 or 5.7 because you need to use the timing cover from one of them and either should work. Then you will need the Vortec balancer or have your balancer machined to remove the same amount of material as the thickness of the Vortec 4x Crank reluctor wheel.
 
Fuelie74 said:
The crank sensor on a Vortec is up front behind the balancer. It is very easy to replace if it goes bad.

I said 4.3 or 5.7 because you need to use the timing cover from one of them and either should work. Then you will need the Vortec balancer or have your balancer machined to remove the same amount of material as the thickness of the Vortec 4x Crank reluctor wheel.
Click to expand...

What is that wheel made of?? sheetmetal with holes in it?? or a piece of thicker aluminum with magnets in it?? if it's sheetmetal...maybe I can just let the balancer go out 1/16 or less....humm....

you say I need the timing cover...what is different about it? where the coil is??

can the coil be replaced without pulling the cover off??

:bonkers:
 
As they say a picture is worth a thousand words. I did some searching and found a couple pictures for you. They should answerer most of your quotations.
L31timcvr.jpg
Timingwheel.jpg
 
That would be your best option. It's not for nothing that the stock one is encased. As precise as crank triggers are, their biggest drawback (aftermarket ones) is their vulnerability to road debris.
 
Thanks for finding those pix, appreciate it.....never messed with a LT1 so the question is, can it work with the L98 serp setup and will the water pump clear the cover?? IF I have a offset problem, how much is it??

IF it's like a 1/8 inch, I can simply put washers behind the accessory brackets and it's cured...if it's a whole lot, like over 1/4 inch, I into a custom carnk pulley , or totally unknown territory

wonder if there would be any particular advantage to that change...I can see the precision theory for a race engine, but wonder how much slop there is in reality ....vs the L98 setup....

also to think of getting a few holes in the stock pulley, and like I said, position the Ford sending units near by and call it a day....

shoot, for that matter, get the balancer drilled/indexed....not on the rubber weight, but on the center mass....

TT, what kind of dirt is attracted to the pickups?? they have magnets and there is enough iron trash on the roads to be attracted there???

if so, simply wonderful....

back to the LT setup....
 
Twin_Turbo said:
That would be your best option. It's not for nothing that the stock one is encased. As precise as crank triggers are, their biggest drawback (aftermarket ones) is their vulnerability to road debris.
Click to expand...

Please explain that one. :huh:
 
The Vortec is not an LT1. It is basicly the same block as you have. I think the cover will fit under you water pump but I can't say that for sure.

As for the balancer issue. Once you have yours off and the wheel. Take both to a machine shop and just have them machine the thickness of the wheel off the balancer. It should cost very much to do that and would beat shimming everything.
 
Fuelie74 said:
The Vortec is not an LT1. It is basicly the same block as you have. I think the cover will fit under you water pump but I can't say that for sure.

As for the balancer issue. Once you have yours off and the wheel. Take both to a machine shop and just have them machine the thickness of the wheel off the balancer. It should cost very much to do that and would beat shimming everything.
Click to expand...

There you go, better creative thought....love it...I wuzzn't thinking very good....

:clobbered:
 
big2bird said:
Twin_Turbo said:
That would be your best option. It's not for nothing that the stock one is encased. As precise as crank triggers are, their biggest drawback (aftermarket ones) is their vulnerability to road debris.
Click to expand...

Please explain that one. :huh:
Click to expand...

What's there to explain? if it gets damaged by a rock, or a branch or whatever, you have a problem. Also, they probably won't work too well in the snow, probably also problematic with heavy rain/water.
 
Gene, if you put washers under the water pump it'll leak.:cussing: And I know how much you just hate leaks.
 
Twin_Turbo said:
big2bird said:
Twin_Turbo said:
That would be your best option. It's not for nothing that the stock one is encased. As precise as crank triggers are, their biggest drawback (aftermarket ones) is their vulnerability to road debris.
Click to expand...

Please explain that one. :huh:
Click to expand...

What's there to explain? if it gets damaged by a rock, or a branch or whatever, you have a problem. Also, they probably won't work too well in the snow, probably also problematic with heavy rain/water.
Click to expand...

I'll remember that for my next off road snow plow project.:D
 
Don't be afraid to put a crank trigger on a street machine. I've had mine in for around 4 years. Rocks? Unless your engine isn't in an engine compartment, rocks stand almost no chance of hitting the crank. The tires are on the sides and don't throw anything in the vicinity. Snow? Get serious - you aren't driving a Vette in snow, are you? Wouldn't matter anyway since snow won't affect the magnetic action of a CT.
 
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