How I Reverse Engineer - Very Precise Measurements

[dave w]

I usually hang out (post / reply) on the Injection Section only. I think a few pictures is worth many words. I wanted to make my own EFI SBC Trigger Wheel, so I used some measurement tools and 3D CAD. Maybe my method of doing a very precise measurement will help others with their own reverse engineering (aka fabrication)?

dave w

 

[Blue85]

Here's how I made mine. It doesn't change the pulley alignment at all.

 

[dave w]

Here's how I made mine. It doesn't change the pulley alignment at all.

Very clean looking / functional design. I'm going with a Vortec SBC Harmonic Balancer, to keep the pulleys aligned. The Vortec used a reluctor ring behind the harmonic balancer, which I won't be using. My trigger wheel is the same thickness as the Vortec reluctor wheel.

dave w

 

[mtnman]

Nice work!

 

[dave w]

I have the trigger wheel from the CNC Mill. Up next is the sensor bracket.

dave w

 

[Stomis]

Very cool! I need to venture into the other sub forums more often if good tech like this is what I'm missing.

 

[4X4HIGH]

Very clean looking / functional design. I'm going with a Vortec SBC Harmonic Balancer, to keep the pulleys aligned. The Vortec used a reluctor ring behind the harmonic balancer, which I won't be using. My trigger wheel is the same thickness as the Vortec reluctor wheel.

dave w

So i'm curious how you're going to achieve this since the reluctor wheel on the Vortec engine is inside the timing cover and what you're making is going to mount on the harmonic balancer between the pulley and balancer. I'm pretty sure that the Vortec balancer has material removed from the snout portion of the balancer to make up the difference of the thickness of the reluctor wheel.

 

[dave w]

So i'm curious how you're going to achieve this since the reluctor wheel on the Vortec engine is inside the timing cover and what you're making is going to mount on the harmonic balancer between the pulley and balancer. I'm pretty sure that the Vortec balancer has material removed from the snout portion of the balancer to make up the difference of the thickness of the reluctor wheel.

I'll be using the Vortec harmonic balancer on a NON-Vortec engine. If a Vortec harmonic balancer is installed on a NON-Vortec engine the crank pulley will be miss aligned by about 0.100". (Note: A NON-Vortec engine will not have the plastic timing cover, and a NON-Vortec engine will not have a trigger wheel mounted behind the sheet metal timing cover) The trigger wheel I have designed is 0.100" thick at the pulley mounting surface, so using a Vortec harmonic balancer with the trigger wheel mounted on the pulley mounting surface, should line up correctly. That is if I've done my homework correctly. By the looks of things so far, I think I'm good the homework I've done.

dave w

 

[Blue85]

So are you using the Vortec ECM?

 

[dave w]

So are you using the Vortec ECM?

I could use the Vortec "Black Box". I will be using the 12200411 LS PCM.

I have a thread here: http://coloradok5.com/forums/showthread.php?t=272519 It's a long read (about 6 pages of tech)

dave w

 

[bronc3buster842001]

The difference in the balancers is in the snout. The vortec snout is shorter than the non-vortec.

 

[Big Ray]

Looking good Dave..

 

[4X4HIGH]

The difference in the balancers is in the snout. The vortec snout is shorter than the non-vortec.

That is what i'm trying to tell him. Unless there is enough clearance between the outside of the timing cover and the backside of the balancer when installed what he wants to do won't work as the harmonic balancer will either hit the timing cover because of no clearance or it could be really close and possibly rub a hole through the timing cover.

 

[Big Ray]

if I'm reading correctly, he's gaining the clearance by using a non vortec (thinner) timing cover...the added clearances gives the space required.

timing cover - moves back< [reluctor] >balancer - moves forward

 

[4X4HIGH]

if I'm reading correctly, he's gaining the clearance by using a non vortec (thinner) timing cover...the added clearances gives the space required.

timing cover - moves back< [reluctor] >balancer - moves forward

He makes no mention of what timing cover he's going to use.

 

[dave w]

That is what i'm trying to tell him. Unless there is enough clearance between the outside of the timing cover and the backside of the balancer when installed what he wants to do won't work as the harmonic balancer will either hit the timing cover because of no clearance or it could be really close and possibly rub a hole through the timing cover.

"It's all good" I have 0.425" of clearance between the back of the Vortec harmonic balancer and the old school sheet metal timing cover. The new clearance is about 0.100" less clearance than the old school TBI harmonic balancer and old school sheet metal timing cover. The trigger wheel brings the pulley mounting surface back to factory specification.

dave w

 

[Big Ray]

He makes no mention of what timing cover he's going to use.

check post # 8...

 

[dave w]

The sensor mounting. Update with pics.

dave w