I have both of those and that is what they measure with the deg wheel I have.
I think the 6x trigger wheel I make for the distributor will need to be the same.
I have also thought about just milling the harmonic balancer. It has a ridge around the front of it.
4.0l jeep balancer.jpg
It's budget / skill / math decision. You got this.
The dual trigger distributor option provides for a very clean installation. The dual trigger distributor will require 6x crank triggers evenly spaced and 1x cam trigger. The alignment or synchronization of CKP / CMP signals is the next challenge.
Pictures below show alignment of the V8 24x crank trigger, V6 alignment similar.
dave w
DSCN3088.jpg
DSCN5358.jpg
Dave, thanks for the info and words of encouragement.
I'll let you know what I decide to go with.
Wouldn't the slight slop between the cam gear and distributor gear cause problem with the crank reluctor/sensor in a distributor? Those reluctors are usually very fixed to the crankshaft with no movement. I now it is small but still there is going to be some rocking between the gears.
I'm not worried so much about the gear backlash as I am the slop in the timing chain.Originally Posted by 2xls1
The backlash between the gears is probably not going to be any concern at all. Besides every distributor fired ignition system ever made has the same thing.
But I'm not really worried too much about that. It's just an OLD engine that I'm going to play with.
If this works I might Do the same thing to my 1987 Wrangler that has a 2.5L 4 banger in it.
Well there is injection timing as well since I don't think it will be running batch fire but it probably won't make much difference since I doubt you will care about misfire detection either.
2xls1 the total error should be less than 4 deg on the crank. and it really won't matter on this engine. We'll just have to wait and see how it runs
But you're right I'm not going to worry about misfire detection. I'm not going to turn it off unless it becomes an issue.
For a nearly perfect 100% CKP/CMP signal accuracy, maybe use the harmonic balancer for both CMP and CKP? Maybe the outer ring / larger ring the CMP? Maybe use the inner ring / smaller diameter ring for 3x CKP? If I'm thinking my engine math correctly, then maybe machine two 87.5 degrees segments (175 degrees CMP trigger wheel divided by two) from the outer ring? Custom CKP - CMP brackets required. Custom balancing for the I6 Harmonic Balancer required. The BBC 8.1 Liter CKP sensor will read the Harmonic Balancer modified 175 / 185 degrees.
Link for the BBC 8.1 liter Timing chain and gear set: https://www.carid.com/melling/engine...3-4sr50sc.html
dave w
The CMP won't work off the crank. The crank makes one full revolution+185 deg. before the CMP gets a signal.For a nearly perfect 100% CKP/CMP signal accuracy, maybe use the harmonic balancer for both CMP and CKP? Maybe the outer ring / larger ring the CMP? Maybe use the inner ring / smaller diameter ring for 3x CKP? If I'm thinking my engine math correctly, then maybe machine two 87.5 degrees segments (175 degrees CMP trigger wheel divided by two) from the outer ring? Custom CKP - CMP brackets required. Custom balancing for the I6 Harmonic Balancer required. The BBC 8.1 Liter CKP sensor will read the Harmonic Balancer modified 175 / 185 degrees.
Link for the BBC 8.1 liter Timing chain and gear set: https://www.carid.com/melling/engine...3-4sr50sc.html
dave w
I'm in no way trying to say it won't work. More just inquiring as I know of no OEM crank sensors that read anywhere but directly off the crankshaft. I hope you will keep this thread updated with whatever issues you run into. It will be interesting. And the cam sensor does not need anywhere near the accuracy of the crank sensor. It's just telling the PCM TDC either compression or exhaust. OEM vehicles using a P01 don't even need the cam sensor to run. Without a CMP signal on start the PCM will guess TDC on compression. If no start it will wait 180 degrees and fire the plug again. Once it starts it will sync on that position until the next key cycle.
That's what I love about this site, You can never tell when somebody will teach you something. I love learning and I didn't know that.
So if I put a CRP on the crank and drop a big cap HEI in this engine it'll run? That would be crazy.
All I really need is a way to run the fueling.
I can't say for sure on a V6 OS which I think you'll be using but for sure on 4.8, 5.3, 5.7, and 6.0 will run without a CMP signal. You can get an extended crank while the PCM figures out compression TDC. One thing is do not disable the DTCs for the CMP sensor. The PCM has to see the CMP code set for it to run without the signal. I've just never tested it on a vehicle with the CMP in the distributor. The V8s have the cam reluctor either directly on the back of the cam or up front on the cam gear.
I may try it both ways and just see what I get. I'm going to use the 2002 Chevy S-10 L35 4.3L 4L60E (12212156) bin I posted in the start of the thread.
I've still got to swamp in a manual trans sec.
I don't know if either a V6 or V8 using the '0411 with a distributor mounted CMP will run without a CMP signal, that theory of operation will need to be tested.
What I've learned from the dual trigger distributors I've built is the alignment between CMP / CKP is CRITICAL. If the distributor mounted CMP is not accurately aligned with the CKP, the engine will not start.
dave w
I'm not sure what will happen with both CMP and CKP on the crank without an oscilloscope.
What I know works . . . CMP and CKP in a distributor or dual trigger distributor works in a Chevy L31 V8 using 8x crank triggers and 1x cam trigger.
Likely everyone would agrees Inline 6 requires 3x crank triggers.
Likely everyone would agree that the engine math is two crankshaft rotations equals one distributor rotation. The camshaft timing chain gear is twice the diameter of the crankshaft timing chain gear.
So using the reverse logic to make a dual trigger Harmonic Balancer the cam signal would need to half the signal of the distributor mounted cam signal?
Let's say for simplicity reasons, the distributor mounted cam signal is 175 degrees, so half of 175 degrees is 87.5 degrees.
So now it's time to use an oscilloscope on a 4.3 V6 and reverse engineer a solution, or maybe not?
dave w
CKP_CMP_waveform_relationship_001.jpg
Crank Cam.jpg
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