Ok, I give up. 7 start thread

Here's a question I haven't seen asked.

Is that "thin" crest uniformly thin from start to finish?

If not, does it start thin, then get better, or vise versa?
 
I'd bet that that thin thread is a tiny error in the pitch measurement and occurs between the first and last tooth cut. Is there a reason for indexing by advancing the tool by the pitch, rather than indexing the workpiece? As I said, it's rather hard to measure accurately on an existing helical gear. If you don't get it spot on you're going to run into issues like this. You could try fudging it by playing with the pitch, of course.
 
What if you just make very shallow (scratch) cuts. You can then more easily determine you are getting the proper 52deg separation. If it looks good at this point then slowly increase the thread depth until you start to see the anomaly. If the tool is cutting too wide then it should start to show up as you get close to full depth.
 
Boswell said:
What if you just make very shallow (scratch) cuts. You can then more easily determine you are getting the proper 52deg separation. If it looks good at this point then slowly increase the thread depth until you start to see the anomaly. If the tool is cutting too wide then it should start to show up as you get close to full depth.
Click to expand...

I don’t know for sure but 360/7 is not 52degrees and if he is using 52 degree separation that’s is definitely the problem

His machine should just offset the z axis by .115(1/7 the pitch) each time but maybe his works differently. I saw not somewhere up the thread about offsetting the z an amount different than that and that could be a problem aswell.
 
I just ran a couple of parts. The narrow thread is between thread 2 and 3. Goes all the way around.

The z offset between starts is .1164 with a F.815.

I also need a 9 start gear. I'm going to try and figure the input for that one and see if the same thing happens.

I think it's great everyone here is working together and putting out ideas. I appreciate everyone's help.
 
For the 5.3 Holley has plug, and play LS compatible EFI kits.
I'm thinking about your 50* input, is CNC like how computers were in the beginning, the input had to be an exact match or the search did not work?
 
The 5.3 the guy has is out of a 2013 tahoe. According to a guy I talked with about making a harness for it says I need the throttle pedal and the ECU from that engine. Said without those I have no hope of getting it running. I don't know much about LS engines, I'm a SBC and BBC guy. I'm trying to figure out which LS would be best to buy. I have a carb setup for the 6.0 I have, but would really like to go fuel injection for better mileage and driveability.
 
Holley Dominator EFI, and a GM throttle by wire pedal assembly should do it. OEM, and aftermarket assemblies are online.
 
If you want a EFI swap, you need all of the sensors and all of the actuators from the donor engine, with the ECU. Simple.

If you want to mix and match components at will, and know your way around electronic engine management, you can go with a customizable system like Megasquirt. I've built two of them, there is nothing better. DIYAutotune has LS plug-and-play units, just program it for your sensors/actuators and go. I can't speak highly enough for the system. You'll have to confront a learning curve, though- nothing is free.
 
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