Tach mod with pics

[Brent Nowell]

wanna watch your rpms closely while milling? Good way to detect when your tank is almost out, also to make sure your not going over max rpms..


Found a good spot for it when your pushing, drilled a hole to wire it. Used an electrical grommet from local hardware store, and shrink wrap to seal the deal.
The 395 spark plug boot is a real PIA, careful if you plan to remove it. I found out the hard way that if you pull it off, you will not get it back on easily. Eventually it ripped right off the wire. Big ol *uck went off in the garage...
Trimmed some of the cord down about 3/8-1/2” to expose more wire, then crimped the plug coil shank into a very tight U shape. Looped the wire through and over then fluxed and soldered. Seems to work, plug is getting spark. It’s a solid connection now, but it was before I f*d it up before too
Gonna take thee ol Alaskan mill out tomorrow am, we will see how useful of a spot I chose.
You can see in first pic shrink wrap just below coil of wire, this is how I made it semi permanent, however I did not get a pic of that particular finished part.

 

[BobL]

Here are mine.

441


880 - also with Temp gauge.

 

[Brent Nowell]

Here are mine.

441
View attachment 739188

880 - also with Temp gauge.
View attachment 739189

Doh you one upper you

Looks great!

 

[Brent Nowell]

Temp sensor is another one that’s just as important to have, if not more important. What did you use?
What are normal operating temps? Thank you!

 

[BobL]

Temp sensor is another one that’s just as important to have, if not more important. What did you use?

That is a TRAX thermocouple used on RC cars/vehicles.

What are normal operating temps? Thank you!

It depends where you locate your sensor. The problem is the cooling fan won't allow for any sort fo reliable reading when the sensor is located outside.
More info here - you re lucky these pics are still there as I put them back after the great picture loss a few years back.

 

[Brent Nowell]

Interesting, hmm i wonder if a drill and tap could be done with an appropriate probe...

 

[BobL]

Interesting, hmm i wonder if a drill and tap could be done with an appropriate probe...

The most accurate/appropriate temperature to measure/monitor would be the exhaust gasses. There are probes that could be hung in the exhaust path that could be used.

 

[rarefish383]

The local High School was fazing out their votech, I bought an engine dyno at the auction. I called the manufacturer and they said it was a Votech model with a heat sensor in each exhaust manifold. If I wanted to use it for tuning race engines I would need to order, or make, headers with a temp port in each tube to measure heat in each cylinder. Tune till all ports were the same temp. So, I'd say Bob is right.