Want to install a tachometer (1 Viewer)

[MtnClimber]

I want to install a tachometer in my '73 40. I searched what I could with the key words I could come up with but haven't found my answer. What is the factory redline for a '73 F engine? I want to see if I'm winding the piss out of it on the highway. It maxes out at 67MPH while the speedo barely reads 55. Thank the 34s for that.

 

[Mark W]

Toyota never spec'd a redline for the F engine. Peak horsepower was rated at about 3600. Safe redline depends on the condition of the engine. In nominal condition I would turn it to 4000 for short periods (running through the gears) without any concern. I would keep it at or below 3000 for any sort of highway cruising. Stress on the rotating assembly goes up geometrically with RPM, not linearly. And the oil takes a real beating at continued high Rpm too.

5000 and above you are looking for breakage even with a like new motor.


Mark...

 

[matt.mcinnes]

There is a thread on mud some where that shows how to convert a BJ42 taco for an FJ40. This retains the factory look some what as the BJ42 diesel did have a taco.

Hit search.

 

[dgangle]

...Stress on the rotating assembly goes up geometrically with RPM, not linearly...

I think he means exponentially or logarithmically

take no offense...good advice. Just busting Mark's balls.

a gas tach only needs 3 wires: ground, power and a lead from the negative side of the coil. A 4th useful wire would be for lights only if you want to see the gauge at night.

 

[matt.mcinnes]

I think he means exponentially or logarithmically

take no offense...good advice. Just busting Mark's balls.

a gas tach only needs 3 wires: ground, power and a lead from the negative side of the coil. A 4th useful wire would be for lights only if you want to see the gauge at night.

Gauges you can see at night, hmmmm are we talking 40's here Bio luminescent organisms give off more light

 

[IDave]

Auto Meter

Mounted nicely on my steering wheel shaft. Nice match for OEM speedometer.

 

[lobo loco]

Tachometer

The small Sun Pro II worked for me. About $30. at Autozone. Mounted to column with hose clamp under the plastic switch cover. Best to keep engine under 4k.

 

[MtnClimber]

Well, I think the engine is original. The Odo says 20,600 and I am not sure if it is a flipped reading. Once I get the Tach in, I'll get to see where I am at on the RPMs on the highway. The 40 has a 4 speed swapped in from a more recent model, but no over drive. I would like to get a 4 runner 5 speed if it bolts up.

 

[joeyg1973]

5000 and above you are looking for breakage even with a like new motor.

I partially agree with this. If your motor is balanced you can hit 5k. The bottom end of the 40 is so far out of wack it is crazy. Talking taking out a gram or two to get a crank balanced. This will drastically reduce the vibration and allow for higher RPMs. On a stock not so new motor... 3600, 4000 for very short bursts.

 

[joeyg1973]

Well, I think the engine is original. The Odo says 20,600 and I am not sure if it is a flipped reading. Once I get the Tach in, I'll get to see where I am at on the RPMs on the highway. The 40 has a 4 speed swapped in from a more recent model, but no over drive. I would like to get a 4 runner 5 speed if it bolts up.

4 runner 5 speed won't bolt up. You need an H55 and those don't come cheap.

 

[Mark W]

I think he means exponentially or logarithmically

take no offense...good advice. Just busting Mark's balls.

LOL... yep... you are right.... I knew sumtin wern't right with the statement...


Mark...

 

[Source3]

Two weeks ago I installed a small Sun Pro II from AutoZone (~$30) on my 9/72 FJ40. I straightened the mounting bracket that came with the tack, drilled the mounting holes larger, and attached it to the steering column support underneath the dash. When I had it on the column with hose clamps my knee kept hitting it as I got in and out of the vehicle. Also, if you hook up the positive lead from the tack to the battery for temporary testing, remember to disconnect the wire or you will drain the battery; for final placement you will tap somewhere into the wiring harness at a place that is cold when the key is in the off position. This wiring stuff is nicely discussed in the instructions for the tack.

I am out of town but will post pics in a few weeks if needed.

 

[MtnClimber]

I am out of town but will post pics in a few weeks if needed.

Sure. Pics would be good and helpful for future search results for others as well.

 

[olymon]

tach install

I hate to hijack a tread but has anyone installed a tach in their rig that has a hei distributor from heidizzy on ebay? I just want to know what you have the tach hooked to. Thanks, Olymon

 

[dgangle]

I hate to hijack a tread but has anyone installed a tach in their rig that has a hei distributor from heidizzy on ebay? I just want to know what you have the tach hooked to. Thanks, Olymon

No hi-jack, read or re-read the 3rd sentence of post 4

 

[olymon]

dgangle, thanks, I wasn't sure if it applied to the hei distributors or not.

 

[subzali]

There is a thread on mud some where that shows how to convert a BJ42 taco for an FJ40. This retains the factory look some what as the BJ42 diesel did have a taco.

Hit search.

You can also go get a tach that's designed for a J**P CJ7 application, and with a 3" hole saw and some wiring ends up working great too.

I think he means exponentially or logarithmically

Mathematically, geometric progression is a possible mechanism to describe the rate of increase. But it probably doesn't apply in this instance, and Mark admitted to having been out of his mind when he wrote that, so