How do I measure my RPMs with no tach ?

Sears is the place!

I agree. Sears has all sorts of excellent automotive tools.

Actron Dwell Tach Volt Meter: Sears # 00902165000
Craftsman Engine Analyzer: Sears # 00921029000
Actron AutoTroubleShooter Digital Multimeter & Engine Analyzer: Sears # 00920925000

I have the Actron AutoTroubleShooter Digital Multimeter & Engine Analyzer and it works great.
 
KStang65B said:
I agree. Sears has all sorts of excellent automotive tools.

Actron Dwell Tach Volt Meter: Sears # 00902165000
Craftsman Engine Analyzer: Sears # 00921029000
Actron AutoTroubleShooter Digital Multimeter & Engine Analyzer: Sears # 00920925000

I have the Actron AutoTroubleShooter Digital Multimeter & Engine Analyzer and it works great.


I have the same one. Works great since my tach doesn't work.
 
Well the only way to measure RPM is with a tach. You can get aftermarket tach's, or things like timing lights with a tach built in...but the only way to measure RPM is with a tach.

Of course: you can calculate RPM if you know your tire height, transmission gear ratio, and rear axle gear ratio.
 
Here are two affordable tachs.

http://www.jegs.com/webapp/wcs/stor...irect&categoryId=22425&parentCategoryId=10339

Auto Meter Z-Series Gauges

2-1/6" Electrical

105-2697
5,000 RPM
$97.99
105-2697.webp




105-2698
8,000-RPM
$97.99
105-2698.webp
 

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My car doesn't have a tach (yet) but I needed to know what RPM to set my idle at, so I borrowed a hand-held tach from work. Basically I just put a piece of reflective tape on the crank pulley, aimed the pickup (looks like a timing lite) at the tape and squeezed the trigger. I've seen similar units at various tool sales catalogs for under $20.
 
What if you don't have a video camera? That would be the classic situation, wouldn't it? Some guy figures he can't afford a $90 tach, so he buys a $600 video camera to do a frame-by-frame shot of his damper! Sounds like a guy I used to know, he had a fairly quick Karmann Ghia drag car, but no driving skill whatsoever and kept missing shifts and blowing up fragile VW motors. After the third motor in six races, my brother asked him why he didn't buy an ignition with a rev limiter to at least help keep the motor semi-safe. His response was, "...I can't afford it, those things cost over $200..." Never mind the fact his big cc VW motors were going for about $1800 a pop...