[C1] Tachometer accuracy
Thread Starter
Cruising
Joined: Mar 2017
Posts: 13
Likes: 0
From: Stillwater Ok
Tachometer accuracy
trying to get my tachometer to read accurately It reads way faster than the engine. Its running off the generator. Ive gone to the largest pulley available.
This is a 6500 redline tach. Its the original tach.
Where distributor drive tachs the same. Running a 350 hp 350 with oe pulleys
My firewall has the oval hole in the center for tach drive cable. Im using an Accel dual point no tach drive.
Anyone ran into this
This is a 6500 redline tach. Its the original tach.
Where distributor drive tachs the same. Running a 350 hp 350 with oe pulleys
My firewall has the oval hole in the center for tach drive cable. Im using an Accel dual point no tach drive.
Anyone ran into this
Race Director
Joined: Feb 2007
Posts: 15,500
Likes: 8,972
From: northern california
C2 of Year Finalist (track prepared) 2019
That hole in the firewall obviously indicates your original tach is designed to be distributor driven. As such, it will read 2X cable speed. It should even have an ink stamp on the case saying so.
In any event, trying to run it from the generator will never give accurate results. Tachs which were intended to be generator driven read 1X cable speed. You'd need a generator pulley twice the diameter of the crankshaft pulley to get that tach to read accurately.
Your options as I see it:
1. Get a tach drive distributor and connect the tach cable there
2. Get a tach designed and calibrated to be driven by a generator.
3. Convert to an electronic tach
In any event, trying to run it from the generator will never give accurate results. Tachs which were intended to be generator driven read 1X cable speed. You'd need a generator pulley twice the diameter of the crankshaft pulley to get that tach to read accurately.
Your options as I see it:
1. Get a tach drive distributor and connect the tach cable there
2. Get a tach designed and calibrated to be driven by a generator.
3. Convert to an electronic tach
Race Director
Joined: Feb 2007
Posts: 15,500
Likes: 8,972
From: northern california
C2 of Year Finalist (track prepared) 2019
Race Director
Joined: Feb 2007
Posts: 15,500
Likes: 8,972
From: northern california
C2 of Year Finalist (track prepared) 2019
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From: Mustang OK
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NOT until the 62 model did ALLLLLLLLLLLLLLLLL engines have a tach drive distributor. The generator tach drive was last used in 61.
