58' Corvette Tachometer Adjustment

I thought that the 58 Vette tach was distributer drive not electric? Now it is interesting that the tach shows 2x the rpm of the tester. The tach drive is connected to the distributer which is connected to the camshaft which is driven at 1/2 the speed of the crankshaft rpm...... So the tach will show twice the speed of the distributer/crankshaft.

Here's my website that shows you how to verify your electric tach us> The Tach of my 58' Corvette always shows approx.the double RPM of the

Well, no, Eugene. The factory '58 tach runs off the generator - it bolts to the rear of the housing with the cable running from there to the dash. *IF* hotchrome still has the original, then perhaps someone substituted pulley diameters somewhere in the "fan" belt setup and that's why it shows double speed.

Here's waving to ya - \||||

Owen ___

'67BB & '72BB

-- not affiliated with JLA forum in any way -- alt.autos.corvette is original posting -- ___

"To know the world intimately is the beginning of caring." -- Ann Hayman Zwinger

My Tach is generator mounted,not distributor. Thank you, Hotchrome

hotchrome schrieb:

The lower and upper pulley are 17cm diam.,generator pulley is 9,3cm (3-5/8'') diam., the bigger one of the two originals 58' pulleys,the two generator transm.wheels are new but original diam. 58' Vettes had generator and distributor tachs,on the tach magnetic gear(inside tach housing) there is a number ,,2'' , double rotation??? Thanks to all, Hotchrome/Austria

hotchrome schrieb:

Well isn't that the dumbest thing I've heard yet. A generator drive tach..

Strange but True.

Perhaps it was a gimmicky thing in the beginning - made it more sports car for the image crowd like but saved money. Does anyone know if other GM vehicles of that era used a direct engine connected tach? Maybe it was not engineered as distributor driven yet.

"Who Knows?" -Donald Rumsfeld

Here's waving to ya - \||||

Owen ___

'67BB & '72BB

-- not affiliated with JLA forum in any way -- alt.autos.corvette is original posting -- ___

"To know the world intimately is the beginning of caring." -- Ann Hayman Zwinger

And the correct way to do that in 1958 was?

Maybe the correct way for Chevies but the rest of the world didn't do it that way.. btw I was waiting for someone to get their shackles up over my comment...

Doesn't bother me, just wanted to know the right way that it should have been done. So by what you're saying you don't know the right way. Don't believe that there were very many cars with tachometers back then to compare it to.

By the way, isn't it "hackles" and not "shackles", or is that the right way where you come from?

Hackles is right - its just me screwing up another phrase again...

I did a search >

Actually it was an easy way to use the current technology, and parts available to slap together a cheap tach for the Corvette just as it was to use the standard sedan chassis. GMs way of leading the field of automotive advancement.

I did a lot of measuring of the standard Chevy kingpin suspension while machining my own replacement balljoint suspension (lots of work) and was very surprised to find that the kingpin suspension was a horrible design concerning bumpsteer. Here's my webpage on my measurements: