| ||||
| ||||
| Moderated by: Greg Fletcher |
|
||||||||||||||
| tach | Rate Topic |
| Author | Post |
|---|
| Posted: 09-04-2006 10:31 pm |
|
1st Post |
|
upstate mike Member
|
Hi, the more I drive my 4 speed 74 JH the better the tach seems to work. The previous owner didn't put alot of miles on it for the years I have his service records for. Anyway I'm wondering how accurate my tach is reading 3000 rpm at 60 mph in 4th gear . Thanks in advance, Mike K
|
||||||||||||||
| |||||||||||||||
| Posted: 09-05-2006 06:05 pm |
|
2nd Post |
|
edward_davis Member 
|
Mike, if you have the stock 185/70HR13 tires, the circumference of the tire should be about 6 feet. At 60 mph, you're going ~90 feet per second, which works out to about 900 rpm for the wheels. With the stock axle ratio of 3.727:1 and the 1:1 top gear, the engine should be going about 3350 rpm at 60 mph. The stock JH tach often has difficulty with rpms in the midrange, but ~300 rpm is good for 30 year old electronics.
|
|||||||||||||
| ||||||||||||||
| Posted: 09-10-2006 10:00 pm |
|
3rd Post |
|
upstate mike Member
|
Thanks for the info, Mike K
|
||||||||||||||
| |||||||||||||||
| Current time is 09:17 pm | |
| > Jensen Healey & Jensen GT Tech > Engine & Transmission > tach | Top |
