How many revs at 70 mph

J

Jaguarpeter

New Member
Hi guys,

I have a 1973 V8 auto. Every time I drive the car I wonder how many revs it is making. At 70 mph the rev counter is already Well above 4000 rpm. Although I have never driven the car at top speed I assume the rev counter wiil be off scale by then.Can anyone tell me what is a normal rev count at these speeds?
Tanks, Peter
 
hi sorry to hijack the thread but I was wondering if the temp gauge in the pic was in the "normal" position as that is where mine is and doesn't really go above that.

many thanks
coop
 
It's a very typical position - of my 4, if Ethel's temperature gauge strays into the green it means a hissy hose. Daffodil the same - always in the white. The Blue McFoo likes to stay amidships in the green and the car in this photo, Hildegarde, has no fixed fan, only an electric fan on a thermostat so it varies.
 
Nice oil pressure too .You'd have to be happy with that .
My temp sits midway .
I wish my fuel gauge was in that position . I think my wallet may have a leak in it .
:LOL: :LOL: :LOL: :LOL:
 
Jaguarpeter said:
Hi guys,

I have a 1973 V8 auto. Every time I drive the car I wonder how many revs it is making. At 70 mph the rev counter is already Well above 4000 rpm. Although I have never driven the car at top speed I assume the rev counter wiil be off scale by then.Can anyone tell me what is a normal rev count at these speeds?
Tanks, Peter
Click to expand...

70mph in a stock V8 is almost exactly 3,000rpm. Mine is now 2,5000 as I have the 5 speed box.

Is it actually revving at 4,000 or is there a problem with your tacho?

Richard
 
quattro said:
Jaguarpeter said:
Hi guys,

I have a 1973 V8 auto. Every time I drive the car I wonder how many revs it is making. At 70 mph the rev counter is already Well above 4000 rpm. Although I have never driven the car at top speed I assume the rev counter wiil be off scale by then.Can anyone tell me what is a normal rev count at these speeds?
Tanks, Peter
Click to expand...

70mph in a stock V8 is almost exactly 3,000rpm. Mine is now 2,5000 as I have the 5 speed box.

Is it actually revving at 4,000 or is there a problem with your tacho?

Richard
Click to expand...

Could it be stuck in 2nd gear?
 
I have calibrated the speedo with my sat nav and despite some erractic reading at low speed seems to be accurate.
but 70 mph reads 5000 rpm. Gear changes seem ok, the car is in 3rd gear. Could it be that there is something wrong with the torque converter? I read something in the Haynes manual but I cannot relate my symptoms to the diagnoses described. Or could it be that the rev counter is faulty? Not sure how to check this.
 
Torque converter should not affect tacho as its electrical not mechanical.
If satnav speed says speedo is pretty accurate,it has to be electrical.
Does the tacho red line start between 5000/5500?
If not you may have a 2000/2200 tacho in there which is calibrated to a 4 cyl.
Also the speedo's vary.
Its very possible that in the past the whole pod was swapped,and they didn't know they were different.
 
So I think I have the right rev counter with the 5000-5500 rpm red area. The needle of the rev counter wobbles quiet a lot just like the speedo. This eventing I took the car to the motorway and accelerated to 120 km/h (about 75 mph) the rev counter needle did not remain constant but swept between 4000 and 5500 rpm.Could it be that the cable needs cleaning and some fresh grease orr oil?
 
Jaguarpeter said:
the rev counter needle did not remain constant but swept between 4000 and 5500 rpm.Could it be that the cable needs cleaning and some fresh grease orr oil?
Click to expand...

The tacho isn't cable operated. It's electrically triggered so you're looking for a problem with that. Has the car been fitted with electronic ignition?
 
No, car has still it's original type ignition (new points and spark plugs though). I must say that the car has been out of use until quite recently. So check the wires and connectors?
 
You can check connectors, and as it still has points I'd check the dwell because if thats incorrect it could affect the way the tacho is triggered.
 
hi I believe dwell is the amount of degrees of rotation of the distributor that the points are closed. for the v8 its between 26 and 28 degrees

hope that helps
coop
 
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