Cambelt Tension

[Guest TerryBarry]

Does anyone know of a method of measuring the cambelt tension on a Pinto engine without using the Ford tension gauge?? What does this gauge measure - pulling or twisting force.

I'm fitting a new belt and from the Haynes manual the Ford gauge reading should be 10 to 11 for a new belt compared to 4 to 5 (what units ???).

Other engines I've come across that don't have auto-tensioners have specifications like ( 30lbs pull to deflect belt 1/2 inch on longest sector).

I'm having bit of a problem interpreting "moderate pressure (see illustration)" as the book says.

I've got a bit of time before I need to fire up the engine - Like get it in the chassis first.

Thanks,

Terry

[Big Jim]

If you get hold of the belt on the longest run on the "slack" side you should be able to twist the belt 90º with your finger & thumb. You'll know if it's too tight when you start the engine up, it makes a noise unlike anything else.

[Longboarder]

Wot. A snapping sound followed by clanging as the valves destroy themselves and then an eery silence, broken after a short pause by the sobbing of the owner? Ouch!

Nigel

[Guest Ant]

The first time I ever replaced a cam belt I took it to a garage (as instructed to by haynes), and asked them to tension it. They took the cover off, wiggled the belt, and then said "looks fine to me". That's all they do when they replace them.

 

Since then I've replaced several, on all sorts of cars. If they're too tight then as the engine warms up you'll hear a slight whining noise. As a general rule I use the 90 degree test. If I can do that without hurting my thumb then it's about right.

 

Ant

[Guest TerryBarry]

Thanks Gentlemen,

I think that I can interpret those instructions

I do wonder if my local Ford dealership has one of these gauges.

My local B-L dealer never stocked any of those various locking tabs you were supposed to replace on Minis

"Oh our guys just reuse the old ones"

Cheers,

Terry

[Guest paul mercer]

having just re-built my cosworth engine and fitting it, i started worrying one night about the tension. i went with what jim has now advised but thought i'd better check it with the proper gauge. i hunted around at work and found a rare as rocking horse **** cambelt tension gauge. it does have a proper name, but i can't remember it. the units are non existent, but after checking what i'd done with the 90deg twisty thing, the tension was pretty spot on according to the gauge. as a plus point, none of my valves carresed my pistons either. what a bonus

 

happy building

[Big Jim]

See! us old B.....ds aren't as thick as you young un's make us out to be!

[Guest Peejay]

Stethoscopes for twin SU's and a screwdriver to locate mysterious engines noises eh Jim??

 

Pete

[Big Jim]

Don't knock it until you've tried it!