torque angle gauge

[SilverShadow]

When tightening con rod bolts, haynes manual states to torque them to 20nm and then a further 70 degrees.

Am I ok to tighten to 20nm with a torque wrench and then estimate the 70 degrees?

Or should this only be done with an angle gauge?

[DanThe]

Estimating 70 degrees would never get you 70 degrees

[maxfield]

In the past I've marked bolts with tipexed and guessed.

But for the sake of a fiver might aswell get a torque angle gauge.

[SilverShadow]

Bllx! con rod bolts are stretch bolts and I estimated the angle

Start again with the same bolts or leave them alone now?

[Speedtouch]

As long as you got reasonably close to 70 degrees, they'll probably be fine.

[SilverShadow]

Thanks Speedtouch!

What kind of tolerance would be adequate? Between 10/20 degrees?

[Speedtouch]

I would guess a +/- 10 degree tolerance would swing it.

Isn't there a definitive torque they should be tightened to?

[DanThe]

As long as you got reasonably close to 70 degrees, they'll probably be fine.

Lamping in the old ones with a rusty half inch ratchet and an ill fitting english socket on a saturday morning with a terrible hangover would probably be fine too, but it wouldnt be right

[DanThe]

Bllx! con rod bolts are stretch bolts and I estimated the angle

Start again with the same bolts or leave them alone now?

If they were new they will be fine to reuse, its not something you will get the chance to do again properly if the big ends start knocking

[SilverShadow]

Connecting Rod Cap Bolts/Nuts (M20 & M40 Engine) - 20Nm then angle-tighten 70°

This was taken from the wiki.

[SilverShadow]

They were new bolts @ £6.00 each.

[Speedtouch]

Bllx! con rod bolts are stretch bolts and I estimated the angle

Start again with the same bolts or leave them alone now?

If they were new they will be fine to reuse, its not something you will get the chance to do again properly if the big ends start knocking

Not something you want to be doing with stretch bolts:

"If you look at the specs for the M20 you will see it has a initial torque, this seats the cap and bolt to a even clamping load. Then you will see it says to 'angle' tighten 70*. When you pull this 70* angle you are stretching the bolt, not only are you stretching it, you are placing it into a 'elastic' state. Once removed the bolt is stretched and elasticized and is no longer considered usable."

[DanThe]

elasticized

Look that word up in the dictionary

[Speedtouch]

I didn't spell it that way - it was a quote from another E30 Tech website.

But, you get the gist...

[SilverShadow]

If the torque/angle is way out what kind of consequences could it cause?

Keeping in mind that these are con rod bolts (new)?

[Speedtouch]

I don't really see how you could get them "way out" - I mean, 70 degrees is fairly close to 90 degrees and significantly more than 45 degrees isn't it, so as long as you tightened them to approximately 70 degrees, that should be OK.

[SilverShadow]

I don't really see how you could get them "way out" - I mean, 70 degrees is fairly close to 90 degrees and significantly more than 45 degrees isn't it, so as long as you tightened them to approximately 70 degrees, that should be OK.

True say, I think I was just panicking lastnight.

I also had a mate with me who was guiding me as well when doing the angle torque.

Thanks for all your help on this!

[Brianmoooore]

After you have done the initial tightening with a torque wrench, make a mark on the bolt head with a permanent marker pen. This will allow you to check the further angle that you turn them, and ensure you haven't missed one.