Rocker End Float

[Rusty Bolts]

I'm going to do my valve adjustment this weekend. Last time I checked them the rocker end float one side was 0.4 and 0.05. Both within tolerance but what is the collectives view on where they should be? Should I aim to get them in the middle I.e. 0.25 or toward the 0.5? Does it make a difference or have an effect on smoothness?
And the final question, that is the procedure for tightening the head bolt nut. Do you torque it down to x Nm and then 180 degrees? If so does anyone know what the torque value is.
Cheers in the expectation of an avalanche of abuse

 

[Bendy toy]

When I did mine there was no effect on engine smoothness that I could feel. It might have been slightly more tappet sounding. (Its a single cam with locknuts but the principles are the same).

Ideally, all clearances should all be similar. Setting them close to the low side will mean another check sooner as they have less safe range. Setting them to the wider end of the range makes them slightly noisier.

When I did my Yamaha valve shims (Oh such fun!) it was certainly more tappetty - so much that I took the cover off again to make sure I'd not made a mistake. It was fine.

 

[Rusty Bolts]

Cheers Bendy
It looks like I'll aim for them all around 0.25mm.
Just got to find out the torque and angle to tighten the head nut through.

 

[manxgser]

Just done mine rocker end float that is set them to .05 I'm sure it's the first time thay have ever been done and it's done 30000 miles thay were three times that befor I did them the valve clearances were spot on the motor is much quieter now so realy happy with that job

 

[mikeyboy]

just my opinion
my target figure is between .15 and .10 toward the lower end ,but no risk of pinching the rocker

 

[Rusty Bolts]

Cheers for the replies so far
Any thoughts on the torque figure and final tightening angle?

 

[Rusty Bolts]

I managed to get my reprom disc working by polishing out the scratches. Anyway, according to ReProm its 18Nm for the little TX bolts and 20 Nm for the M10 nut. Following the torquing down of the M10 nut, it should be tightened by 90 degrees and then a further 90 degrees. Not sure why it doesn't say 180 degrees but it must be like that for a reason.

 

[TimboLeMatelot]

Re Rusty's comment I suspect the intention is to torque each in turn 90, then each again 90?

I'm reading this with interest as mine is a keeper and I will be self servicing soon

Is there more than one?

 

[Rusty Bolts]

Re Rusty's comment I suspect the intention is to torque each in turn 90, then each again 90?

I'm reading this with interest as mine is a keeper and I will be self servicing soon

Is there more than one?

You only have to undo one of the cylinder head bolts when doing the end float. There are other TX bolts to undo but they are tightend to a torque and then left alone.

 

[BlueBird]

Lazy?

If you would care to do a search or have a look its all detailed in an excellent How To by Steptoe

 

[Rusty Bolts]

If you would care to do a search or have a look its all detailed in an excellent How To by Steptoe

Sorry I was asleep.

 

[Bendy toy]

Torque to around 25Nm then two stages of 90 degrees is common on car engines. But they are one shot bolts not supposed to be re-used.
They have up be done in the correct sequence

 

[Beemerman59]

From the manual for my '08:

Bearing cap to timing-gear carrier

M8 x 30
18 Nm

M8 x 40
18 Nm

Nut, tie bolt, M10
Closing torque, 20 Nm

Initial torque, 90°

Final torque, 90°

 

[MattW]

As you're only doing the one head bolt the 90 then 90 thing is redundant (that's for when you're doing all the bolts in sequence). Just torque it to the initial figure then do the 180. If you want (or if it's easier) to do the 180 in two 90 degree stages then feel free but it won't make any difference when you're dealing with the single head bolt. I don't use a degree disc for this - I just eyeball it.

Did this countless times on my 1100 and nothing exploded.

 

[Rusty Bolts]

All done. I followed Mikeyboy's advice for the end float of between 0.15 & 0.1mm. It's a tight 0.15mm but an easy 0.1mm.
I can see the 90 degrees, followed by a further 90 would be appropriate for tightening the cylinder head back on, so thanks for the clarification Matt
The RH cylinder head nut was very loose so I'm not sure what that is all about
Engine does sound quieter

 

[JimVonBaden]

I managed to get my reprom disc working by polishing out the scratches. Anyway, according to ReProm its 18Nm for the little TX bolts and 20 Nm for the M10 nut. Following the torquing down of the M10 nut, it should be tightened by 90 degrees and then a further 90 degrees. Not sure why it doesn't say 180 degrees but it must be like that for a reason.

The 90/90 is for a new head gasket and torqueing all 4 nuts. For just the one the spec is 20Nm and a 180° turn. That is it.

As for the number. it is .05 to .40mm. I set mine to .10mm to ensure they are near the low end, but no chance of pinching.

Jim

 

[Rusty Bolts]

The 90/90 is for a new head gasket and torqueing all 4 nuts. For just the one the spec is 20Nm and a 180° turn. That is it.

As for the number. it is .05 to .40mm. I set mine to .10mm to ensure they are near the low end, but no chance of pinching.

Jim

Cheers Jim

 

[Mistacat]

All done. I followed Mikeyboy's advice for the end float of between 0.15 & 0.1mm. It's a tight 0.15mm but an easy 0.1mm.
I can see the 90 degrees, followed by a further 90 would be appropriate for tightening the cylinder head back on, so thanks for the clarification Matt
The RH cylinder head nut was very loose so I'm not sure what that is all about
Engine does sound quieter

Keep an eye on that loose nut, The lower studs have been known to pull out of the crankcase.
Easy repair but obviously need to remove head and barrel.
BMW do a repair special helicoil insert but I understand it is a dealer only part.
Not trying to worry you, just to keep an eye on it.

 

[Rusty Bolts]

Will do
When tightening it, it did 'tighten up' if you know what I mean.

 

[Bendy toy]

BMW do a repair special helicoil insert but I understand it is a dealer only part.
Not trying to worry you, just to keep an eye on it.

The may have to use a jig to be sure the drill and tap go in straight so probably not a DIY job even if you can wield spanners.