Head Bolts

[bondy]

hi all the head bolts on my 199A. do i really need to buy a touqe wench? or is it ok to just tighten them up in order? how thight do they have to be? i mean i know they have to be thight but i dont want to buger the threads up as i had to have the helicoiled. the last owner had helicoiled them him self and did a crap job. so now they have been done proper ive just put the motor back in today just got the head to put on and the exhaust.

[pschrauber]

Hi Bondy,

The question is how good are your skills depending fastening the bolts? Some people very used to this job can do this without a torque wrench.

I use a torque wrench and would recommend you to use one too.

The pattern how to fasten the bolts is shown here:

EDIT:

The number give you the order where to start,

The thigthening torque for #5 #7 and #6 #8 is 19Nm.

The thigthening torque for #1, #2, #3, #4, #5 and #6 is 15Nm.

At first thigten all srews and nuts by hand!

Then you thighten the screws and bolts in steps beginning with 3Nm from #1 to #6.

Then again with with 6Nm and so on until you reached the 15 / 19Nm.

regards

Patrik

Edited May 23, 2012 by PSchrauber

[bondy]

great help thanks. the motor is in the frame ive loosley put the mounting bolts in with the nuts loosley on. know do i tighen the mount bolts up before i tighten the head up? and the engin sump plate is also on this has been tightend up

[bondy]

hi patrick it says in my manual it should be 12ft lb for all the cylinder head nunts and bults i checked with bultaco uk and he said that this was the torque setings

[pschrauber]

There is one "problem" I did myself while I wrote up the specs, I forgot the #7 and #8 bolt/screws, it was probably a little bit too late when I did the post ...

Numer #7 and #8 get 19Nm while #1 to #6 get 15Nm, btw: Spain uses as Germany the metric system in Nm or the older metric system kgm, the given torque in feet - pound was never used by Bultaco. And I have no clue how much ft lb is in Nm or kgm, but there exist some converter in the www.

12ft lb is 16.3 Nm in metric, pretty close to 15Nm, a little bit more then you should use.

11ft lb is 14.9 Nm in metric, a little less then you should use.

My manual from 1980 says 15Nm (for #1 to #6) and 19Nm (for #7 and #8):

I used it for maintaining my Bultacos since 1980 and it worked pretty well:

I used the given specs for my 199b and also for the 221 it worked very well and I posted it already a year ago,

here: http://www.trialscen...__1#entry276344

Edited May 23, 2012 by PSchrauber

[pschrauber]

To the lower engine mounts, I did it like this and had no issues while mounting the bashplate, the engine,

the swing arm or the head stady, btw. never had a broken headstady so far!

I first mount the bash plate and mount the screws but only thighten them by hand, (little loose fit),

the I mounted the rear engine support to the engine case, bolts again loose fit,

then I place the engine in the frame and mount the front engine bolt, (loose fit),

Now the swing arm, and the swing arm axle and thighten it.

then I thighten the the engine bolts front and rear, thereafter the bash plate bolts.

Then I unscrew the rear cylinder bolts and mounted the head stady the bolt to the frame again first with loose fit.

Now I thighten the cylinder head srews with the head stady and at last I thightend the bolt where the headstady

is mounted to the frame.

This way the in my experience the engine / bashplate / swingarm / headstady and cylinerhead mount should work out very smooth.

[bondy]

thanks i will loosen the bash plate. the engin is in the frame but nothings been tightened up yet am just waiting for a torque wrench to come. then i can torque all the bults and nuts. thanks again for your help