Simple question but how do i fit carbs using thackeray washers?? Is there a measurement i need to take on the compression of these washers to ensure they are fitted correctly???
When I did mine years ago I just wound them right up, but without going mad on them...
Steve
I use nylocks
What for?
Thakeray washers are what should be used in that situation...
Steve
quote:
Originally posted by Mr Whippy
I use nylocks
From ebay:
"These are a set of 8 thackeray double coil washers to mount your carburettors to the inlet manifold correctly. They can be used in conjunction
with the bonded Misab plate or the plate & 2 O rings available in the ebay shop . The spring washer is tightened until it reaches a gap between
the coils of 25 to 40 thou, this enables the carburettor to remain flexibly mounted to the inlet. Lock nuts 5/16 type are also for sale."
Dan
I think you are supposed to be able to get a 10 thou feeler gauge between the coils or something I think the key is not to over tighten as it can lead
to frothy fuel and ultimately damage the seal between carb and flange.
I would use nylocs and Thackwray washers as the washers don't seem to stop the nuts coming undone. - also threadlock for the studs in the
manifold.
Cheers
mark
The thackeray washers are like little springs and just allow some flexibility to stop fuel frothing aren't they?? They do then need nylocs to
stop them coming undone.
My old car had the little brass cups with rubber o-ring between that need compressing until the cups were a set distance apart. I guessed there must
be a similar setting for Thackeray washers
quote:
Originally posted by worX
What for?
Thakeray washers are what should be used in that situation...
Steve
quote:
Originally posted by Mr Whippy
I use nylocks
Yes they are Paul
Excellent - just what i needed. So thats around 0.6 - 1.0mm in new money so i'll go in the middle of that range.
Cheers
Paul
quote:
Originally posted by Bluemoon
From ebay:
"These are a set of 8 thackeray double coil washers to mount your carburettors to the inlet manifold correctly. They can be used in conjunction with the bonded Misab plate or the plate & 2 O rings available in the ebay shop . The spring washer is tightened until it reaches a gap between the coils of 25 to 40 thou, this enables the carburettor to remain flexibly mounted to the inlet. Lock nuts 5/16 type are also for sale."
Dan
Sprung washers are just there to provide a know pre-load on the gaskets I guess. I expect the idea is things vibrate/shrink/expand/gaskets extrude the
pressure is constant thus providing a good seal. That will be the function of the sprung washer.. The next job is how to lock the nut, normally this
is achieved by the correct torque (with the nyloc as a backup), but with a sprung washer you need a different approach as the torque is less, hence
some form of locking nut..
Normal nuts and bolts/studs use the elastic stretch of the bolt to hold it all locked, I guess there is not enough give for mounting the carbs..
Dan
You've just reminded me! (It was quite a few years ago!)
When I ordered the Thackeray washers I also bought the specific locking nuts that they suggested as what was correct for use in conjunction with the
washers...
Steve
Yup - got the correct nylocs with the carb mounting kit from Martin (who is sunning himself on Cyprus and so will miss the big start up hopefully this
afternoon) so the carbs are now all mounted and pretty much ready to go.
I am hoping to get the engine running this afternoon. Just got a couple of jobs to do first after lunch. Go and get a can of fuel. Set the fuel level
guage with 5L in there. Check for spark (clean all the spark plug contacts and set the VR sensor wiring to the correct polarity etc) and then
hopefully we'll be ready for blast off. Had a battle this morning to get the gearbox plug out - why i didnt do it before i fitted the engine i
really dont know, but its now filled with oil so i'm good to go i hope (famous last words)!!
quote:
Originally posted by worX
You've just reminded me! (It was quite a few years ago!)
When I ordered the Thackeray washers I also bought the specific locking nuts that they suggested as what was correct for use in conjunction with the washers...
Steve
there was a post within t he last month about these and there is an alternative -little rubber bobbins with cups - these asre supposed to last
better.
but back to your question about doing up the washers - I have the figure somewhere about measuring the distance between coils but that is easier said
than done.
what I have done is do them up so that the bit in between the two "end washers" is about the same thickness as the "washer". It
is still possbuile to wobble the carbs whcih is the intention of these fittings.
nothing has gone wrong as yet but when they were done up looser, I had droppped an o-ring - these expand over time due to the petrol - you know when
that happpnes 'cause your idle goes ballistic and you may get quite impressive explosions on over-run! 