Hi,
I have recently (yesterday) adjusted the valves on my 36hp beetle and they seem to be noisier now that before. I adjusted them to .006" which I know is the specs for all later engines but I could not find and specs for the 36hp. I have double checked them and everthing but now they seem to be a bit louder that before, in particular the LHS ones.

Any suggestions?? is .006" the right clearance?

The valves were done cold so you can eliminate that.

Cheers.

Ian Bugden

Were they tight before?

36hp are .004"

use 0.006" better and VW approved for all engines

Did you take out the adjuster screws and remove or re round the faces of the tappet so there no gaps and you have 2 clean faces to set the clearence gap to.

sometimes theres an excessive gap when the tappet screws isnt sitting flat against the valve stem

Hi,
The valve train was strarting to get a little noisy hence why I thought I would do the adjustment. Some seemed tight, others felt loose. I haven't checked if they are long studs or short studs that hold the rocker ass. as I have heard and read that the clearance needs to be different.

What makes the valve noisy, is it too much clearance or too little? I know tight valves will ruin the valve seats.

Ian.

To much clearance will make them noisy.Not trying to be a smartass..but did you do them in the right order ?? ie... compression stroke TDC on number 1 and 180 degree rotation BACKWARDS to do number 2 etc etc..? Setting them to 006 is the way to go. If it was me I'd be trying to do them again and double checking everything:beer

Hi Ian,
In this case looser is better ;-) I would agree with .006"
I'd recheck them making sure that the order you turn the engine and adjust each valve is spot on.
To risk stating the obvious again possibly, you should feel slight drag (not binding) with the feeler guage when the gap is right. Also check it again after you tighten the adjusting nut.
You may have a reground cam in which case the valves might just be a bit noisier than on a new cam due to the adjusters acting on the valve tips at a different angle. Or the adjusters might be worn as Dave suggested.
Hope this helps.
Toby :thumb

[ Edited on 27-6-2007 by type3lover ]

Yes do them in order makes a difference with the engine being rotataed in the correct direction takes all the slack out

also thought of another cause

remove the rocker arm assemblies and pull apart and check the rocker arm shafts for wear .... if these are worn it wont matter how many times you adjust they will always be out of wack

Hi,
OK, I know that I hand No.1 on tdc, and yes i did rotate the engine backwards and start at 1 then2,3,and then 4. I will re chack them again and re adjust on the weekend as it is too bloody cold to do them after work.

Thanks

Will let you know on progress.

Ian

Yeah, definatly on No. 1 tdc rotor cap pointing at the mark, and no3 on the rocker. Found3 valves that were a little loose so adjusted them and the engine is quieter, but still one the louder side of normal, I am thinking of adjustiong them to 5 thou. I have a aneaking suspision that the 36hp is meant to be at 4 thou but I will play it safe and go 5 thou.

Ian.

did u pull the rocker assys and check the wear in the arms and shafts

did you re face the tappet screws ???

leave them at 0.006 and you wont have any problems

Volkswagen put out a service bulletin in about 1972 or so stating that all tappet clearence adjustements on Air cooled engines be revised from 0.004 to 0.006"

Lots of manual stated 0.004 but this is incorrect

Often the tip of the valve also gets a little dished
and so even though a .004 feeler will fit nice it may easily be twice that.
Use a dialindicator to see if that is the case.
Will most likely need the tips machined or new valves eventually.
6 or 4 will be fine, as long as it is real.

36ers all have short studs I think.
The ones you are thinking of are the early 40 horse deals that had .008" I think.

I once had a rattly tappet and kept going tighter till it burnt the valve.
On dis-assembly I found thet 'tappet' noise was infact a loose bush in the conrod
where the gugeon pin runs.

Yeah it seems odd that the slightedt tweak in valve adj has made them noisy. I will pull the rocker arms and grind the faces. Do I grind them flat or rounded??? The engine was out for the first time about 7 years ago and had a top end rebuild useing good 2nd hand parts and has been very well looked after in the 8 years I have owned the car. I wouldn't think the ends of the valves to be that concave so am assuming it to be the rocker.

Ian.

the tips of the tappet screw should be rounded

dam, i did my 40HP to .004" coz i thought they were too wide. Sounds like it'll have to put em to .006 then... gaaah

Dave, I've still gotta check the type of studs I got! Yes, i'm a slack cint.

Chris i thought u would have dont that ages ago

It keeps on slipping my mind. I've adjusted my tappets 4 times, but i havn't had a good look at my studs yet. Mark tells me it could be a noisy valve guide too - which makes sense as the noise occurs when the engine is warm and at constant throttle...

get under that bloody car