Click Adjust?

[Pythias]

I've been using a click-adjust for a number of years, not
being all that good as determining a "sliding fit"... i have a cam by
OREGON CAM REGRINDERS that is recommended to have the valve lash set
at .018" HOT.... ..

i have always assumed that the threads on the adjusters were 1/4" 28
TPI. ... that worked out mathematically (28 tpi X 30 clicks per
revolution, X .018) to 15 clicks..... been doing that for years.....

now i find out (thanks Hal) that they are 26 TPI!

i went back and read the instructions.. it says use 8 clicks to get
012... hmmmm... something is off here.....me or the instructions....

so i went back and read a critique of the click-adjust. on thing is
that i've been using the math on the adjuster side, BUT there is that
1.2 or 1.3 to one ratio NOT taken into account.....hmmmm! ?

if the instructions ARE correct, i should be using 12 clicks to get
018 (8/12 = 12/18)....i've been running .022 HOT for a long time.....?

i have noticed that the engine doesn't like to go over 4500 rpm under
load... .... . would this be the effect?.. ..of too loose a valve
lash?

do i have to go back this weekend and set with feeler gauges before i
set out for LoTO, or should i leave it alone having been succesfully
running like this for years and reset it when i get home again?...

before i set them last weekend, i averaged 38.8+ mpg on a 500 mile
trip to Vancouver BC at 60 mph...

 

[tosoutherncars]

I can't see how having your valves set four thou looser than spec would affect top end. (Someone wiser may chime in.) More usually a distributor / timing / carb / fuel delivery issue, no?

 

[jlaird]

True.

 

[Pythias]

I've often wondered about this cam... in the 1098 (that i have) i can pull 4th gear from 1200 or 1300 rpm with no lugging, but it runs out of steam about 4500 under load.. it's wind to over 5k in the three lower gears but not the high gears.. one thing is that the lobe seperation is 109 degrees.. VERY wide which may better explain the lack of high end power.


.. so what IS the effect of having the lash too high?

 

[Trevor Jessie]

Noise for one.

 

[tosoutherncars]

Let's see, your valves wouldn't open quite as early, or as wide, or stay open quite as long... reducing the charge of air and gas. Slight power loss maybe, all other things being equal? But again, if we're talking about 0.004" off listed spec, I can't imagine it would be significant?

 

[jlaird]

Not significant at all but should sound a bit loud.