• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR6 TR6 Valves/Adjustment

Share this page

bcbennett

bcbennett

Senior Member
Offline
Hello all,

A few weeks ago, I adjusted my valves per the instructions in both the owners' manual from '74 and the Haynes manual (same instructions): put the car in gear, rolled it back and forth, and used feeler gauges to test and adjust. Then, when I took it to my very competent and trusted British mechanic for other work, he told me I had pretty significant "valve lash," which he corrected. What is that, and could I have made it worse by mis-adjusting? Am I missing something about this simple procedure?

Thanks in advance,

CB
 
Valve lash is just another term for the "space", "gap" or "clearance" between the rocker arm and the valve stem.
It sounds like he thinks you went over the recommended .010 ?
 
Not to sound overly suspicious, but I'd be interested to know what your mechanic set the clearances at? There are some folks, including "trusted" mechanics, who can't stand the sound of any valve train noise and therefore set clearances tighter than factory spec. As for me, a: I don't mind a bit of noise, and b: I'd prefer to err on the side of a bit loose rather than too tight! :laugh:
 
My trusted mechanic built an XKE engine for me several years ago. It ran strong but had clacking valves. I finally got around to checking them, what a mess. No where near what they were suppose to be. As Poolboy said, double check his work. Loose is better than tight.

Marv
 
Wonder if your mechanic checked them when the engine was COLD?
I'll bet a lot of "mechanics" might consider hot the norm to set the valves.
 
bcbennett said:
Did I read somewhere that too tight clearances can cause exhaust valves to burn out?
Click to expand...
Could be; I'm not sure. I do know that clearances set so tight that the valves actually never quite close completely can lead to...well...no running at all. Had that happen once on my autocross Spitfire 4; I've no idea how the clearances had gotten so tight, but a quick resetting was all they needed! :hammer:
 
The theory is that the valves need adequate contact time with the head and seat to transfer some of their heat.
You don't give the valve enough seat time and sooner or later a piece may burn off.
 
I agree. In addition, the exhaust clearance can close up slightly while the engine is being driven hard, because the valve gets hotter (and hence expands more) than the rest of the valve train.

Until it gets really huge, a little excess lash only increases noise and reduces performance slightly. It won't damage anything.

I would check them again, if only to see what the difference is.
 
yea and everytime I take my car to the shop they always find something to change, fix or replace and when I take it in seem a short time later its back to fix something, I would check everyones work, and did he really adjust them or just charge you to, wink wink, adjust them

Hondo
 
hondo402000 said:
and did he really adjust them or just charge you to, wink wink, adjust them
Click to expand...
Exactly what I was thinking, just didn't want to say it.
 
Back
Top