Hardened valve seats or not

[bluemiata90]

I decided to completely inspect the internals of my TR3 engine while I had it out of the car. Pleasently surprised, I've found that it seems to have been rebuilt in the past.I measured the pistons and found them to be 87mm across. I assume that means they have replaced at one time with new jugs and pistons.Pistons and jugs look clean (no scoring. I have a double timing chain, another indicator of a rebuild. My question is, is there a way to determine if the valves have been replace with hardened seats and valves without removing them from the head. I can visually seem them and they look like they've been replaced (they have very little build up of carbon). Did the originals have markings on them, cause these don't. I'd rather not have the head taken apart if I don't have to. Any help would be appreciated. /ubbthreads/images/graemlins/driving.gif

 

[Keoke]

Miata90, Here is just a thought.Generally, when a head has been modified for unleaded fuel you will find that Bronze valve guides have also been installed.This is not laid in concrete but is usually the case.-FWIW---Keoke /ubbthreads/images/graemlins/patriot.gif

 

[piman]

Hello BM,
clean the chambers as much as you can then look for a concentric ring around the exhaust valves, this may be very obvious or not depending on if any chamber blending was done. Don't mistake it for a spot face that may have been part of the original machining of the seats.
You say you don't want to strip the head, but I suggest, as the head is off, that it is short sighted not to remove the valves and lap them in. In that case the inserts, if fitted will be easier to see.

regards,
Alec

 

[waltesefalcon]

You really ought to go ahead and remove the valves, and lap them in. Its not a hard process and one you can do best by hand. But if you clean up the area around the valves you should be able to see the ring alec mentioned, as evidence of new seats being put in sometime in the past.

 

[bluemiata90]

Thanks for all the replies. FYI, after a lot of research, I found in How to Restore Triumph TR2/3 Enthusiast's Manual on page 110 under picture 8-5 a little known way of finding out if the valves are hardened. Use a magnet on the valves and if it is attracted to the valves, they are not unleaded use valves. Unfortunately, the magnet was attracted to my valves, so I guess they should be replaced. /ubbthreads/images/graemlins/savewave.gif
thanks again

 

[Rick O.]

Generally speaking, hardened valve seats are advisable only if you do a lot of sustained high-speed driving and rack up a ton of miles. Otherwise, simply keep track of valve seat recession by adjusting valve clearances frequently, noting excessive loss of clearance. Such clearance loss would likely indicate seat recession.

 

[piman]

Hello BM90,
that is not a 100% indication, it may tell you if the valves are stainless steel, but, also, it does not follow that if the valves are stainless then the seats are hardened. In my case I have stainless valves and standard seats. I did not buy them because they were stainless but because they are performance 'flowed' valves which happen to be stainless.
As Rick suggests there is no point going out and getting the head modified if it is serviceable, wait until it needs seats before you modify it. You might as well get all the life out of it you can.

Alec