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TR2/3/3A What type of valve to use when rebuilding the head?

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Joel Lester

Joel Lester

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Shortly I’ll be moving towards rebuilding the head on my TR3 engine. In getting my new parts list together I see that the type of valve you can order vary a great deal in price. From about $10 a valve to $35. Or $80 versus $280 for the set. Is the quality worth the price? Is it the alloys in the metal what makes the difference? I will not be racing but want a reliable strong running motor. Running 89mm pistons with a Newman “road” cam. Any advice or input would be greatly appreciated!
Joel
 
Thanks for the input. I will plan on getting the machine shop to install the guides and do the valve seats. Part of me thinks that an extra $200 is not a huge amount but on the other hand if it's not really necessary then...
 
Agree with Hamish. How about middle of the road on intakes but I would go better on the exhaust valves where all the heat is ! Good luck on your build !
 
I have yet to hear of a TR valve failing, other than burning from old age which is not a quality issue. I bet the prices are more a reflection of the supply chains for the different stores. Case in point:

We needed a new water pump pulley for our Range Rover. It is a 2004 with the BMW engine. I went to the Land Rover dealer and he wanted $1300. I then went down the street to the BMW dealer and bought the exact same pulley, exact same part number, for $36. I fully believe the valves you are looking at are likely manufactured by the same company.

Now, the big difference in valves is the stem diameter. The early valves used a thinner stem, and it was later increased to 3/8". Just make sure , as Hamish pointed out, that you buy guides to match the valves. You can also buy valves with larger tulips for a slight performance edge. Avoid those for your street motor. They also slightly reduce the life of the head.

There is a good chance you will need exhaust seats. The heat tends to cause the cast iron to wear, so the exhaust valves recess into the combustion chamber. Hardened seats bring them back up and will prevent them from ever receding again. In severe cases, the intakes can also recess, but that is less common.
 
Thanks John! I really appreciate the advice. That plan (new exhaust seats and standard valves) sounds solid. I'll make sure the guides and valve stems are appropriately sizes too. Someday I will share some pics of my project - I must admit it looks pretty good. :cool:
 
Get yourself some good valve springs ! Didn't hear anyone mention them. They are one of the most important and highly stressed components in our engines !
 
Thanks Superwrench! I was planning to get new ones - the set that has three exhaust from Moss. Didn't even think about the difference of quality between various vendors. I was thinking of going stock. Any recommendations?
Also - what about the larger intake valves? I see they are offered but not really sure they would make much of a difference? Since I'm getting new seats ground at the shop it doesn't seem like it would be that big of a deal though.
Decisions.. decisions...

Joel
 
don't over spring your valves - they can be too much and wear your cam. you only need really strong springs for racing and where you are going above about 6.5 7k rpm to prevent valve bounce.
i also wouldn't go too big on the valves for a road car. you loose a lot of material between the valves in each cylinder head pocket.
you can see i have done everything i have advised you NOT to do here
the head is at about 1.36 this is a professional race spec head.
 
Agree with Hamish but the $49 set from Moss should be fine. Get your headshop guy to compare them to your original springs. Maybe only put the 2 outer coils in, instead of all 3 ? I have done that before on a street engine. Good luck !
 
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