The Triumph Dolomite Club - EzBoard Archive

Hello all, I've greatly enjoyed reading from this discussion board for a few months now. It's really a relief to hear some people actually tuning the 1850/Sprint engines. I've always been a big fan of the Sprints since reading an artical about one in Practical Classics many years ago. My intension since then was to convert my TR7 to a Sprint engine but somehow I worked myself into just sticking with the 8v. Seems no one really does much with the 7 engines in the states and just drops the Rover V8. So once again, it's nice to see people really working with the Triumph slant four. <br>
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So I've got the TT10204 (Fast Road 34-66 280) cam with TT aluminum deep valve caps and TT single springs on the TT flowed SS valves. No installation center line was provided but I calculated 106 degs. which I was wondering if anyone can verify. Also I haven't seen much on this board about the aluminum valve caps and somewhat question the durability of aluminum in this application. Is there any experience with these parts good or bad? <!--EZCODE EMOTICON START :rolleyes --><img src=http://www.ezboard.com/intl/aenglish/im ... s/eyes.gif ALT=":rolleyes"><!--EZCODE EMOTICON END--> Of course these are acedemic questions since everything is together, but there's always next time... <br>
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Cheers,<br>
Scott<br>


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Hi Scott,<br>
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Welcome to the forum.<br>
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You will find a lot of info here for the budding Slant 4 tuner<br>
A well built 8 valve will give a fair bit of power, it is cheaper than the Sprint lump, and a bit easier to work on (a cam change in 30mins). My last TR7 had 125bhp at the wheels, which is reasonable for a road car (with the same cam as you) <!--EZCODE LINK START--><a href="http://www.bodgerben.com/images/_TR7_Engine.jpg" target="top">TR7</a><!--EZCODE LINK END-->.<br>
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I have no experience with the Alloy valve caps - but personally would only use them as you have - to get away from using huge shims on a reprofiled cam. I would not use the standard size alloy caps.<br>
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I did note that the 8 valve cams have a vastly reduced opening flank - they accelerate the valve very quickly, this does lead to high follower wear around the edge - keep an eye on the sideways movement of the followers, and replace and re-shim as required. You could probably keep an eye on the shim not wearing through the side of the valve cap at the same time. In normal circuimstances the hard metal, edge of shim, will wear before the soft metal, valve cap. But that may not be the case with the caps. Think followers and head - the edge of the followers, hard, will wear long before the head, soft alloy.<br>
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A tiny bit of useless info about my old TR's is here :<br>
<!--EZCODE LINK START--><a href="http://www.bodgerben.com/tr7_8.htm" target="top">TR fings</a><!--EZCODE LINK END--><br>
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Ben<br>
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<!--EZCODE LINK START--><a href="http://www.dollysprint.com" target="top">www.dollysprint.com</a><!--EZCODE LINK END-->

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These are possibly ok for a road engine, but I did have an instance where the valve collets pulled right through the cap, and also others pulled further down into the caps. I would not use them if I could help it.

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Pulling through was really the kind of failure I was worried about. Since I had the longer stem TT valves it kind of forced me to stick with the alloy caps. Funny thing was that I still needed to use extra thick shims even though the TT catalog said using the longer valves would allow the use of the normal shim range. I'll have to keep an eye on any early signs of failure if I track the car a significant amount <!--EZCODE EMOTICON START :p --><img src=http://www.ezboard.com/intl/aenglish/im ... tongue.gif ALT=":p"><!--EZCODE EMOTICON END--> <br>
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This engine was put together with a new head and new tappets so that should give decent life with reguard to wear. The car doesn't get much mileage, 1000 miles in 3 years so far. Next time the cam is out I will give a good inspection to the wear area you described.<br>
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I thought they were a good idea until my engine dropped a valve due to one pulling through <!--EZCODE EMOTICON START >: --><img src=http://www.ezboard.com/intl/aenglish/im ... ns/mad.gif ALT=">:"><!--EZCODE EMOTICON END--> <br>
I must take a photo of the valves and post it up

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