1300/1500 cylinder head/valve issues

[tinweevil]

Question for the pushrod gurus.<br>
<br>
Since putting the new head on orange (1500HL) I've done about 2000 miles. In the last 500 or so prior to the Le Mans break it's running got noticably and steadily worse. By the time I got home at the start of June it would barely idle and was idling horribly lumpy. It was also running hot. I thought it just needed tuning having never done it so set about it on Sunday. After checking everything, changing cap, arm, points and condenser and going through the carb tune routine twice I wasn't getting anywhere. Out came the compression tester. IIRC it was something like 150, 100, 145, 105, bingo. All the tappits had closed up a lot. Adjusted them up and now its sweet as again. Checked the comp again and got them all in the 145-155 range.<br>
<br>
Is it normal for tappits to drift that quickly? All the lock rings were tight, I could go tighter but don't want to damage them. Can they be torqued and if so what to? They had all closed up a lot, inlet and exhaust. I didn't measure all the gaps precisely but all were under 0.1 mm (should be 0.25mm). I find it hard to believe they've all recessed that quickly or that evenly. Wear anywhere else would open the gaps. S'pose if i'd thought of it I should have photo'd them after setting them this time so I can tell if they've moved in a month or so. Much wierdness.<br>
<br>
Ran a real treat on Monday morning, apart from this niggle I'm becoming a fan of pushrod power.<br>
<br>
Cheers, Julian

<p></p><i>Edited by: <A HREF=http://p206.ezboard.com/bthetriumphdolo ... omiteuk</A> at: 1/11/06 10:27 am<br></i>

[Jon Tilson]

had this at all. All my pushrodders, mostly Spits but not any real difference...stay completely static.<br>
Only thing I can think of is valve seat recession...did you put new valve seats in?<br>
<br>
Jonners

<p></p><i></i>

[tinweevil]

Nope. Just de-cobwebbed, degreased and on it went. T'was very crude.<br>
<br>
I thought recession only affected the exhausts as the inlets don't get so hot?<br>
<br>
Julian

<p>1978 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/704">Dolomite Sprint</a><!--EZCODE LINK END--> Blue, a bit tetley.<br>
1972 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/754">Spitfire IV</a><!--EZCODE LINK END--> No name, in bits.<br>
1968 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/705">GT6 II</a><!--EZCODE LINK END--> Little blue, nice!<br>
1973 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/755">Dolomite Sprint</a><!--EZCODE LINK END--> VA41, seriously tetley.<br>
1980 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/864">Dolomite 1500HL</a><!--EZCODE LINK END--> Orange, current daily drive.</p><i></i>

[1300dolly]

its possible that some/all the rods were not sat right when you set it up. did the rods go back in in the same holes or did you muddle them up?<br>
<br>
Justyn

<p></p><i></i>

[Jod Clark]

The rods would have to be getting longer to close the rocker gap...<br>
<br>
Re-torque yer head when the engine is stony cold, reset all the clearances and keep an eye on it. How many miles has it done?<br>
<br>
Jod

<p><!--EZCODE IMAGE START--><img src="http://www.towingandleisure.co.uk/images/bash.gif" style="border:0;"/><!--EZCODE IMAGE END--></p><i></i>

[tinweevil]

Good point Jod, forgot to do the retorque, good job it's not a slant. I'll do that, reset 'em again and photo the adjuster positions next time it's home, weekend of the 8th / 9th. 96k on the clock.<br>
<br>
Ta, Julian

<p>1978 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/704">Dolomite Sprint</a><!--EZCODE LINK END--> Blue, a bit tetley.<br>
1972 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/754">Spitfire IV</a><!--EZCODE LINK END--> No name, in bits.<br>
1968 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/705">GT6 II</a><!--EZCODE LINK END--> Little blue, nice!<br>
1973 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/755">Dolomite Sprint</a><!--EZCODE LINK END--> VA41, seriously tetley.<br>
1980 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/864">Dolomite 1500HL</a><!--EZCODE LINK END--> Orange, current daily drive.</p><i></i>

[MalcGE]

Are you running an additive in your fuel or just neat unleaded. Jury is out as to whether OHC's need it as it's alloy with inserts, personally, I take no changes and run with Superblend in my Sprint and a B Series engined family classic. <br>
<br>
OHV heads, being cast may well fit into the B series category. When leaded first went west, P Classics ran a BMC 1800 on neat unleaded, completely tetley'd the head in something like 2000 miles, VSR. You are doing long M'way journeys so those vlave seats are going to be at max temp 'consistently' for a lot longer than tootling about town. If ever there was such a thing as 'leaded memory' then I reckon that will have been blasted out your zorst somewhere near Knutsford on your 2nd return trip to Manchester

<p></p><i></i>

[Jon Tilson]

that PC article and the newly rebuilt head they used.<br>
All I can say is my own experience which has seen some 20k miles in an o/d spit 1500 and several k more in various slant 4 cars with very little use of anything other than ordinary unleaded.<br>
I drive a bit like Jod I suspect....as fast as I safely can with very little regard for what the lackys put in red rings at the side of the road.<br>
I've experinced NO valve seat recession.<br>
Jonners

<p></p><i></i>

[Jod Clark]

I favour the high-mileage, softly-driven engine as a head donor for a Jodsport engine when using standard valves. after 80,000 miles of fire-down-the-hole and gentle taps from the exhaust valves, work-hardening is fully established and the seats are plenty hard enough. Nice new guides and you're away. Lovely.<br>
<br>
Jod

<p><!--EZCODE IMAGE START--><img src="http://www.towingandleisure.co.uk/images/bash.gif" style="border:0;"/><!--EZCODE IMAGE END--></p><i></i>

[tinweevil]

4 and 8 were a bit tight but not beyond setting tolerance. The rest were spot on. Wierd.<br>
<br>
On the way back on Friday the downpipe gasket blew. Got a new one in there with pleanty of pug but I'll be back to it in the not too distant I reckon. Front stud is practically threadless. From the state of the surface between the tubes on the downpipe this isn't the first time. Think it's probably going to need both sides refaced.<br>
<br>
Tin<br>
<br>


<p>1978 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/704">Dolomite Sprint</a><!--EZCODE LINK END--> Blue, a bit tetley.<br>
1972 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/754">Spitfire IV</a><!--EZCODE LINK END--> No name, in bits.<br>
1968 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/705">GT6 II</a><!--EZCODE LINK END--> Little blue, nice!<br>
1973 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/755">Dolomite Sprint</a><!--EZCODE LINK END--> VA41, seriously tetley.<br>
1980 <!--EZCODE LINK START--><a href="http://www.triumphowners.com/864">Dolomite 1500HL</a><!--EZCODE LINK END--> Orange, current daily drive.</p><i></i>