pistons identity help

[TONYSPRINTER]

hello i was given a tr7 block with a new set of pistons inside trouble is i cannot identify them they have 2 indents for the valves and they measure 90mm across the face they have the following numbers on ID19 T49A +508 are these oversize? and by how much? thanks in advance.<!--EZCODE EMOTICON START :hat --><img src=http://www.ezboard.com/images/emoticons/pimp.gif ALT=":hat"><!--EZCODE EMOTICON END-->

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[TONYSPRINTER]

sorry forgot to mention will these fit my spare sprint block? thanks.<!--EZCODE EMOTICON START ;) --><img src=http://www.ezboard.com/images/emoticons/wink.gif ALT=";)"><!--EZCODE EMOTICON END-->

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[2F45T4U]

Yer but are a lower compression. TR7s are 9.25 comp ratio and Sprints are 9.5. Both are 90.3 mm bore though and even the same stroke (78mm)

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[TONYSPRINTER]

thanks for that info adam<!--EZCODE EMOTICON START ;) --><img src=http://www.ezboard.com/images/emoticons/wink.gif ALT=";)"><!--EZCODE EMOTICON END-->

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[MaddMart]

I think the +508 is the metric equivelent of +0.020".

<p>Martin<br>
<br>
<!--EZCODE LINK START--><a href="http://www.dolomitesprint.com/" target="top">www.dolomitesprint.com</a><!--EZCODE LINK END--></p><i></i>

[TONYSPRINTER]

thanks mart<!--EZCODE EMOTICON START :D --><img src=http://www.ezboard.com/images/emoticons/happy.gif ALT=":D"><!--EZCODE EMOTICON END-->

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[george]

tr7 & sprint have same pistons the export tr7 has lower comp ones the difference in comp ratio is down to the heads sprint being 16v hemi type compared to tr7 <br>
both being 2.0l leyland parts bin

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[2F45T4U]

Ahh never though of it that way George! <!--EZCODE EMOTICON START :D --><img src=http://www.ezboard.com/images/emoticons/happy.gif ALT=":D"><!--EZCODE EMOTICON END-->

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[george]

the diff is .25 adam looking at my data book <br>
......and i'll soon find out how early my sprint block is will be digging it out of the garage very soon i know it's early but how early i dont

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[TONYSPRINTER]

can anyone else confirm that the +508 is 20 thou oversize thanks<!--EZCODE EMOTICON START :) --><img src=http://www.ezboard.com/images/emoticons/smile.gif ALT=":)"><!--EZCODE EMOTICON END-->

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[tinweevil]

0.020" is exactly 0.508mm according to <!--EZCODE LINK START--><a href="http://www.megaconverter.com/mega2/" target="top">megaconverter</a><!--EZCODE LINK END-->. Not conclusive without a markings decoder for this piston manufacturer.<br>
<br>
Julian<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>

[TONYSPRINTER]

thanks julian<!--EZCODE EMOTICON START ;) --><img src=http://www.ezboard.com/images/emoticons/wink.gif ALT=";)"><!--EZCODE EMOTICON END-->

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[MalcGE]

TR7 Pistons <br>
UKC8519 Europe<br>
UKC1304 AUS/CDN/J/USA<br>
<br>
Sprint Pistons<br>
UKC0881 to VA1899E<br>
UKC2483 from VA1899E<br>
RTC2266 76 On<br>
<br>
you guys sure Sprint & TR7 Pistys are the same, Similar ?

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[george]

strange as the very first tr we striped had sprint pistons and subsequent ones the same<br>
cant account for the part nos but as the tr7 is 8v<br>
then the pistons require no notches for valve clearance<br>
as the differance on the cr is only .25 this would be down to the head design piston height is identical dia is as well <br>
maybe a ploy from leyland to extract the max money from sprint owners ? jags used parts and the part nos were different for the identical thing for triumph<br>
<br>
if they were already producing sprint pistons then it would have been more cost efective to just adopt sprint pistons in what is a sprint block<br>
does seem strange though<br>
notice that the part nos changes in 76 does the tr7 do the same ?

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[alun n]

The '7 engines I have stripped have always had dished pistons, but I've only done three of them. I thought with the 'vertically paired' valves they needed the dish to prevent interference...<br>
<br>
Knowing of Pringle of old he did some strange things...

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