MARK Posted April 2 Report Share Posted April 2 I have a spare cylinder head which is fitted with single valve springs. I wish to fit this to my TR6 1973 uk car but with double valve spring configuration. I asked a well known supplier to send me what I would need but I'm not sure that I have been sent correct parts. The diagrams of workshop manuals are vague. The Brown book states that ' Later PI cars the valve collar arrangement on both inlet and exhaust valves is as diagram A' - which shows a one part upper valve collar. However double valve configuration is not shown. The diagram shows a valve spring seat with a raised centre part. I have been supplied with 12 valve spring spacers part number 149717 which will only space the inner spring from the head. This would leave the the outer spring sitting directly on the head is this correct? The inner spring spacers 149917 may be a replacement for the original lower spacer. The valve Spring set I have been supplied is red marked, part no.CVS6686K TR5/TR6 Double valve Spring set. I would very much welcome information as to the correct configuration of valve seats for CR and the correct part numbers. Thanks in advance to the Sages out there! As my mate John Morrison promotes, this Forum is a great tool ! MARK Quote Link to post Share on other sites
Kenrow Posted April 2 Report Share Posted April 2 Did you get uprated springs? Both Moss and Rimmer state: VALVE SPRING SET, twin fitment, uprated Notes: Our uprated valve spring sets replace all standard combinations. They must be installed without the use of any lower spacer collars between the base of the springs and the cylinder head top face. Quote Link to post Share on other sites
MARK Posted April 3 Author Report Share Posted April 3 The suppliers have now admitted that the springs and other parts sent are for the earlier CP TR6 not CR! They assure me that they will fit ok providing I use the two piece valve caps for the exhaust valves. I don't know why this should be so. I believe later TR6 use the same single piece upper valve cap for both inlet and exhaust. Can anyone explain why they apparently used different upper valve caps on earlier cars for inlet and exhaust ? Would it be ok to use the one piece type on on the exhaust valves with earlier springs? To me the later type one piece valve cap seems to fit well with the double valve configuration and a better fit !. Doing some research the earlier type valve springs may be more suitable for my fairly high lift camshaft as apparently they were softer. Any help would be much appreciated ! MARK Quote Link to post Share on other sites
stuart Posted April 3 Report Share Posted April 3 If you value your cam be careful fitting so called uprated springs. Stuart. Quote Link to post Share on other sites
Waldi Posted April 3 Report Share Posted April 3 2 hours ago, stuart said: If you value your cam be careful fitting so called uprated springs. Stuart. That is why I fitted the standard double valve springs from Chris Witor. These were recommended by other members when I ordered them. Before installing I checked their spring rate and height and they complied with the values in the WSM. Waldi Quote Link to post Share on other sites
Schnippel Posted April 4 Report Share Posted April 4 On 3.4.2024 at 14:09, MARK said: Die Lieferanten haben nun zugegeben, dass die eingesandten Federn und anderen Teile für den früheren CP TR6 und nicht für CR bestimmt sind! Sie versichern mir, dass sie gut passen, vorausgesetzt, ich verwende die zweiteiligen Ventilkappen für die Auslassventile. Ich weiß nicht, warum das so sein sollte. Ich glaube, dass spätere TR6 die gleiche einteilige obere Ventilkappe für Einlass und Auslass verwenden. Kann jemand erklären, warum bei früheren Fahrzeugen offenbar unterschiedliche obere Ventilkappen für Einlass und Auslass verwendet wurden? Wäre es in Ordnung, die einteilige Ausführung an den Auslassventilen mit früheren Federn zu verwenden? Meiner Meinung nach scheint die spätere einteilige Ventilkappe gut zur Doppelventilkonfiguration zu passen und besser zu passen! Wenn ich etwas recherchiere, sind die Ventilfedern des früheren Typs möglicherweise besser für meine Nockenwelle mit ziemlich hohem Hub geeignet, da sie anscheinend weicher waren. Jede Hilfe wäre sehr dankbar! MARKIEREN Hello Please use the soft valve spring variant from the early CP engine. Sports camshafts also run perfectly with it. The two-part valve spring caps decouple the spring. This means the valve can rotate better on the seat. Regards Ralf Quote Link to post Share on other sites
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