Nobbysr Posted February 27, 2021 Report Share Posted February 27, 2021 Does anyone know how much valve guide should be showing above the cylinder head on a TR3a engine Kind regards Steve P.S I'm putting together a vent lid rebuild kit which is all stainless steel if there is any interest i will makes some up they are identical to the original item just in stainless steel Quote Link to post Share on other sites
TomMull Posted February 28, 2021 Report Share Posted February 28, 2021 Mine protrude just shy of 3/4 inch, measured with a rule. I've always had the machine shop put them in so I trust they have them right. I have not measured them with an accurate instrument but can do if necessary. Tom Quote Link to post Share on other sites
Nobbysr Posted March 1, 2021 Author Report Share Posted March 1, 2021 Hi Tom many thanks for your help would be grateful for any information, as long its no hassle regards swteve Quote Link to post Share on other sites
TomMull Posted March 2, 2021 Report Share Posted March 2, 2021 Apparently this is not listed in the TR2-3 Factory Service manual but the TR4 manual says "Valve guide protrusion above the top face of the cylinder head - 0.78 in (19.84 mm)." Mine varied from 19.64 to 19.73 mm. I'm not sure what the top face refers to and I measured mine to the surface next to the guide, which is a cast and not a machined surface so it does not seem that they were looking for precision. Tom Quote Link to post Share on other sites
Ralph Whitaker Posted March 2, 2021 Report Share Posted March 2, 2021 1 hour ago, TomMull said: Apparently this is not listed in the TR2-3 Factory Service manual but the TR4 manual says "Valve guide protrusion above the top face of the cylinder head - 0.78 in (19.84 mm)." Mine varied from 19.64 to 19.73 mm. I'm not sure what the top face refers to and I measured mine to the surface next to the guide, which is a cast and not a machined surface so it does not seem that they were looking for precision. Tom Is it not machined where the spring seats? Mr Haynes states measure the height of the guide from the spring seat before removal and insert the new guide to the same depth, but in the specs quotes 0.780 for the TR4, but nothing for the TR3. Ralph Quote Link to post Share on other sites
TomMull Posted March 3, 2021 Report Share Posted March 3, 2021 15 hours ago, Ralph Whitaker said: Is it not machined where the spring seats? Mr Haynes states measure the height of the guide from the spring seat before removal and insert the new guide to the same depth, but in the specs quotes 0.780 for the TR4, but nothing for the TR3. Ralph You are right Ralph, on closer inspection and cleaning of my ancient head, that spring seat does seem to be a machined surface. Tom Quote Link to post Share on other sites
Lebro Posted March 3, 2021 Report Share Posted March 3, 2021 Is it not more important to position the guide to be flush with the wall of the inlet / exhaust ports. Bob. Quote Link to post Share on other sites
Ralph Whitaker Posted March 3, 2021 Report Share Posted March 3, 2021 5 hours ago, Lebro said: Is it not more important to position the guide to be flush with the wall of the inlet / exhaust ports. Bob. I suspect there is a maximum allowable to ensure no clash with the valve stem collets or cap, one can then grind away the excess as required in the ports for gas flow.. Ralph. Quote Link to post Share on other sites
TomMull Posted March 5, 2021 Report Share Posted March 5, 2021 While the exhaust guides are pretty much flush on the inside of the port, the intake comes through at a considerable slope in the port and protrudes more than a quarter inch on one side. Best to use the tops as reference as the TR4 manual indicates, imo. Tom Quote Link to post Share on other sites
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