molten Posted July 17, 2012 Share Posted July 17, 2012 Hello GentsI am certain that one of you guys will have this info but...What is the MK3 grind cam timing settings. I have seen them on here somewhere but blown if I can find them.Help needed quick so I can get this done tomorrow.CheersScott Quote Link to comment Share on other sites More sharing options...
That Man Posted July 17, 2012 Share Posted July 17, 2012 2597 wrote:Hello GentsI am certain that one of you guys will have this info but...What is the MK3 grind cam timing settings. I have seen them on here somewhere but blown if I can find them.Help needed quick so I can get this done tomorrow.CheersScottHi Scott,I assume you mean the valve timing for when you're putting the timing chain on ? if so, it's std Triumph camshaft profile, so it should be as per the manual, how are you doing it, head on or off ?Gordon Quote Link to comment Share on other sites More sharing options...
sparky_spit Posted July 17, 2012 Share Posted July 17, 2012 I agree with him ^^^. Assuming this is a Canley's Mk3 grind-on-a-large-journal cam then you just time it using the marks on the sprockets, exactly the same as if you were putting your 1500 cam back in. Quote Link to comment Share on other sites More sharing options...
Richard B Posted July 17, 2012 Share Posted July 17, 2012 MkIII Spitfire is the same timing as a MkII GT6 and early MkII PI Saloon Quote Link to comment Share on other sites More sharing options...
piman Posted July 17, 2012 Share Posted July 17, 2012 Hello cott, also look at this thread for an alternative method. :-Sorry , link no longer availableAlec Quote Link to comment Share on other sites More sharing options...
molten Posted July 17, 2012 Author Share Posted July 17, 2012 thanks gents.I just put head on today after seting TDC, but think I accidentaly moved the crank when putting head on so now not confident about TDC.Would it be ok to take head back off when gasket has been compressed to reset TDC? Engine out of car for the record.cHEERS Quote Link to comment Share on other sites More sharing options...
sparky_spit Posted July 18, 2012 Share Posted July 18, 2012 If the head has been torqued down onto a new gasket then it's not ideal to remove it again. If it's a Payen gasket you'll probably find that some of the plasticky/silcone type coating may stick to the head or block, and then it's knackered. If it's an OEM type, or cheaper type, you may get away with it.Why take it off? If you are concerned about finding TDC for valve timing purposes, then a stick down the plughole would be accurate enough, bearing in mind you are only ever going to be within the tolerance accuaracy of one sprocket tooth's degree of rotation. Unless you have vernier sprockets of course Quote Link to comment Share on other sites More sharing options...
molten Posted July 18, 2012 Author Share Posted July 18, 2012 good point sparky :) Quote Link to comment Share on other sites More sharing options...
Richard B Posted July 18, 2012 Share Posted July 18, 2012 There should be a scribed line on the backplate and the flywheel, line them up for TDC Quote Link to comment Share on other sites More sharing options...
piman Posted July 18, 2012 Share Posted July 18, 2012 Hello SS, you can do better than one tooth, I think from memory it is 1/4 tooth. This is achieved by fitting the camwheel using the optional holes (the holes are not symmetrical, and also by reversing the wheel giving four alternative settings.Alec 1 Quote Link to comment Share on other sites More sharing options...
Richard B Posted July 18, 2012 Share Posted July 18, 2012 piman wrote:you can do better than one tooth, I think from memory it is 1/4 tooth. This is achieved by fitting the camwheel using the optional holes (the holes are not symmetrical, and also by reversing the wheel giving four alternative settings.Yes 1/4 tooth.Thats the advantage of a simplex gearset of a duplex gearset.Duplex only goes down to 1/2 tooth. (Unless you buy a vernier kit) Quote Link to comment Share on other sites More sharing options...
molten Posted July 18, 2012 Author Share Posted July 18, 2012 ok fellas, next question. How can I tell which orientation is which to come down to 1/4 tooth accuracy?At present i have the punch mark near the teeth of cam sprocket adjacent to the punch on the cranshaft sprocket (piston at TDC as spied through plug hole). Steel rules says these line up ok. Only problem is that there ia also punch 180 degrees to the one on the cam sprocket which also lines up along steel rule.If I understand correctly, positioning the cam sprocket 180 degrees will give half tooth adjustment - yes?Will flipping the sprocket round (and securing back to front) give it 1/4 tooth accuracy? Or have i lost the plot here :) Quote Link to comment Share on other sites More sharing options...
Richard B Posted July 19, 2012 Share Posted July 19, 2012 2597 wrote:If I understand correctly, positioning the cam sprocket 180 degrees will give half tooth adjustment - yes?Will flipping the sprocket round (and securing back to front) give it 1/4 tooth accuracy? Or have i lost the plot here :)Yep flip the wheel over and one pair of holes gives 1/4 tooth, the other pair of holes gives 3/4 tooth.Neat huh? ;) Quote Link to comment Share on other sites More sharing options...
molten Posted July 19, 2012 Author Share Posted July 19, 2012 Richard_B wrote:Yep flip the wheel over and one pair of holes gives 1/4 tooth, the other pair of holes gives 3/4 tooth.Neat huh? ;)Great Thanks Rich. I will play about with this at weekend.Cheersscott Quote Link to comment Share on other sites More sharing options...
drofgum Posted July 19, 2012 Share Posted July 19, 2012 Scott,Turning the camshaft sprocket 90 degrees and refitting the chain moves the cam 1/2 tooth. Fitting the sprocket back to front, then turning it 90 degrees and refitting the chain moves the cam 1/4 tooth. This is if the sprockets are as Triumph supplied them. Some new sprockets do not have the holes offset from the tooth centers and this adjustment isn't available when using them. Cheers, Paul Quote Link to comment Share on other sites More sharing options...
junkuser Posted July 19, 2012 Share Posted July 19, 2012 One trick for finding TDC is to make something like an extended spark plug that stops the piston reaching the top of the stroke.Mount some card behind the engine pulley, rotate the crank either way and mark where the timing mark stops. Half way between in TDC.Easier if you use a timing card, but not necessary.How you make the stopper depends on what you have to hand, if you can't borrow one. Quote Link to comment Share on other sites More sharing options...
hypoid53 Posted July 19, 2012 Share Posted July 19, 2012 Duplex sockets do not have the range of adjustment of a simplex. I could not get better than 2 degrees on the my 25/65 camshaft/4 degrees on the crank on mine so bought a vernier gear from Chris Witor. I used a large timing wheel and DTI for precision. It has certainly livened up the Spitfire! Quote Link to comment Share on other sites More sharing options...
piman Posted July 19, 2012 Share Posted July 19, 2012 Hello Paul,"Some new sprockets do not have the holes offset from the tooth centers"I hadn't heard that, are these aftermarket spares? Alec Quote Link to comment Share on other sites More sharing options...
drofgum Posted July 21, 2012 Share Posted July 21, 2012 piman wrote:Hello Paul,"Some new sprockets do not have the holes offset from the tooth centers"I hadn't heard that, are these aftermarket spares? AlecAlec,Yes, aftermarket spares here in the States. I've no idea where they are actually being made. Cheers, Paul Quote Link to comment Share on other sites More sharing options...
Dannyb Posted February 23, 2023 Share Posted February 23, 2023 When timing my 1500 cam. I did it with tappets 8 & 9 on the rock at TDC by using feeler gauges. I take it you can't do this with a mk3 grind as the inlet and exhaust are not opening and closing at the same degrees. Am I correct in thinking this. Danny Quote Link to comment Share on other sites More sharing options...
PeteStupps Posted February 23, 2023 Share Posted February 23, 2023 (edited) Hi Danny, what Spitfire engine are you running with 9 tappets?? 😉 Principal is the same though for the mk3 cam, it's symmetrical so valves 7 & 8 should be equal lift at compression TDC on cylinder no.1 Edited February 23, 2023 by PeteStupps Typo Quote Link to comment Share on other sites More sharing options...
Dannyb Posted February 25, 2023 Share Posted February 25, 2023 (edited) Just ordered mk3 grind cam from Canleys. None in stock at moment but not needed until next winter. Planning ahead. Will order followers and gaskets during the year. Danny Edited February 25, 2023 by Dannyb Typo 3 Quote Link to comment Share on other sites More sharing options...
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