slate Posted August 20, 2017 Share Posted August 20, 2017 I am currently building a Mk2 vitesse engine which has a 308778 cam and a 517528 head.This head has single springs where all the parts lists I can find show the vitesse having twin springs?My question is do I have the wrong head or did they swop to single springs at some point ?Or could it have been previously built using single instead of double springs?The head also has a dab of yellow paint on it if that helps? Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted August 21, 2017 Share Posted August 21, 2017 It's the right head number for a Mk2 Vitesse, GT6 Mk2 and early Mk2 2000. I would expect it to have double springs, but anything could have happened in the last 50 or so years.....Nick Quote Link to comment Share on other sites More sharing options...
JohnD Posted August 21, 2017 Share Posted August 21, 2017 Its less a case of what you have, more what you want.Double springs aren't for extra strength, by using two with different stiffnesses, the frequency at which they will resonate is multiplied and the valve bounce inhibited in the rev range usable by the engine. So if you intend to rev your engine,double spring it. If you dont no need to change.John Quote Link to comment Share on other sites More sharing options...
slate Posted August 21, 2017 Author Share Posted August 21, 2017 Thanks for the repliesI was mainly concerned that what I have is correct and not a lash up, but as i'm sure the engine has been reworked once already (020" Pistons & 010" crank ) and the head looks like it has unleaded seats (slightly proud on exhaust valves) albeit they are somewhat burnt and pitted especially no 2 whose spring was upside down.It appears that most engine Re-manufactures re-build to the latest spec which appears to be single spring and as iv'e no intention of going racing etc i think i will stick to standard specs. Quote Link to comment Share on other sites More sharing options...
RobPearce Posted August 22, 2017 Share Posted August 22, 2017 My Vitesse also has single springs because the engine rebuilder who converted it to unleaded (for the previous owner) changed it over. The other (questionable) benefit of single springs is that they leave room for valve stem oil seals. But our cars don't really need them. Quote Link to comment Share on other sites More sharing options...
JohnD Posted August 22, 2017 Share Posted August 22, 2017 Valve spring? Upside down? You have progressive valve springs? Definitely not standard!John Quote Link to comment Share on other sites More sharing options...
sparky_spit Posted August 22, 2017 Share Posted August 22, 2017 Quoted from JohnD Its less a case of what you have, more what you want.Double springs aren't for extra strength, by using two with different stiffnesses, the frequency at which they will resonate is multiplied and the valve bounce inhibited in the rev range usable by the engine. So if you intend to rev your engine,double spring it. If you dont no need to change.John John - on a rebuilt and balanced 1500 engine that's unlikely to go north of 5000/5500 rpm very often, I was planning on using single Jaguar springs. Do you reckon that rev limit is acceptable for single springs? Quote Link to comment Share on other sites More sharing options...
Steve P Posted August 22, 2017 Share Posted August 22, 2017 Single Jag springs in my 2.5 tuned up Vitesse.10,000 miles so far.Steve Quote Link to comment Share on other sites More sharing options...
Martin M Posted August 23, 2017 Share Posted August 23, 2017 Single Jag springs happy to rev above 6000 in the GT6 😀 Did someone try the Chris Witxxx double springs he offers for the TR5 type engine?Martin Quote Link to comment Share on other sites More sharing options...
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