James H Posted September 27 Report Share Posted September 27 (edited) Hi all, so I recently acquired a 1966 Vitesse MK1 16/6 cabriolet converted to a 2 liter which I've got running great but have a query nonetheless... Its had an unleaded conversion in the past and over here in France I'm running it on 98 octane. Using a strobe, engine at 1000rpm and vacuum disconnected I initially set the timing to 10° advanced, noticed as expected what I believe is some pinging under heavy load and have slowly reduced it over time. The pinging is now gone under any condition but the thing is it now reads a few degrees retarded from zero based on the pulley markings. Nonetheless it has run flawlessly like this for weeks (its my daily), does approx 26 mpg, temps are spot on and stable, starts perfectly and power is far from sluggish (although obviously is improved with advancing but at the expense of pinging). So my question is just how trustworthy are the markings and if its possible to mount a pulley incorrectly ? I'm sure the previous owner did his best but I've had to rectify many other questionable things on the car. Should I trust my instincts and leave as is or would this indicate an issue that should be investigated despite the car running so well ? Cheers in advance Edited September 27 by J Hobbs Link to comment Share on other sites More sharing options...
JohnD Posted September 27 Report Share Posted September 27 (edited) J Hobbs, What many do not know is that the crank pulley that carries the TDC marking does double duty, as a pulley to power water pump and alternator, AND a crank damper, to suppress torsional vibration. This is entirely different from engine balance vibration, as the straight six has the best inherent balance of any other engine configuration. Torsion vibration derives from the firing stroke that 'rings' the crank, and if it coincides with one of the resonant frequencies of the crank can lead to damage. In four cylinder engines a damper isn't necessary, as all the harmonics are too high for resonance, but like an organ pipe, the longer six cylinder crank vibrates at lower frequwencies, within the rev range. So Triumph provided a damper in the pulley, by having a rubber ring between the metal hub and the outer ("inertia") ring which carries the timing marks. This is a so-called 'viscous' damper, and works well, but when these were made the rubber was similar to tyre rubber. Over the years the rubber has deteriorated, and may no longer have the viscosity to provide damping. Worse, it can loose adhesion, and the ring turns on the hub. Then the markings become nonsense! I suggest that you use a piston stop method to determine exactly where TDC is. If it is not where your pulley markings say then the pulley should be replaced. The usual suppliers sell new ones. This YouTube video shows someone checking TDC on a Triumph straight six, He finds that the markings are wrong, but does not know the reason why! Good luck! John Edited September 27 by JohnD Link to comment Share on other sites More sharing options...
James H Posted September 27 Author Report Share Posted September 27 John hi and thanks for the quick reply, ok had no idea about that either so in any case I'll investigate the pulley mech integrity and continue to trust my ears and instincts then regarding the timing, cheers I realise it would be going off topic but I've always thought it sits lower than others I've seen and can't work out why, its recently MOT'd, bushings look ok and it has a Canley Classics spring. The car handles fine and I like the low look so dont wish to change it but curious nonetheless, any ideas ? Link to comment Share on other sites More sharing options...
johny Posted September 27 Report Share Posted September 27 Also as said many times before some pinging is acceptable. The recommendation is for setting the timing so pinging stops when reaching 2000rpm in 4th gear accelerating hard on a flat road - to avoid it below this limit you can change down a gear. As you say youre possibly loosing power and fuel economy (I can get quite a bit better than 26mpg) by retarding so much.... Link to comment Share on other sites More sharing options...
James H Posted September 27 Author Report Share Posted September 27 (edited) Johny, interesting, yes I am being a "perfectionist" about it. If I accept pinging uphill in 4th between 2-3000rpm and very occasionally on the flat as you say I can easily run it at close to 10° advanced with better performance and economy but I've always thought pinging was to be avoided at all costs, hmmm... Also thats 26 UK not US mpg, what can you get out of yours ? Edited September 27 by J Hobbs Link to comment Share on other sites More sharing options...
Steve P Posted September 27 Report Share Posted September 27 The car does look low at the back, you mentioned a Canleys spring, does it have a lowering block or maybe a swing spring from a Spit/GT6 which IMHO is no good on a Vitesse?. Steve Link to comment Share on other sites More sharing options...
James H Posted September 27 Author Report Share Posted September 27 (edited) Steve hi, how would I identify a swing spring from a Spit/GT6 ? I attached a photo of the spring reference and there is no sign of a lowering block, it looks low all round to me but especially at the rear, strange huh Edited September 27 by J Hobbs Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 27 Report Share Posted September 27 a search for the marked 305495 is unknown but from canley's 305945 is 1600/Mk1 a std. rear spring may be the felt pen marker was dyslexic ???? so not a swinger which will give some low rides on a vitesse a carefull look for a drop plate seems a need to resolve this canley have a good reputation for spring suppliers if the ride height gets too low you can end up sitting on the bump stops inside the shocker. (got that tee shirt from trying a swinger) Link to comment Share on other sites More sharing options...
James H Posted September 27 Author Report Share Posted September 27 Cheers Pete, yes have no doubt re the spring quality, whats a "drop plate" so I can look for it .) ? Also whats your take on acceptable levels of pinging ? Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 27 Report Share Posted September 27 the drop plate or drop block fits under the spring and locates in the top of the diff they come in 1/2" 3/4" and 1" thicknesses . to preserve you pistons you dont want any persistent pinking it can fail a piston in time without any warning definitely check the damper ring we had this on our 1600 back in the early 2000's makes for good head scratching , you could turn our ring with your fingers , i would not waste any funds on octane boosters ,your 98 should be fine (providing thats what you actually got) most of us run on 97/98 with factory setting and they are fine do you have a std distributor or some after market hopeless replacement ???? Pete Pete Link to comment Share on other sites More sharing options...
James H Posted September 27 Author Report Share Posted September 27 (edited) Ok gotcha will look for a potential drop plate. Re the pinging then it sounds like in this case being a perfectionist isn't the way to go and "some" pinging is a better compromise, especially as there is no way I have "persistent" pinging at factory setting, just some under extreme load so I think I'll go that route but will still verify as John suggested the accuracy of the timing marks Distributor is stock but first rotor arm fire is at upper right not lower left so I believe 180° out... Edited September 27 by J Hobbs Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 27 Report Share Posted September 27 180 doesnt matter a hoot so long as the leads reach its fine what spark plugs are you using dont want any with an R in the suffix Pete Link to comment Share on other sites More sharing options...
James H Posted September 27 Author Report Share Posted September 27 (edited) Good to know re the distributor Busted... I have actually put in multi electrode NGK BUR6ET. I'm aware you and many others are anti them but since there are just as many who have nothing but positive experience with them it objectively seems one of those grey areas that perhaps only production quality / quality control can explain. Anyway for me at least they are a noticeable improvement over the BP6ES that were in it especially at idle, extremely easy starting and smoother running but if things deteriorate I will let you know Edited September 27 by J Hobbs Link to comment Share on other sites More sharing options...
johny Posted September 27 Report Share Posted September 27 2 hours ago, J Hobbs said: Johny, interesting, yes I am being a "perfectionist" about it. If I accept pinging uphill in 4th between 2-3000rpm and very occasionally on the flat as you say I can easily run it at close to 10° advanced with better performance and economy but I've always thought pinging was to be avoided at all costs, hmmm... Also thats 26 UK not US mpg, what can you get out of yours ? As I say there should be no pinging above 2000rpm when on the flat. Mines a saloon with the 2L version of your engine and no overdrive so easy cruising at 50mph gives 33 - 34mpg(uk)... Link to comment Share on other sites More sharing options...
James H Posted September 27 Author Report Share Posted September 27 2 hours ago, johny said: As I say there should be no pinging above 2000rpm when on the flat. Mines a saloon with the 2L version of your engine and no overdrive so easy cruising at 50mph gives 33 - 34mpg(uk)... Mine is the same 2 liter but I also have a Ford type 9 five speed gearbox so hard to compare but with some compromise with pinging I'll try to get closer to your figures Link to comment Share on other sites More sharing options...
johny Posted September 27 Report Share Posted September 27 Its strange and has been commented on before but I used to get pinging and rather than retard ignition went to adding octane booster to 95 which definitely helped. However now I run on 95 E5 and pinging has disappeared, so much so that Im following suggestions to advance timing more than factory setting! I have made other modifications over this period but it does seem that ethanol has made the fuel much less prone to pinging... Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 28 Report Share Posted September 28 19 hours ago, J Hobbs said: Hi all, so I recently acquired a 1966 Vitesse MK1 16/6 cabriolet converted to a 2 liter which I've got running great but have a query nonetheless... Its had an unleaded conversion in the past and over here in France I'm running it on 98 octane. Using a strobe, engine at 1000rpm and vacuum disconnected I initially set the timing to 10° advanced, noticed as expected what I believe is some pinging under heavy load and have slowly reduced it over time. The pinging is now gone under any condition but the thing is it now reads a few degrees retarded from zero based on the pulley markings. Nonetheless it has run flawlessly like this for weeks (its my daily), does approx 26 mpg, temps are spot on and stable, starts perfectly and power is far from sluggish (although obviously is improved with advancing but at the expense of pinging). So my question is just how trustworthy are the markings and if its possible to mount a pulley incorrectly ? I'm sure the previous owner did his best but I've had to rectify many other questionable things on the car. Should I trust my instincts and leave as is or would this indicate an issue that should be investigated despite the car running so well ? Cheers in advance If it's running well, enjoy it as is. The Triumph 1960s equivalent of 'computer says' means the same as that phrase nowadays, not always correct and sometimes way off. My last GT6 ran perfectly at an indicated 23 degrees PTDC and any attempt at reaching recommended markings left it running like a bag of nails. Tune it by how it drives, not always by what the book says. BTW it looks remarkably like mine, bar the wheel trims and that black tonneau cover... and of course the extra two cylinders on yours... Link to comment Share on other sites More sharing options...
James H Posted September 28 Author Report Share Posted September 28 21 minutes ago, Colin Lindsay said: If it's running well, enjoy it as is. The Triumph 1960s equivalent of 'computer says' means the same as that phrase nowadays, not always correct and sometimes way off. My last GT6 ran perfectly at an indicated 23 degrees PTDC and any attempt at reaching recommended markings left it running like a bag of nails. Tune it by how it drives, not always by what the book says. BTW it looks remarkably like mine, bar the wheel trims and that black tonneau cover... and of course the extra two cylinders on yours... Colin hi, yes indeed from the same distance very similar but up close I very much doubt it ! Yours is worthy of a show, has decent looking panel gaps and a nice shine to it, mine not so much but hey I like it that way, its an ungaraged daily driver afterall The last Triumph handbook gem I came across was recommending higher tyre pressures at the rear, whats that all about for a front engine rear wheel drive car ?? Maybe there is sound logic behind it but after experimentation I'm running 30/32 psi front and 28/30 rear, works well on our country roads... Link to comment Share on other sites More sharing options...
johny Posted September 28 Report Share Posted September 28 yes with tyre pressures its never been determined if the recommended values were an error right back at the beginning or if tyres have changed that much since then or it was a measure to reduce the risk of back axle tuck under... Anyway most people now do as you have done and settle with pressures that seem to work best👍 Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 28 Report Share Posted September 28 depends where you look for data you cn find some 6cyl with 22psi front to support the ground anchor modern tyres need a few more psi for them to handle correctly front and rear toe/tracking correct makes all the difference to any bunny hops or rear steer bumps worth a read Link to comment Share on other sites More sharing options...
johny Posted September 28 Report Share Posted September 28 yes just seems counter intuitive, even for back in the day, to have more weight (front) but less pressure than back. Surely idea is to maintain the same tyre profile in contact with road so vary pressure to acheive that for different weights? Link to comment Share on other sites More sharing options...
James H Posted September 28 Author Report Share Posted September 28 yeah experience tells me that not always but most of the time common sense prevails so probably a misprint by Triumph re the tyres, hence also why the biggest risk of issues and/or real head scratching is for those who choose to ignore it 👍 Link to comment Share on other sites More sharing options...
JohnD Posted September 28 Report Share Posted September 28 Try Shell V-plus. 99 octane. I run it in SofS that has a CR of 10.5:1. When you factor in the cost of octane booster, it's not that expensive. The tyre pressures suggested in the day were all for cross plies, and irrelevant for radials. Best time to find out your optimum is a track day. Take with you an Infrared thermometer. Drive three laps, come in, jump out (be as quick as you can!) and measure the tread temps, inner, outer and middle. They should be even. Temp in the middle >> temp on shoulders = pressure too high and vice versa. A slower way is to measure the wear with a tyre tread depth gauge. Excess wear in the middle = pressure too high. John Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 28 Report Share Posted September 28 you need a plate glass floor and a pit to draw the footprints out ....Hmmm so much tyre construction has changed since the 60s /70s the wsm is best for the mechanicals as they dont change but the specs for tyres is hopelessly out of date tryes vary so much more than the old crossplys of the day Pete Link to comment Share on other sites More sharing options...
James H Posted September 28 Author Report Share Posted September 28 1 minute ago, JohnD said: Try Shell V-plus. 99 octane. I run it in SofS that has a CR of 10.5:1. When you factor in the cost of octane booster, it's not that expensive. The tyre pressures suggested in the day were all for cross plies, and irrelevant for radials. Best time to find out your optimum is a track day. Take with you an Infrared thermometer. Drive three laps, come in, jump out (be as quick as you can!) and measure the tread temps, inner, outer and middle. They should be even. Temp in the middle >> temp on shoulders = pressure too high and vice versa. A slower way is to measure the wear with a tyre tread depth gauge. Excess wear in the middle = pressure too high. John Thanks and wish I could but I'm in France and only have access to the claimed 98 octane, works well enough though Re the tyres its not the pressure thats questionable, its the front/rear difference, would be interesting to know if you ever did those tests and found it was preferable to have less in the front ? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now