trophy160 Posted June 18, 2018 Share Posted June 18, 2018 Having reinstated my Saracen’s reverse flow cooling and replaced a worn out carb that caused plugs to foul I now have a Saracen that completes the relatively short journeys I ask of it (5-10 miles). However, when faced with a steep hill I need to drop it down to third and even then it it not brimming with power. On the flat I only drive it at around 30 mph as I’m generally on country roads, but even on the flat if I do give it more throttle it just feels down on power. My question is, is what I have described normal or should it have a bit more get up and go? Nic Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted June 18, 2018 Share Posted June 18, 2018 Hi Nic, Private message sent. Quote Link to comment Share on other sites More sharing options...
daleheywoodtanks Posted June 19, 2018 Share Posted June 19, 2018 Hi Nic, I am also having the same trouble. She is an FV610 and not up armoured. Feels pretty strong on the flat, but start climbing a hill, and power seems to gradually diminish. I had an exhaust manifold leak, which we fixed with a new 2into1 and new gaskets. Cleaned the carb, new leads, new plugs, all to no avail. I will keep trying, but not sure what to do next. Quote Link to comment Share on other sites More sharing options...
trophy160 Posted June 19, 2018 Author Share Posted June 19, 2018 Richard Farrant has pointed out that mine being up armoured and with the large wheels will not be able to tackle hills in higher gears. What I’m not clear about is just how fast Saracens whizzed up hills, after all they’re pretty heavy and by modern standards don’t have that much power. Richard has also suggested advancing the ignition a bit so I’ll give that a go. Quote Link to comment Share on other sites More sharing options...
daleheywoodtanks Posted June 20, 2018 Share Posted June 20, 2018 Thanks for the reply Trophy. I currently have 20 x 12 trakgrips on. She has done 52mph before now on a flat road, (closed road !) therefore she can be a good one when she wants. I think the next thing to try will be timing ! Stay tuned Thanks again. Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted June 20, 2018 Share Posted June 20, 2018 Nic, Another thought, you need to ensure the brakes are not binding and that the handbrake is releasing properly, anything that will inhibit progress! Having driven all types of Saracens I can say the Mk6 is definitely slower and needs to be really moving before going in to 5th gear. If you feel the gear is engaging and taking up slowly, then the upchange was done too early. regards, Richard Quote Link to comment Share on other sites More sharing options...
trophy160 Posted June 21, 2018 Author Share Posted June 21, 2018 Hi Richard, I don’t think the brakes are binding and I suspect I probably have a tendency to change up too soon when going into 5th. I do wonder however what others experience when doing a (near) standing start at the bottom of a steep hill where you don’t really get the opportunity to wind her up. Quote Link to comment Share on other sites More sharing options...
David Herbert Posted June 21, 2018 Share Posted June 21, 2018 I think you need to remember that this is a 60 year old armoured vehicle. When they came out they had a very acceptable performance for the day but if it has bigger tyres and been uparmoured that will have greatly reduced that. Try working out the power to weight ratio of a vehicle that you do consider to have acceptable performance and compare it to the Saracen. I suspect that you will find that the Saracen has about 1/4 of the power to weight ratio which is why you can't roar up hills. Putting it differently, plenty of modern cars have the same horsepower as a Saracen. One resonably fit person could push the car on the level. See how many people it takes to push a Saracen on the level. Something that has not been mentioned so far is that because Saracens have all the wheels on each side permanently geared together, if the tyres are not of precisely the same circumference they will try to turn at slightly different speeds. This loads up the drive line causing vast amounts of drag which saps power. David Quote Link to comment Share on other sites More sharing options...
andyroo Posted June 21, 2018 Share Posted June 21, 2018 I had a similar problem with my MK6 about 10 years ago. Ran great on the flat achieving 45mph quite easily. However any hills and it was change down 1 or quite often 2 gears. Took me weeks to find the problem. Turned out to be the fuel pipe from the tank to the filter had rusted and a few very small pin prick holes were letting in air. Replaced the steel pipe with copper and all has been well ever since. Quote Link to comment Share on other sites More sharing options...
trophy160 Posted June 21, 2018 Author Share Posted June 21, 2018 Interesting, I don't think I've got that problem as I've fitted an electric booster pump just before the filters. I think if there were pin holes I would hear it ticking away as it sucked air. I tend only to use the pump at start up but it might be worth switching it on when going up hills to see if that makes a difference. Quote Link to comment Share on other sites More sharing options...
daleheywoodtanks Posted June 21, 2018 Share Posted June 21, 2018 Thanks for that Andy, I will be all over the fuel system early next week. The sarry can be seen trying to keep up with the shielder in this video taken earlier this evening. I'm in the shielder, and Dave is driving the Sarry More of an incline rather than a hill, but still could not get revs up in third gear. We will keep exploring options. If it was easy, everyone would be doing it ! Quote Link to comment Share on other sites More sharing options...
Grasshopper Posted June 22, 2018 Share Posted June 22, 2018 16 hours ago, trophy160 said: Interesting, I don't think I've got that problem as I've fitted an electric booster pump just before the filters. I think if there were pin holes I would hear it ticking away as it sucked air. I tend only to use the pump at start up but it might be worth switching it on when going up hills to see if that makes a difference. On our M55 the electric pump we fitted aided start up, but restricted fuel flow when power was required. We switched back to the mechanical pump and the issue went away. Quote Link to comment Share on other sites More sharing options...
trophy160 Posted June 22, 2018 Author Share Posted June 22, 2018 Good point, if that is the case I think I should be able to test for that by leaving my electric pump on. As the engine's demand for fuel increases so should the ticking of the pump (it's a double SU) so I guess a rapidly ticking pump would indicate that it is working hard and possibly not meeting demand. Quote Link to comment Share on other sites More sharing options...
andyw Posted July 15, 2018 Share Posted July 15, 2018 We also have a very steep long hill on our route , we call it angina hill and both ours have to drop to third and sometimes second gear . They are 60 plus old ladies so we don't push to hard , just keep revs to a reasonable rate in the gear it's happy with . Well it works for ours . Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted July 15, 2018 Share Posted July 15, 2018 26 minutes ago, andyw said: We also have a very steep long hill on our route , we call it angina hill and both ours have to drop to third and sometimes second gear . They are 60 plus old ladies so we don't push to hard , just keep revs to a reasonable rate in the gear it's happy with . Well it works for ours . Good advise to keep the revs up in lower gear Andy as if you let them labour, the flywheel oil overheats and cooks the seal, then leaks. Seen it happen. regards, Richard Quote Link to comment Share on other sites More sharing options...
andyw Posted July 15, 2018 Share Posted July 15, 2018 Thanks Richard , I was expecting to get negative replies that is why I don't post . But to get a positive from the master has made my day . 1 Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted July 15, 2018 Share Posted July 15, 2018 18 minutes ago, andyw said: Thanks Richard , I was expecting to get negative replies that is why I don't post . But to get a positive from the master has made my day . Andy, I have had to deal with the aftermath of too many cooked flywheels, thanks for your reply. Quote Link to comment Share on other sites More sharing options...
andyw Posted July 15, 2018 Share Posted July 15, 2018 Yes to true , bad D+M , but luckily I was L.A.D so we hooked it and sent it back to you workshop guys Quote Link to comment Share on other sites More sharing options...
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