Escadrille Ecosse Posted April 17 Share Posted April 17 5 hours ago, JohnD said: I'll have you know, Colin, that I've got way beyond the Jack and Jill go to School book! Blimey, that wasn't yesterday. Flashback time! It was Janet and John for me though I think? Oh my, a very long time ago... Link to comment Share on other sites More sharing options...
Nick Jones Posted April 17 Share Posted April 17 Janet and John….. Damn I’m old…… Link to comment Share on other sites More sharing options...
JohnD Posted April 17 Share Posted April 17 Not so long ago: Terry Wogan reads the first of the Janet & John stories CD1 (youtube.com) Link to comment Share on other sites More sharing options...
rogerguzzi Posted April 17 Share Posted April 17 Hello Alll I used to love them and have a CD somewhere with some on Roger Link to comment Share on other sites More sharing options...
Escadrille Ecosse Posted April 17 Share Posted April 17 The Terry Wogan verion is rather 'different' from what I remember... are you allowed to use scissors? " and while I was there she showed me the little fir she'd been growing since she was a teenager and she let me trim it into an interesting shape with some scissors" This is what I remember from my schoolday in Aden, but as it was a long time ago and I was very young maybe I missed some of the plot Link to comment Share on other sites More sharing options...
Hamish Posted April 19 Share Posted April 19 OMG. i think the phrase is. Janet and John yup I feel old too. i guess you can tell I wasn’t clever enough to finish the whole set !!!! Link to comment Share on other sites More sharing options...
egret Posted April 20 Author Share Posted April 20 Cam timing is now sorted. Rear carb bowl decided not to fill, but now also sorted. Ongoing are: Possible airlock after refilling the cooling system. Dodgy power to the megajolt, via the inline fuse holder I put in. Ignition barrel still not sorted. However, it now drives the best I've ever had it. It does still feels a bit sluggish at higher rpms, I think it should feel more eager to meet 6k rpm, but that should come out in the wash at the rolling road. Hopefully I'll get a good few drives in before then to flush a good amount of fuel through the system and get the carbs happier. 1 Link to comment Share on other sites More sharing options...
egret Posted April 26 Author Share Posted April 26 Well it's improving. I generated a map from a calculator I found a link to an ignition table calculator. This was the result of dissapperaing down a bit of a rabit hole reading up on ignition timing via megasquirt or speeduino. Calculator is here: www.useasydocs.com/theory/sparktable.htm and using some basic excel skills, I interpolated it into a 10x10 table for my megajolt. This ran significantly better than the previous map I'd been using. I still am not certian the offset is right, probably within a few degrees so I'm not going too extrememe on the map. Once I've refined it on the rolling road I'll put it up on the ignituion/fuel map thred. I also put my 3D printed velocity stacks (the flat donut type ones) into the airbox having got around to putting a skim of filler on the back to make them flat (to rectify some 3d printing warping issues). These were printed about 3 years ago for £30 from etsy (https://www.etsy.com/uk/listing/1006717518/x2stubstack-part), so very likely you could get these cheaper and better nowadays. I can probably dig out the file if required. I'm not sure they are making any real difference, but they help make me feel like I'm doing all I can! My burrent concern is the map sensor. It doesn't seem to get below about 50kPa and the signal seems very odd. The attached grab shows some fairly lengthy periods of full throttle which seem to be spiky, rather than consistant, and I can hear some of these periods of accelleration when the dial is showing 100kPa. I can't see that there's a way of calibrating the MAP sensor, so I'm getting suspicious that its a dodgy map sensor. Before I get too carried away I'm going to install the plenum Toby gave me, check the soldering on the board, and look into the cost of a new map sensor. Any thoughts from sideways on things I've missed or overlooked? I'm trying not to be biased, but I have a suspicious mind to the thing being broken which is probably clouding my judgement... I've included a screen grab of the drive recording, and a photo of all the spitfire related maps I've found, including the one I'm running at the bottom, called generated map. I think the matt and rob maps are both generated by forum members here! Link to comment Share on other sites More sharing options...
Nick Jones Posted April 26 Share Posted April 26 What map sensor and how connected to the manifold? Link to comment Share on other sites More sharing options...
egret Posted April 26 Author Share Posted April 26 (edited) The MAP sensor is integral to the megajolt. With the slight caveat that it's the map sensor from the old megajolt, soldered to the new megajolt. There is revision change between the two units, but I'm 90% certain the sensors are the same. It's connected via a hose linked to the manifold vacuum takeoff at the point where the original distributor vacuum advance was connected. The new hose is maybe slightly longer as the megajolt is in the passenger seat footwell, but shouldn't be enough to cause issue. EDIT: I think I just found the spec. of the sensor. It's discontinued, but RS have stock. https://uk.rs-online.com/web/p/pressure-sensor-ics/7191074 For £25 I should probably just take a punt on it. The countdown to the rolling road day is still 2 weeks away, so I'll take a look at the bits this weekend and maybe order one if I can't see an obvious improvement. Also, although it feels a little presumptuous given the above, I should probably pester @mpbarrett to borrow his timing light and get the offset dialed in properly - little point sharing a map if it's got a consistant offset. Edited April 26 by egret Link to comment Share on other sites More sharing options...
mpbarrett Posted April 27 Share Posted April 27 22 hours ago, egret said: Also, although it feels a little presumptuous given the above, I should probably pester @mpbarrett to borrow his timing light and get the offset dialed in properly - little point sharing a map if it's got a consistant offset. I am away in surprisingly cold and wet Wales at the moment (Wonder Wool, my wife is a spinner) but back on Monday. Will find it in the garage and let you have it. Cheers Mike Link to comment Share on other sites More sharing options...
egret Posted April 29 Author Share Posted April 29 Hmmmm, I might have done something silly. I soldered a MAP sensor onto the newer megajolt I'm now using as it was tps only when I got it. This thread (https://forum.autosportlabs.com/viewtopic.php?f=4&t=1518&p=6898&hilit=mpx4250+calibration#p6898) suggests that using TPS overwrites the MAP sensor calibration table, so it's possible its a calibration issue, not a sensor issue. I currently have no idea how to load that text document into the megajolt software, but I'll give it a go. Maybe a firmware re-flash would achieve the same result? Either way, I'll try a bit of computer based prodding around and will report back when done. Link to comment Share on other sites More sharing options...
egret Posted May 4 Author Share Posted May 4 Oil change done for the rolling road. Also I had a revelation and maths to calculate what 10,12,&15° on the crankshaft pulley was in circumference mm, then made a hoop of paper to do over the pulley. A centre punch and some white paint means I now have several marks on the pulley and can identify idle timing with my dumb strobe, so timing is now accurate and I will be able to share my maps. Ignition key faught me all the way. The inner section of the barrel is cracked and two separate pieces, causing the No1 pin to come out too far and jam in the keyway. I managed to remove this pin and it seems to work now. But had to stop before I got it all back together. Once the steering is back together I just need to check the valve clearances and I should be rolling road ready! 1 Link to comment Share on other sites More sharing options...
Nick Jones Posted May 4 Share Posted May 4 I have also done an oil change today. On the Vitesse - as the oil had undergone a rather significant colour change after Wednesdays whipping . Also checked tappets and plugs which were basically ok. Need to whip the brake drums off to knock out the dust then reset the adjusters. Also drove the GT6 about 15 miles and put some fresh fuel in it. It was in a good mood and drove nicely. Clutch has a lovely action….. Link to comment Share on other sites More sharing options...
egret Posted May 4 Author Share Posted May 4 That's good nick. That thrash must have got everything nice and hot , and I assume high flows for extended periods of time. I'm sure it's just transfers old much into the oil and probably insides of your engine is now spotless! Mine was pretty clean actually, but only about 300 since the build. I've put some millers semi synthetic in, so hopefully it likes that. I do have an ongoing issue with the rear float valve sticking closed. It happens after it's sat for a few days. Its happened a couple of times and takes me a little while to twig because this engine runs/drives better on two cylinders than the old one did on three! Link to comment Share on other sites More sharing options...
Nick Jones Posted May 4 Share Posted May 4 1 hour ago, egret said: this engine runs/drives better on two cylinders than the old one did on three! ! Link to comment Share on other sites More sharing options...
egret Posted May 7 Author Share Posted May 7 Well it went back together ok, and really is driving as nicely as ever, but still seems a little out of puff above 4k rpm. I'm hopefull this is either timing or fuel, both of which can be sorted on the rolling road, rather than unrealistic optimism! I also fully agree with Nick's dislike of molex connectors, they aren't really suitable automotive connectors. I've a couple of dodgy pins, that need sorting. I'm also off to try and get either a wire, or jsut cheap set of feeler gauges so I can set the valve timing. The dents (possibly wear patches) in the rocker arms are narrower than my feeler gauges making vave adjustment challenging. I'm rather looking forward to the rolling road on friday now. I'll do my best to record it in case of exceptional noises, or calamity. Link to comment Share on other sites More sharing options...
PeteStupps Posted May 7 Share Posted May 7 1 hour ago, egret said: I'm rather looking forward to the rolling road on friday now. I'll do my best to record it in case of exceptional noises, or calamity. Good luck with it, hope your RR experience is better than mine! Decidedly underwhelming - maybe my expectations were too high. I took a video of one dyno run capturing live AFR and RPM, which was useful for analysing later on. Ideally I would have set up a video camera to look down the carbs as well, to see approx needle station and AFR simultaneously. But the rolling road bloke wasn't particularly patient. 1 hour ago, egret said: Well it went back together ok, and really is driving as nicely as ever, but still seems a little out of puff above 4k rpm. Odd to run out of puff above 4k rpm, that's where it should be perking up. Hopefully you find the cause easily. It's on the original mk3 camshaft right? Link to comment Share on other sites More sharing options...
egret Posted May 7 Author Share Posted May 7 Original Mk3 camshaft. I'm using HS4's with the standard 1500 ABT needles. I'm pretty sure there are much better needle choices available, and the guy at the rolling road said he had plenty to chose from, so I'm hoping we can get close and if maybe even refine further after the day using the lambda readings and the mintylamb calculator. I've also not been that agressive on the timing as I'm hoping we can do this on the rolling road with an expert listening for knock, rather than me attempting to hear it from the drivers seat. I'm pretty sure there are improvements which can be made, I'm not really expecting much more horsepower. It is good enough to keep up with traffic and cruises nicely at motorway speeds, so anything more in terms of drivability and power is really only a bonus. I fear I might have been spoiled by motorbikes, but the current engine performance feels like it's leaning more towards being torquey than the revs based delivery I'm after. I'm sure the rolling road will put some numbers to my naivety. Link to comment Share on other sites More sharing options...
zetecspit Posted May 7 Share Posted May 7 I was really happy with the rolling road session for my Toledo. The chap s-=checked a few bits, ran it up a cpuple of times. Pulled the entire dashpots off the carbs and filed the needles. Did that 3 times, perfect AFR across the rev range. He then nudged teh dizzy a few times, but reckoned there were no improvements to be had. All in took him 45 mins. The car was transformed, much perkier and economical. Sadly that was the very last session he did before moving to a new place where he couldn't have a RR. But my take on running out of puff is pull the choke and see if that helps. Very likely running too weak. 1 Link to comment Share on other sites More sharing options...
Escadrille Ecosse Posted May 7 Share Posted May 7 19 minutes ago, zetecspit said: But my take on running out of puff is pull the choke and see if that helps. Very likely running too weak. Quite likely. And a nice easy check to do. Just add choke very slowly as it is richens very quickly 1 Link to comment Share on other sites More sharing options...
Nick Jones Posted May 7 Share Posted May 7 What they say about the choke experiment. On the clockwork dizzy the timing will be all in by 4k @ maybe 32 degrees. Sometimes there’s some gain from putting a bit more in higher up, but that’s best tested on the RR. 1 Link to comment Share on other sites More sharing options...
egret Posted Friday at 05:31 PM Author Share Posted Friday at 05:31 PM Rolling road was great. The place was absolutely fantastic, and let me change needles and do much of the hands on stuff. They diagnosed the main issue, which was the fueln lines to the jets were kinked and very old. Replacing these with new jets that have longer fuel lines prevents them kinking and they can deliver enough fuel over 4k rpm. Long and short is that I went in with very little if anything much above 3k rpm, and left with about 70hp at the flywheel. Or a smidge over 30hp at the wheels went up to just shy of 50. So nothing heroic, but we ran out of time and still struggled to prevent it leaning off at top end. We ended up with aam needles, took the springs out because it helped (although I'm going to sit and think about what's actually happening there), and it's still a bit lean at top end. Oh, and it drives much better! Link to comment Share on other sites More sharing options...
PeteStupps Posted Friday at 05:54 PM Share Posted Friday at 05:54 PM That sounds like time and money well-spent! Very good, you got a better result than I managed - and that AFR plot is very useful. 21 minutes ago, egret said: took the springs out because it helped (although I'm going to sit and think about what's actually happening there) Damper springs? Interesting... Link to comment Share on other sites More sharing options...
Nick Jones Posted Friday at 08:02 PM Share Posted Friday at 08:02 PM 30 -> 50 at the wheels….. is a gain worth having!! That’s knocking on double - you’ll notice that! 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