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Post by threelitre on Sept 15, 2011 9:12:58 GMT
It was the Nürburgring (Nordschleife) Sabine is quicker than I am though... I did six continous laps in about 1h45' and a bit. Regards, Alexander
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Post by threelitre on Sept 14, 2011 9:54:37 GMT
Agreed - it has got lots of road presence as it is called today. I still do not get on too well with the front end from some angles. Reading old reports back in the day, it seems that general proportions, side and rear appearance were generally liked, the rear always praised. The side is a strange mix of early 60s shapes with the low amount of decor of the upcoming 70s - very pleasing to me. After being used to an 1800 all my life before getting my 1st 3Litre, the long bonnet needed really getting used to, but now when I am less often exposed to an 1800, I can see the point that people in the 60s found the 1800's proportions odd.
The big thing has loads of character in every way though!
Regards,
Alexander
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Post by threelitre on Sept 13, 2011 22:06:44 GMT
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Post by threelitre on Sept 13, 2011 12:38:31 GMT
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Post by threelitre on Sept 1, 2011 13:02:15 GMT
He suggested going back to the steel pipe from pump to carb as a first try, rather than using rubber hose and the inline filter. Now that reminds me something: I once had a Maxi with occasional lean running problems that got worse with time - but only in 5th gear and only when passing about 90kph. It could do 110 in 3rd I first thought ignition, but an experienced mechanic spotted the inline filter the owner before me had fitted to the fuel hose (the one across the engine) and said that this will be the cause. He was right. Due to the car having stood a longer time, there was always some very small rusty particles in the fuel and these accumulated in the paper element in the filter - but on the backside of it that I could not see. When I changed in fith engine revs dropped and the fuel pump (engine driven) could not deliver enough pressure anymore. Try removing this filter - the SU's are very tolerant to all sorts of dirt anyway. Regards, Alexander
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Post by threelitre on Aug 19, 2011 11:42:53 GMT
Without reiterating too much, I have had totally (I mean totally) clapped out engines that would idle and not misfire. Yepp, same here. Even with a fully worn carb spindle they can be made to run smooth with ease (as long as it's a single carb). Tommy, which parts did you NOT change over the last weeks? Regards, Alexander
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Post by threelitre on Aug 19, 2011 9:26:19 GMT
The R-series has a different crankshaft, so it will not be a straight fit... As the head is basically the same on E4 and R (R has the fuel pump on the head - this is the only difference), I think even the camshaft has the same lift and timing as the single carb Maxi. The differences boil down to - shorter stroke than a 1750 - Carbs, inlet and exhaust - ignition (electronic distributor)
There is not enough space to fit the carbs from any R-series Maestro to the Maxi, so the advantage of the well designed manifolds or double Webers sadly has to be skipped. (It has obviously been tried!) The distributor from an R-series Maestro can make a good addition and is known to have been used. I don't know if the SU or Weber spec suits the Maxi better though.
There are ways to extract between 110 and 120 reliable PS from the Maxi engine: Mostly through better manifolds - downton did such things, also BL sold special tuning kits to bolt on. You could also try to adapt the EFi system from a Rover 216 EFi to the E-series. This has been done, but a manifold needed to be made to fit the engine bay.
The Maxi's engine bay is much narrower than the 1800's, fitting an E6 will be a very massive task...
Regards,
Alexander
PS: The R-series MG never got that carb cooling fan. And has massive hot starting problems...
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Post by threelitre on Aug 18, 2011 8:48:32 GMT
Did you see (Penguin) Chris' fuel consumption of 36+MPG on a long journey fully laden by the way. A bit better than yours! Very impressive indeed! I know that while traveling the UK I always get lower (=better) consumption figures than here on the continent. But I was very happy for the 1800S (fully standard) to get any more than 31.4mpg. The Maxi can better 36 with not too much trouble - and don't ask about the 3litre I just returned from my hols and our fully laden Rover Tourer with 1.6 K-series managed a bit more than 40.5mpg whilst averaging exactly 63mph with A/C on over a distance of 700 miles. There has been some progress over the years! Regards, Alexander
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Post by threelitre on Aug 17, 2011 14:28:39 GMT
Oh my - I'm on a holiday and this thread has increased by 3 more pages...
But I am lost with these details of the engine, as I have not yet torn one apart - and from reading manuals not all of your findings (and Dave's knowledge) would be able to find an explanation. The thought of something sticking seems quite logical to me. Has it got single valve springs? I found the single valve springs on one of our A-series so weak that I at first had trouble to adjust the clearance because I was used to the stiff springs on my Maestro's A+. With such weak springs some stick-slip effects might keep the valves from operating correctly.
Regards,
Alexander
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Post by threelitre on Jul 31, 2011 0:05:48 GMT
Have you ever tried using a colortune plug to get the mixture right? These things are worth a lot if you think you have fuelling trouble. A wideband O2-sensor will be a step further - expensive in comparison and not really needed for an engine close to standard. It may well be that the standard needle does not match the engine anymore.
Stick a straw in the dashpot of the carb and leave the damper out. Will the piston lift all the way when the engine accelerates? (or look into the back of the carb with the airfilter off. If the airfilter restricts the engine, then it will be at high load and high rpm - when the engine needs most air. I tend to set up my cars with the air filter off and never found a significant change when I put it back on.
Regards,
Alexander
Regards,
Alexander
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Post by threelitre on Jul 20, 2011 9:26:32 GMT
The valve seat recession is a problem with LPG, a little more so than with unleaded but due to the same reasons. I run my Maestro with an unleaded head since about 100k kms not using leaded fuel or lead substitutes. Of these the last 60k kms have been on LPG only. At first I ran it with the standard ignition timing and checked valve clearance every 5k kms. At first the recession was hardly noticable, but then it started to appear so much so, that the exhaust valves (only these of course!) were tight every 5k kms. Then I advanced the ignition timing a lot (6 or 8 degrees, I forgot how much) and immediatly found the engine pulling much better on LPG at low to medium revs. If needed it still does run on petrol, but I just used that in emergencies two or three times since. The slower burn of LPG compared to petrol does indeed allow more advance, but this also reduces the heat seen by the exhaust valves - recession slowed down quite a lot. I assume that with the petrol timing setup the exhaust valves are exposed to unburned or just burned mixture. Right now the exhaust valves sit about 1mm higher than the inlet valves, but they still do seal well. For the case of a burned valve eventually I have a head set aside with factory fitted unleaded-spec valve seats.
When resetting the ignition I am not too worried about not detecting pinking. I think it can be heard quite well when fully established. The point is to get to the point were it actually is pinking and then back up quite a bit (2 or 3 degrees should do), the onset of pinking might indeed go unnoticed. The A+ in the Maestro is much more refined, since it uses a VW gearbox end on. But on my father's 1800 S it was always easy to find it pinking when filled with the wrong fuel (in the 70s and early 80s it did usually not like Shell fuel, Aral was always fine!).
Regards,
Alexander
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Post by threelitre on Jul 18, 2011 13:18:48 GMT
Nice link that!
I have indeed considered modifying the dizzy, in particular as I have 2 more of them here as spares. As the Maestro's distributor is already an electronic one, the difference to a 123 just replicating the original curve would not be big. The 123\tune offers a good package, again not cheap, but easy to install. A MegaJolt would offer even a little more (i.e. I'd be able to program a fuel shut off on overrun for LPG on this), but the installation is quite a bit more involved.
First thing would be to find out a good (or even optimal) ignition curve! Without a rolling road I tried already to look for alternatives: In the old days a stop watch would have been the choice of weapon (plus a vac gauge). I looked into using a GPS and derive acceleration from the positional data. As the updates are slow, it would not work with a supercar, but given the (very, very) modest performance of a 1.3 Maestro on LPG, I think, that full acceleration on a flat piece of road in 3rd will give useful results with the possibility to find out performance changes in relation to rpm (and current distributor setting obviously). Repeating the road at given speeds on part throttle with the vac gauge should give the vacuum advance... So far I have not yet found the time, but the plan is to do a set of runs with the distributor turned 2 degrees a time and later compare graphs at home.
With these tools recurving a distributor to a good custom set should be more or less free - apart from a bit of fuel and some spare time. It would obviously work on other cars too...
Regards,
Alexander
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Post by threelitre on Jul 18, 2011 11:37:00 GMT
I have not had it on the 1800 yet, but the old family bus (an S) is running very well. I've used it with an probe to fit the tailpipe on a VP 1300 (with lots of modifications). My initial adjustment was not bad - but dipping to 0.8 on acceleration seems a bit heavy. It does not really replace a pair of colourtunes on a mulit-carb car though...
Having a 123 tune built to spec sounds good - but also serious money just for some small perfectionism...
Alexander
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Post by threelitre on Jul 17, 2011 13:19:55 GMT
I've seen that - but that's of no help. Using a wideband O2-sensor I have the mixture on LPG setup spot on - ranging from slightly weak on cruise to rich on full throttle at low to medium rpm and slightly rich above. This 123/LPG is (just) another closed loop device for Venturi installations - a fairly expensive one at that. I am considering a programmable ignition with switchable maps, as the car pulls way better on LPG in the low-medium range when I run it with an additional advance of 6-8 degrees. At rpm above 3500 it starts to run out of steam with these settings... I could reprofile the standard distributor, as I don't use petrol at all unless I need a 'get-me-home' when run out of LPG - last time 2 years ago...
Regards,
Alexander
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Post by threelitre on Jul 15, 2011 22:23:02 GMT
Have you looked at the 123 "Tune" ignition. That's the one I meant - sadly not available for A+ engines... Alexander
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