Lotus Europa Community
Lotus Europa Forums => Members Cars => Topic started by: Grumblebuns on Thursday,January 15, 2015, 11:24:59 AM
-
Spent most of the morning hooking up a temporary battery to my TCS for it's initial road test. For now I've given up trying to safely secure a group 26R battery to the car. I decided to substitute an Odyssey PC680 from my S2 until I can fabricate a more solid battery mounting system for the original battery.
I believe the car is ready to go. I've driven it up and down my drive way a couple of times, so I know that it runs. This is the TCS that I bought back in the summer of 2013 and spent all this time making it road worthy. For some reason, I have this weird feeling of dread on the eve of it's first road test.
Well, have lunch, have a couple of beers and get over it. Wish me luck.
-
Hey Joji,
I know exactly what you're going through. That first time is always really anxiety provoking. Since you've driven up and down the driveway, maybe the next step is around the block. Then a little further... From what I know about you, I doubt you missed something and everything is very likely just as it should be. Take that deep breath and let us know how it went.
Good luck!
-
Good luck, Joji
Have a nice drive. :pirate:
-
Our "moment of apprehension" won't be for a while yet...
I know it will be a "mark the calendar event" though, as I have pushed a Lotus, jacked a Lotus,
wrenched on a Lotus, & got it running, but never DROVE a Lotus...
So, needless to say, It will be a very special day!
Congrats & hope all goes well!
-
It'll be fine, but just in case you decided to wait until today for the inaugural run, don't forget that essential tool for your Lotus Toolbox.....
a "Lotus-approved" cell phone !
Brian
ps - well, come on, how did it go then ?
-
Well, nothing smoked, caught on fire or fell off (nothing major at least that I could tell). I only drove it six miles total, turned around just before I hit the main road into town. I was pleasantly surprised just how well the car drove. There were two issues that I came across. Going up a fairly steep grade, the car started losing power. Giving it more throttle did not help, had to down shift into second and that was the second issue. It was ridiculously easy to over come the reverse spring detent and I momentarily touched reverse trying to downshift to downshift. The TCS should have easily made it up the grade in third gear.
On the power issue, I'm suspecting that I have to look at the carbs. Either the it's a loose linkage between the two Strombergs or possibly one or both carbs have diaphragm/damper oil issues. The car runs beautifully under low load.
For the hitting reverse issue, if a car ever needs a reverse lock out this one is it. Peter, I have to dig out your reverse lock out kit. I'll try to get to it in the next few weeks. Anyone know if it's possible to install a stronger spring as an interim measure.
Joji Tokumoto
-
Which transaxle are you using? 365? My memory with it was that it was difficult to get it into reverse (good) and maybe just as difficult to get it into fifth (bad). If that's what you have, you could put a stronger spring in the reverse/fifth "detent" cam mechanism or shim the spring to apply more preload to the ball that rides on the cam.
Obviously, a lockout is not a bad idea. IIRC, there are some plans for them on the yahoo group.
-
Well, nothing smoked, caught on fire or fell off
hmmm, (shakes head sadly) that can't be a proper Lotus you've got there then....
:)
Actually, that doesn't sound bad for the inaugural run. I always count getting home without pushing it as a win !
On the power thing - if the carbs check out, how about a failing coil under load, how many revs did you have on when it started losing power ?
Brian
-
Congratulations!
Either the it's a loose linkage between the two Strombergs or possibly one or both carbs have diaphragm/damper oil issues.
When mine had similar symptoms, both carb diaphragms were deteriorated/torn/cracked. The good thing is this is super easy to check and fix.
-
I'm still reveling in the moment. A Lotus making it home under it's own power in it's inaugural road test, is almost unheard of.
I'll tackle the issues in a couple of days; the weather is too gorgeous to be stuck in a dark garage. As I hadn't even looked at the Strombergs before installing them, they will be the first item to check out. The car was running before it blew the head gasket for the PO, so I assumed they would still be fine. The coil looks to be a fairly newish Lucas sports coil. No road grime on it so, I'll check that if the carb are not the problem. Going up the hill, stepping on the gas pedal had no discernible increase in RPMs. It felt like the engine just hit the wall around 3k and kept slowing down. On flat ground, I can to push it to around 4k with no hesitation or miss. I didn't stress the engine any further than that.
On the gearbox issue (it's a 365), the ease of getting into reverse caught me by surprise. My original TCS had a stiff detent going into reverse or fifth. I remember that I had to slam the lever against the detent to get into either gear. When I was installing the engine/gearbox assembly into place, I had to grind down of the bolts securing the gearbox to the bracket because it was fouling the down tube on the chassis. I removed the ball and detent assembly to keep it clean of metal chips. I wonder if I lost any shims that may have been in place.
-
Congratulations on your inaugural run!!! That is really great news! I think I'll throw in with those who blame the carbs. I might check the fuel line for kinks (you do have a metal 'T' between the carbs, right?) and of course, linkage.
I don't think there are shims under the detent spring (I don't remember any or see them in the parts manual, anyway), I just suggested it if other fixes were not practical. Of course, another thing you might do is stretch the spring a little to give it more compression.
Show us the pictures (or did you have a movie crew? :) )
-
Good to hear, Joji. Congratulations! ;D
If the carbs hasn't been touched for a long period, I would also start with checking them. The diaphragms has already been mentioned, but check also that the damper rods move freely and has been filled with oil. Also check for air leaks: The cold start (choker) mechanism, temperature compensator, bypass valve and various idle and mixture screws all must contribute with the right amount.
How about the speedometer cable? is the pedal bottoming out before the throttles are full open? (BTDT)
Regarding the shifter detent, I seem to remember that the housing can be adjusted/moved some millimeters. A quick fix would be to move it closer to the cam and 'to the one side' so that you at least have a strong working cam for the reverse gear. Never mind that it is impossible to adjust it for the 5th gear at the same time, selecting 5th instead of 3rd is only annoying but not critical for using the car. Then you can put some miles on the car, until you find the time to put on the detent parts I sent you.
-
Before I decided to go to an NG3, I figured I would fill down the cam for the 5th gear detent. I've never heard of anybody doing that, though.
-
I managed to get in a quick visual inspection on the Strombergs. All linkages are tight and the shafts move freely. The diaphragms look to be fairly new. The only oddity appears to be the force required to move the air valve up with finger pressure. It takes a lot of effort and takes a long time (4-5 secs?) to force it up. Looks like it's time to play with different damper oil viscosities to see if that makes any difference.
I did run the engine and checked the operation of the air valve with increasing the RPM. I couldn't see the air valve so I had to stick my finger in the opening to feel if the piston was opening. Slowly running the RPMs up, I could feel the piston fluttering up and down but did not open up any appreciable amount.
-
Following on from your latest comments, it does sound like petrol supply is the first thing to investigate.
I have little experience of strombergs, only ever having had them on one car many years ago. I think in those days I just used to put what we called "3 in 1" oil in the carb dashpots, which is a mineral oil and slightly thinner than 20/50. ( I'll also admit to having put plain 20/50 into SU carburettors which operate on a similar damped piston theme :-[ )
I guess the other thing to check is the fuel pump/supply lines as BDA says. If it's been standing the pump might be full of silt or have sticky internal valves ? And easy check anyway with a glass bowl.
As an aside, if you haven't tried a "Gunsons Colortune" plug then I'll admit to being a big fan of such things for diagnosing fuel problems. With one in place it's very easy to lift the revs and watch the colour of the flame, so if it's a weak mixture that's causing your hesitation around 4k then you should see it clearly. You get similar information from the spark plug of course, but being able to watch the flame at a given rev range is handy if you are checking mixtures through the range - for example checking the needles/jets are suitable.
Brian
-
We use Dexron 2 or 3 automatic transmission fluid in the dampers. It's lighter and does not affect the diaphragms.
Pull off the dashpots and clean everything out thoroughly. Before filling the dampers, the dashpot should rise and fall easily with just light finger pressure.
-
I didn't know you could use ATF for damper oil. I had heard that 20wt would work and I suspect there is Zenith-Stromberg damper oil in a small container for a ridiculous price also.
I would add that it might be a good exercise to drain the current oil and check how it works to make sure there is no binding anywhere. I might also check your throttles. IIRC, there are two - a main throttle and a secondary one for the crossover pipes. If your pipes were taken off, the secondaries might be taken out and the holes plugged (I don't remember exactly what was done for that). Anyway, it might be a good idea that you're getting WOT and there's nothing that would "get in the way" like a butterfly closing when it's not supposed to. Having said that, it sounds like your problem is probably the wrong oil in the dampers.
Just an FYI: it may be useless information but for some reason, I feel compelled to say that you don't NEED oil in the dampers for the carbs to work. I never used any in the SUs for my MG Midget race car. That is surely less appropriate for a street car that is not usually wide open most of the time, but who knows, it might be an interesting thing to try.
-
For those who don't know, the damper oil delays the rise of the piston giving a momentary richer mixture when the throttle opens. It fulfills the same function as an accelerator pump in a non-CV carb.
-
I did more poking around this morning with the TCS. I remember using Marvel Mystery Oil back when I had my running TCS for the dashpot oil. Not being able to find the long forgotten bottle, I had some Dexron III available so I changed out the original oil and replaced it with the ATF.
I also decided to re-read the service manual on overhauling the Stromberg and came upon this interesting tidbit of info. The two depression sensing holes for the diaphragm are suppose to be behind the air valve piston. It appears that the mechanic that the PO used to rehab the TCS did not read the manual. Both holes were blocked on one piston and one on the second, no wonder the pistons wouldn't rise under a vacuum. In the second picture, the mechanic did not make sure that the tab on the diaphragm fit in the slot in the valve body for proper alignment.
I'm pretty sure that I've found and fixed the problem but won't know for sure until I do another road test.
-
Congrats on the successful run, Joji. Exciting stuff. Hopefully your new found carb assembly issues solve the problem.
Regarding the problem of hitting reverse when down shifting into 2nd, mine is the same way. Shifting from 3rd to 2nd will easily find reverse if I am not diligent. Same goes for shifting from 5th to 4th. When pulling it out of 5th I pull the stick towards the left then push it all the way to the right before pulling it down to 4th. Otherwise, when I pull it down it will hit reverse.
And speaking of 5th, I find getting it into 5th takes a very firm shove through the detent. I very rarely ever use 5th so it's not as big an inconvenience as it sounds, but I find diligence and an acquired technique is required to effectively shift the Europa (or at least the 365 trans). Double clutching the down shifts makes a big difference too. I think it will soon be time to give Peter the nod for one of his reverse lock-out devices, and perhaps try BDA's suggestion of trimming the 5th gear detent.
Anyway, well done on the road test, and looking forward to hearing more. Cheers :beerchug:
-
Good find ! I'd never have guessed that one as the cause, not in a million years. Amazing what the Mk1 eyeball can suss out......
Brian
-
Interesting discovery, that could explain why the pistons don't move sufficiently. Now, careful with the gas pedal when you get to try the car again. ;D ;)
Trevor, what you're describing with the gear change is exactly my experience with the original Lotus detent mechanism: The constant slamming of the gearstick wears out the linkage, until it gets sloppy and one has to align the stick to either side to hopefully select the wanted gear.
Maybe you don't know it, but I now ALSO have the 5th gear internal detent plunger ready, so that one can get rid off the Lotus detent housing completely. See the following message:
http://www.lotuseuropa.org/LotusForum/index.php?topic=127.msg5746#msg5746
(I hope it's OK, inserting this personal ad in the thread) :)
-
The piston and carb body both have alignment notches, the diaphragm has inner and outer nubs, all to make sure the piston is properly positioned.
-
I just got back from another short test run this morning, the same route as yesterday. It appears that the carburation problem has been fixed. Going up the same hill, no need to downshift and I could even accelerate a bit in third.
Regarding the shifting the 365 gearbox, I can live with the sloppiness. I just have to adapt to the idiosyncrasy of the gearbox, like downshifting using just your fingertips. There is absolutely no slop in the linkage so besides fitting Peter's reverse lockout kit, I have to live with it. This gearbox operation is very similar to what Trevor described with his.
The other issues that I have to look into is the cold start or lack of. The car won't start when it's stone cold without starting fluid even with full choke. I'm wondering if the same mechanic mess up the choke feature when he rebuilt the Strombergs. I'll fix the problems as they crop up and I appreciate all of the tips.
-
and the results were ? are you polishing it lovingly or kicking the tyres and using lots of foreign sounding words ? :)
-
Congratulations on your find, Joji! Given your attention to detail, I was sure you'd figure it out. :beerchug:
Now tell us how your latest test drive went!
-
Obviously I wasn't going to push the motor this early the first time out but my seat of the pants feeling was that motor wise it was very comparable to my S2 wedge head with the 45 DCOE side draught. I want to put on a few hundred more miles before I start pushing the motor. I expected a bit more but then I was only shifting at 4k rpm.
I'll do a longer 20 mile trip into town tomorrow and really push it a bit more.
-
For those who don't know, the damper oil delays the rise of the piston giving a momentary richer mixture when the throttle opens. It fulfills the same function as an accelerator pump in a non-CV carb.
Hmm... Interesting. Unless there is a difference in theory of operation between the SU and Stromberg or I'm missing something (never to be discounted), that seems counter intuitive. Assuming they operate under similar principles, that would imply that oil would be required or at least beneficial in a race car since I would think you would certainly want a richer mixture on acceleration otherwise you might get detonation which would be extra bad for a race car. I had always assumed the oil was to dampen out the fluctuations in the motion of the piston rather than adjust the mixture. I also assumed (or maybe someone all those years ago told me) that it also enhanced throttle response. What am I missing, John?
-
Great news, Joji! :trophy: (I didn't see your post when I posted).
Is your shift linkage sloppy everywhere or is it just a problem with R & 5th? As you know, there are several places up and down the linkage that can cause general sloppiness (the nylon "hat" bushings at the shift lever, the pivot at the bell housing, the U-joint, the roll pin at the selector shaft).
-
and the results were ? are you polishing it lovingly or kicking the tyres and using lots of foreign sounding words ? :)
Went back down to the garage after my last post with a cup of coffee and did a visual inspection. Amazing, nothing leaked or is leaking. Yeah, I'm starting to feel a bit more confident with the car now.
BDA, I also did a comparison with my other TCS (non running) shifting through its gears. Although the reverse spring appears to have the same effort (very little) as the this TCS, shift action however has a lot more resistance (think walking through molasses) which I prefer and I know that the linkage is worn on that car. I went through the entire shift linkage before re-installing in the car and the PO had replaced everything so it's tight except for the sloppy action.
-
For those who don't know, the damper oil delays the rise of the piston giving a momentary richer mixture when the throttle opens. It fulfills the same function as an accelerator pump in a non-CV carb.
Hmm... Interesting. Unless there is a difference in theory of operation between the SU and Stromberg or I'm missing something (never to be discounted), that seems counter intuitive. Assuming they operate under similar principles, that would imply that oil would be required or at least beneficial in a race car since I would think you would certainly want a richer mixture on acceleration otherwise you might get detonation which would be extra bad for a race car. I had always assumed the oil was to dampen out the fluctuations in the motion of the piston rather than adjust the mixture. I also assumed (or maybe someone all those years ago told me) that it also enhanced throttle response. What am I missing, John?
BDA, just a guess on my part but this is the reason on why I think the ZS carbs need damper oil for the air valves. Each carb needs to feed two cylinders through a siamesed intake with each cylinder at a different part of the combustion cycle. Without dampening oil, the air piston would be cycling all over the place for each pulse of the piston with the most vacuum and may not be able to respond for the other cylinder for it's turn for fuel mixture. The dampening oil evens out the pulses and reduces the extreme cycling.
Motorcycle carbs generally have CV type carbs for each cylinder and as far as I know, do not have oil. But since each carb is responsible for one cylinder, the air valve operates for that one cylinder only.
As I said, this only a wild ass guess on my part.
Joji Tokumoto
-
The damper oil is for dampening the air valve in only the opening direction. When you unscrew the damper rod you will see that it has some seemingly loose shims and tube parts hanging down into the tube with oil. This is in fact a very clever oneway oil valve, restricting the air valve from moving up, but allowing it to drop rapidly. 8)
This is the dampening that you, Joji, felt with your finger. And also the dampening that John has mentioned as necessary for the fuel enrichment when accelerating. 8)
-
Race cars are usually jetted quite rich and may not require the extra enrichment provided by the oil in the dampers. It's also very common to disable accell pumps on motorcycles tuned for racing. Cars/bikes tuned for the road, however, try to eke out as much economy as possible which will leave them rather flat footed when the throttle is suddenly opened.
The oil in the damper provides enrichment by slowing the rise of the piston. This causes a temporary increase in airflow across the jet which provides the necessary enrichment.
-
Joji, That seems like a reasonable enough theory.
Thanks for the explanation about rich jetting in race cars, John. I don't have any way to verify it but it sounds plausible.
All this talk is reminding me of how I can think I understand the principles behind a design but only get the obvious part and miss critical aspects. I don't remember what the internals of the Stromberg look like, but it may have a similar design to the SU. It has a jet that sits in a sort of an upside down 'V' shaped rise that goes across the entire throat and was probably 1/3 the diameter of the throat (see crude text picture):
__
| |
/ \
/ \
/ \
At the top of the 'V', there was a squared off section where the jet opening was. It was common to give a slight radius to the piston to increase flow and some tuners would hog out the 'V' shaped part and just put a ramp the width of the jet in front of and up to the jet. Of course, that let in a lot more air and the ramp was supposed to allow increased air flow to pull the fuel out of the jet. Well, I got the bright idea to radius that 'V' taking off the square part on top figuring that would give more flow and that flow wold suck up the required fuel. Well, it didn't work, I burned a few pistons and to trying to get around that, I had to make it so rich, it wouldn't run (thinking about it, it might have worked with the correct needles but I didn't have ready access to a dyno or a practice track). I think the reason it didn't work is that the square part induced turbulence that sucked out more fuel and properly mixed it up. I don't know how the carbs with the ramps worked.
(thanks for indulging my short walk down memory lane!)
-
BDA, I was just thinking out loud with my explanation, probably way off base with that one. Also, trying to improve or modify fuel/air mixture without years of experience and access to a flow bench or dyno is probably pretty difficult with just seat of the pants impressions.
I just got back from a 20 mile run this morning on the TCS and I'm pretty happy with how the car performed. Was able to go through the gears even into fifth. Everything seems to work fine except for the feeling in the steering during turn in, very little input from the tires. The PO installed a set of semi economy Nexen tires. I would say that the TCS is now "on the road".
This morning I discovered another landmine left by the PO. I had been meaning to check the gearbox oil before the first road test but got overlooked. I remembered to check it this morning and discovered that the box was dry. Been trying to figure out why he would drain the oil if no work was been done on the gearbox. It's been refilled and wondering what damage, if any, was done running without oil. One saving grace is that I only put on 12 miles running 30-35 mph during that time. I don't expect any catastrophic failure of the gearbox, but I'm sure that there is some wear. I'll change out the oil when I re-torque the head in a few hundred miles.
At least I found out why the shifting was so vague and sloppy before. It feels a lot more crisp now. Also attached a couple of pictures heading down the mountain into town.
Joji Tokumoto
Fallbrook, Ca
-
Nice pictures! I wish we had that sort of roads where I live. :D
I've been meaning to ask you how your Nexen tires performed, since I saw the photos in your 'Picked up TCS' thread. I am always interested in finding new brands in the 13" size, for use with the Lotus wheels and for road use. It's not so good, that they seem to perform not so well. :-\
In your photos it looks like the front wheels are swapped, so that the thread direction is the wrong way. Or is it just me, that need to polish my computer monitor? ::)
-
Even in single-carb installations, SU and Z-S carbs had dampers. According to SU themselves, dampers were introduced as a means of ensuring a quick pickup with rapid throttle openings.
Anyone who has experienced the flat spot you get with pre-WW2 SUs when you open up too quickly will understand!
-
Things keep getting better and better for you and this car! Glad to hear the comfort level is getting pretty high! I hope it continues!
...trying to improve or modify fuel/air mixture without years of experience and access to a flow bench or dyno is probably pretty difficult with just seat of the pants impressions.
You're not kidding! A rather expensive lesson of youthful arrogance and idiocy!
-
Nice pictures! I wish we had that sort of roads where I live. :D
I've been meaning to ask you how your Nexen tires performed, since I saw the photos in your 'Picked up TCS' thread. I am always interested in finding new brands in the 13" size, for use with the Lotus wheels and for road use. It's not so good, that they seem to perform not so well. :-\
In your photos it looks like the front wheels are swapped, so that the thread direction is the wrong way. Or is it just me, that need to polish my computer monitor? ::)
Peter, sharp eyes you have to pick up the arrows pointing in the wrong direction they are indeed mounted wrong. In regards to the Nexen tires, I don't have enough miles on the car to get a real feel for them. But for the short drive that I had this morning, they felt OK. I need to put more miles and push them a bit harder to see how they really stand up to my mountain test road. I should have an evaluation in a few weeks. Also, all four tires are 185/60R/13s. That may make a difference in the handling.
-
Change the oil again in 100 miles. Carefully road test:
- Is it quiet on and off throttle at high speed?
- Noisy in any gears? (especially 5th)
- Drained oil clear and clean?
Yes to all of the above? You're OK.
- Shifts clean