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Hi! I made this little movie this summer. I used a cheap 'made in china' key chain spy cam and a smal key chain LED light plus some cable ties and a piece of alloy. To film my SU carb in action.   What's happening in the vid, since you can't see the road: start in a 20MPH zone, move to 30MPH zone and then hit a 60+MPH zone in 2nd & 3rd. A Mercedes blocks the road, chnage to 4th. Then a 2nd acceleration sequence from ~8mph in 1st to 80mph in 4th going back the same route. Then again the 30 & 20MPH zones with various throttle/gear positions during the run. Second video shows mainly low RPM/low speed & full throttle acceleration (from 4th gear doing ~25MPH). you may notice that I run my SU carb without a damper; in fact I made these videos to proof a fact: that it is very possible to run SU carbs without a damper. De facto the dampers were not used in the MG T modell range untill the early MG TCs, which first got dampers after the 2nd World War. I don't know for sure but I guess they were not the only ones of theyr time with damperless SU carburettors. Anyway, this thread is not about the dampers (I don't want to start an argument - it seems to happen everytime I mention it...). I just thought maybe the one or other fellow RRer might be interested in seeing an SU carburetter in action  It's filmed in my Mini btw. (see sig). Hope you enjoy! Oh, and whilst I'm at it; this might be of interest for the Mini people using MG manifolds. I've seen quite a few MG manifolds now which were like this: img146.imageshack.us/img146/5628/hifvergl.jpgIf you look at the left picture you can clearly see that the manifold's opening is too smal - and not just by a little bit...  This is about the worst that can happen for the airflow (=power)! But can be solved in a few minutes with a grinder... Cheers, Jan |
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Nice one very cool to see them in action
When I heard of these cameras it did cross my mind
Heres a simular idea
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mikey5
Part of things
Posts: 124
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while ur on the subject of dampers ive got a twin su set up on my pinto ive heard of people removing the dampers but what advantage do u get from not running the dampers?
cheers mikey
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Much better acceleration & throttle response. However it's not a "remove damper & go" job, it requires some modifications. Since his english is better than mine: Des Hammill goes into detail about runing SUs without dampers in his "The SU carburetter high performance manual" (ISBN 978-1845840730). also a good read if you want to know more about SUs and how to profile needles etc. A disadvantage is worse cold starting & runing. It takes a little longer for the carb to 'settle'. But once it's warmed up - nice! Cheers, Jan |
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SU carb action shots...BenzBoy
@benzboy
Club Retro Rides Member 7
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I like those vids a lot!  I've not heard of running no dampers on the carb - I've read endless discussions about what grade oil to use in the dampers to give different throttle responses etc. Do you not find you get spikes of rich / lean mixtures when the throttle rises and falls very quickly? I know you said this post isn't about the damperless carb but I'm genuinely interested. |
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purplevanman
Posted a lot
Way too orangey for crows
Posts: 3,829
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it surprises me that the sliders are so slack, Strombergs are the same. Watching the slider shake about makes me wonder if it would be more efficient if it fitted better but then again they have been around for a while now so perhaps not |
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nice vids
tell me more about the hardware
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Someone just shot the elephant in the room. |
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I've not heard of running no dampers on the carb - I've read endless discussions about what grade oil to use in the dampers to give different throttle responses etc. Do you not find you get spikes of rich / lean mixtures when the throttle rises and falls very quickly? I know you said this post isn't about the damperless carb but I'm genuinely interested. as a rule of thump; the thinner the oil, the better the throttle response - up to a point were it doesn't work anymore. Unless you tweak it a bit (carb and ignition). You may notice in the videos that the damper floats a bit. I don't know yet if this is solely down to being damperless or not, and if it gives lean/rich spikes. I will do a direct comparison this summer. If I can find a reasonably priced rolling road I'll compared it on the rollers too - as I am too interested in finding out. If not, a lambda sensor should work too. However, I don't think it's much of an issue. Cheers, Jan PS: I almost expected this would be the part that interesst people the most - I just don't want to argue over it. |
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nice vids tell me more about the hardware As precise as possible: - 1275cc A-Series (A+) - slightly portet MG Metro manifold - K&N filter in MG Metro air filter box - MG Metro camshaft (252/268° duration) - ~10:1 CR - std. pistons - Innocenti Cooper 1300 head (36/29mm valves) cleaned ports - Innocenti Cooper rockers (a wee more lift over std. rockers) - Maniflow LCB medium bore manifold - RC40 twin box exhaust - HIF6 carburettor, ported intake elbow (connection to box) - 3,21:1 final gear / 10" wheels Basically it's a slightly modified, home build MG Metro engine. Nothing special realy... Top speed is about 105MPH, so I guess (hope ;D) it's got about the same power as a Cooper S 1275 (70 odd HP) which had a similar top speed. It's interesting, as this mod doesn't seem to work with any engine, but with those with good breathin capabilities. And I noticed that without the air filter (videoing) throttle response was even better than with the K&N & box. |
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err thanks
but i meant the video hardware
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Someone just shot the elephant in the room. |
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Whoopsy, sorry ;D Google for "808 key chain spy cam". It's one like this: cgi.ebay.co.uk/808-3-Spy-Car-Key-Camera-Video-PC-Cam-keychain-30fps-/160525113046?pt=UK_CCTV&hash=item25600ad6d6#ht_3539wt_990Mine cost me 18€ incl. 4GB memory card and delivery from Hong-Kong. Delivery took 7 days. Video quality is ok for the size & price. It's a bit better than those youtube vids since I cut & compressed them further. A downer is the handling... As you never know exactely where you'r pointing at. I solved this by putting it into place, take a photo, connect it to the laptop and check where it is pointing at. It takes a bit to adjust it this way but you get good results. Also the angle is not great and zoomed in a bit (fixed). Here's a review: |
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The Doctor
Club Retro Rides Member
Posts: 3,434
Club RR Member Number: 48
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SU carb action shots...The Doctor
@thedoctor
Club Retro Rides Member 48
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cool to see! This is exactly the reason I bought some of those camera's too! So far I only used them for picture-in-picture movies of myself on a track, because i've got nothing interesting going on under the bonnet! I think with my TwinTurbo engine, i'm going to try to melt one by filming the turbo's |
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That's a very interesting video! I'm always intrigued by SUs, and despite the fact that I generally know how they work I still view them as a bit of 'black magic'.
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Gilesy
Part of things
Posts: 229
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Cracking little videos there mate, and it's good to see a Vizardised piston too ;-)
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1991 Mini Neon - Gone
1991 Polo Coupe - Gone
1987 Scirocco Scala - Gone
1991 Scirocco GTII - Gone
1980 Mini 1000 - Gone
1998 Fiesta - in flux
1999 Saab 9-5 2.3t SE - the tidy, blown Swedish modern
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while ur on the subject of dampers ive got a twin su set up on my pinto ive heard of people removing the dampers but what advantage do u get from not running the dampers? cheers mikey I'm intrigued, twin SU's on a pinto? PICS!!!! |
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1953 Minor (Long term project)
PT Cruiser
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ChrisT
Club Retro Rides Member
Posts: 1,637
Club RR Member Number: 225
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SU carb action shots...ChrisT
@christ
Club Retro Rides Member 225
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cool video, makes me want to get one and do something similar..... That's a very interesting video! I'm always intrigued by SUs, and despite the fact that I generally know how they work I still view them as a bit of 'black magic'. my thoughts exactly, always good to see something in action working how you think it should |
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CIH
Posted a lot
Posts: 1,466
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I really enjoy these videos that show things at work that aren't normally visable. This is what a knackerd trailing arm bush on a BMW does:
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Last Edit: Jan 2, 2011 14:24:01 GMT by CIH
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Seth
South East
MorrisOxford TriumphMirald HillmanMinx BorgwardIsabellaCombi
Posts: 15,513
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Interesting to see one being driven. Des Hammill goes into detail about runing SUs without dampers in his "The SU carburetter high performance manual" (ISBN 978-1845840730). also a good read if you want to know more about SUs and how to profile needles etc. I second that recommendation. A really useful book for learning about SUs and how to set them up, particularly in a custom application. Following his instructions meant mine on the MX5 engine were already spot on up to about mid throttle so saved plenty of time on the rolling road.  |
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Follow your dreams or you might as well be a vegetable. |
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This is about the worst that can happen for the airflow (=power)! But can be solved in a few minutes with a grinder... 
