| ausmini https://ausmini.com/forums/ |
|
| 45 Weber jetting https://ausmini.com/forums/viewtopic.php?f=2&t=99971 |
Page 1 of 1 |
| Author: | MINI66 [ Thu May 07, 2020 7:22 pm ] |
| Post subject: | 45 Weber jetting |
Hi all Thought I would post my jetting so far for comparison with others/feedback. 1293cc (1100s engine ) 12g940 stock head apart from minor porting, unknown cam (sounds stock/mild). Dish top pistons. 160psi comp all 4. 12 deg idle adv. 34 @ 2900. Maniflow headers, twin box 1 7/8 exh.. 45 dcoe 13 , Warnerford manifold, ramflo Chokes 38mm Aux 5.0 Idle 50F8 Tubes F16 Mains 155 Air 190 60 pump with 100 exh Idle mixture 0.8 turns out (late fine taper screws) AFR Idle 13.5 Slow cruise 11.0 (60kms) Fast cruise 13.5 (110kms) WOT 12.5 to 13 Pretty good. Fairly smooth transition. Plan to work on slow cruise with a 45f8. Also leans out a bit between WOT gear shifts to 16 momentarily so going to try 180 Air correctors. Also seems to run out of puff at 5500 but is still 13afr? Really good down low pulls well. Any feedback appreciated. Cheers Rick Sent from my SM-G950F using Tapatalk |
|
| Author: | timmy201 [ Thu May 07, 2020 8:00 pm ] |
| Post subject: | Re: 45 Weber jetting |
Do you have any F2 emulsion tubes? |
|
| Author: | MINI66 [ Thu May 07, 2020 8:05 pm ] |
| Post subject: | Re: 45 Weber jetting |
No. I ordered some but they were lost in the post so didn't bother again. I believe they are slightly richer than the f16 but only very minor from my research. Not too sure though Sent from my SM-G950F using Tapatalk |
|
| Author: | timmy201 [ Thu May 07, 2020 8:25 pm ] |
| Post subject: | Re: 45 Weber jetting |
I found that getting the emulsion tube was nearly the most important part. I struggled to get mine to be lean enough until I changed the emulsion tube to a richer one and then backed down the jets. I was lucky in my case that my friend and I both had Dellortos and had a decent range of jets to try I found this when looking at F2 v F16 from here: https://www.pegasusautoracing.com/produ ... duct=61450 Quote: The F2 will lean out the low end and initial throttle response (F11 and F16 also lean out the low end, to a lesser extent). Attachment: s-l1600-64.jpg
|
|
| Author: | MINI66 [ Thu May 07, 2020 8:56 pm ] |
| Post subject: | Re: 45 Weber jetting |
Thanks mate. Might be worth another look the F2s. To lean out the slow cruise. I have read that the faj Chinese tubes are rubbish and should stick with genuine. Not cheap. What size chokes are you running? From the research books that I have read they list f2 as overall richer than f16. |
|
| Author: | drmini in aust [ Fri May 08, 2020 5:32 am ] |
| Post subject: | Re: 45 Weber jetting |
If your cam is near stock, I reckon 38mm chokes are too big. 34s are more usual for road use, 36s maybe. Dellorto seem to tolerate slightly bigger chokes than Webers do. Many Nb racers run 36s in a Weber 45. Including GR. |
|
| Author: | MINI66 [ Fri May 08, 2020 8:59 am ] |
| Post subject: | Re: 45 Weber jetting |
Thanks drmini I have a set of 34s (chinese faj brand) and was running them in the initial tune but when I swapped over to the 38s (genuine) it seemed to go better across the range with no loss in low end tractability (no hesitation). I am thinking that the rich idle jet must be masking this a bit, however at 50F8 it is not exactly rich in the scheme of things comparing to Vizard recommendations of 50F2. I am not even out 1 full turn on the mixture screws. If anything it is a bit sluggish at top end, even though the AFR looks good which is confusing??. Possibly an E tube up to as suggested F2 may help. I have read that F2 tubes are really only good for large chokes of 38+ even in siamese. Maybe I am just used the forced induction top end pull. cheers Rick |
|
| Author: | drmini in aust [ Fri May 08, 2020 9:26 am ] |
| Post subject: | Re: 45 Weber jetting |
With a stock Cooper S or mild sports cam it'll lose interest over 6000. An re13 or similar 274 duration cam is good power up to 7000. Peak power around 6500. My 282 gave peak hp at 7000+, but it's still quite tractable at 50 kmh in 4th gear at light throttle. Takes full throttle from 2500. |
|
| Author: | MINI66 [ Fri May 08, 2020 9:43 am ] |
| Post subject: | Re: 45 Weber jetting |
Ok thanks. I might be asking a bit much then from an (assumed) stock cam. I can feel the drop off at about 5500rpm. Goes surprisingly well below that though (for an na 1275) Here are Vizards recommendations that kind of steered me toward trying the 38 chokes. With the electronic ignition, maniflow headers and exhaust and the minor port clean up, i kind of placed it between stock and modified. The weber also came with 38s and F16 E tubes when I got it so $ was also factor. Stock 1275 Choke 35, Mainjet 150, Air Cor 180, Em. Tube F2, Pump Jet 40, Idle 50F2, Aux Vent 4.5 Modified 1275 Choke 38, Mainjet 165-170, Air Cor 180, Em. Tube F2, Pump Jet 45, Idle 50F2, Aux Vent 4.5 Full Race 1275 Choke 40, Mainjet 200, Air Cor 175, Em. Tube F2 or F9, Pump Jet 55-60, Idle 50F11, Aux Vent 3.5 cheers for your help |
|
| Author: | MINI66 [ Sun Jul 19, 2020 9:38 am ] |
| Post subject: | Re: 45 Weber jetting |
Hi Guys Just thought that I would post my final 45 dcoe 13 jetting after much fine tuning, this is spot on. No hesitation even if you stomp it. Might help someone. 1275 (1100s engine) - Stock cam/head - 20 thou over - Headers and Maniflow 1 & 7/8 twin box. Choke - 34 Aux - 5.0 Main - 145 Air - 190 Idle - 40F8 Em Tube - F16 Pump Jets - 30 (smallest you can get) Pump Bleed - Blocked Idle screws - 1.5 turns (late design screws) AFR Idle 13.5-14.0 Slow cruise 13.5 (60kms) Fast cruise 14.0 (110kms) WOT 12.0 to 12.5 It is a little hard to start when hot (after sitting for about 15min) but not too bad. Possibly more work to do there. (Could be leaking fuel into intake when stopped or possibly some vapour lock - will see) cheers Rick |
|
| Page 1 of 1 | All times are UTC + 10 hours |
| Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/ |
|