Author Topic: 4688R  (Read 3642 times)

0 Members and 1 Guest are viewing this topic.

Offline Certified Lotus

  • Super Member
  • *******
  • Joined: Aug 2016
  • Location: Princeton, NJ
  • Posts: 1,686
Re: 4688R
« Reply #15 on: Tuesday,July 11, 2017, 03:34:41 AM »
Looks great Alex! My wife's only concern about my Lotus obsession is that it doesn't interfere with her house decorating habit  ^-^.

Offline 4129R

  • Super Member
  • *******
  • Joined: May 2014
  • Location: Norfolk, United Kingdom, not far from Hethel the home of Lotus.
  • Posts: 2,439
Re: 4688R
« Reply #16 on: Tuesday,July 11, 2017, 10:34:44 AM »
Looks lovely and another thumbs up for the colour. Notice you have twin Weber fitted, did you change the head? Also narrow pancake filters so short trumpets on the carbs.

New head from QED. Not cheap. 145bhp cams, gas flow, and new 40DCOEs. I don't want more than 145 in case I start breaking gearboxes as I understand replacement parts come from Unobtainium which is 1 parsec and 72 light years away.

I took the long trumpets off completely as I had visions of a stone being kicked up by the rear wheels and being sucked into the engine. Bang.

One thing that is puzzling me is I have far too much negative camber on the left rear. I will start measuring the bottom arms etc next weekend. Luckily 3089R is 6 feet away and fully assembled, so I can compare to see what is wrong.

Alex in Norfolk.

Offline BDA

  • Super Member
  • *******
  • Joined: Jul 2012
  • Location: North Carolina
  • Posts: 9,421
Re: 4688R
« Reply #17 on: Tuesday,July 11, 2017, 11:13:50 AM »
I use these K&N filters (https://www.knfilters.com/search/product.aspx?prod=56-1350). They allow me to use the normal Weber air horns.




Offline buzzer

  • Hero Member
  • *****
  • Joined: Mar 2013
  • Location: Beaconsfield UK
  • Posts: 672
Re: 4688R
« Reply #18 on: Wednesday,July 12, 2017, 06:10:01 AM »
On the the inlet trumpets, I would look into thicker filters as BDA suggests. If you have fitted short trumpets you may get away with it, it will change the power characteristics tho. In my experience running with no trumpets upsets the high end performance (dependents on overall induction pipe length). I ran a tuned crossflow for a while with pancake filters and no trumpets and it wouldn't run cleanly over 6,000. Put 2" trumpets and set of K&N filters on and the car was transformed.
Dave,

Other cars. Westfield SEiW. BMW E90 Alpina D3. BMW 325 E30 convertible and Range Rover CSK

Offline 4129R

  • Super Member
  • *******
  • Joined: May 2014
  • Location: Norfolk, United Kingdom, not far from Hethel the home of Lotus.
  • Posts: 2,439
Re: 4688R
« Reply #19 on: Wednesday,July 12, 2017, 09:39:13 AM »
I took the 2" trumpets off. Maybe I will re-fit them with gauze filters to stop lumps getting sucked in.

Offline EuropaTC

  • Super Member
  • *******
  • Joined: Jun 2012
  • Location: Lincolnshire, UK
  • Posts: 2,983
    • LotusLand
Re: 4688R
« Reply #20 on: Wednesday,July 12, 2017, 02:09:01 PM »
I think I'd look at options to reinstate them Alex. There's a thread on lotuselan.net commenting on the OEM Lotus airbox and how close it is to #4 trumpet, but no-one has suggested running without and like Dave has posted, I thought they were important for the carb function although even on the proper Lotus set-up it doesn't conform to what's written in most books (about 1" clearance ?)

I'd also be wary of running without or with just stone guards. When I first bought my elan it had no air box cover or filter, just the backplate with the trumpets sticking out. (it was trendy 70s y'know, made the car faster)  Anyway the first time the carbs spit back and I saw fumes rising was enough suggestion for me to go out and fit the proper air box & remote filter. I've always been the nervous type where petrol and sparks are concerned  :)

Brian

Offline 4129R

  • Super Member
  • *******
  • Joined: May 2014
  • Location: Norfolk, United Kingdom, not far from Hethel the home of Lotus.
  • Posts: 2,439
Re: 4688R
« Reply #21 on: Wednesday,July 12, 2017, 02:58:55 PM »
Before I got the timing right with a strobe, flames regularly came out of the carbs !

Offline BDA

  • Super Member
  • *******
  • Joined: Jul 2012
  • Location: North Carolina
  • Posts: 9,421
Re: 4688R
« Reply #22 on: Wednesday,July 12, 2017, 03:18:50 PM »
Lean mixture can also cause spitting.

Offline 4129R

  • Super Member
  • *******
  • Joined: May 2014
  • Location: Norfolk, United Kingdom, not far from Hethel the home of Lotus.
  • Posts: 2,439
Re: 4688R
« Reply #23 on: Saturday,July 15, 2017, 03:36:15 AM »


One thing that is puzzling me is I have far too much negative camber on the left rear. I will start measuring the bottom arms etc next weekend. Luckily 3089R is 6 feet away and fully assembled, so I can compare to see what is wrong.

Alex in Norfolk.
[/quote]

One arm was 7mm too long and the other 18mm too long. I measured others and the length centre bolt to centre bolt is 467mm.

Getting the 1/2" bolts back out is a challenge.

Luckily I had a pair of adjustable rose jointed bottom arms so slight adjustment to get them both 467mm, and put the arms on. 

As the rosejoints are much thinner than the bushes, I have had to make spacers to get the arms in the right place on the gearbox, so I have drilled the threads out of 1/2" nuts, and ground them down to get the right thickness. They look right, and do the job perfectly.

Offline 4129R

  • Super Member
  • *******
  • Joined: May 2014
  • Location: Norfolk, United Kingdom, not far from Hethel the home of Lotus.
  • Posts: 2,439
Re: 4688R
« Reply #24 on: Sunday,July 30, 2017, 09:54:25 AM »
I have just spent the last 3 weekends sorting out all the wiring problems.

Even with a brand new Banks loom, still absolutely nothing worked when I connected up the brand new battery, using a 30 amp fused feed, just in case.

I have traced every circuit, every fuse, and one by one I have found a whole variety of faults. Earths not working, in line bullet connectors not working, forgetting to put the bulbs in the number plate lights, window switches not working, the brushes on the window motors and the commutator needing cleaning, and I have now got everything working except the indicators, and the started solenoid. That will have to wait until I return from a holiday in Borneo travelling via MH???, presumably on a 777, from Heathrow to KL. 

You have to be in the right mood when tracing the wires, especially when adopting the full Lotus position in the footwell under the dash, tracing the back of the dash connections.

Then I have to find out why the gearchange seems to have lost reverse and 5th. I think it has something to do with  that mysterious ballbearing right at the back.

Alex in Norfolk.





 

Offline BDA

  • Super Member
  • *******
  • Joined: Jul 2012
  • Location: North Carolina
  • Posts: 9,421
Re: 4688R
« Reply #25 on: Sunday,July 30, 2017, 02:26:00 PM »
I don't envy your wiring problems. Getting in the Lotus Position is one of the worst part about working on these cars and sometimes can't be avoided. I'm glad you appear to be nearing the end of your wiring woes and that you may have a handle on the shifting problem.


Good luck! Have a great vaction in Borneo!