Jump to content


Photo
- - - - -

Weber 28/36 Dcd With Maniflow Exhaust Manifold


  • Please log in to reply
38 replies to this topic

#1 mini-auto

mini-auto

    Mini Mad

  • Just Joined
  • PipPipPipPip
  • 102 posts
  • Location: N. Yorks

Posted 02 January 2021 - 08:37 PM

Hi, Happy new year.

 

The inlet manifold I have for my weber 28/36 dcd has clearance on its underside to clear the middle pipe on the exhaust manifold.

 

Unfortunately the clearance doesn't quite line up with the middle pipe of my Maniflow exhaust manifold and as a result won't let the mating face of the inlet manifold go flat against the cylinder head.  see pics below.

 

Can I adjust the clearance to suit by locally grinding the underside of the inlet manifold to clear the pipe ?

 

How much clearance does there need to be between the inlet and exhaust manifold ?

 

Will the inlet manifold get too hot ?

 

Could coolant flow through the inlet manifold provide some cooling rather than heating ??

 

Any general thoughts or guidance on the use of this inlet manifold would be much appreciated.

 

Thank you.

 

Q33LTCg.jpg

 

upexUo4.jpg

 

JBxJ8Sk.jpg

 

kg5oaVA.jpg

 

0DZtJ13.jpg


Edited by mini-auto, 02 January 2021 - 08:43 PM.


#2 nicklouse

nicklouse

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 17,898 posts
  • Location: Not Yorkshire
  • Local Club: Anonyme Miniholiker

Posted 02 January 2021 - 08:45 PM

Having run on of those back in the 80s I would get rid of it and fit an HIF44.



#3 Dusky

Dusky

    Crazy About Mini's

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 5,322 posts
  • Location: Belgium

Posted 02 January 2021 - 08:50 PM

Ding the maniflow pipe. Then grind whatever you need. Also plumb the inlet manifold in the cooling system, especially with a Weber. These carbs are quite good. And a lot easier to finetune than filing a needle.

#4 Dusky

Dusky

    Crazy About Mini's

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 5,322 posts
  • Location: Belgium

Posted 02 January 2021 - 08:52 PM

Ding the maniflow pipe. Then grind whatever you need. Also plumb the inlet manifold in the cooling system, especially with a Weber. These carbs are quite good. And a lot easier to finetune than filing a needle.

Amazing how people can’t give advice to help but instead have to keep repeating their own opinion over and over on every Weber user’s thread.

Edited by Dusky, 03 January 2021 - 12:17 AM.


#5 MiniMadRacer

MiniMadRacer

    One Carb Or Two?

  • Members
  • PipPipPipPipPipPipPip
  • 847 posts
  • Location: Essex

Posted 02 January 2021 - 08:53 PM

I am with Nick on this one...



#6 cal844

cal844

    Crazy About Mini's

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 9,482 posts
  • Location: Ballingry, Fife
  • Local Club: TFMOC

Posted 02 January 2021 - 10:16 PM

Fit an HIF carb, much easier to use and set up

#7 3VILC

3VILC

    Stage One Kit Fitted

  • Noobies
  • PipPipPip
  • 61 posts
  • Location: Bay of Plenty

Posted 03 January 2021 - 06:33 AM

I had the same issue moons ago trying to fit an LCB with the factory inlet manifold divorved from the exhaust. After trying to grind it back and making a hole right thru the manifold and welding that back up, it seemed the general idea as already mentioned tho no ideal is to whack a dent into the center pipe



#8 The Principal

The Principal

    One Carb Or Two?

  • Members
  • PipPipPipPipPipPipPip
  • 763 posts
  • Location: Sussex

Posted 03 January 2021 - 08:32 AM

i had the same problem 20 years ago trying to squeeze the manifolds so close together, I had air leaks on the inlet via the gasket as the manifolds just wouldn't sit right.



#9 MiniMadRacer

MiniMadRacer

    One Carb Or Two?

  • Members
  • PipPipPipPipPipPipPip
  • 847 posts
  • Location: Essex

Posted 03 January 2021 - 08:58 AM

if you start bashing and dinging the exhaust LCB you will restrict the flow, which is kinda defeating the purpose of fitting an LCB in the first place



#10 Dusky

Dusky

    Crazy About Mini's

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 5,322 posts
  • Location: Belgium

Posted 03 January 2021 - 12:02 PM

if you start bashing and dinging the exhaust LCB you will restrict the flow, which is kinda defeating the purpose of fitting an LCB in the first place


It wont make a difference at all.
https://www.dailymot...m/video/x3vupq0

#11 Cooperman

Cooperman

    Uncle Cooperman, Voted Mr TMF 2011

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 23,014 posts
  • Location: Cambs.
  • Local Club: MCR, HAMOC, Chelmsford M.C.

Posted 03 January 2021 - 12:38 PM

I have no real experience with using a 28/36DCD on a Mini, but there is no reason why it would not be OK. Of course, a straight inlet flow will always be better so long as the carb/manifold can flow sufficient mixture amd the carb is set up correctly, so a big SU or a pair of twin SU's might be better. I do know that some engines do go well with multi-barrel downdraft carbs, typically Fords (Cortina GT, Escort RS2000, etc). The design of the manifolding and the inlet location are important too.

Personally I would measure how much more clearance is needed then either 'lightly ding' the manifold and/or file a bit of the inlet manifold away. Just make sure the inlet manifold still has enough metal left. Don't go below about 80 thou remaining wall thickness.

Make sure that you have a clear air gap between the ma nifolds after final installation. I would say that 0.10" would be the minimum, but a bit less may be OK.

Let us know how it goes when it is up-and-running.



#12 whistler

whistler

    Camshaft & Stage Two Head

  • TMF+ Member
  • PipPipPipPipPipPipPipPip
  • 1,699 posts
  • Location: Cardiff

Posted 03 January 2021 - 12:42 PM

See if you can find an Oselli Manifold for the 28/36 DCD weber. Mine doesn't touch with an LCB.



#13 Shooter63

Shooter63

    One Carb Or Two?

  • Members
  • PipPipPipPipPipPipPip
  • 747 posts
  • Location: Essex

Posted 03 January 2021 - 02:27 PM

I would grind the bottom of the inlet manifold, as it has a wrong placed relief already, I would presume that there would be enough metal to place the relief in the right place, obviously measuring the thickness while you go just to make sure.

Shooter

#14 mini-auto

mini-auto

    Mini Mad

  • Just Joined
  • PipPipPipPip
  • 102 posts
  • Location: N. Yorks

Posted 03 January 2021 - 07:07 PM

Thank you for the replies and comments.

 

I owned an Anglia and a Mk1 Cortina back in the late 80’s and early 90’s and have fond memories of the 28/36DCD being reliable, giving good performance and easy to setup.

 

(The Cortina cost me £350 from an ad in motoring news.)

 

zYab1ep.jpg

 

xJ0TItR.jpg

 

TYD2t5A.jpg

 

The big yellow Vizard book describes the 28/36 DCD as a highly functional piece.

 

As suggested I’m going to grind some clearance into the underside of the inlet manifold whilst keeping an eye on wall thickness, I’d prefer not to reshape my nice new Maniflow exhaust but might have to give it a little tap or two, I was concerned that it might affect flow, the exhaust bashing video is interesting, will see how it goes.

 

It would be good to find an Oselli inlet manifold to suit the 28/36 but I don't think that's going to happen.

 

 

 



#15 nicklouse

nicklouse

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 17,898 posts
  • Location: Not Yorkshire
  • Local Club: Anonyme Miniholiker

Posted 03 January 2021 - 07:24 PM

The big yellow Vizard book describes the 28/36 DCD as a highly functional piece.

He also says there is nothing between it and an appropriate SU they had to do three power runs on each carb and average the results to get any difference. And don’t forget these were all done without having the bonnet in the way. To be able to run a half decent filter you will need a bulge or a cut out.

Like I said not worth it no real power gains bonnet needs modifying and then paint. For about 1 BHP but with less low to mid range torque.






1 user(s) are reading this topic

0 members, 1 guests, 0 anonymous users