questions for upgrades in 1275cc Minor

[Mogs]

Hello,
I have rebuilt my '58 Minor with a reconditioned 1275cc (now 1298) engine, servo assisted Marina disc brakes, anti-tramp bars, telescopics all round, baulk ring synch g/box, and recon high ratio diff (plus a lot more). I have 3 resulting issues and seek advice:
1. Is there an exhaust manifold out there for twin 1.5 SUs (I have a Maniflow 3 branch with single HS4 and twins would foul the outlet pipes)?
2. Does anyone know of a Speedo recalibration firm in the Thames Valley (mine under-reads by around 10% because of the changed diff of course)?
3. Can I replace my 1950s single wipers with a twin speed unit using the original rack?
Thanks in advance for any help!

[philthehill]

As you have a Maniflow exhaust manifold why not go for the Maniflow twin 1.5" SU carb manifold.

https://www.maniflow.co.uk/index.php?vi ... oduct=1101

Have you fitted a better cam to maximise the fitment of twin 1.5" SUs?

There are always 1.5" twin SU manifolds on 'e' bay for sale.

https://www.ebay.co.uk/itm/Classic-Mini ... Sw5ydcj2ry

There will be adequate clearance between the LCB exhaust manifold and inlet manifold. Been there done that.
Below my Minor when fitted with twin HD4 1.5" carbs carbs with Janspeed/Maniflow LCB and Oselli inlet manifold.

[Mogs]

Sorry, I should clarify, I have the inlet manifold for twin SUs, it's a suitable exhaust manifold to clear the bottom of the carbs (the Maniflow LCB would go right through the position of the twin carbs).
"yes" I have a 731 profile cam in situ and matched electronic distributor to work with the Twin SUs.

[Mogs]

My maniflow LCB branches come out almost horizontally for the first 9 inches or so, so I can't use it with normal twin inlets.

[philthehill]

I am not familiar with your particular exhaust manifold so a photo of the exhaust manifold would be appreciated.

The Maniflow LCB exhaust manifolds listed for the Morris Minor do not fit your description.

There are spacers between the carb and the manifold when using twin SUs on a twin SU manifold. If they are left out the carbs will foul the exhaust manifold pipes.
They are similar to those in the link below.
They not only keep the heat away from the carb but they also lift and push the carb away from the manifold.

https://www.ebay.co.uk/itm/CLASSIC-MINI ... XQWzNSgo53

You can use several spacers to give more clearance providing you use a gasket between them.

The slight increase in inlet tract length will benefit the 731.

[Mogs]

I tried various spacers between the carbs and the (Oselli type) inlet manifold, but the bottom of SUs couldn't clear the exhaust.

IMG_20190407_162904798_HDR[1].jpg (2.71 MiB) Viewed 1536 times

IMG_20190407_162843028[1].jpg (2.66 MiB) Viewed 1536 times

[philthehill]

Thank you for the photos.
You have a standard Maniflow LCB manifold as advertised by Maniflow as suitable for the Minor 1000/1275cc and which is the same as shown in my photo above.
I currently have the same style manifold but the race version with larger pipes.
You should have no problem fitting a twin SU manifold with twin SUs with that LCB manifold.

100_1239.JPG (1.35 MiB) Viewed 1536 times

A photo of the Oselli style inlet manifold would be of benefit.

If the inlet manifold was second hand the flange that fits to the head could have been faced off to give a shallower carb angle which is not unknown.

[Mogs]

Thanks for your reply (yes you can see the "maniflow" tag on the front pipe)....but sadly, as I said, I've tried and the bottoms of the HS4s foul this exhaust (A manifold with HS2s also did before I put them on my Riley Elf instead). I tried pairing up thick spacers with gaskets between all, but inevitably ran out of stud lengths. I'll see if Hifs have better clearance than the base jet adgustment parts under the HS carbs. Yours clearly are not HS4s?
I have a Dellorto Twin choke 45 but no manifold or I'd consider that (but it's jetted for my tuned MGB GT).

[Mogs]

Any thoughts on the Wiper question anyone? : cry:

[Mogs]

Thanks for your patience, Phil. The inlet manifold was "as original" and had the same angles as the Cooper HS2 manifold I'd tried. I've since given the Oselli one to a friend after fitting the single water heated HS4 option to the Moggy.

[philthehill]

The carbs on my Minor are as you can see Webber & are 45 DCOE 13. All four chokes are used with a Manx Racing 7 port head.

The same style manifold as you have fitted has been used with 1.5" SUs for many years.

I would suggest that there is something so basic that we are not seeing it.

[Mogs]

Yep. It'll come to me eventually I guess. By the way, the dent you see in my exhaust manifold is where I clouted it in exasperation when I couldn't clear it (so that shows the location of the problem)! Cheers

[Mogs]

Yep. It'll come to me eventually I guess. By the way, the dent you see in my exhaust manifold is where I clouted it in exasperation when I couldn't clear it (so that shows the location of the problem)! Cheers

[Sleeper]

Mogs
Question3 , Yes , but you need to alter the sweep , I take it you have clap hands wipers...and fabricate ( or buy ) a mounting plate... and a little re-wire.


John

P.S What number is on the face of your speedometer.

[philthehill]

The carb/manifold angle of the Mini twin SU manifold is different to that of the twin SU carb manifold fitted to the MG Midget/Sprite.

My Oselli twin SU carb manifold as shown above was for a Midget/Sprite and had plenty of clearance for the HD4s which have more underside bulk than the HS4s and did not require spacers of any kind.

Again there is something being done or possibly not being done that is causing the problem.

Was the standard HS4 butterfly return spring bracket as seen in your photo above fouling the manifold as the return spring set up for twin SU carbs is totally different.

If you project the carb forward there is plenty of clearance between carb and LCB.

I have a Oselli inlet manifold for a 45DCOE if you are interested

100_1701.JPG (1.67 MiB) Viewed 1514 times

Phil

[Mogs]

Thanks for replies:
John: Speedo S/N is 4406/00 1625

Phil: The underside of the carbs themselves (float chambers on HS2s catch, and between float chambers and jet housings do on HS4s). I think my Dellorto would pair to that inlet manifold but I'd like to use SUs if I can overcome the issue. I'm more used to tuning them.

Cheers Gents
Richard

[Sleeper]

Richard
What you need is a 1462 speedometer,the nearest that I know of for a MM is either 1408 ( 4% over reading ) or a 1504 ( 3% under reading ) , the other option is to find a speedometer ( nearest available is 1472 , less than 1% out ) and change out the mechanism ,failing that Speedy cables can re-calibrate to your needs..

John

[Monty-4]

I had similar issues fitting twins (although just HS2s) with clearance to the exhaust manifold. My solution was to swap the studs for longer ones to give room for an extra spacer.

[Mogs]

Thanks John.

Yes, Monty, I ran out of stud length with a mix of spacers (alloy and/or bakolite plastic) but I'll look at longer studs. I'm glad it's not just me, but a friend tells me this isn't an isolated problem, although Phil was able to avoid it....
Richard

[philthehill]

Just make sure that you have the right twin SU manifold.
If you go on the various Mini web sites there is quite a lot of information re twin SU inlet manifold inlet angles (not just Mini) and also float chamber angles and the need to ensure that the float chamber is at the right angle. You can get an adjusted float chamber mounts to bring the float chamber to the right angle if required.