Holbay question

Paul Goldsmith

Paul Goldsmith

0
Originally the Holbay engines had a twin weber carb setup and manifold, these I understand are quite thirsty and also expensive to buy. So I'm thinking whether the twin Stromberg manifold will still fit the Holbay head and also whether being quite similar I could fit twin SU carbs (HS6 ) instead.

Any thoughts - what are you fellow Holbayers running with ?

Cheers


P1000021-2.jpg

Commer 'Hi Tor' by TorCars
 
the inlet manifolds for holbays are different from the Rapier/Alpine ones and don,t fit, so whatever carb/s you use it will have to have a holbay manifold. Personally i wouldn,t use webbers either, the best option would be Keihin flatslide bike carbs, but these are nearly as expensive as webbers [xx(]. strombergs and Zeniths aren,t very good, so the only real option left is the S.U. Twin carbs is no real advantage unless the manifold allows each cylinder to draw on both carbs, and creates linkage and set-up hassles.
For cost/ease/simplicity and best all round set-up i would use one 1 3/4" (44mm) S.U. I can modify a holbay manifold to suit if you want :)

"you were only supposed to blow the bloody SLIDING doors off"
 
The webers (or the N/S seat;)) wont fit.
I am getting good power the with the Holbay 150cd Strombergs, although I did fit a cold air box and blower to compliment.

http://66.129.69.181/forum/topic.asp?TOPIC_ID=1382&whichpage=2


Cheers
Jules

RatSport www.ratsport.co.uk
 
Thanks for that link Jules, great to have that information to hand again [8D]

If I understand correctly, the twin Stromberg 150CD manifolds differ between Rapier/Alpine alloy and Holbay head versions ?

With the Weber manifold therefore was merely an option on some Holbay engine rather than standard ?

Another question, as Strombergs I believe are 'copies' based on the SU design, will twin SU carbs fit maybe with some tweaking to a twin Stromberg manifold ?

Our Triumph Stag is running twin Strombergs 175CDs which took a specialist to setup nicely but have been on song ever since :p. So I'm not adverse to a twin carb setup but can see the appeal of the simplicity of a single SU setup on the Commer.

Tim - what Holbay manifold would you need as a source for a Holbay single SU setup - I've seen previous posts where I think you've done this on a non-Holbay single carb manifold.

BTW : My 1st car was a Triumph Acclaim which bizarrely had twin Keihin bike carbs on 1335cc [:0]


P1000021-2.jpg

Commer 'Hi Tor' by TorCars
 
I think holbays were only fitted with webers [?]
the main difference is the smaller ports on the holbay head
twin S.U,s can be fitted to the stromberg manifold, but only the earlier remote float ones, unless the flange is changed to suit the later HIF type .
if you have a manifold that fits the head properly then we can use that to modify for 1 or 2 S.U,s [^]

"you were only supposed to blow the bloody SLIDING doors off"
 
I think the later hillman hunter gls holbay engine might have had twin strombie 175s. I've seen a couple of these manifolds come up on ebay over the years, but not very often.

The holbay head has smaller inlet ports, the centres are the same as the other 1725 engines and it is possible to mount one on the other - but you end up with a nasty step that does nothing to help airflow.

i agree will tim, 4 carbs are better than 1... failing that the 1 3/4 HIF is a good bet. with a van torque is going to be more important than top end power.

The problem with strombie is that there are hardly any rolling roads around that will have a stock of the needles. Everyone knows SUs.
 
I think it was the Hunter GT models that had the twin SU set-up. Not sure if any had twin Strommies though. The Holbays were all twin 40 Webers as far as I know. I have these to go on Madge (my Singer Vogue) eventually:

Webers.jpg


BAZROCKS.jpg
If I told you I was a pathological liar, would you believe me?
I'M GETTING A HIGHWAYMAN !!!
 
Cheers everybody, think I've finally got my head around the options [8D]

Just in case our Holbay lump is just a lump, I picked up this possible alternative for just £31 at the weekend (& just down the road from me too) ...

DSC00288.jpg


Turns over by hand, so might be a go-er - if not might yield some useful parts ;)

ps. tasty looking Webers Baz !
P1000021-2.jpg

Commer 'Hi Tor' by TorCars
 
Looks like a Rapier lump:p
Remember to change all the core plugs before it goes in - that is for any engine :I


th_morris.gif

Trahh la laaa - Harvey's around here somewhere
 
[^] Nice work Paul. those manifolds will do the job ok ;)

"you were only supposed to blow the bloody SLIDING doors off"
 
quote:
For cost/ease/simplicity and best all round set-up i would use one 1 3/4" (44mm) S.U. I can modify a holbay manifold to suit if you want


Tim,

If I stick with our Holbay engine and can source a Holbay inlet manifold, am I correct that you could modify this to take a single 44mm SU ? Would it be possible to modify for twin SU's too ? Could drop me a PM with likely estimates for this work.

Cheers

ps. Am I correct in assuming I'll need SU HIF44 carbs - are there any versions to avoid that you're aware of ?


P1000021-2.jpg

Commer 'Hi Tor' by TorCars
 
quote:
Originally posted by commerjules

The webers (or the N/S seat;)) wont fit.
I am getting good power the with the Holbay 150cd Strombergs, although I did fit a cold air box and blower to compliment.

http://66.129.69.181/forum/topic.asp?TOPIC_ID=1382&whichpage=2


Cheers
Jules

RatSport www.ratsport.co.uk



Oh yes they will with some very slight mods to the battery tray behind passenger seat;)If the webbers are set up correctly and maintained correctly they will give you many a happier smile as you listen to the induction noise sucking up small children from the pavement as you go by! lol :D:D;)
 
quote:
Originally posted by Paul Goldsmith

quote:
For cost/ease/simplicity and best all round set-up i would use one 1 3/4" (44mm) S.U. I can modify a holbay manifold to suit if you want


Tim,

If I stick with our Holbay engine and can source a Holbay inlet manifold, am I correct that you could modify this to take a single 44mm SU ? Would it be possible to modify for twin SU's too ? Could drop me a PM with likely estimates for this work.




ps. Am I correct in assuming I'll need SU HIF44 carbs - are there any versions to avoid that you're aware of ?


P1000021-2.jpg

Commer 'Hi Tor' by TorCars







Yes, i can sort it for 1 or 2 s.u,s, although i would recommend a single carb ;)
Cost wise will be under £100.
HIF44 is the best one. just be careful that a single carb has a vacuum take off for the dizzy, as if its one of a pair (rover v8) it needs to be the right one, late Mini one is a safe bet :)


"you were only supposed to blow the bloody SLIDING doors off"
4129400434_9eb90651a0_o.jpg
 
quote:
Originally posted by Jon

quote:
Originally posted by commerjules

The webers (or the N/S seat;)) wont fit.
I am getting good power the with the Holbay 150cd Strombergs, although I did fit a cold air box and blower to compliment.

http://66.129.69.181/forum/topic.asp?TOPIC_ID=1382&whichpage=2


Cheers
Jules

RatSport www.ratsport.co.uk



Oh yes they will with some very slight mods to the battery tray behind passenger seat;)If the webbers are set up correctly and maintained correctly they will give you many a happier smile as you listen to the induction noise sucking up small children from the pavement as you go by! lol :D:D;)



Thats great Jon. Could you post a pic please? Then I can copy[8D]

Cheers
Jules

RatSport www.ratsport.co.uk
 
quote:
Originally posted by commerjules

quote:
Originally posted by Jon

quote:
Originally posted by commerjules

The webers (or the N/S seat;)) wont fit.
I am getting good power the with the Holbay 150cd Strombergs, although I did fit a cold air box and blower to compliment.

http://66.129.69.181/forum/topic.asp?TOPIC_ID=1382&whichpage=2


Cheers
Jules



RatSport www.ratsport.co.uk



Oh yes they will with some very slight mods to the battery tray behind passenger seat;)If the webbers are set up correctly and maintained correctly they will give you many a happier smile as you listen to the induction noise sucking up small children from the pavement as you go by! lol :D:D;)



Thats great Jon. Could you post a pic please? Then I can copy[8D]

Cheers
Jules

RatSport www.ratsport.co.uk



All will be revealed ;)
 
Here we go commer jules the said webbers in place;)
http://66.129.69.181/forum/topic.asp?TOPIC_ID=2568&whichpage=5
 
quote:
Originally posted by Jon

Here we go commer jules the said webbers in place;)
http://66.129.69.181/forum/topic.asp?TOPIC_ID=2568&whichpage=5


Dribble :p:p:p

P1000021-2.jpg

Commer 'Hi Tor' by TorCars
 
quote:

Yes, i can sort it for 1 or 2 s.u,s, although i would recommend a single carb ;)
Cost wise will be under £100.
HIF44 is the best one. just be careful that a single carb has a vacuum take off for the dizzy, as if its one of a pair (rover v8) it needs to be the right one, late Mini one is a safe bet :)

"you were only supposed to blow the bloody SLIDING doors off"
4129400434_9eb90651a0_o.jpg




Many thanks for that Tim, I will most likely go the SU route for simplicity and fuel economy & be in touch soon but tempted by the full Weber setup just posted !

P1000021-2.jpg

Commer 'Hi Tor' by TorCars
 
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