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TWM intake manifold (weber 45)

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TWM intake manifold (weber 45)
#1
JuancarlosMGB Avatar
JuancarlosMGB Juan Carlos Perez Velasquez
Madrid, Madrid, Spain   ESP
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1974 MG MGB "Carol"
Hello Gents, sorry for making question too often; but I want to take advantage of my anual vacations.
I am running with a Weber 45 and I want to install a TWM intake manifold; but the the inlet ports are 40mm instead of 45mm. I suppose I need to port match the manifold with the carburetor; but will it work properlly? or I'd better get another manifold?
I'm attaching a pair of pictures comparing the TWM, at the right, with a short manifold I used some time ago, so you can see the different inlet port sizes.


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Re: TWM intake manifold (weber 45)
#2
Tom Kat Racing Team Avatar
Tom Kat Racing Team Thomas & Keith Brooks
Burton upon Trent, Staffordshire, UK   GBR
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Hi
No need to say sorry for asking questions.
In short yes its very important the carb, intake and port are all matched. You could either port your manifold out but to be honest (this maybe just the pic) your TWM manifold still looks a little short and swan necked to be ideal. If you can get hold of a 45 long oselli manifold that may be better. They have a nice relatively straight "shot at port" design.
Tom

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Re: TWM intake manifold (weber 45)
#3
fast-MG.com Avatar
fast-MG.com Dave Headley
Cortez, 4 corners, Colorado, USA   USA
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Tom, I think that is the long TWM, no longer available IIRC, and it's about the same length as the Oselli. IMO, the long TWM and the Oselli have similar performance capability. Both the TWM and Oselli need port work to be at their best as the runners are as-cast.

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Re: TWM intake manifold (weber 45)
#4
JuancarlosMGB Avatar
JuancarlosMGB Juan Carlos Perez Velasquez
Madrid, Madrid, Spain   ESP
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1974 MG MGB "Carol"
In reply to # 2891666 by Tom Kat Racing Team You could either port your manifold out but to be honest (this maybe just the pic) your TWM manifold still looks a little short and swan necked to be ideal. If you can get hold of a 45 long oselli manifold that may be better. They have a nice relatively straight "shot at port" design.
Tom

Tom,in the picture, the TWM looks shorter than it actually is; maybe because it has some elevation change; but in fact, the carburetor and small air horns barelly would fit in the car with that TWM.
I am wondering if TWM makes (or made) different manifolds for weber 40 and 45.



Edited 1 time(s). Last edit at 2015-01-09 09:04 AM by JuancarlosMGB.

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Re: TWM intake manifold (weber 45)
#5
JuancarlosMGB Avatar
JuancarlosMGB Juan Carlos Perez Velasquez
Madrid, Madrid, Spain   ESP
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1974 MG MGB "Carol"
In reply to # 2891713 by fast-MG.com Tom, I think that is the long TWM, no longer available IIRC, and it's about the same length as the Oselli. IMO, the long TWM and the Oselli have similar performance capability. Both the TWM and Oselli need port work to be at their best as the runners are as-cast.


So, I will be ok if I port match the TWM with the weber and making internal porting to the manifold. Thanks.

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Re: TWM intake manifold (weber 45)
#6
fast-MG.com Avatar
fast-MG.com Dave Headley
Cortez, 4 corners, Colorado, USA   USA
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Yes, And while your at it. machine the head side flange at a 5* angle to tip the carb up a little for more fender clearance.

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Re: TWM intake manifold (weber 45)
#7
JuancarlosMGB Avatar
JuancarlosMGB Juan Carlos Perez Velasquez
Madrid, Madrid, Spain   ESP
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1974 MG MGB "Carol"
In reply to # 2891738 by fast-MG.com Yes, And while your at it. machine the head side flange at a 5* angle to tip the carb up a little for more fender clearance.

Thank you. I will do it. Notice that I follow the advices taken from this Fórum cool smiley

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Re: TWM intake manifold (weber 45)
#8
MGST Avatar
MGST Andrew Metford
Auckland, Auckland, New Zealand   NZL
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1966 MG MGB
1973 MG MGB GT
1974 MG MGB GT Racecar
Exactly how long is that TWM manifold? 100mm?


1973 MG BGT - Harvest Gold / Black interior

1974 MG BGT - Bracken / Autumn Leaf interior - http://forum.britishv8.org/read.php?13,11702

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Re: TWM intake manifold (weber 45)
#9
Tom Kat Racing Team Avatar
Tom Kat Racing Team Thomas & Keith Brooks
Burton upon Trent, Staffordshire, UK   GBR
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Juan
I highly recommend you build an aiŕbox with a cold air feed too.

Tom

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Re: TWM intake manifold (weber 45)
#10
JuancarlosMGB Avatar
JuancarlosMGB Juan Carlos Perez Velasquez
Madrid, Madrid, Spain   ESP
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1974 MG MGB "Carol"
In reply to # 2892060 by MGST Exactly how long is that TWM manifold? 100mm?

The shorter manifold you see at the left in the picture is about 100 mm long; the TWM is 150 mm.

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Re: TWM intake manifold (weber 45)
#11
JuancarlosMGB Avatar
JuancarlosMGB Juan Carlos Perez Velasquez
Madrid, Madrid, Spain   ESP
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1974 MG MGB "Carol"
In reply to # 2892069 by Tom Kat Racing Team Juan
I highly recommend you build an aiŕbox with a cold air feed too.

Tom

Thaks for the advice. I'll figure it out how to build one. We have a very hot weather at the race track, so temperature and air density are issues indeed.

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about 2 months and 5 days later...
Re: TWM intake manifold (weber 45)
#12
JuancarlosMGB Avatar
JuancarlosMGB Juan Carlos Perez Velasquez
Madrid, Madrid, Spain   ESP
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1974 MG MGB "Carol"
My engine bay is not as clean as I would desire; but the new manifold is port matched with the carburetor and the linkage is ready. As you can see, I still have the stock brake pump, so I barely have a Little gap for small air horns. In the future I will install another brake system and I will have the space for an air box.


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Re: TWM intake manifold (weber 45)
#13
dcharnet Avatar
dcharnet Donald Charnetski
NA, NA, USA   USA
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I have the stock brake servo and Feb-Tek long TWM, and was able to install a cold air box per the attached, shown with plenum cap and rad wall removed.



Edited 2 time(s). Last edit at 2015-03-16 09:00 AM by dcharnet.


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Re: TWM intake manifold (weber 45)
#14
fast-MG.com Avatar
fast-MG.com Dave Headley
Cortez, 4 corners, Colorado, USA   USA
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Don, he appears to have the power brake booster which moves the MC ahead.

Juan, the brakes will work better for racing W/O the power brake booster and you'll save some weight.

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Re: TWM intake manifold (weber 45)
#15
Glenn Polly Avatar
Glenn Polly
New York, NY, USA   USA
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1970 Triumph MC Daytona
1971 MG MGB
2009 Suzuki MC TU250
should look like this when your done, mine is the long manifold - did you know Moss Europe has them in short, medium, & long - different manufacturer - Dave made sure mine was angled 5 degrees as well.


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