[E-Type] Five-minute Strangleberg fix?

E-Type
1

Roger Los has an XJ6 as well as an E-type and was asking on the XJ
forum about the Strangleberg setup those cars were inflicted with
instead of twin 2’’ SUs in the rest of the world.

It reminded me I’m not sure if I’ve read, or mentioned myself, the
dead easy partial fix I’ve done on two of my own Federal E-types.
I’ve read lots about removing the throttle plates, removing
everything and plugging the holes etc but don’t recall this ultra-
quick reversible option. Apologies if it has already been covered
but here’s the XJ post repeated:

''One trick I’ve done on a couple of Federal E-types which may work
on the XJ6 Strangleberg set-up takes five minutes and gives you 85%
of the benefit of removal.

The ‘Crespin mod’(?) just needs you to disconnect the secondary
throttle link at the carb end and leave it dangling attached to the
secondary plate quadrant. The secondary throttle plate (on E-types
at least) is spring-loaded to close. If you wriggle the link
around, you can jam it against the engine side of the manifold (for
which you need to open the secondary plate to make room) and the
return spring holds it tight against the manifold.

In doing so. the secondary closes a very slight amount, so it’s not
as good as complete removal, although it does jam the secondary
almost totally open. It therefore eliminates the major obstruction
that causes the mixture to divert at lower revs and messes up gas
flow at medium revs too. It also avoids all possible secondary
throttle mis-timing (which is pretty common), be it from
maladjustment or due to incorrect carb spacer thickness that messes
up the opening geometry.

Offered in case it helps you overcome those terrible power-sapping
intake arrangements Jag were forced to inflict on you. Doing it by
sleeving, or total removal and plugging is better, but you have to
love that five-minute timescale as an interim step. Many will
settle for it as final choice.’’

Pete–
1E75339 66 D, 1E33100 66 FHC, 1R7977 69 OTS, 1R9720 69OTS
Gaithersburg (in transit), United States
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3 Likes
2

In reply to a message from PeterCrespin sent Fri 29 Jun 2012:

Great advice, and stiff upper lip given the context. Wish
I’d known this before embarking on an SU retofit.–
1968 E-type S1� OTS since 1982, 1954 XK120SE OTS since 1991
Niagara, Ontario, Canada
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3

In reply to a message from Nick S. sent Fri 29 Jun 2012:

I have both of my intake/inlet manifolds off the car right
now and it would be easy to remove the secondary
butterflies. What is the recommended way to plug the
openings where the butterfly shaft was removed?–
DrewScherz, 1969 FHC
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4

In reply to a message from DrewScherz sent Fri 29 Jun 2012:

I just removed the secondary butterflies, left the shaft. Easily
done and easily reversible.–
The original message included these comments:

I have both of my intake/inlet manifolds off the car right
now and it would be easy to remove the secondary
butterflies. What is the recommended way to plug the
openings where the butterfly shaft was removed?

–
Ralph, 1970 FHC, XKE Data - 1R27295 - Jaguar E-Type (XKE) information, articles, photos and register
Pine Beach, NJ, United States
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5

In reply to a message from RGK sent Sat 30 Jun 2012:

Did you have to remove the carbs to get access? Or just the
air filter canister?–
The original message included these comments:

I just removed the secondary butterflies, left the shaft. Easily
done and easily reversible.

–
Benny 1968 4.2 S11/2 OTS
Old Bridge NJ, United States
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6

I have both of my intake/inlet manifolds off the car right
now and it would be easy to remove the secondary
butterflies. What is the recommended way to plug the
openings where the butterfly shaft was removed?

Drew, couple of things I would do/did do…1) remove the shaft,
then tap the hole with a suitable tap (sorry can’t remember the size),
insert bolt finger tight and look down the throat to get an idea of
how much you need to cut off to make it flush. Cut it and then
loctite it back into position…2) bolt the two manifolds back
together OFF the engine and look down the throat to see how badly they
are misaligned to each other (mine were awful). Mark, using a scriber
or some such, the misalignment and then unbolt and remove the excess
material to provide improved airflow.

While I was at it I smoothed out the innerds of the rough casting where I could.

All very easy to do and quite satisfying!On Sat, Jun 30, 2012 at 1:15 AM, DrewScherz drew@austin.rr.com wrote:

–
Les…'68 S1.5 2+2

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7

In reply to a message from BTR sent Sat 30 Jun 2012:

The carbs were on the car. Just be careful removing the screws,
you don’t want to lose any into the manifold. I used a gripping
screwdriver after the screws were loosened a bit, and had a rag
stuffed in the back. Took all of 15 minutes.–
The original message included these comments:

Did you have to remove the carbs to get access? Or just the

–
Ralph, 1970 FHC, XKE Data - 1R27295 - Jaguar E-Type (XKE) information, articles, photos and register
Pine Beach, NJ, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

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8

In reply to a message from Les Halls sent Sat 30 Jun 2012:

Hi,
I could sure use a detailed explanation. I have 3 69/70 E
types 2 of which run very well…the 3rd is dead so I could
pull a carb etc of it to learn…also I have 3
spitfires…2 are 74’s and one is 79…does this apply to
these also.

Can anyone give me a detailed explanation? On or off list.

Mitch
Several E’s–
Mitchell Roe
Hasty, United States
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9

In reply to a message from Mister Mitch sent Sat 30 Jun 2012:

Sleeving the secondary is not too difficult once the manifold
if off the car. Buy some lengths of 2’’ brass tubing, 0.032
thickness. This will be just slightly too large in the
outside diameter to slip into the manifold passages. Problem
is solved by heating the manifold to over 400 degrees on your
barbecue, and putting the tube sections in a bucket of ice
water next to the grill. When the manifold is hot enough,
you will be able to slip fit the tubes, while the manifold is
sitting on the grill. Let it cool, cut the ends off with a
dremel, and you are done. This made a big difference on my
Series I XJ6–
Kevin Kemper http://jaguaretype.wordpress.com
Auburn, CA, United States
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10

Sleeving the secondary is not too difficult once the manifold
if off the car. Buy some lengths of 2’’ brass tubing, 0.032
thickness. This will be just slightly too large in the
outside diameter to slip into the manifold passages. Problem
is solved by heating the manifold to over 400 degrees on your
barbecue, and putting the tube sections in a bucket of ice
water next to the grill. When the manifold is hot enough,
you will be able to slip fit the tubes, while the manifold is
sitting on the grill. Let it cool, cut the ends off with a
dremel, and you are done. This made a big difference on my
Series I XJ6

Kevin, what are you “sleeving” and what’s the purpose?On Sat, Jun 30, 2012 at 12:43 PM, Kevin Kemper kmkemper@sbcglobal.net wrote:

–
Les…'68 S1.5 2+2

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11

In reply to a message from PeterCrespin sent Fri 29 Jun 2012:

Peter - Any chance you can point me to a picture or diagram
that clearly shows this? I see a lot of potential disconnect
points (well maybe 2 or 3 of them) and would hate to botch
it up.

Thanks,
Craig

p.s. Hoping for the best on your cars.–
The original message included these comments:

The ‘Crespin mod’(?) just needs you to disconnect the secondary
throttle link at the carb end and leave it dangling attached to the
secondary plate quadrant. The secondary throttle plate (on E-types
at least) is spring-loaded to close. If you wriggle the link
around, you can jam it against the engine side of the manifold (for
which you need to open the secondary plate to make room) and the
return spring holds it tight against the manifold.

–
Craig Gilbert - '68 E-Type FHC
Birmingham, AL, United States
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12

In reply to a message from Les Halls sent Sat 30 Jun 2012:

The sleeving is for the secondary manifold, used with the
twin ZS set-up. In stock configuration, the secondary
manifold has both a separate set of throttle plates
(butterflies) along with complex internal passages to mix and
heat the air-fuel mixture before it enters the primary
manifold. Pete’s fix is to trap the butterflies in the open
position, which helps a good bit and is easy to do no matter
what. If you want to take it further than that, the next
step is to remove the butterflies, either just the flaps or
the shaft as well. If the shafts come out, there is the
matter of plugging the shaft holes, not that big a deal. But
this still leaves the air passages open and (dys)functional.
Sleeving the secondary with brass eliminates the need to plug
the shaft holes and blocks the internal passages. At this
point, the secondary manifold is really just a spacer, but
the coolant lines are still left connected. I can send
photos of what I am talking about. Have meant to put them up
on the website, but have been too busy of late to do that.–
Kevin Kemper http://jaguaretype.wordpress.com
Auburn, CA, United States
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13

In reply to a message from golfnut324 sent Sat 30 Jun 2012:

PM me. I have one picture but am writing a book so don’t want to
broadcast all my info. (Bit late, I know!)–
The original message included these comments:

Peter - Any chance you can point me to a picture or diagram
that clearly shows this? I see a lot of potential disconnect

–
1E75339 66 D, 1E33100 66 FHC, 1R7977 69 OTS, 1R9720 69OTS
Gaithersburg (in transit), United States
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14

The sleeving is for the secondary manifold, used with the
twin ZS set-up. In stock configuration, the secondary
manifold has both a separate set of throttle plates
(butterflies) along with complex internal passages to mix and
heat the air-fuel mixture before it enters the primary
manifold. Pete’s fix is to trap the butterflies in the open
position, which helps a good bit and is easy to do no matter
what. If you want to take it further than that, the next
step is to remove the butterflies, either just the flaps or
the shaft as well. If the shafts come out, there is the
matter of plugging the shaft holes, not that big a deal. But
this still leaves the air passages open and (dys)functional.
Sleeving the secondary with brass eliminates the need to plug
the shaft holes and blocks the internal passages. At this
point, the secondary manifold is really just a spacer, but
the coolant lines are still left connected. I can send
photos of what I am talking about. Have meant to put them up
on the website, but have been too busy of late to do that.

Ah, now I see…have to say I didn’t go that far, just closed the
shaft holes and cleaned up the mismatch between the
manifolds…and left it at that. Car seems to run great!On Sat, Jun 30, 2012 at 6:19 PM, Kevin Kemper kmkemper@sbcglobal.net wrote:

–
Les…'68 S1.5 2+2

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15

In reply to a message from PeterCrespin sent Fri 29 Jun 2012:

Just tried the 5 minute mod recommended here and could not
believe the results! Seems like the engine could breath and
had a lot more power in the lower rpm ranges. Unfortunately,
due to a weak clutch I couldn’t really press into it but I
will definitely be pulling the secondary throttle plates,
plugging the holes and rebuilding the carbs while the engine
is out for the clutch.

I would recommend this quick mod for those not needing or
wanting to get into more of a project.–
The original message included these comments:

The ‘Crespin mod’(?) just needs you to disconnect the secondary
throttle link at the carb end and leave it dangling attached to the
secondary plate quadrant. The secondary throttle plate (on E-types
at least) is spring-loaded to close. If you wriggle the link
around, you can jam it against the engine side of the manifold (for
which you need to open the secondary plate to make room) and the
return spring holds it tight against the manifold.

–
Craig Gilbert - '68 E-Type FHC
Birmingham, AL, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

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1 Like
16

I hate to say, “I told 'ya so”, (not toyou) but that’s what I have been saying all along. At partial throttle openings the difference is quite noticeable.
LLoyd

My driveway is long enough that you can appreciate the conflict between the desire for privacy and the terror of being completely lost .----- Original Message -----
From: “golfnut324” caggilbert@gmail.com
To: e-type@jag-lovers.org
Sent: Sunday, July 1, 2012 8:31:17 PM
Subject: Re: [E-Type] Five-minute Strangleberg fix?

In reply to a message from PeterCrespin sent Fri 29 Jun 2012:

Just tried the 5 minute mod recommended here and could not
believe the results! Seems like the engine could breath and
had a lot more power in the lower rpm ranges. Unfortunately,
due to a weak clutch I couldn’t really press into it but I
will definitely be pulling the secondary throttle plates,
plugging the holes and rebuilding the carbs while the engine
is out for the clutch.

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1 Like
17

In reply to a message from golfnut324 sent Sun 1 Jul 2012:

Which do you disconnect A B C or D? Or any one of
them,and do you leave the spring loaded one and tap it to
hold the plates in the open position. Just checking and want
to be sure and able to reverse it if anything goes out of
wack… Thanks

http://i47.tinypic.com/4j23r4.jpg--
The original message included these comments:

In reply to a message from PeterCrespin sent Fri 29 Jun 2012:
Just tried the 5 minute mod recommended here and could not
believe the results! Seems like the engine could breath and
had a lot more power in the lower rpm ranges. Unfortunately,

–
Benny 1968 4.2 S11/2 OTS
Old Bridge NJ, United States
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18

In reply to a message from BTR sent Mon 2 Jul 2012:

Good photo. Can you send me an original for the book please?

Disconnect B and put the clip back on the pin. Then turn C
anticlockwise and flip the arm BD round so that D is roughly where
B is and jammed up against the manifold under spring pressure. This
keeps the throttle plate almost fully open for the trouble of one
spring clip prised off per carb.

You can undo A and take the arm AB off and then put the nut back
on. Then just swing BD round as before but you will now have AB
dangling looselyfrom the B end where it presses against the
manifold. ‘Same difference’ but prying the clip off may be easier
than undoing a nut. Neither takes more than a few seconds and is of
course totally reversible. I think you’ll see less extra gain from
pulling the plate or spindle out than you will with this mod, which
accounts from probably 80% of the gains available at mid throttle
and maybe 70% of the max throttle improvement from total removal?
It definitely gets you the ‘low-hanging fruit’ power gain for very
little work un-strangling the intakes.

Pete–
1E75339 66 D, 1E33100 66 FHC, 1R7977 69 OTS, 1R9720 69OTS
Gaithersburg (in transit), United States
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19

In reply to a message from PeterCrespin sent Mon 2 Jul 2012:

Thanks Pete,
I’ll give it a try.
Send you pict in e-mail–
The original message included these comments:

Good photo. Can you send me an original for the book please?

–
Benny 1968 4.2 S11/2 OTS
Old Bridge NJ, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

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20

In reply to a message from PeterCrespin sent Mon 2 Jul 2012:

Disconnected the secondary throttle link today as per Pete’s
inst. Took the car out for a spin…WOW can’t help taking off
like a rocket from stop…This mod is great and reversable
in 1 minute…–
The original message included these comments:

Disconnect B and put the clip back on the pin. Then turn C
anticlockwise and flip the arm BD round so that D is roughly where
B is and jammed up against the manifold under spring pressure. This
keeps the throttle plate almost fully open for the trouble of one

–
Benny 1968 4.2 S11/2 OTS
Old Bridge NJ, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

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1 Like