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Here are some messages covering that subject.
My '68 series 1 1/2 has the two strombergs. I was wondering if there is any
real power gain if it was replaced with the triple SU setup. Does anyone
know if its worth the cost, I've heard its about $1000. Is the performance
gain worth it. Are there any tuning considerations when using the triple
carb setup? Timing, plugs, etc. Where is the best place to look for the
manifold and carbs? Hemmings? Any third parties. Any general info would be
appreciated.
J.White
The dual stromberg setup was used on all Federal Spec cars from
late 67 onwards. These are the E-types with the poorest performance
and probably the most tuning problems. The dual Strombergs are nothing
but constant trouble, being difficult to tune and keep in tune. Yep, your
best bet would be going with the triple S.U. setup. These carbs are the
model HD-8. They can be found on many other vehicles besides the E-type.
The Rover "P" series also ran these carbs, and occasionally they show up
in Pick-a-Parts. The S.U. carb is a very simple instrument with only two
moving parts. Once the function of the "Constant Depression" carburetted
is understood, You should be able to tune and sync the triple carb setup
in about 15 minutes. This setup will provide more horsepower, with less
trouble. The 4.2 engine has no problems gulping the additional fuel/air
mixture. If racing setups are your bag, three Weber 45 DCOE's work
very well, but are tough to tune. Mikuni and Solex also have side draft
carbs for this application. You will need: 3 HD-8 Carbs, triple carb
intake manifold(s) (3.8/4.2 either will work), linkage, fuel lines, and
some other misc. stuff. If your car has the x-over rail from the exhaust
manifold,
You'll have to block that off or get a proper non-smog manifold.
The smog goons in your state may have laws against these alterations,
or they may not be sharp enough to know the difference. You may want to
research this topic before you start taking your intake apart, and buying
parts.
The cost for everything from the cylinder head out (which is what you'll
need) will cost at least 1,000.00. then you'll probably want to rebuild each carb
and detail the whole set-up so it looks good. The result will be a much
more reliable and better performing motor car.
Good Luck
Jan -
There's been a lot of discussion on this subject over the last few
months. I recommend you check the digests from late January (which
included my discussion on the subject) and late March (including a
very useful post from Larry Schear). BTW, I get my car back
tomorrow after having the triple SU for dual Stromberg swap
completed. I will give you an immediate answer to your question
about power gain on Monday!
Regards,
Dave Lowenstein
I think the cam profiles were changed on the S2 motors (less carb/less cam
for smog). Does anyone know for sure? This would have an effect on any
performance gains you might see from the SUs. Be careful, this is how it all
starts. If you do new cams, you should do headers, and then there is porting
and if the motor is making more hp you'll need 4 piston vented brakes, and that
suspension kit from GTJ would be nice... It never really ends :-/
Mark McChesney
Jan:
There has been much written on this topic by people much more knowledgeable
than me.I can only relate my experience, the PO retrofitted with 3 SU's to
my 70 S II and its really quick. Fuel consumption is about 15 MPG.
Only down side is getting the car through the California Smog Test. If you
live in a location with tight smog test do be careful. It took a lot of work
and expense to finally get my car through the test.
Hope this helps
Steve Patchel
As I recall, the 2 carbs to three switch makes about ten horsepower increase.
I don't imagine it would be noticeable except a the top end. Oh - and this is
replacing the cams also...
LLoyd
Since someone brought up the subject of cams...
The cam profiles are different. I am switching to the 3 SUs setup and
changing the cams. The set of cams I was interested in, I had read about
in an article about a light blue SII FHC that was raced in England, the
article tittle was "Fire in the Belly". I don’t remember which Magazine.
I have misplaced my copy of the magazine, and if anyone remembers the
article or has a copy or remembers the name of the company that produced
the cams or .... I would be greatly appreciative.
Dann Poindexter
I too have a '68 OTS which I switched over to triple Solexes. I am very
happy with the performance, although as noted you can expect a decrease in
milage. In an engine swap years ago I wound up with a '64 engine which
might have had the proper cams in it, although I didn't feel there was a
great deal of difference attributable to the carbs between the engines.
Oddly it seems to me that fuel consumption is much higher at loafing low
speeds. When blazing away out on the highway it improves. Go figure.
Someone out there probably knows why this is. I have never had the
slightest tuning problems with these: they seem rock steady. I would guess
that triple SU's would be about the same difference in street applications
and be easier to find someone to look at if needed while touring. Also they
would likely be easier to find complete with all the odds and ends. On the
other hand there is a Walter Mitty sort of boost seeing all those
side drafts lined up just like a Le Mans D Type :~)
Pat suggests the 45's...I was advised to gt 48's and did. Maybe milage
would be better with smaller ones? At any rate it doesn't seem to suffer
from over carburation..
Also of course, don't lose all the gear for the Strombergs. California or
not, sooner or later, you or someone else is going to need them.
Bill Spear
The Article "Fire in its Belly" is from Classic and Sports Car 6-95.
The Cam Profile run in this Series 2 was done by the owner.
It is 460 thousands lift and 270 thousands duration. This is not the stock profile.
According to the factory workshop manual, the stock profile for a
U.S. Federal spec 4.2 smog motor is no different from the earlier cars.
The lift is shown to be .375. The duration is not listed. The car tested in
the article also has a lightened flywheel, improved fuel system, and an
uprated oil pump. Horsepower is listed at 306bhp, as opposed to
a stock series 2 of about 190-200 bhp. He was running a triple S.U.
setup.
Commonly known logic tells us that More fuel and CFM of
air = more power. There is an excellent book called "S.U. carburetters,
tuning and techniques" Which is highly recommended for anyone
contemplating any carburation changes. There is a whole chapter
devoted to carb. choices. Remember, the U.K. spec series 2 ran
3 S.U.'s as they were'nt subjected to U.S. smog regs. While the
265 BHP claimed by Jaguar is totally false, The pre-smog/triple
carb cars produce a lot more H.P. than the dual Stromberg models.
The Road & Track test car for 1964 whomps the 1969 car fair & square
in the period road tests. I took my 3.8 down to the street legal drags
in Pomona CA, and it ran a brisk 15.55 in the 1/4, with a speed of
92 MPH. I seriously doubt the smog motors would approach a 17 sec.
time.
The benefits of triple vs. dual carbs is a complex question, which
would require a serious cost/benefit analysis by anyone contemplating
this changeover.
Good luck & Happy Motoring
Pat Harrington
In view of all the carb chatter I thought I would I would repeat my
question of a few months ago that went unanswered..
I am restoring a 64 XKE OTS car with a great looking engine that has
triple dual throat WEBER 40DCOE carbs that look like new.
I have never fired it up and it is not ready yet.
Does anybody have any experience with these and any comments on
performance, problems, expectations etc.??
Thanks
Tony Clarke
>I am restoring a 64 XKE OTS car with a great looking engine
I have two of them on my 1800 cc Water cooled VW in my Formula Atlantic race
car.
I am surprised that it only takes three of them to feed an engine that is
more than twice the size of mine. But then, maybe I am over feeding
mine...#8-) It does suck up alot of 115 octane.
They are hard to set the idle mixture on and the only way I have found to do
it is with a Colortune. If you dont get them set properly it will idle
rough. That isn't a problem with my car since once its rolling it never
gets below 2000 rpm anyway. The rough idle sounds real tough, but probably
not on a street car.
You can buy a book on Weber carbs at most racing shops that will help you
tune them.
Jim
A friend of mine had triple 45DCOE Webers (and other hot bits, cams
etc) on his MK2 when he was racing it. It was very fast - over 220 hp
at the back wheels on the dyno. My virtually standard 3.4 Mk 2 made
120 on the same dyno which the dyno owner said was about normal.
Expect horrific fuel consumption - like single figures. Also just
remembered a 3.8 E-type with triple webers and other gear was timed
here at 172 MPH during a speed trial in the 1960's. It was a roadster
- not sure if windscreen fitted or not for that speed.
John McDonagh
Jan:
A friend asked me today if I knew of anyone who would be interested in
an early Series 1, 4.2 engine. It is complete with triple carbs
(including choke linkage), water pump, flywheel and pressure plate (no
bell housing), no starter or alternator. He said it was in very good
material condition. The head shows no signs of corrosion and the
cylinder liners are excellent. In his opinion, the engine and head
needed only minimal work.
He also said he would provide a set of AE bearings and a set of original
Hepolite rings with the engine.
He's asking $1800. The engine is in Southern California.
Jan, I realize this is more machinery than you need, but the total price
for 3 carbs, a manifold and cams could make this a worthwhile package
and you would have a spare engine, too.
The owner is building a new shop, is not on the net, and is difficult to
reach by phone on a regular basis. If you or anyone else is interested,
send me your phone numbers and I'll have him get in touch with you.
Regards, Dick Cavicke
120 OTS, FHC
Thanks to all of you for the fine feedback on the Stromberg/SU conversion
question! One thing I failed to ask is whether the conversion has any
impact on originality or resale value.Would the car be more desirable with
triple SU's, or would it have a negative impact on value because its not
original equipment? I don't plan on ever having this beast judged, I'm just
going to have fun driving it, so it really doesn't matter to me, but you
never know, some day I may be a PO! Thanks again for all of your input!
Jan White
About Webers: I recently had the extraordinary pleasure of chatting
with Lee Mueller of the V-12 E-type factory racing team of the early/mid
1970's. He ran the car for the Huffaker crew. Anyway, we got chatting
about Webers, and this is what I was told.
Webers are not tuned merely by turning screws. They must be
jetted for the specific application.
Expect a big decrease in MPG.
The DCOE carb is for racing, not touring, and perform best at
high RPM's
They are noisy. The intake will become much louder.
There is a big difference in quality of associated componentry.
The Webers must be perfectly sync-ed, and a cheap linkage
will throw them off balance.
This conversion is BIG bucks. Expect about $1500.00 on up
for 3 new carbs and quality hook-ups.
Tuning should be left to an expert familiar with Webers.
It was a true pleasure speaking with Lee, he is truly a remarkable
man, having survived a heart transplant AND dealing with the
factory Jaguar people. I was truly inspired by his knowledge,
experience, positive attitude and kindness.
Good Luck to all
Pat Harrington
On 05/27/97 23:04:24 you wrote:
Actual is around the 210 bhp on th dyno....
kind regards
VICARAGE JAGUAR............. Specialist Jaguar Restoration
Anthony Parkinson - Owner
> From: vicarage@ix.netcom.com
Is that a rear-wheel reading on a rolling road dyno or a flywheel reading on an
engine stand dyno?
Thanks,
Jan White wrote:
The reason that crossover pipe has to be removed is because the new
intake manifold for a three carb manifold will not have anyplace to
connect it. Actually you only need to replace the rear exhaust manifold,
which is what the crossover pipe connects to. Assuming, that is, that
you can find one for sale by itself. Possibly someplace like Jaguar
Heaven in Stockton, CA. See George's page for the number and address!
If I've mis-stated any details, I'm sure they will be promptly corrected.
Dan Buringrud
Isn't it like that:
265 bhp = SAE (US) PS
My Series 1 2+2 4,2 litres (3 SU HD8 / US re-import) has a German license
of Oct 1995 saying "150 KW" (Kilowatt) = 204 PS. 1 KW = 1,36 DIN-PS.
Any more guesses ? There are a few Jag friends around here also wondering
Stephan
We got about 260 hp at the flywheel after a complete rebuild, including
carbs and no exhaust installed on our '67 series one engine with 9:1
pistons. I'm sure that figure dropped severely after the engine was
installed in the car.
Larry S
I have been talking with a few folks about what I need for the Stromburg/SU
conversion. I still am unsure of exactly what I need. If anyone could
answer the following questions:
I am attempting to find as few sources for as many pieces as I can. Any
help would be greatly appreciated. Thanks!
Jan White
To convert a dual Stromberg car to S.U's you will need:
The upper cooling hose might work. (I'm not sure if it's the right length)
Your best bet would be finding a used assembly from an E-type
or Mk10, or 420G. Just order everything from the cylinder head outwards
and an air cleaner assy. The linkage should hook up to the firewall
pivot on the rt. side of the firewall. The triangular air box looks like
it should work with the triple feeder trumpets.
The E-type documentary is available from Classic Motorbooks
1-800-826-6600.
I hope this helps
Pat Harrington
Just a warning boys, the intake manifold and enriching device on a Mk 10 or
420 G are different from the E-type. The intake manifold is turned upwards
on these cars and with it in an E you can't close the bonnet. I know as I
have been there. The enriching device is the standard electrical one on a Mk
10 and on the E a manual one, this wouldn't matter much I suppose, most
people prefer the manual and it would be more original.
Frans.
Jan -
I just completed a dual Stromberg to triple SU conversion on my 67
S1.5 OTS. I can answer some of your questions. However, it sounds
like you may end up a little confused, because some of my responses
conflict with others who have responded as well. The reasons for
some of these differences may be that my car originally had the
tricarb setup (a PO swapped it for the Strombergs), whereas fitting
a tricarb to a newer car may require different pieces. I am
assuming you have the 4.2L motor:
> 2. Can I use my existing triangular air box that sits a top the air
Perhaps others have had a different experience, but I found that the
air box in addition to the trumpet connector had to be replaced. With
the trumpet connector, you should try to find one from a 4.2L tricorn
motor. The 3.8L trumpet connector looks very similar, but has a
smaller breather pipe. If you're only able to find a 3.8L trumpet,
it can probably be modified by reaming the hole in the plate, and
fitting a larger pipe, but I suspect that would be a real hassle.
Similarly, the triangular air box looks the same for 2-carb and 3-carb
4.2L cars, but the different trumpet connectors have different
mounting points. It appeared possible to rework the mounting
connections to allow my existing air box to mate to the new tricarb
trumpet, but instead I traded my air box with a guy who had the
correct one and needed mine. The air cleaner is the same (at least
on a 67 - newer cars this may not be true).
> 4. Are the radiator/cooling hoses radically different? Are they
You will need a new upper radiator hose (the one which connects to
the header tank). All the good E-type parts houses will have it.
I did not have to replace the rear exhaust manifold since my car
originally had the tricarb setup. I can't say for sure it won't
work, but I was warned to stay away from a 3.8L intake for a 4.2L
conversion.
I wholeheartedly agree with Frans that you also stay away from
tricarb SU setups from any car other than an E-type. I avoided
learning this the hard way when my mechanic demonstrated for me the
pitfalls of trying to use the 420 tricarb setup. It doesn't fit
without some really unpleasant modifications (at least on a 67
S1.5).
Once you're finished, this conversion is really worth it. The car is
noticeably faster, idles more smoothly, and sounds better.
Good Luck!
Dave Lowenstein
67 E-Type OTS S1.5 driver
I have a set of triple Weber carb's that came off my old TVR. I would
like to put them on my '67 XKE to replace my triple SU's. The Weber
carb no. is #50 101.
Will these carb's work on my XKE and what jets do I need to use?
Where do I get jets and other parts for these?
Where can I get a manifold, or a manifold conversion?
Thanks
Chris
Carburetor FAQ's
![]()
This is a very popular subject. Especially the S2 Stromberg to SU conversion.
From: "Jan White"janco@netonecom.net
To: e-type@jag-lovers.org
Subject: Triple SU's
Date: Wed, 21 May 1997 21:49:24 -0400
From: "pat harrington"patharr@gte.net
To: e-type@jag-lovers.org
Subject: Triple S.U.'s
Date: Wed, 21 May 1997 21:12:04 -0700
Pat Harrington
64FHC
patharr@gte.net
From: David Lowenstein dlowenst@mastermind-tech.com
To: e-type@jag-lovers.org
Date: Thu, 22 May 1997 10:09:44 +0000
Subject: Re: Triple SU's
Washington, DC
dlowenst@mastermind-tech.com
From: Mark McChesney mmcchesn@ford.com
Date: Thu, 22 May 1997 09:42:11 -0400
To: e-type@jag-lovers.org
Subject: Re: Triple SU's
'65ots
From: Steve Patchel spatchel@radford.com
Subject: Re: Triple SU's
Cc: e-type@jag-lovers.org
70 ots
Date: Thu, 22 May 97 08:49:06 PDT
From: LLoyd 3030P@vm1.cc.nps.navy.mil
Subject: carbs/cams/H.P.
To: e-type@jag-lovers.org
Date: Thu, 22 May 1997 11:07:26 -0500
From: Dann Poindexter dpoindexter@dayton.adroit.com
To: e-type@jag-lovers.org
Subject: Re: Triple SU's
70 XKE OTS
Date: Thu, 22 May 1997 17:20:45 -0300
To: e-type@bitcon.no
From: Bill Spear bill@wmspear.com
Subject: twin carbs to triple
http://www.carmelnet.com/spearpins
From: pat harrington patharr@gte.net
To: e-type@jag-lovers.org
Subject: Tri-power and Cam profiles
Date: Thu, 22 May 1997 16:06:24 -0700
64FHC
Date: Thu, 22 May 1997 14:21:50 -1000 (Hawaiian Std Time)
From: Antony Clarke tclarke@soest.hawaii.edu
cc: e-type@jag-lovers.org
Subject: Re: Tri-power and Cam profiles
XK150 DHC 1960
XKE OTS 1964
Date: Thu, 22 May 1997 19:54:55 -0500
From:James A. Isbell JISBELLJR@mail.utexas.edu
Subject: Re: Tri-power and Cam profiles
Cc: e-type@jag-lovers.org
>that has triple dual throat WEBER 40DCOE carbs that look
> like new. I have never fired it up and it is not ready yet.
>Does anybody have any experience with these and any
>comments on performance, problems, expectations etc.??
Date: Fri, 23 May 1997 14:15:25 +1200
From: John McDonagh MCDONAGJ@tui.lincoln.ac.nz
Subject: Re: Tri-power and Cam profiles
Cc: e-type@jag-lovers.org
Department of Accounting Finance and Property Studies
Lincoln University
Christchurch
New Zealand
Date: Thu, 22 May 1997 17:36:15 -0700
From: f8driver@pacbell.net
To: e-type@jag-lovers.org
Subject: Re: Triple SU's
65 E-type OTS
From: "Jan White" janco@netonecom.net
To: e-type@jag-lovers.org
Subject: Triple SU's
Date: Fri, 23 May 1997 01:32:59 -0400
68 E-type OTS
65 Corvette Coupe 327/365hp (4 speed)
88 Corvette Roadster (Auto, ugh!)
70 BMW R-750 (2 Wheeler!)
From: "pat harrington" patharr@gte.net
To: e-type@jag-lovers.org
Subject: Jags, Webers, and Going Fast!
Date: Thu, 22 May 1997 23:01:47 -0700
64FHC
From: vicarage@ix.netcom.com
Date: Wed, 28 May 1997 07:11:32 -0500 (CDT)
Cc: e-type@jag-lovers.org
Subject: Re: Triple SU power
>
>Re: '68 Series 1 1/2
>
>Also, someone mentioned the 265hp rating of the 4.2
> triple SU setup was totally false. Does anyone know what
> the actual (gross) horsepower rating is for this engine?
tony
USA/uk/Netherlands
Florida Tel 1 305 866 9511
fax 1 305 866 5738
Web Site: www.jagweb.com/vicarage
From: "John T. Horner" jthorner@garlic.com
Cc: e-type@jag-lovers.org
Subject: Re: Triple SU power
Date: Wed, 28 May 1997 07:32:51 -0700
> >Also, someone mentioned the the 265hp rating of the 4.2
> >triple SU setup was totally false. Does anyone know
> >what the actual (gross) horsepower rating is for this
> >engine?
>
> Actual is around the 210 bhp on the dyno....
>
JH
Date: Wed, 28 May 1997 07:53:12 -0700
From: Dan Buringrud dano@castles.com
Cc: e-type@jag-lovers.org
Subject: Re: More Triple SU Questions
>
> Re: '68 Series 1 1/2>BR>
>
> Pat Harrington mentioned that if I switch to a 3 SU setup
> that the cross-over rail from the exhaust manifold will
> have to be removed and plugged. Is this just a pre-heater
> and can remain or must it be removed in order for the
> engine to be properly tuned.
>
Jan,
68 OTS
Also hoping to go to some 3 carb setup in the future
Date: Wed, 28 May 1997 20:30:25 +0200
From: Stephan Perthes jaglinks@perthes.de
To: e-type@jag-lovers.org
Subject: Re: Triple SU power
210 bhp = DIN (Germany) PS
'66 E-Type 2+2 S.I 4,2
www.perthes.de/jaglinks
.
From: "Larry J. or Linda L. Story" llstory@coffey.com
To: e-type@jag-lovers.org
Subject: Re: Triple SU power
Date: Wed, 28 May 1997 18:24:16 -0600
.
'67 E-Type roadster
From: "Jan White" janco@netonecom.net
To: e-type@jag-lovers.org
Subject: Triple SU Conversion
Date: Wed, 28 May 1997 21:27:29 -0400
From: "pat harrington" patharr@gte.net
To: e-type@jag-lovers.org
Subject: S.U. conversions and E-type videos
Date: Wed, 28 May 1997 21:43:30 -0700
64FHC
Date: Thu, 29 May 1997 11:26 +0200
From: Frans HOEKEMEIJER hoekemei@ps.msm.cern.ch
To: e-type@jag-lovers.org
Subject: RE: S.U. conversions and E-type videos
From: "David Lowenstein" dlowenst@mastermind-tech.com
Date: Thu, 29 May 1997 10:59:17 +0000
Subject: Re: Triple SU Conversion
CC: e-type@jag-lovers.org
> cleaner? Is it the same one except for the adaptor plate for the
> 3 trumpets? Is the air cleaner the same?
> available aftermarket, or can I just jerry rig it so it works.
Washington, DC
71 Olds Cutlass Convertible
79 Triumph Bonneville
Keeping parts guys in business nationwide
Date: Sun, 01 Jun 1997 11:03:26 -0400
From: Chris Veenstra Seaborne@coca.net
To: E-TYPE@jag-lovers.org
Subject: WEBER CARB'S
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