Tripple SU's VS Tripple Stromberg's

[browny]

Hey there
plan on building a hot grey motor in the near future
And I have no experience with either setup just
Seeking some advice pro/con's,it probably will only
Be driven few times a month so planning a bit of a
Grumpy motor

[Blacky]

Is it going into an FB/EK Browny ? a lot of triple carb manifolds will require surgery to the firewall and relocation of the battery box

[browny]

Yeah Blacky going in my ek ute. Maybe I should just
Go with twin strommies do they need any extra
Clearance? Thinking along the lines of having a bit
Of fun with a spare engine i have and be able to swap
It back out with the orginal at a later date

[Harv]

Twin Strommies are cool, but pretty common. Easy to tune, easy to get parts for.
Triple Strommies are cooler (IMHO). Bit more capacity for high rpm shenanigans, but can be a bit more hesitant at low revs.
Triple SUs are also cool. Less likely to be hesitant. Easy to get parts for too. Needs a bit of finesse to get the needles right. Can be bolted up with no mods to the guard/firewall, but as Blacky points out some longer manifolds will clash.

Cheers,
Harv

[Craig Allardyce]

Browny there's a few options. I've run with twin 1 3/4 Su's bolted to a Warnerford DCOE Manifold (Uses a Lynx adapter).

DSC01202.jpg (91.43 KiB) Viewed 2827 times

The grey motor lends itself well to hand built manifolds as well (simple round port and flange bolt up) There are a lot of fabricated manifolds kicking around that others have made to adpate twin Webers (side & downdraught) and there are some newly made items such as Sonic Injections 2 barrel Weber manifold. I guess the choice is yours. Mine was done so it could be reversed back to standard if I wanted to (no panel mods or battery relocation). I also used SU's for better drivability and ease of tuning. I had a DCOE Weber but expense of jets and ability (mine and its) to get it to work with the manifold was poor. As I'll mention below the port size of the manifold is so important. If your going lumpy cam then I would stay with SU's although I wont discount any others such as Thommos very lumpy grey with triple downdraught Strombergs.
If I can suggest a few things that you should keep in mind when changing to different carbies:
Manifold and port sizing is very important. Don't go too big and don't go too big in carby throat size. Intake velocity must be kept at a reasonable speed otherwise you will suffer with poor low down performance and flat spots.
IF you can try and employ some sort of manifold preheat system. This is rarely done but IMHO is important to good fuel atomisation and drivability when cold. It also reduces run time on the choke and prevents cylinder wash-down which increases bore wear. Su's can also suffer from icing on the throttle plates even when the manifold is warm from external heat generated from the exhaust and under bonnet temperatures. I'm thinking of doing a simple air induction preheat drawn from the engine pipes. Hope fully I can rig a bypass that will open up and draw from colder air when the engine warms up (similar to hotbox on grey, using a bimetallic spring controlled flap arrangement)

[D-MAN]

Real men run SU's on their greys
Way way cooler you can also run twin SU's and second hand manifolds come up every now and then...

[browny]

Harv making some pretty good points there im thinking
of going tripple SU's (or if I get stuck twins) at this point and running twin strommies
On the stocka

Craig now thats a nice looking engine I never
Thought to much on the manifold ports size
More on the carb throat size .heated su manifold
Would be a pretty interesting setup

D-man bit biased there

Are su's really touchy to weather changes ive talked
To a few friends and they were saying that they need
Re-tunning fairly often or is an example of su's
That were never tuned properly to start with?

On the su learning curve

[WayneXG95]

Keep your original gear, you might find you'll get sick of it and want to return to standard.

Wayne speaks from experience!

[Craig Allardyce]

Browny re having to re-tune them regularly is rubbish (I am prepared to be howled down on this). If they are set up correctly in the first place they will stay in tune and they are very reliable. Usually the Su's "running out of tune" is due to worn throttle shafts, worn piston and damper assemblies, and worn needles and jets (later biased needle types), and incorrectly centred jets (Early type).
Fuel pressures are also over looked as SU's cant handle high fuel pressures and will flood easy.

[Harv]

Browny re having to re-tune them regularly is rubbish

Amen. Fully agree with you Craig.

Cheers,
Harv

[GreyEJ]

I have triple SU's and will never go back. The look is amazing. I also like the look of triple stromies but SU is the way to go. I'm pretty good friends with a few of the racers and they all go triple SU or Twin webber blocking off 1 port. I like you drive it only on weekends. It hop along pretty bad in second due to the cam but thats part of the fun. One thing thats not so great is that without an electric fuel pump it can take some cranking to re-fll the bowls. That or I have one of the sock on the ram tubes loose so I spray some fuel in for first start after that perfect. Triple SU is probably a little bit cheaper also as the stromberg manifolds are really expensive.

Having said that dads EJ will be triple strommies just because.

Bearing that in mind I do have a brand new genuine Lynx triple SU manifold here if interested and fuel block.

[parisian62]

I love the look of tripple strombergs which is the setup/look (I stole from Thommo ) and put into Old Timer my wagon.

Like Craig said if the carbs are all rebuilt with new bushes, shafts, good linkages etc you shouldnt have any ongoing tuning problems. My set up has been going strong now for over 2 years. I have had to get them retuned once...because I blew up my pertronix...

Check out this thread for some inspiration http://www.fbekholden.com/forum/viewtop ... grey+motor

Stewart

[WayneXG95]

Never had a problem with my Tripple Strombergs...(Watch me get pounded here)..

SU'S belong on Morris Mini's, MGB's and Austin Freeways, Ya don't want those..

[Harv]

SU'S belong on Morris Mini's, MGB's and Austin Freeways, Ya don't want those..

Them thar's fightin words . BMC made some nice vehicles.

SUs also have a place sitting on Normans

Cheers,
Harv

[parisian62]

Never had a problem with my Tripple Strombergs...(Watch me get pounded here)..

hmmm....please explain???