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MG MGB Technical - Ram trumpets 1.5'

I just won a Ram trumpets for 1.5" SU carbs on the ebay, and would like to know if they are safe to use on a normal 1800 engine with standard carb needles.
Regrs
Alfredo
Alfredo

Not unless you are racing and plan on rebuilding your engine soon. I would strongly advise against running your engine without air filters due to the grit which will inevitably get into your engine. Some do put the trumpets on at car shows after they turn their engine off to dress up the appearance of the engine bay.
Frank

I would never run a car without airfilters because of the resulting (bore!)wear. Even race-engines mostly use airfilters with their trumpets in a (cold)airbox. You might try if your newly bought treasures fit into the normal airfilterhousing?

In my '73 European spec MGB with twin HIF4's I fitted K&N airfilters with (standard) AAU needles because the recommended AAA's where much to rich for me.
An alternative is to use the nr.6(?) needle from the earlier carbs, suitably modified by the supplier (a sleeve/jacket must be added to fit in the preloaded/biased HIF).

The standard factory european spec setup is very good with the large airfilterhousing that acts as an coldair box and the contoured mounting plate that acts as a stub-stack (= short trumpet).

David Vizard warns in his "Tuning the A-series Engine" that a lot of trumpets are badly shaped and actually REDUCE airflow.....
Willem van der Veer

Thanks for the advise, i have to get rid of them...but they look nice..brand new.
Alfredo
alfredo

I run My DCOE without Filters however i put fine gauze over the holes to stop such deposits i know its not as effective as a filter but the Webber sounds so nice
Nathan

I have the short 'tumpets', inside my K & N air filters.
We call them velocity stacks.
Grassroots Motorsorts magazine did a series of tests, on a dyno, and the short stacks inside the K & N air filters, gave a gain of 3-4 HP.
Well worth it!
The stock air filters, the back-piece that is next to the carbs., has a stack, or trumpet, built into to it.
Take a look!
Maybe BMC knew what they were doing!
Safety Fast
Dwight

Dwight McCullough

Alfredo,
did you plan on using them without filters? I wasn't clear on that from your post. They will work very well if they are the full radius lip type, such as TWM makes. They work as well as the stock base plates mentioned above. As far as air cleaners go with trumpets, use filter socks. I use PiperCross foam filter socks and they work very well. I'm sure there are other manufacturers. If you're flowing more air, you'll probably need richer needles. Are there any other airflow mods besides the trumpets?
Wade Keene

K&N web site allows you to search for air filters by dimensions. The early B without power brakes has some extra room. A tall air cleaner with trumpets should work real well.
Barry
Barry Parkinson

Wade,
i bid them because they would look nice, and thought they had filters inside.i will try to fit them with my K&N as Dwight does.
this is what the seller says to me.

....so long as you use some
filter 'socks' you should have no problem with these
on your B. you may well need to set the carbs a bit
richer though...

Alferdo



Alfredo

Hi Alfredo

I run Piper-Cross filter socks on a pair of trumpets on my midget.

The induction sound is just terrific and the socks are held in place with cable ties. When I want to show the car I remove the cable ties and take the socks off.

It's a nice, and nice looking period mod to the car.

James
James Reinhardt

JAmes,
how do they look like...Piper-Cross filter socks...?

alfredo
Alfredo

Alfredo,
You might also want to check out this site, http://www.hotelling.com/mgb7.htm , for some general instructions on gaining a little performance from your carbs. You can use the rear air filter base from the Original Equipment Coopers air filter setup as this site mentions ~ a pretty cheap way to go. Or you can make your own backing plate from 1/4" thick sheet aluminum and use the air horns/velocity stacks Dwight mentions. FYI
Bob Muenchausen

I ran some filter socks on the trumpets of my Weber 45 and I lost power on the rolling road. Stuck to using a proper filter (K&N, etc).

Running no filter is just daft,most of our race cars use filters as well.

Tony
Tony Crossley

Hi Alfredo

The Piper-Cross filter socks are basically foam cylinders which are open at one end. Mail me off line and I can send you a pic showing what they look like on my car's carbs. As your B has 1 1/2" SU's as opposed to my car's 1 1/4" carbs you'll have to hold the picture a bit closer to your face to see what the larger carbs will look like.

James
James Reinhardt

Hi Guys,
Thanks for the info, my trumps has a built in mesh at front, i may need just a foam type of filter wrapped round the carbs like James to prevent the thin dust to go into the manifold.
Alfredo
Alfredo

<<my trumps has a built in mesh at front>>

Alfredo,
I am really sorry to spoil your fun, but those meshed trumpets will rob you of several HP's. If you only want it for the superb looks, that's OK, but don't expect your car to be faster (it will sound faster though!)

Here's a picture of really sexy good flowing trumpets, I think APT has connections with/is owned by David Vizard himself:
http://www.aptfast.com/Images_Parts/SU/RP-HS4.jpg
Willem van der Veer

This thread was discussed between 07/02/2005 and 14/02/2005

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