Page 1 of 2

RV8 in my Stag - need to modify the carbs

Posted: Wed May 06, 2009 12:38 pm
by russ spake
Hi, anyone know where I can get the pots on my SUs modified so that they sit under a standard Stag bonnet. I'm getting the boby work restored and the bonnet which has had a bulge inserted badly is shot, thanks.

Russ

Posted: Wed May 06, 2009 1:13 pm
by topcatcustom
I wasn't aware that you could get them modified- I'm sure they were made that size for a reason...!

Posted: Wed May 06, 2009 2:54 pm
by kiwicar
You may find the Stromberg is slightly shallower, however I have never measured them. I have never heard of machineing the pistons/ dash pots to make them shorter, I don't see much could come off as that would restrict the piston lifting.
Mike

Posted: Wed May 06, 2009 3:05 pm
by harvey
I've seen strombergs fitted to clear the bonnet on Stags with the RV8, but I have also seen the mod to the SU's which IIRC involved taking the little chimney off the top, and than machining a threaded hole into then what becomes a flat topped dashpot, this being threaded to take the larger SD1 dampers which have to be shortened accordingly.

Mind you it was a good while ago that I saw them.

Posted: Wed May 06, 2009 3:20 pm
by russ spake
Thanks for your comments guys. You're right Harvey I've seen carbs modified as you described, but I'm struggling to find someone to do them, will keep looking.

Russ

Posted: Wed May 06, 2009 4:04 pm
by topcatcustom
There isn't a chance you mistook a HIF for a modified HS carb? Both are SU's and the HIF's generally look stumpier...

p.s. it can't be hard to put the dashpot in a lathe and part some of the neck off, then just re-tap it! Maybe the engineering shops you have asked got the wrong idea- it sounds like a half hour job, though maybe they are worried about being responsible if they don't work properly when they give them back to you!
If you research it and find you dont actually need the length or travel inside the dashpot, it shouldn't be hard at all.

Posted: Wed May 06, 2009 8:26 pm
by RoverP6B
Hello Russ,

This gent may have the answer. He is selling his Stag fitted with an RV8, and the SU carbs have been modified.

http://www.carandclassic.co.uk/car/C53088/

May well be worth a phone call!

Do lets know how you get on.
Ron.

Posted: Wed May 06, 2009 10:26 pm
by russ spake
Guys,
thanks very much - I'll let you know what the outcome is Ron, thanks.
Russ

Posted: Wed May 06, 2009 11:14 pm
by JC.
You could bin the SU's and fit a webber 4 barrel on an offenhauser 360 inlet manifold. That is a much lower setup and would give you the clearance you need.

Posted: Wed May 06, 2009 11:25 pm
by CastleMGBV8
Russ,

I think the factory MGBV8 had the SU carbs with shorter dashpots.

You could call Burlen Fuel systems who make SU's and see if they can help, if you get stuck I could probably find out the model number,

Kevin.

Posted: Thu May 07, 2009 3:07 am
by ppyvabw
JC. wrote:You could bin the SU's and fit a webber 4 barrel on an offenhauser 360 inlet manifold. That is a much lower setup and would give you the clearance you need.
:lol: He could do. Then he could fit a towbar on the back so he could pull a tanker round with him to keep filling up with fuel lol.

They do tend to be thirsty compared with SU's I find :lol:

Posted: Thu May 07, 2009 6:47 am
by russ spake
Thanks for the advice - fortunately my Stag already has a two bar, just need to modify the heating oil tank in the garden and fit it with a set of wheels to expand the fuel tank capacity! :) Maybe I'll try and get an offy/webber set instead, though I don't really want to pay £500 for a new set, anyone where there's a good second option?

Posted: Thu May 07, 2009 10:05 am
by kiwicar
Have you thought of trying the MGB Su manifold? if you can find one that is lower, yes it is not a performance item by any stretch, but it is an option.
Mike

Posted: Thu May 07, 2009 11:04 am
by topcatcustom
I have some old SU carbs in the scrap bin- if you like I could have a quick shot at modifying one and let you know how it goes...

TC

Posted: Thu May 07, 2009 12:15 pm
by russ spake
Thanks for the tip Mike - my brother has an MGB, I'll check his spares box/contacts!

TC - that would be great, please give it a go and let me know, thanks.

Russ