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Post by lockie1994 on Feb 4, 2013 19:18:37 GMT 12
has anyone on here had experience doing this conversion is so what was the outcome as i have read this it the perfect carb for a relativly standard 1256 lump(exept from a down draught but dont want holes in my bonnet for air ect)
any advice would be appriciated
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Post by taistorm on Feb 5, 2013 21:55:38 GMT 12
Ran one in my old Shuvit bro. Went a hellovalot better than the standard carb but was no weapon. nzgem.proboards.com/index.cgi?board=membcar&action=display&thread=874&page=5  Basically what I did was... -Got the 28/36 Weber and had Murray at Weber Specialties rejet it to suit. -Managed to find an intake manifold (one Tim had lying about) that was already set for a downdraft setup. However it was for a different carb so I had to hack it up, weld on some more alloy and mill/grind the crap out of it to suit. From what i've been told Murray can source manifolds to suit but they will probably be fairly pricey. -Make up a mount for the throttle cable to line up with the 28/36. -Voila up and running! Deleted the choke as well as it was unnecessary with the larger carb. Just needed to pump the throttle a few times and she was sweet. Hope that helps dude. |
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Post by lockie1994 on Feb 8, 2013 23:50:43 GMT 12
yes that helps heaps, can these carbs be ran as a side draught rather than a down draught? dont want to have to boulge my bonnet, also do you still have the specs for jets ect cheers
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Post by gordo on Feb 9, 2013 1:28:14 GMT 12
No, the float wouldn't work and all the passages would be in the wrong orientation.
I had been sonsidering a 175 CD Stromberg*, but a 'mate' broke the good engine before I had a chance to do it..
Either on an adaptor with the OEM manifold inlet welded and bored out, or with a new mount to suit welded to a OEM manifold, with a well radiused inlet.
Sounds like you really want a twin 150, like Craig (Bulldog) had at one stage, or a 40/45 Weber or Dellorto sidesucker on a suitable manifold. 40 for a mild tune, 45 for a full on tune.
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Post by taistorm on Feb 9, 2013 11:24:35 GMT 12
Depending on the height of the manifold and height of the air box, you probably wont need to 'boulge' your bonnet. Mine sat with a decent amount of clearance running a Ramflo airfilter.
Tai
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Post by taistorm on Feb 9, 2013 11:25:54 GMT 12
Forgot to mention I don't have jet specs. Also I had to make up amount for the return spring on the throttle setup (can see in picture). Piece of piss though.
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Post by lockie1994 on Feb 9, 2013 15:35:51 GMT 12
ok cool cheers i have heard the 1256 engines flow better with downdraught on them anyhow because the ports are almost directly down
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Post by gordo on Feb 9, 2013 18:24:59 GMT 12
if anything, I'd expect better from a side draft as it has a less abrupt entry into the port. many years ago there was a IDA (?) manifold available from Blydenstein (sp?) that was a more direct manifold, but it definitely required a hole in the bonnet. Thought I'd have a look on Ebay, found this 'tuning' book - I had a copy about 30 years ago (think it was the same book) and while it isn't that useful, it tends to suggest what to buy and who to get to do the work, and was too early for the Chevette, it does have some useful suggestions and information, including suggested camshaft spec's and, I think, some carb' options. I'd say it would be worth the $10-15 for some of you guys, just out of interest. Some things i think they overlooked, though. If you're fast (and rich) - cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=290857285999&fromMakeTrack=true&ssPageName=VIP:watchlink:top:enForgot the link to the book - www.ebay.co.uk/itm/Tuning-Vauxhall-Vivas-and-Firenzas-Coburn-Blydenstein-Droopsnoot-Slant-4-GT-/200888972211?pt=UK_CarParts_Vehicles_Manuals_Litterature_ET&hash=item2ec5ea73b3 |
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Post by lockie1994 on Feb 9, 2013 21:55:49 GMT 12
that manifold would suit me good. im not after heaps of power just a bit more pep to keep her moving with a few more people in the car and for camshaft specs, who does good camshaft grinds
cheers
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Post by gordo on Feb 9, 2013 22:27:51 GMT 12
Kelfords can do them and they're almost local to you - but i expect they'll need a cam to grind. Piper and/or Kent in the UK still do re-grinds, AFAIK, also. However the stock one is pretty good for low, mid and even upper range (6k+ rpm) and if I were you, I'd be looking more to the head, the exhaust and the intake side first, especially as a cam' will normally raise the rpm range with a loss lower down. If you haven't done so, I'd suggest checking out my early posts where I discussed some basic modifications (if you've the basic skills and access to gear, of course) that made around 25-30% more torque around the 2-5k range. Oh, lastly (yeah, right), I'd recommend picking up a copy of a Mini tuning book, such as one of Vizard's, and seeing how that can be used with the 1256, as they're very similar in some ways, for example the heads are both basically 5 port ones, the Stromberg is very similar to the SU, etc, and the main tuning principles will apply to both.
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Post by lockie1994 on Feb 10, 2013 12:56:22 GMT 12
for some reason this site does not allow me to read early posts  not shure why tho |
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Post by gordo on Feb 15, 2013 21:58:12 GMT 12
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Post by lockie1994 on Feb 17, 2013 10:18:29 GMT 12
gordo, I had a good read thru that post seems to be some good info there. you say leave the camshaft standard for road driving? im not after huge rpm but being able to rev to 6k would be nice with that bit of extra power to get it up to speed faster. what can i do to head with leaving std valves in? i have a whole spare engine that i can do stuff to the parts then swap them over,
cheers
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not shure why tho