Hi, not great at forums so hope this is more or less in the right place...
Hoping somebody can advise me on a choice of carb/s.... I'm building a rat rod (kind of...) pickup on a 1936 Austin 12, engine is an ex r rover 3.5 injected. I'm hoping to unbolt the top of the plenum, replace with a plate and fit 1 or 2 downdraft carbs. I was considering 2 dgav's as they are plentiful and cheap...I'm used to working on diesels so carbs are a bit of a mystery to me, flow rates, jetting etc.... (the engineering aspect of actually making something fit isn't a problem). All I want is something relaitively cheap and easy to set up that drives ok - and that looks right - no injection, su's or 4 - barrels... - don't want massive power gains as i'm on bike sized tyres and cable brakes... Would be good to retain lpg too, but that's something of an afterthought... Any thoughts or advice would be greatly appreciated.
Kind regards, Edward the right place...
Carb advice please...
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Hmm. Most Austins had distinctly marginal brakes for their standard engines - let alone something with 6 times the power.
Fitting a downdraught carb to a RV8 is a common conversion. But you'll also need the appropriate manifold. Holley is the usual make.
Fitting a downdraught carb to a RV8 is a common conversion. But you'll also need the appropriate manifold. Holley is the usual make.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
Fitting a plate instead of the plenum will give naff fuel distribution. With the trumpets removed the plate may just fit but the fuel will tend to go straight to the runner directly below the carbs.
Twin 2 barrel carbs have been fitted to the RV8 with success but the proper manifold is hard to come by.
As DaveEFI said, the norm is a 4 barrel holley or similar fitted to an aftermarket manifold.
Cheers Denis
Twin 2 barrel carbs have been fitted to the RV8 with success but the proper manifold is hard to come by.
As DaveEFI said, the norm is a 4 barrel holley or similar fitted to an aftermarket manifold.
Cheers Denis
1950 A40 Devon Hotrod with 5.0 twin turbo RV8.
EDIS8 wasted spark, Holley Injection.
Been as far as the Moon and back in 57 years of driving. Same Car, 5 engine upgrades !!!
EDIS8 wasted spark, Holley Injection.
Been as far as the Moon and back in 57 years of driving. Same Car, 5 engine upgrades !!!
Hi
the simplest carb to get it running on is the SU, it is a constant velocity venturi carb, basically in practicle terms it means it gives a fairley constant fuel to ari ratio regardless of what engine it is fitted to, then you modify that fuel to air ratio for points in the rev range by means of a spring and needle.
The second simplest carb to use (from the point of view of fitting it and running it, then tweeking as you go) is a 4 barrel with vaceum secondaries, mainley because hundreads have been used on rovers and someone on here will have the setup you need and it is less critical for linkage set up than a mechanical secondary set up.
Alot of the choice is down to how you want it to look and how much fabricating you ant to do, and also what your budget is, SUs on a rover manifold will be cheapest, Sus on a boxer type next (but you have to find 4 Sus, not easy these days) a 4 barrel on suitable manifold, but if you get a 4 barrel buy new or be prepared to wait around for one under 3 years and 40K miles old and even then overhaul it when you get it, they are very cheeply made (unless you buy a specialist one made entirly from aftermarket parts) and full of small passages and were never designed to last like an SU or even a Stromburg.
Avoid Stromburgs unless they are new old stock and have been stored properly.
If you want to fabricate something then do so, but I would do alot of research first and base it on a sheet metal tunnel Ram with some method of progressivly bringing succesive carbs into play, like using Vac secondary carbs or a 3X2s type linkage used of stromburg 32 carbs on 1960s US manifolds.
Best regards
Mike
the simplest carb to get it running on is the SU, it is a constant velocity venturi carb, basically in practicle terms it means it gives a fairley constant fuel to ari ratio regardless of what engine it is fitted to, then you modify that fuel to air ratio for points in the rev range by means of a spring and needle.
The second simplest carb to use (from the point of view of fitting it and running it, then tweeking as you go) is a 4 barrel with vaceum secondaries, mainley because hundreads have been used on rovers and someone on here will have the setup you need and it is less critical for linkage set up than a mechanical secondary set up.
Alot of the choice is down to how you want it to look and how much fabricating you ant to do, and also what your budget is, SUs on a rover manifold will be cheapest, Sus on a boxer type next (but you have to find 4 Sus, not easy these days) a 4 barrel on suitable manifold, but if you get a 4 barrel buy new or be prepared to wait around for one under 3 years and 40K miles old and even then overhaul it when you get it, they are very cheeply made (unless you buy a specialist one made entirly from aftermarket parts) and full of small passages and were never designed to last like an SU or even a Stromburg.
Avoid Stromburgs unless they are new old stock and have been stored properly.
If you want to fabricate something then do so, but I would do alot of research first and base it on a sheet metal tunnel Ram with some method of progressivly bringing succesive carbs into play, like using Vac secondary carbs or a 3X2s type linkage used of stromburg 32 carbs on 1960s US manifolds.
Best regards
Mike
poppet valves rule!
RV8 carbs,,,
Many thanks to you guys for your helpful replies re carb choice for my rover v8, lots of food for thought!
I think I will definitely go for something that has been done before and is known to work, otherwise there are too many unknown factors!
Re brakes... I've been undecided from the start whether to keep the original wheels / rear axle / brakes... I am now thinking I'd be best to upgrade all three at the risk of losing authenticity... Otherwise things are going to get broken - probably me included! No point in having the v8 if I'm scared to use it...
Thanks again for all the advice, Edward
I think I will definitely go for something that has been done before and is known to work, otherwise there are too many unknown factors!
Re brakes... I've been undecided from the start whether to keep the original wheels / rear axle / brakes... I am now thinking I'd be best to upgrade all three at the risk of losing authenticity... Otherwise things are going to get broken - probably me included! No point in having the v8 if I'm scared to use it...
Thanks again for all the advice, Edward
