lpg in B20
 

I would like to put lpg directly into my b20 which has twin su's at present
Can I rig some way of bipassing su's or getting rid of them and having a direct feed of lpg only through the inlet manifold?
Any help/knowledge welcome
Jamie

Yes it can be done. Might I ask why yu want to bypass the su carbs. If you could explain a bit further a what you want to achieve I can advise you accordingly. I have a lot of experience of lpg from performance vehicles to the old and basic including gas only vehicles.

Mike

lpg in B20
 

Hi
I have got a 100l tank in the boot so plenty of miles in the tank and she started well, before I pulled her apart, on a single carb with lpg. So I do not see the need for complicating things with carbs when I can start and run her on lpg and forget the carbs. Is my thinking wrong?
All the best and thanks for your input
Jamie
PS I may well run the rebuilt engine in on petrol for the first 500 or 1000 miles. After that I will put the gas on it. If I was to keep the carbs somebody said I would need to put some vacuum device to hold the pots up whilst running on lpg, does that mean anything to you?
Jamie
PPS Have you used dellortos or solex? Everyone says stick with su's, except for this guy....
The Mikuni flat slide carb is a modern, bolt-on SU replacement that will do it all - more power, better fuel mileage and easy tuning in one package. Now there is no reason to stick with obsolete, leaky, hard to tune SU carbs or having to chose between sidedraft Webers for power or a downdraft Weber for economy. Uses the stock SU intake manifold. Improved for 2007 with smaller float bowl needles and seats to handle higher fuel pressures. As with any carb swap, expect to do some tuning to match these carbs to your engine and get maximum performance and fuel economy. With linkage & manifold adapters - $765. With black top K&N air filters $840, with chrome top filters $855. ( The chrome filters do not have provision for a breather hose. ) Add $95 for silver ceramic coated aluminum SU intake manifold - $50 for the manifold used, uncoated.

I would say that your choice of carbs depends on the state of your present ones. If your SUs are tight and don't need any work then stick with them.

Tom

Tom spot on. If the carbs are A1 then dont wast money fixing what aint broke.
On teh other hand if the su's are **** then there are a few possible ways around it. 1 way would be to use injection mini throttle body's or you could opt to make a manifold for bike carbs if you want maximum go.

Gas only is great but there are odd times when it is nice to have petrol. Trust me I've been there.

Cheers!

The main reason I am holding off this conversion is that Eurotunnel still haven't lifted the ban on lpg tanks, and I like popping to France to stock up on my booze twice a year.

Tom

what about my PS?
 

PS I may well run the rebuilt engine in on petrol for the first 500 or 1000 miles. After that I will put the gas on it. If I was to keep the carbs somebody said I would need to put some vacuum device to hold the pots up whilst running on lpg, does that mean anything to you?
Jamie

Some installers seem to thing that the pots wear out quickly while running on gas as tehy are not getting lubricated by the petrol. I've not noticed this myself with them.

If running gas only there is no reason why you cant just fit a simple throttle body of an injection engine. That is what I have done with one of my cars.

I think these installers must be not thinking straight, as the only contact is between the damper piston tube and the surrounding tube in the suction chamber. You don't get petrol up in there anyway, and the lubrication is by spillage from the dashpot oil.

I have driven my twin carb 122S for 350.000 kms on LPG without any problems with the needles or anything else. (Still running like new)
My 133GT also runs on LPG, for 50.000km now.
I don't believe the story that the needles wear out due to lack of lubrication, because the needles don't touch the jets if they are well adjusted.
If they do touch the jets, than they would wear out when you are running on petrol too.
The pistons rise when you drive the car, so that way they are lifted without any special device.
Also because LPG is widely available in Holland, there is no need for me to run on petrol, but sometimes I do run on petrol, just to keep the system working, but not for a long time because the price of petrol is almost 3 times the price of LPG.