LPG Eberspacher and Coolant Circuit

CycloneMike

I want to fit LPG to my Subaru T25.
My cooling circuit is made up using Richards kit and with the exception of having no rear heater (yet) uses the design below.
http://www.rjes.com/html/circuit_design.html
I also have a Hydronic Ebber to go in with the associated rear heater matrix, calorifier water heater and 7 day timer. All to add into my camper.
Can anyone offer me some simple step by step advice as to:
1 Where in the circuit I should tap in for the LPG vapouriser? Should it tap in line after the bypass valve on the way to the front heater matrix?
2 Where should the ebber go. I think this should then go in after the vapouriser?
I know if I get it wrong my engine is at risk of overheating so any advice apprieciated.
Regards,
Mike.

rjes · Posted: Thu Jan 22, 2009 7:04 pm Post subject:

Hello Mike,
When the LPG is off, the vapouriser ought to be a sufficient heater bypass, plumbed in the middle of the 'H' shaped adaptor from the kit. The bit which is an unknown so far is whether, when the LPG is on, the vapouriser will be capable of removing enough heat from the coolant to induce the problem for which Tom Shiels in Canada makes his 'cold climate thermostat housing' to solve. Also, it will depend on ambient temperature and whether your heater is on. Basically, if too much heat is removed from the coolant getting back to the engine, the thermostat cab close as it thinks the engine is cold. 'Norway' on here has just fitted one of Tom's kits in his Syncro, as it's pretty cold in Norway too, and said it works very well.
In the UK it does not get cold enough to need Tom's kit, but it may effectively do if you have the heaters on, on a cold day, running on LPG. I would try it without first, and watch the temperature gauge carefully when on LPG, especially on cold days. If it does get hotter than normal, get one of Tom's kits and see if it helps. It should.

How you plumb the Eberspacher depends on ehat you want it to do. If it's just for running your rear heater and calorifier, then it doesn't need to be lpumbed in to the engine at all. If you want it to run the front heter too, or preheat then engine (not cold enough in the UK????), then it's going to be considerably more complex. My ex ambulance has a factory fitted Webasto which heats the front and rear heaters without heating the engine. The plumbing is comples to achieve this, and uses 2 non return valves, each with 2 in's and 2 out's, plus a solenoid valve. It seems over complicated to me. I suspect it may also be able to preheat the engine too, but haven't spent too long thinking about it.
_________________
Regards,

Richard,

R J Engineered Solutions
Quality Subaru Powered VW Components
www.rjes.com

CycloneMike · Posted: Thu Jan 22, 2009 9:50 pm Post subject:

Thanks for your advice today Richard.
I think I have got my head round it now!

richbaker78 · Teacher of Padawans Joined: 31 Jan 2006 Posts: 1298

IM very interested in this as i will also be fitting a eber D5W plus LPG although with a radiator system instead of blown air.

if you have a chance to describe/ ideally draw or photograph your system set up I would be very interested.

I was hoping to use the D5w as a preheat so that switchcover temp on the LPG is a little sooner - altho if it proves too hectic i will probably stick to a normal set up.

Are you using an ex Bt D5W?

rjes · Posted: Thu Jan 29, 2009 6:05 pm Post subject:

Hello Rich,
I wouldn't bother with the preheat in the UK. Eberspachers are fairly thirsty (well mine seems to be), so it's probably not worth the plumbing complexity, especially if you want to choose between interir and / or engne preheat. Just let it warm up on petrol for longer. Some systems will apparently start fine on LPG. Try it and see, or read up about which seem to be good at it (then raise your compression ratio to take advantage of the high octane rating too, and forget petrol....in theory). I imagine a very powerful spark is needed to satrt on LPG, but your engine probably already has coil on plug?
_________________
Regards,

Richard,

R J Engineered Solutions
Quality Subaru Powered VW Components
www.rjes.com

sven · Jedi Guardian Joined: 27 Dec 2006 Posts: 814

Richard, it must be either a thirsty one you've got or a really old one. The Eber's gives almost 100% heating capacity compared to the amount of energy they consume, a lot better in cold weather than having the engine running.
On the other hand, do you ever get minus degrees? Happy

So in the end your assumption is probably right, they are maybe not needed in the UK.