Originally Posted by niki_rx7' post='901990' date='Jun 15 2008, 02:49 AM
hi, guys i live in Bulgaria in eastern Europe, here is very popular to drive on propane and i have another car on lpg but i wonder if to use it on my rx7 too. but i have some doubts about the lubrication of the compression seals.of course the oil metering pump and oil injectors will go on with delivering the oil into the intake and inside the combustion chamber, but isn't there any difference between the gasoline/air and the propane/air mixture. the gasoline is liquid and wet but the propane is gas and is dry.i have seen it coming out of the hose and it is almost invisible and quite dry.will it mix well with the oil and lubricate properly the seals ,or it could cause a dry condition work and insufficient lubrication to the seals.can the use of propane cause this way an abormal and premature wear on the housings,seals and seal grooves?i see there are some people who have already done this fuel conversion, so please share some experience about that.thanks.
so far, no problems, the oil injectors meter directly to the apex seals
i turned my wick up slightly ( retrofitted s4 mech OMP )
the motor was torn down to replace a failed stationary gear and crank ( related to thermal crank pellet fail )
and was clean as a whistle inside, showing no abnormal wear 20 000 LPG km in
-on already s/h seals with more than 100 000 km import history
( done another 20 000 km mild ported since then, AOK )
you can see the OMP "stripe" and absence of normal carbonization of the rotor ( particularly on the sides )
the turbo turbine wheels of the turbo's used so far are stark white !
- longevity= no issue, the rotary is particularly suited to dry fuel due to its OMP and cold side intake with no valves
i highly suspect a rotors long stroke high surface area chamber is suited to the lack of boundary cooling and continuous slow burn characteristics of LPG
i think thats also why they are using H2 now !!!
my apex seals and housings are AOK with normal wear
and spark plugs go forever, unlike with petrol
it will even ping softly and give much warning that the tank level is low, or today's batch has a little more butane in it
( even if you run aggressive ignition timing )
petrol will NOT !!!!
for all those s5 FC and FD and rx8 engines with electronic OMP
i have paired up with a wizz and helped develop this -
( full 3d map and rev and TPS version soon )
look me up on youtube to see the prototypes development
I will not be stepping back from LPG
-even blow through mixer/ carbs run rings around some aftermarket EFI for smoothness and hassle free operation
and cheap EFI does not compete for cost of operation or ease to live with
( only range for the tank fitted, does petrol have a small win )
cheap as chips, cheaper than a modern multicam 2L family sedan to operate
and goes like hell , smooth as silk
this is the way to go
- if you have vapour injection available, and some added injector sockets , the cost is high, but difficulty easy
and the result is a huge saving over the carb/ mixer style in LPG usage
( an even better cost effective solution )
- but for rotor turbos, the mixer is entirely adequate, and surprisingly effective when you sort you ignition timing out