Well , v i and i set off for Blenheim palace car show this monday , and ,apart from losing each other ,after i roared off down the a40 from witney ,leaving her at the stn , we met up again at the palace ,and waffled into the show ground .(oh by the way , the pressure air feed to the vap did not work.... horrible surging... had to stop and rip it off)
now ... it may be me and my huge ego , but it seemed to be a bit of a magnet , and even more so when v talked me into the centre arena for a modified cars interview session .
the poor bloke on the radio microphone ,started counting trumpets out loud, talking to the crowd , then sort of realised it had 2 engines and demanded to find the owner ,he then grilled me for 10m ,and got me a big round of applause and a special plaque too. lots of fun.
we parked it up ,and according to v i then talked non stop to people for 4 hours .
tell you what that exhaust silencing has basically been digested , its got a hell of a bark on start up ...as everyone nearby will testify when we went .
so back home we roared , cruising much better at 60 mph .and brakes now dip the front on application so thats a big driver aid .
v took these for me , i particularly like the last one .,,looks like its about to bite someone !
so now to the next part of the development program...
since i had filled up at the stn until full , i could now drive back and fill it again, AND SEE MY MPH ..
um ,well this is when i got a little bit of a shock .
now you might say ,hey ,15 ,20 mpg not too good , but liveable with for short trip here and there on lpg ?
how about ,
ready for it ?
THREE POINT SEVEN SEVEN to the GALLON !!!!!!
yup thats 3.77 mpg and gee is about right ! costing me 77 pence per mile ,and 20 mile range on a 40 l tank .
so OBVIOUSLY there is something not quite right in the land of straight 12's , and my next series of steps is devised to sort it out .
firstly , it oiling down the guides, fouling plugs ,which then misfire ,so a new set of guide seals are needed .
its not got enough spark , and so i have my friend Andy trying to fix my old msd Alan fried , and also found what may just be an expensive ally box for 25 quid on ebay , but looks like it may be a viable msd6 china knock off, sold as spares or repair .
next i need to find out how evenly the copper pipes are feeding the cylinders ,and then fit a tap to each feed ,so i can adjust each cylinder separately , my suspicion is that some cylinders are pig rich ,and some lean , so that the end reading looks good , but is, in reality, a sack of pooh.
so to do this i have hoicked out an old pico thermocouple logger that runs 6 egt probes , and i can read the separate pipe temps ,and adjust till even ...how to fit the lpg taps into the system i have not quite decided ... i really don't want to cut my copper pipes up ....so may try to tap the ally mixer stubs for a cross bolt.
to understand the internal condition of the engines , i did a compression and a leak down test on all 12 cylinders ..
the 4.0 was good at 170 psi on all 6 , the 3.6 not so good at 105 to 144 psi on all , however leak down the 3.6 was 10 to 20 % on all cyls, and the 4.0 was 12 % on 3 and 36% on 3 , so i am assuming rusty bores , all the leakage was down the bores not the valves .
weird the 4.0 would have such good comp but poor leakage , i reckon the oiling down is sealing the rings on that one a bit .
so that's where i am so far , oh no i forget i did a scan of the timing curves out my home made distributors , oh you will laugh !
the base setting was 7 d btdc , the 4 litre was getting to 15d total at 3k rpm ,and staying there all the way through ,and 3.6 was getting to 25d total,and staying there ..
so i wanted bae of 15d and 14d advance and i got 18d centrifugal on the 3.6 and 10d on the 4.0 (after i tested it again at 450 rpm and its base was then 5 ).
so i will have those apart and file down the stop on the 4 and build it up a bit on the 3.6 ,then put a slightly heavier spring in th 4.0 and a lighter one in the 3.6 .then set base at 15 ,and this should made a bit improvement in economy .
fun fun FUN .