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 Post subject: Stock S2 rx7 12a with 13bt inlet (for LPG) install Questions
PostPosted: Tue Nov 07, 2006 7:37 pm 
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Hello, I need a few questions answered in regards to putting a 13bt inlet onto a 12a so i can use parts i have to run on LPG.

I am using an adaptor along with lower/upper manifolds and throttle body from a FC rx7. I am doing this so i can use a impco 225 lpg mixer. Car is pretty much stock s2 rx7 with 12a.

1. 13bt manifolds-> The holes left from the removal of the emmsions gear are usually blocked off by plates, can i just use come chemiweld putty stuff to fill the holes or do these gaps inside the manifold relate to something else.

2. Again how should i block the injector holes, they have a mesh kind of thing inside does this come out?

3. OMP from the 12a has 2 lines, the 13b oil injectors are still there can i connect these together or put the 12a ones into the manifold, the lines also dont seem to be long enough. any ideas? (and no i cant run premix :wink: )

4. On top of the engine are some solenoid things running from the carby, the book says are for aircon and vacum advance, should i leave these and connect to the manifold, would I use the usual bottom vac nipple on the 13bt throttle body for everything?

5. As for timing and what to do, please give suggestions, should i just try running stock timings and see what happens (lock or with vacum as question 4), all other posts refer to turbos in regard to running lpg.

6. When it finally is running and tuned what AFR should i be asking to see, whats too lean and whats too rich in my case.

Ill post up some pictures and add questions as I go.
Thanks


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 Post subject: hope this helps
PostPosted: Wed Nov 08, 2006 11:41 pm 
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why even use the fc manifold at all???


i was running the standard 12a rx7 manifold and adapter plate(over the counter purchase $60 if i remember correctly) with impco 425 mixer (square bore base)and 1 convertor and ran like a trooper before i changed my system to add a supercharger and am still using the 425 with it again..less throttle plate

the other way u can go using the 225 mixer is to make ur own adapter plate to mount an EA falcon throttle body directly to ur existing manifold and hog out the original 4 ports to make it one open ported manifold and the mount the 225 mixer directly on top of the throttle body..easy as

suss the pics on the old setup....just remember this was very early days when i tried to run it as a blo through with minimal success..gerrrrr (kept blowing the top hat gasket due to the constant boost of the blower....till it all got changed...check my thread

http://www.ausrotary.com/viewtopic.php? ... t=blown12a

old
Image

as u can see in the pick there is a spacer plate(actually is a nitrous plate)where i was goin to add propane fumigation to the system..look it up!!

new
Image

i been playin with gas for a few years now and tried many different ways of setting them up..stick with impco or gasresearch as the newer positive pressure systems seem to not work too well on rotas unless u get an adjustable prime gas safety lock otherwise they will flood a rotor on initial prime(i actually gave my adjustable one to my dad..doh....impco's are dumb and simple= they just work and parts arent stupidly priced either

i actually went back to impco after tryin the newer system




10.30 worth of gas for 150klms.....in its current configuration and thats payin 59.9cpl too im cheerin

up the timing till she starts to ping and back it off a smidge as gas likes more advance..u can even lock off ur distributors mechanical advance

i can get u the proper exact figures if u like

i just tune mine by smell but it doesnt hurt them to go a little bit richer than 14.7 to 1
u can tell if the high speed mixture is too far out via the perfomance ...screw out till she dogs and screw in till it starts doggin again and go in the middle..same deal on the 225 as its only a restricter paddle thingy majigy thing

with my setup u can still keep the orig solenoids in place too..but with lpg u can legally remove all emission equipment on the vehicle...hehe

for the omp pump u can actually pull out the brass original omp tubes out of the orig carby and u will see they actually have a step in them when u have ur inlet manifold off u can drill 2 holes(the smaller diameter of the step) and loctite them into ur manifold into the ports somewhere ...if u arent gonna turbo it in the future


when i had my car sit for nearly 12months with troubles with the blower gear (blower actually injested a bit of metal)and was starting to die in the compression department i went back to naturally aspirated and everything other than the blower setup in the old system picture to get sum miles back on the car till she came good again




Ray :lol: :lol: :oops: :oops:


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 Post subject:
PostPosted: Thu Nov 09, 2006 5:04 pm 
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Location: Under a car, NSW
I have a gas research setup to suit 12a with custom manifold/plenum for sale if you're interested. Going to lpg injection :wink:


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 Post subject:
PostPosted: Thu Nov 09, 2006 6:13 pm 
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blown12a thanks for the info very helpful, the reason i ask these questions and not just a generic, 12a on lpg question is becuase I already have these parts I was going to use on my FC but decieded to sell it and run my s2 on lpg instead to make it even cheaper. All ive had to get is 1 manifold adaptor.


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 Post subject:
PostPosted: Tue Nov 21, 2006 1:17 am 
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I Have fitted all the manifolds and parts.
Only really one final question if someone can help me. related to the oil injectors

I will probably fix the omp fully open or is it ok to only do it half way like on 13bt (these have 4 lines though)

I have taken the 12a lines which have the rubber boots on the end , and connected it straight to the 13bt oil injectors in the manifolds, they fit ok but not that tight, i used the stock little wire clamp things as well.

The oil injectors have the vaccum hoses connected, do these help suck the oil through the injector? it must do becuase it wouldnt suck it back up the manifold away from the engine. I read that these lines have a valve and are there so that on boost the oil is still sucked towards the engine?? help me to understand please.

i blocked off the remaining nipples , 2 on the oil distribution thing, one between the injectors and one about half way up the middle of the UIM. What are the last 2 for?

thanks


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 Post subject: oil metering
PostPosted: Tue Nov 21, 2006 7:20 am 
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ok from what i believe is that when the rotors are in the correct position before the port is open to boost the little valves open via manifold vacuum to let the oil flow into the rotor housings for lubrication of the rotor seals and housing...as it is low pressure if the motor was on boost itl only push the oil away from where its gotta be and everything will run dry internally


when my 12a was blo through turboed i use to feed the oil into the turbo compressor housing(same as what i do with my blower now)see above pic..there is 3 pipes running between blower and throttle body...2 are the oil metering pipes and the other is blower bypass valve feed..so the turbo/blower can suck it in and distribute it and blow it into the motor...kinda like a lpg premix


for a N/A motor just feed em into the manifold rails just under the gas carb..

the factory brass pipes that go into the original petrol carb are good to re use as they will just pull out and are stepped so u just have to drill a hole thats the same as the smaller diameter and tap them in till they bottom out ..use a dab of loctitite on them when u tap em in


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