Anyone with knowledge re: impco 300a system?

[ahud7844]

hi,
1988 3.9 hi comp. engine with a 300a series 1&20 with K&N filter on a 390cfm holley & edelbrock manifold. All new plugs leads cap rotor with scorcher ignition. new converter 2nd hand mixer.
i've read that these systems are unreliable with poor metering capability?
never had a complex mixer system before.
idle fluttery after filter clean, takes a while to settle down. careful to avoid air leaks when reassembling. occasionally when accelerating with foot down it seems to flood, ease off pedal & settles down. i've adjusted for best idle when warm & power set at mark between half & max lean.
any input or ideas welcome.

regards, adam

[bee utey]

I disliked them when I had to fit/service/tune them years ago, I wouldn't willingly fit one now. They can be very stable when new, but when fitted to an offset adaptor are very likely to stall under on-off idle foot movements. The idle mixture adjustment is very touchy, 1/8 of a turn can put it right out. Sometimes the screws holding the diaphragm to the centre piston fall out, that's fun too.

There is much better stuff around on ebay, a suggestion is a new gen mixer and OMVL converter. These are now so commonly sold I hardly bother bidding on them. No too many 4 barrel conversions happening any more.

[ahud7844]

thanks for the reply bee utey. when you say a new gen mixer could be a bit more specific please. i'd like to stay duel fuel for the range. do i take off the holley? The reason i used the 4 barrel was because it bolted straight to the manifold & i wanted to avoid any clearance issues.
regards, adam

[bee utey]

thanks for the reply bee utey. when you say a new gen mixer could be a bit more specific please. i'd like to stay duel fuel for the range. do i take off the holley? The reason i used the 4 barrel was because it bolted straight to the manifold & i wanted to avoid any clearance issues.
regards, adam

I haven't got any new gen pics on my laptop but a quick gargle search brought up this:

Google Image Result for http://www.teamgreenautogas.com.au/Image/Conversions/Petrol%20-%201978%20Ford%20Fairlane%205Lt%20V8/Petrol%20-%201978%20Ford%20Fairlane%205Lt%20V8Venturi%20Syst em%20-%20New%20Gen%20Mixer.jpg (http://www.google.com.au/imgres?imgurl=http://www.teamgreenautogas.com.au/Image/Conversions/Petrol%2520-%25201978%2520Ford%2520Fairlane%25205Lt%2520V8/Petrol%2520-%25201978%2520Ford%2520Fairlane%25205Lt%2520V8Vent uri%2520System%2520-%2520New%2520Gen%2520Mixer.jpg&imgrefurl=http://www.teamgreenautogas.com.au/default.asp%3Fid%3DPetrol%2520-%25201978%2520Ford%2520Fairlane%25205Lt%2520V8&usg=__GtlSdZ-wYl7wOhimxO5R-M6DAPg=&h=480&w=640&sz=104&hl=en&start=0&zoom=1&tbnid=1xRYWIvGAZYEHM:&tbnh=135&tbnw=176&ei=8PKwTcCCEYWevQOMrcWIBw&prev=/search%3Fq%3Dnew%2Bgen%2Bmixer%2Blpg%26hl%3Den%26c lient%3Dfirefox-a%26hs%3D7i7%26sa%3DX%26rls%3Dorg.mozilla:en-GB:official%26biw%3D1382%26bih%3D854%26tbm%3Disch% 26prmd%3Divns&itbs=1&iact=hc&vpx=128&vpy=78&dur=8980&hovh=194&hovw=259&tx=125&ty=62&page=1&ndsp=32&ved=1t:429,r:0,s:0)

They fit on top of Holleys with miminal height and are very good on petrol because of the air plate design which is vacuum lifted on petrol. I modify them slightly to improve their efficiency. My 2 door RR ute has one and it fits nicely.

I have a few spare and could possibly mod one for you after Easter. PM me if you are interested.

Sometimes I modify the 300A adaptors into a fixed opening mixer as in this pic of a WB Holden:

http://www.aulro.com/afvb/attachment.php?attachmentid=35259&stc=1&d=1303442736

I de-gut the 300A head and fit a slotted LPG inlet tube through the cast adaptor. Not hard to do.

[ahud7844]

pm sent