345 Info

G'day all, this is not strictly a restoration question but I'm hoping to pick someone's brains regarding the old petrol v8 Inters?
I've got a 345/Allison auto in a bus based on an Acco B (1981). It's dual fuel but runs primarily on LPG (for obvious reasons!) The thing weighs about 8 ton give or take, blows no smoke and seems mechanically pretty good, starts easy, runs fine. It gets along okay on the flat (for a bus) but show it a hill and it lays down and dies. It winds up in 2nd very quickly screaming it's nuts off doing about 25km/h and getting right up the noses of the queue of traffic stuck behind it >
All I know about Inter motors is the firing order, that you time them off no.8, that they are supposed to be bulletproof but they don't like to rev. I'm hoping there's something wrong with this one and that I can give it a tickle and get some more low down out of it.
My only plan so far is to replace the points dizzy with a leccy one (or get an Ignitor conversion) and maybe fling the fixed fan off the crank and stick an electric one to the back of the radiator. I'm also wondering about disconnecting the vacuum advance and winding the timing forward a little but I have found conflicting opinions about ignition timing and don't want to risk blowing holes in pistons etc. The exhaust is rather dodgy too and I'd love to throw some extractors on it when I get around to replacing it, but I can't find them over here and the cost of freight to bring them over from the U.S. is ridiculous.
Any and all advice on any of these ideas from someone who knows would be most welcome.
Or is this just how these things are and I'm stuck with what I've got???

Extractors are available locally here in Australia. Your local muffler shop should be able to order them in.

No eBay APP ID and/or Cert ID defined in Kunena configurationExtractors here!!!

Cheers Cummins! Now all I need is to convince the missus :

i would put the 4bbl inlet manifold from a 392 inter on it and a 4bbl carb ..that will help the gas get more air into the motor to burn...many moons ago i ran mine on straight gas and modified the carb so that all 4 barrels opened at once ..lpg loves air to help it burn ..also you can run a bit more advance on your timing ..but generally these motors dont pull the weight very well,they can also tend to glaze the bores . . .

extractors may let it rev a bit harder but you actually loose torque i dont have one but you may be able to look at a torque graph and see overdrive / joey box or a 2 speed arse end may be other options don

prob one reason the inter motors arnt overly endowed in the power department (or fuel consumption department) is the ports are overly large and also large valves ... which may not work so well on petrol (at lower rpm where heavy vehicles need their power) but on gas they can be made to perform better . . . also needless to say they are low compression motors . . i dont think the extractors were made for these engines as a power upgrade but as a exhaust upgrade as the original manifolds are prone to cracking . . .

Kenny's on the right track. 4brl manifold and carbie adds at least 10% but it will take you a while to track one down if my experiences are anything to go by. For some other ideas get on the IH Scout forums in the US. Plenty of guys over there looking at suping up the 345s in their scouts.

Take out the auto and bin it. I ahd an Acco 1810c fire truck with the allison, and it sucked. fuel. lots of it. I installed a later process 5 speed out af an 1810a.
much better. By the way,I have 2 allisons for sale if you know of anyone.

the bulk of the acco fire trucks were 392"powered" they should have the 4bbl manifolds ...theres plenty of guys wrecking the old acco fire trucks for their usually rust free cabs