thinking of my next modded log head

[XFlow_Fairlane]

since my EFI head seems to be working out so far I started thinking of maybe doing another crazy modded log head.

first I was thinking of a split plenum idea. cut out where the carb pad is and close up the logs and then put a new pad for twin carbs or throttle bodies on it....then started looking at the exhaust side...

if the ports were rasied up a little it would help flow alot more.SO....

if I cut off the log totally and the exhaust flange surface and welded a new one in a little higher (1/2" or so) and then brought up the intake runners straight so that some bike carbs could be mounted is what I am thinking. most late model bike carbs mount at an angle like 30-45 degrees which would work pretty good then. as far as raising the exhaust port ...with the log trimmed off totally you cna pretty easily get in there to weld it all back up. granted a stock header may not fit too well then but neither will a stock carb either if I can scare up a cheap set of carbs or a rack of throttlebodies off a newer bike then I will give it a go!!

ideas? comments?

 

[Anonymous]

Welding the cast iron head would be a major hurdle I think. Then again, I'm not a welder by any means. Your idea of splitting the log and using 2 carbs sounds real good! 6 Motorcycle carbs could be had pretty cheap from any Motorcycle salvage. Keep in mind 1 cyl on a 200 = 550cc.

I've thought about fabbing my own 5>1 header for a log head using a large primary for cyl's #3/#4 (combined), say 1 3/4" with no port divider and a small sq to round merge at the flange, then running the other 4 cyl's primary pipes 1 3/8"? around the larger (#3/#4) pipe at 12,3,6,&9 o'clock positions at the collector to scavenge the larger primary. Basically using 4 cyl's to scavenge the weaker 2. Just a thought.

 

[TeddyXY71]

I've always thought it would be interesting to cut and drill two new carb pads further out on the log, but instead of cutting out the center section of the old carb pad, use a fabbed up plate to insert into the hole and mostly block flow between the two 'new' log sections (and also fabbed to cover the old carb hole). That way it might act like a balancer between the two sections, but not allowing bulk flow between sections. Not sure if the idea has any merit though.....

Teddy