1980 Head Mods

garyt120r

Well-known member
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So I'm doing 2 mods to my head on the 200. The 2bbl adapter from Classic Inlines is a great addition. The second is the addition of injector bungs. Due to the location of the 2bbl carb adapter, injectors straight into the port isn't a possibility. Turns out the side of the log is milled pretty flat from the factory on my 1980 head. I'll drill 6 holes (3/4" in diameter) and then spot face with a 1" circle. That will sit the injector pretty much inline from the intake port. The major advantage to this is before I weld in the bungs, I can do some port cleanup through the 3/4" hole. Hopefully this will work.:)
 
I chose the port side because I worried that exhaust heat would be too much and fuel would get blown to end cylinders.
I would open up the single opening as large as you can, make adapter to larger round valve body, that does not go over ports.
 
Well here's the thing, I need a carb and distributor for break-in. I have an AEM EMS for this engine. So I'll drop in a cam sync sensor next and tune a coil near plug setup from a GM LS engine. Once my ignition is tuned correctly, off comes the carb and I adapt a throttle body on to it. Then more tuning. Once I'm happy with that, next is the blower. But that's another story.

As for heat I'm going to get the manifold jet hot coated. Someday I'll be dropping on a header and I'll do the same thing.
 
leave the one barrel carb bolt pattern intact, run stock carb.
With boost you need to keep your fuel distribution even, how will you keep the center injectors fuel from getting blown to end cyls. at high duty cycles.
You may think that the injector will inject fuel straight down the port but there is not that much force involved.
 
If you set up a jig with some hardwood wedges you could drill/bore the port for an offset flange through a chunk of aluminum in a drill press to get it away from the port runners.

..wait are you carbing this motor or mpi?
 
I'm using a carb temporarily.

i have been thinking about the fuel being 'blown' to the outboard cylinders... at 45psi i wonder how that will be any different than a TBI setup. I guess the only way to mow is to try it and see. if I'm not happy I'll rip the head off again next winter and try something else.
 
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