New Head Pictures

tri-power 250

Well-known member
I'm still getting the head completed. I have added the 3 Carter/Weber progressive 2 bbl's to my D7 head. In the picture, the Valve cover has plenty of room just below the fuel line inlets on the carbs. As the project progresses it appears the rear carb with an air cleaner is going to interfere with the hood. I have to finish the Throttle Linkage then the Air Filter/Housing.
Here are the Photo's so far:

http://my.opera.com/kat4568/albums/show.dml?id=4969252

Ken
 
Try looking at them again, I think I opened them up to the public. (I thought they were opened up to the public). I it doesn't work, let me know and I'll try to repost them.
Sorry,
Ken
 
Very interesting. The tri-power with Carter 2bbl's's has been on my mind as a viable alternative. 'Will be following your project with interest....
 
The short block will be a 250, 300 rods, custom pistons, the crank will have the small block timing chain/gear set up, the cam is up in the air.
The completed head will have 1.80 intakes and 1.50 exh. I think this is where I messed up :bang: . The valve size would have been 1.75 int. I'll see. I do have another D7 head to retry this idea again if the head breaths poorly.
Mike and I have traded ideas that 3 carbs will be a little much for street driving, I'll remove the middle carb, and see what kind of driving improvement's there might be.
Ken
 
Thanks for the views. That's one of those projects where you just step back and look at it periodically. Really nice.

Are you or Mike going to manufacture the wedges or something?

Could be a cool kit. Three wedges: the center wedge has knockouts for either a block-off plate or a third carb mount.
 
The wedges are to see if the idea works. My original idea was to cast a carburetor mount like the 3x1bbl mount. This is just phase 2 of my idea. Get the idea to work. I am not working with Mike on this yet. If this works and he is interested in getting an adapter cast, then we will work together. I am also interested in trying 3 32/36 Webers. Let's see what happens.
Ken
 
I I like this!
:hmmm: I wonder...
the effective cost of: (related to HP)
the offenhauser 3x1 with 3 1bbl carbs
or
3 2bbls modifying the log head...

I wonder if the CFM through these will be restricted enough to function properly. maybe you can use 3 smaller 2bbl carbs. with a progressive 2nd bbl...

another random Idea is to use a 1bbl in the center for idle and cruz, then the other carbs come in when punching the gas, and if progressive the bbl topology could look like this
1-idle/cruise
3-cruise/light accel
5-WOT
it's random but so it this.. :twisted:
 
MPGmustang,
The carburetors are rated 180 cfm each. They are progressive and the primary and secondary throttle plates are 33mm each, I hope they are rated at 90cfm air flow. They do use Weber jets and emulsion tubes so they are adjustable. I do plan to use a wide band meter to get the air/fuel ratio correct.
I'm sure a 3 x 1bbl will get better mpg's, that's not really my concern. My goal is to build a 1 hps per cid :D . The other reason is I haven't seen this done. My other goal is to build the engine for ~2500.00 complete.
This is my shot at a poor man's down draft weber setup.

Please keep your thought's coming, this give's me something to think about.

Thanks, Ken
 
This is my shot at a poor man's down draft weber setup. ... Please keep your thought's coming, this give's me something to think about.

As I mentioned above, you could make a three wedge kit where one could use two or all three of the plates/wedges. I think the hot tip would be the throttle linkage. Almost every time I see the Offy 3-in-1 on an auction or listed to sell, the throttle linkage is either absent or missing some important parts. One of the guys here build a very attractive progressive linkage for a multi-carb setup with all-thread, clamps and heim joints. That would be the key, I think. The fuel delivery could be handled by the buyer depending on his carb array, using flared pipe and off the shelf brass fittings.

You could also do the wedges and instructions for fabrication of a linkage, like Scarebird does with his brake parts.
 
Did you plane the head yourself or have a shop do it? It looks great. I'd like to go the DIY mode and try grinding flat spots on my spare late model head.
 
Thank you for the info on the shortblock. I'll be watching that portion carefully when you get there; especially the 300 rod/ custom piston combo.

EDIT: Another point of interest is the combustion chamber volume once the 1.800" intake valve has been unshrouded.
 
Today, was a good day. I mounted the carbs and cut the holes in the manifold, removed the chokes from the front and rear carbs. My next adventure is to build a progressive throttle linkage as suggested by MPGmustang, port the head and clean all the casting imperfections. I am also going to make some pieces that will fit in the ends to direct the air into the 1 and 6 ports. I'll post pictures of them when I get them done. Then once the head is completed, the shortblock will be next next.
 
Today, I wrote Tom Langdon, of Stoveboltengineco.com, and asked him how to build the throttle linkage. What a great guy, he told me the carbs are small enough on the primaries that you should run straight linkage NOT progressive. This is a great help, I hope the linkage parts I ordered are in tomorrow, I will post pictures after I get the linkage built.
 
tri-power 250":1yxydcqf said:
Today, I wrote Tom Langdon, of Stoveboltengineco.com, and asked him how to build the throttle linkage. What a great guy.

Yeah, agreed. He is. Always a bit of a surprise after contact with some (most?). We gotta 'save', pass the word on those types.

Us Bronco guys have Chuck Atkinson. Lotta advice/suggestions/helpful tactics, loves the vehicle, V E R Y knowledgeable. All ways innovating & has time 4 U. There're always a charm when met!

U go boy! Keep us posted on yer progress!
 
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