Flat log pics for a 250?

Does10s

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Everyone,
I've found a 250 motor for my wife's '63 Falcon drag car. It's got the D8BE-6090-BA head on it. Is this head capable of holding a Holley 2300 2v carb? I know I'll need to modify the log. Does anybody have some pics of the "flat" log vs. the "hexigonal" head? I've been all over this site and others and have seen homemade adaptors to fit this carb but I need to know if this head is the "flat log" style.
Thanks
Will
 
Will,

I think this is what you are looking for. The "hex" log is to the right. It has three distinct surfaces - each about a 1/2" wide.

The "flat-top" log has a flattened top about 1 1/2 inches wide.

hexVSflatLog.jpg



I'm also including another picture of a pre-1969 log versus a 1969 "M" and newer log. The top log is a 1967, and the bottom log is a 1974 "HEX". You should take note of the "hex" shape of the bottom log in this picture too. We are often asked if the early log is the same as the "hex" log. You can clearly see that the "hex" is a considerably larger diameter.


hexVSsmallLog.jpg


Another FYI is that aftermarket chrome valve covers are made to fit the early head's port runners (the little bumps on the top log in the picture). If you have a persistant oil leak on the carb side of the valve cover with a late head, you need to grind the reliefs on the valve cover to match the much larger port runners of the later head.

Probably more than you wanted to know - but it's just the teacher in me. Hope this guides you along.
Good Luck
 
Thanks Dennis!
Do you know off hand if this head PN D8BE-6090-BA has a flat top log? I want to do the same thing that you did in this pic
Modified-Manifold.jpg

Do you happen to have any more of these adapters laying around?
Thanks for your help!
Will
 
Yes, yes it is a flat top. However it is a D7 not a D8 and I don't remember if it was a BA or a AB. That part is ground off.

That picture is out of our Falcon SIX Performance Handbook too (page 6).

If you note the little arrow pointing to the bolt hole. Those two holes are the original carb mount stud holes. When I elongated the manifold after machining it flat, I left BOTH of the stud's threads intact and with enough meat not to break. I also left about 1/8 flat gasket surface around the outer edge of the log for adequate gasket seal. Because of leaving the stud holes intact, the elongated hole in this head is smaller than the head directly above it. It was also considerably cheaper to do.

I made a gasket out of a Wheaties (Breakfast of Champions) box and put plenty of sealer on it.

The blue log manifold above it is a "hex" log. The inside and outside edges had to be welded up to form a flat surface. The stock attaching bolt holes were ground away during the elongating process. After this picture was snapped, new attaching holes (for the adapter plate) were drilled and tapped. That welding, drilling, and tapping took more time - and more time means more money.

If you've got Adobe Photoshop (or similar program), right click on the pictures and save them. Then you can reopen them with Adobe and enlarge them. It's much easier to see what is in them.

Nope, I don't have any extra adapters lying around. Dave and I haven't gotten into the parts end at all. This is a piece that AL on the transmission thread could easily make.


Mill your log flat. Elongate your manifold. Go to any machine shop and ask if they have 1/2 inch Alum. bar stock about 3 1/5 inches wide. Get a piece about 6 inches long. (Measure the base of your carb first) ( I took a carb gasket with me and got a half price piece out of the scrape pile)

Cut the plate to the shape of the carb base. You can use a saber saw. Drill and tap the four carb stud holes. Put a phenolic (spelling?) insulator and the carb onto the alum. plate and put your valve cover on. Now test fit the carb and plate to your log for clearance to the valve cover. Put several locater marks on both the plate and manifold to index where your homemade gasket will go on to the plate.

Locate the gasket on the plate and scribe the elongated hole on the plate. I drilled about 30 1/8 inch holes about an 1/8 in inside the elongated circle. I then used a saber saw to finish making the hole. When that piece fell out of the adapter. I put a carb gasket on the other side and scribed its hole. (I used a knife to cut out the gasket's bridge between the two carb bores so I had a big oval.) I then used a Dremel to taper and blend the two hole shapes together. You could also use a drill and grinding bits. (FYI - the more expensive of a bit you buy, the better they cut and the longer they last.)

Good luck.
 
Will, that is exactly what I'm planning to do on my 1980 head. I bought the phenolic spacer from Summit Racing.....part # HLY-17-72 it even comes with the correct lenght studs !!!!
$29.95

BTW thanks to Dennis and David for the inspiration. :wink:

Alex
 
Thanks a lot Dennis!
Turns out I've got the Hex. log! I did buy the motor though. I'm picking up a race ready C4 tonight also. So I'll pull the 170/ford-a-matic out this weekend and drop in the 250/C4 for some fittment exercises! Then it's on to fab'ing a turbo exhaust header!
We'll see if this thing can do a 12 with a turbocharged, intercooled, 250 blowing though a Holley 2300. At 2606 lbs. we only need to make around 273hp at the flywheel. No problem! That's only 1.09 hp/cubic inch.
Should be fun!
Thanks again!
Will
 
Thanks Dennis for that response.

I think so many inliners wish to perform this modification but don't completely understand what is involved. With your step-by-step instructions, I fell more and more people will realize how easy it can be to do this log modification. Understanding with vivid descriptions go along way with most.

Thanks again!

Maybe a sticky or tech section post?
 
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