250 is coming together..

[schaferstephen]

Got my 250 back from the shop, bored 40 over, new pistons, oil pump, timing chain, and best of all... Fresh paint!! I ordered a 274/274 108 hyd cam from CI, for now, I plan on running that with the log head until money permits an aluminum head. I will be using a DUI ignition and a set of Mike's headers, and it will sit in front of a freshly rebuilt T5 that I'm running now with my 200. I have two things I'm wondering about, though...

First. I feel like I'm going to have a hard time feeding this through the stock head. My friend and I had the head vatted and tanked, the valve seats look good, putting in new valve seals, and we can do some mild port work to it, but I feel that the 1brl carb will be highly restrictive. I don't have a way to braze the head up to install a real 2brl carb, and I feel like a tri-carb Offenhauser would be very expensive and very hard to tune. I don't really see a way around running a 1brl till I can buy the aluminum head and intake. I have an Autolite 1100, Holley 1940, and a Motorcraft (Weber?) 1brl that came with my 250. What are yall thoughts on selecting one to run, and how to jet it?

Second. I haven't CC'd the head yet, but I understand stock chambers are supposedly 62cc... that puts my dynamic compression way too low. According to Mike's charts and using the IVC at 65 degrees which is correct for my new cam, if I'm running a .050 Felpro gasket (which I plan on) I need chambers around 48-50cc to have a respectable dynamic compression ratio. Sooo... I believe this means I'd need to decrease chambers by 12cc, I believe it's .007" per cc, so that should be 12*.007 = .084" milled off the cylinder head... Right?

Finally... What are yall thoughts on running my V6 T5 behind this? And any thoughts on using the stock mechanical fuel pump? Not a drag car, just lookin for a fun street ride. Any advice is welcome. Thanks yall!

 

[Gene Fiore]

You should be fine with an OEM fuel pump. Here are two links that I have used to calculate static and dynamic compression ratios...just something to validate your numbers with.

http://www.csgnetwork.com/compcalc.html

http://www.wallaceracing.com/dynamic-cr.php

 

[bubba22349]

You might check to see if your carb opening in the head is 1 3/4 inch if not open it up to that. Any of your carbs will work however if you want the best performance from your combo look for a Carter YF 1V or you can also use a bolt on adapter with a Autolite / Motorcraft 2V or a Holley 350 2V won't match a direct mount setup but still is a good boost in performance over the 1V. Good luck

 

[FalconSedanDelivery]

Good Luck with that combo , too much cam , ( not a fan of the DUI ) it will have so low of a vacuum signal it will be difficult with any 1brl , if you had 12-1 compression , it might be feasible along with a distributor that is curved for the combo , the stick shift will help , but help is all

 

[Inline6Merc]

Check this out for adapting a 2bbl to your log head. Gives you two options and does not involve any brazing/welding.

http://classicinlines.com/logmods.asp#2VC

 

[schaferstephen]

Thanks for the help guys... I'm gonna work on setting up the head for a 2brl. If I can get it to run decently until I can afford the aluminum head... I'll be pumped. Appreciate the help guys

 

[FalconSedanDelivery]

Id use a 500 Holley 2brl ( they respond better out of the box for a low vacuum combo ) try and find a used one with the earliest -number , a recurved dist that allows LOTS of initial 18-24 ( not a DUI), and consider a converter rated at 3500 ( it will only stall 2500 in a 250)

 

[xctasy]

Check this out for adapting a 2bbl to your log head. Gives you two options and does not involve any brazing/welding.

http://classicinlines.com/logmods.asp#2VC

Or there is the Crosley method, which is very, very good and has just two clamp points. Better than any other option if your going to use a direct mount. viewtopic.php?f=1&t=56639&p=440076#p440076


or the old Transco adaptor, which puts the carb around the wrong way, but since the Holley 2-bbl is the worst atomizer of fuel known to man, its okay to swing it around...not optimal, but permissible.

I'm using the last method viewtopic.php?f=1&t=70901


because there is a kit around which fixes the awful atomization " rooster tail" to a much better one, viewtopic.php?f=1&t=70906


and its based on proven aviation Schelber Marvel and Ellison electronic injection fuel supply. And once the single 500 cfm 4412 Holley 2-bbl is on, I'm then adding two other 2-bbl "mates".
The linkage and method to fit it all up is being done to ensure a triple 2-bbl carb intake installation can fit under the hood with a 250 in a 68 to 70 Mustang, early Econoline or 250 Fox Ford, the three hardest cars to fit 4.1 liter engines , but it starts with just a single 2-bbl kti and can be up-scaled without having to mill anything.