I'm re-installing a new 250 six in my '66 Elco. I'm using an OD Saginaw by TLowe. I'm going to buy an aftermarket manifold and carb this week, and my first choice is Offy and 390 Holley. I would have left a single barrel on it, but I've had poor experience trying to dial them in. If I get the bogs and stumbles out, I loose highway mileage big time. I need to keep good low end, total HP is not important.

Offy and 8007 Holley? Good choice or...........?

grey, i would suggest using one of the carbs from Tom Langdon. it is a proggresive 2 bbl carb. he sells them reasonable and knows how to set them up for inlines. it should keep the responsiveness you want and have perk in the upper rpms.

you also need to heat the intake. he can help with a offy and heat for it. tom

Tom

I had in mind to call Langdon tomarrow and talk to him. I still have his exhaust manifolds and was cleaning them up, and I have the plate for the HW heat. I used exhaust heat on the old motor and although it looked extremely busy with two 1" pipes run around for the heat, it worked OK. I want to clean it up and plan on HW.

I talked to several people today, 2 Chevy 6 guys including Langdon. The recomendations were all over the map.

1 yea on Holley Weber, 1 nay(they run too fat according to one)
1 yea on Offy/500 Edlebrock, the others thought it too big
2 "OKs" on 390 Holley, the other said it was harder to get right.
1 "the best choice overall is the Carter YF" which was a surprise to me. However, after reading up on it, a carb with a 50 year production life must have had something going for it.
1 "otta build the stock Rochester BV"
3 nay on Monojets, which is what I was playing with.

Tom Langdon was very vociferous about hot water heat, and that "NO" exhaust heat system will counter the "refrigeration" effect of evaporating fuel in the manifold. I have his plate, but just couldn't figure out a nice "CLEAN LOOKING" way of running the water to it, and rigged up exhaust. Maybe it worked OK here in Idaho as humidity is very low.

I can't speak to the performance of a H/W on a 250 as I made the conversion on my 1956 235. I found it impossible to find a decent Rochester/Carter core that didn't have an excessively worn throttle shaft and the same warped air horn so commonly found on the Rochester. I got with Tom L., took his advice and the H/W met or exceeded my expectations right out of the box. When I built up a 1960 235 with all of the normal upgrades, I found that a set of dual Carter/Webers gave me the lower end performance I was after. I was after a "cruiser" engine that made it's torque between 1600-2400 rpms and my 54 truck with a .72 T5 and 3.42 R&P will cruise all day at 70 mph @ 2000 rpms and I AVERAGE 18-20 mpg.

Tom is pretty adament about his "water heat" but I went with the exhaust heat, using an infrared thermometer, I verified that it DOES provide quick heat and after 4500 miles I've noted NO ill effects. The level of performance was excellent with both the H/W and the C/W's. Granted, they do not "look" like the stock carbs but 9 out of 10 folks who comment, mention how the stock carbs just didn't provide great performance even when new.

As you've probably guessed, I'm completely sold on the H/W's and C/W's. If you have access to some good stock carb cores you might be able to retain the "look." However, if you're looking for flawless performance, ease of installation and tuning, and a reasonable initial price, than you might consider the Langdon setups.

Dave

I agree with Dave on the heat. Hot water is better than nothing, but exhaust gas is hotter and faster than coolant, and a leak is less of a potential disaster, as long as the exhaust leak doesn't get into the passenger compartment.

Dave,

I looked at your Webshots. Everyting Looks Great. Thanks for sharing. I found the image of the heat on the single carb manifold with Fentons. That should be the way to add heat if you are using headers. Is there a need for the thermostatic spring and bypass that the stock manifold uses? Probably not, as there cannot be much, if any, loss with hot gas takeoffs. Is there any reasonable way to provide positive flow if one wanted faster warmup in northern states?

I played with the numbers a little bit to try to figure how much water VS exhaust gas would be equal.....and it gets kinda interesting.
all numbers rounded.

Water: one pound.........one pint
exhaust gas: one pound...12 cubic ft.

Water @ 200 degrees expands some, exhaust gas @ 400 degrees is 1/4 the density it would have been @ 100 degrees, or, it'll take somewhere near 48 cubic ft of exhaust gas @ 400 degrees to equal a pound.

The heat energy available in a pound of water heated to 200 degrees should be equal to 1/2 pound of exhaust gas heated to 400 degrees, or 24 cubic feet.

I went out and got Tom's "plate", removed one of the fittings and timed how long it would take to fill a pint container. Average was <12 secs @ 15 lbs pressure. I have no idea what the real flow pressure is in the cooling system so I just used the 15 lbs. In one minute you'd see 5 lbs of water. Equal to about 120cfm of exhaust gas, or the amount of gas you could put in a 5'x5'x5' container.

If I'm anywhere close in those figures, then Tom' tirade was with good cause, as my system won't flow those numbers, and the average temp has dropped a great deal by the time it gets close to help heat the carb. If I'm wrong, tell me, please. It's OK, I'm married, and thus never right anyway, so I'm used to it.

You will get lots of opinions on carburetors.

In the one-barrel variety, there are:

Carter YF (W-1's and WA-1's for multiple carbs).
Holley 1904, 1908, and 1920
Rochester B series
Stromberg B series
Zenith 28 and 228 series

In the four-barrel variety, there are:

Carter 400
Holley 390

I personally go with the ABC's of carburetion: (A)lways (B)uy (C)arter. Others will have differing opinions. I like multiple carbs. 2 Carter W-1's on the 250 would be mighty difficult to beat.

Hot water heat is OK, but MAKE SURE TO SWITCH THE ANTIFREEZE ANNUALLY!!!!! Those electrolysis bugs get hungry!

Another option to exhaust and hot water heat to the manifold is to use a sheet metal heat stove on the exhaust manifold forcing the inlet air to pass through the stove. May not look as neat, but does help to better mix the air and fuel, as well as controlling icing.

Regardless of which carb or carbs you use, if at all possible, avoid using adapters. Buy carbs that fit the manifold.

While each brand has its disadvantages (some actually have advantages!); in the long run, most enthusiasts will be best served by purchasing a brand with which they are personally familiar, or wish to become familiar - or keep it stock. Unless the manufacturer makes a model SPECIFICALLY for your engine/transmission combination, than ALL aftermarket carbs will require something (recalibration, different fuel lines, different linkage, different air cleaners, all of the above, etc.).

Jon.

Jon, could you give us an unbiased truthful opinion on which heat is best - exhaust or water - for a standard 235 or 292 type dual carbed aluminum intake?

Tom - not trying to duck the issue, but if there were a "best" we would all drive brand best, wear best clothes, best shoes, etc.

I don't like the water because it REQUIRES new antifreeze each year or the aluminum will dissolve. But if you change the antifreeze, the water will work.

I would use exhaust, or pre-heat the air; but not saying either is "best"; just what I would do.

Jon.

Well, not shure about the Langdon s Weber/Holley.......economical,yeah!
But midpower/torque is really missing! The engine seems to not get enough torque to push it further,,,( GM 235, 3 speed )
Top end is OK!

When using a triple setup (1bbl Rochester ), or original 1 bbl, this stumbling is not precent.

I heard guys say that too,good fuel mileage,good top end,no midrange power.The 2 stage Holley Weber was originally designed for the requirements of a relatively high reving 120 cube 4 cylinder.On a a low reving engine of twice the four cylinder's displacement,there simply isn't enough carb to fuel the needs at peak torque unless you push down the pedal to open the second barrel.That's why two H/W's work well on a typical inline 6,the carbs flow match the engine better.
That being said,your carb could have a lean mixture issue.

Well, it did come newbuilt and adjusted jetting to suit this engine,,direct from Tom.........

Ok,then in your case,the carb flow isn't enough at part throttle,compared to whatever carb was one your engine before.
These Holley Webers are rated at 280 CFM according to Holley's own specs,that's two barrel cfm,rated different that 4 bbl.In 4 barrel terms,the HW flows about 200 cfm.Does the small primary on the HW flow less than your old carb?

I have a stock 250, with HEI ignition, T5 trans, 3.73:1 rear end. I would like to take it up a notch in performance. I am considering the Stovebolt cast iron headers. Has anyone used just one of T. Langdon's Holley/Weber 2bbl's with an Offenhauser (5416) 4 bbl manifold? If so how does it perform and what adapter did you use? Any input would be much appreciated. Also how does a progressive 2bbl carb work with respect to the second barrel?
Is it controlled by linkage or vacuum?
Ken

Hey guys,, I thought electrolosis was mostly a faulty ground/electrical system problem, which can be corrected with good and correct grounding methods,,the cooling system can also be tested with an ohm meter,some systems can be eating the alum as we speak,, others are dead, none or very little,, I purchased a Griffin rad for my truck, and the tech department walks you through checking your system,,,it is also on their site,,they never mention anything of changing your antifreeze,??? Here in Florida with our boats, electrolosis is terrible at wet docks becuase of faulty dock wiring/grounding,, it eats outdrive components and so on, so we mount zincs,, it eats the zinc first, giving you a tell tale of the level of electrolosis in the sea water around the boat,,,you can buy a zinc that goes into the filler neck of your rad, for the same purpose, you just have to make sure the zinc doesn't lay on the core, the coolant rushing past it will erode the zinc into the core,,it kinda has to suspended in the tank depth,,

fingersix - electrolysis will occur in a cooling system of dissimilar metals. Remember the definition of a galvanic cell is two dissimilar metals in the presence of a liquid.

Its been a long time since I looked at a Periodic Table to see which metal is on top, but one item for which we are often asked (and don't have) is the various spacers which Ford used under their carburetors. These had coolant passing through them, were made of aluminum, and most have been destroyed by the electrolysis bugs. Same thing is true of the water-jacketed aluminum carburetors used by Chrysler and DeSoto in the early 1950's. The throttle bodies on the vast majority of these look like a window screen!

Antifreeze has inhibitors. Inhibitors grow old and don't work as well (same, unfortunately is true of humans). In the case of antifreeze, changing annually will restore the protection.

Jon.

not sure what galvanic cell is,,, looked it up,, still not sure what that has to do with electr. Electrolysis is decomposition from an electric current passing through a host metal, dissimilar metals will corrode without the addition of any water source,,,the tech I was referring to is on Griffins site check it out,,if there is no electric there would not be any electrolysis,,put a piece of alum or steel in a glass jar of coolant, it will be there forever,,if they don't touch or the water doesn't evaporate and the steel rusts,,

As I type, trying not to get egg on the keyboard, Carbking is correct,, I chatted with my engineer/car buddy,, basically it is a mixture of the two, the electricity will add to the corrosiveness, but yes electrolysis happens without electric, becuase the disimmilar metals have a electron property within themselves,gaskets break the chain but the anti freeze (glycal or something) acts as an accelerant /bridge just as salt does for the passing of electrons,,or something like that,,,change the antifreeze, and ohm the coolant (Griffin) to be sure there isn't any faulty grounds, makes a happy cooling system,, it's always nice to know I learned something today,,mmmm,, back to work,, :.(

Fingersix - as one grows older, one must find an alternative use for eggs, the doctor doesn't want me to eat them any more!

But one doctor did say that use on the face would help one's complexion! I should never wrinkle!

Jon.

Interesting,I've been running aluminum water heated intakes on cast iron blocks for at least 10 years.No problems and I change the coolant maybe once every five years.
What about all the iron blocks with aluminum heads,like the millions of late model Chevy LS V engines in trucks? Or the 10 of millions of Japanese engines of similar construction? And all cast iron iron engines with aluminum water pumps like Jeep 4.0's?
Is the aluminum used in these engines anodized or other wise treated to eliminate corrosion?

I was always told to use distilled water in a radiator. Is that not practical anymore?

With the newer rads The anti freez is different Then the Old Green stuff. The newer stuff is Orange Which is safe for alum rads. The Green will eat them up Or it does something to the Plastic tanks,I don't remember.

Yes,it's the new stuff for alloy and steel blocks.I also use disteilled water,it's what all the coolant manufacturers recomend.
That being said,I ran a 261 with an aluminum water heated intake for 8 8-10 years on green coolant,changed it once in that time period,no problems like I said.