Inliners International Forums General Discussion Hi Performance 250 chevy build suggestions

Hello, I', a long time reader, first time poster.

I recently bought a '39 Chevy Master Deluxe Business Coupe and I'm trying to lay out some preliminary plans for the motor.

I know that I want a 250 Chevy backed by a T5 OD transmission. As this car will be a reliable weekly driver.

Here's where I am undecided and hope some of you can give me some insight and suggestions.

I'm considering either a single 4 bbl or a progressive 2 bbl manifold. I know Clifford offers both types of manifolds and Offy has 4 bbl and a dual 1 bbl unit (would using 2-1 bbl adaptors on the Offy hurt performance?). So any recommends on either approach?

Also, undecided on whether cast iron headers or tube type. I would like to stick to an early '50s style theme. Is there any significant advantage power and cost wise one over the other?

One more question for now...several years ago I spoke with Tom Langdon concerning a similiar engine build and he suggested a "dual pattern 260/270 degree cam". Does anyone have any experince with such a cam, how is performance and mpg?

Thanks in advance for all your help!!

Hello and Welcome to the inliners world & B board. sounds like a nice ride to be building. first off I'd go with the offey over the clifford do to the fact that the offey will give you much better lowend power an tork over the clifford and for as heavy as that car is you will need it and be happy that you did. The cast iron will out last the tube headers. What are the rest of the specks on that cam any idea? whos is it? The progressive 2bbl is a nice carb. good for cruiseing and the get up an go when needed.
hope this helps so far.}[oooooo]

Hi -- I'm a huge fan of the Holley/Weber 5200 progressive 2 barrel. Langdon has new holley remans cheap, and if you go with that carb on a mildly built 250 I assure you, you'll be happy. Performance is respectable, cold starting is awesome, gas milage is decent, and there are a bazilion jets available so you can tune it just the way you want it.

Boo Radley

Hi I am a lobsterman here in Maine, I have a 292 chevy 6, I attempting to turbo chare it with a turbo off a saab 900, I have read many posts here about his and have learned much, I am most curious about the carb I should use, I have a 1 bbl rochester, some say smaller is better for turbo charging, what particular carbs do you guys use, you say you retard the timing 5-8 degrees, how does this work? I malso have found a unit from dawes devices that can mnonitor the fuel air ratio wioth a o2 sensor, a good way to make sure you dont burn up, I would like to hear from 1 ton of fun or tlowe you guys have done it, or anyone for that fact. also in a marine application, we are alaways under load , it is like driving up hill allday long, do you have any sudgestions about being in constant boost, rpm range 2-3 thousand. Thanks great site guys

Thanks for the reply Twisted6 and Boo,

I haven't had a chance to check the site for responses until now.

Concerning the cam, I don't have any specifics, just a letter from Tom that mentioned such a cam. I will contact him before long to find out more information.

I have a further question concerning the carburetion; I'm assuming with either a Clifford or an Offenhauser 'log' type dual carburetor intake that one would have better fuel distribution to the cylinders as opposed to a single carburetor intake. I'm I correct? Also along the same thought, one would probably want to have both carbs being progressive opposed to running the one nearest the firewall as the primarily and the other as a secondary through a bell crank linkage setup. Is this assumption correct? I'm just trying to get a handle on the options.

One more question; has anyone used the adjustable lifters similiar to what Rhoads advertises? It seems that these lifters with a more radical cam could give one the best of both worlds. They may be expensive though which would quickly rule out the option.'

Thanks again for all your insight and knowledge. Perhaps I can offer some insight myself to others as I progress.

hello delta norm..look under Post in High Performance-topic> Camshaft question-click on link this is the cam and specs of cam That you are asking about....Many use this cam-but if you chose Rhoads lifters you cccould go at least 1 "step" more-
as far as Rhoads lifters are concerned, others here use them including myself -I have them now in my current street 292 and have used them before in a street 250...by using them you can use a larger cam and still have GREAT low end torque-you are correct when you see the advantage of "both worlds" as u state....Rhoads now has a new design out-the V Max, which allows you to use even a "bigger" cam and still retain great low rpm torque....
Rhoadslifters.com