1957 Fairlane Y Block

[ROKuberski]

Dave,

I've got the same catalog.  It says that decal is for the 1956 292 engine.  I have never seen something that said it was for a 1957 292.  However, if that is the consensus, that's what I will get.

Rich

[KULTULZ]

The 1957 292 was ID'd as THUNDERBIRD -

[hiball3985]

Thunderbird V8 should be correct for a 292, that is what I used on both of mine.

[ROKuberski]

Trans is a T85 OD, rear gears are 3.89, tires are 215 X 14
I like the over all performance of the 390cfm, but at 90 mph it kind of flattens out like its gasping for air 

I just ran the numbers again, a 292 @ 4000 RPM sucks 338 CFM (at sea level.)  Your carb would support 4588 RPM.  I think the pistons fly out of the engine at 4587 RPM.

Rich

[SkylinerRon]

The stock Holley for the 57 312 is 410 cfm.

Ron.

[ROKuberski]

My first call to S & J engines was January 10th, at that time, the desired delivery date based on info they gave me was March 14.  This was not a promised date, but I treated it like it was and for the last two weeks they heard from me frequently.  Well, the engine shipped today and they said it should arrive Thursday.  If it does, I will be pleasantly surprised.  I had allowed 2-weeks to finish my prep work, but the really cold weather now has me behind, but not by much.  I think I have everything I need, including the valve cover decals that I ordered this morning.

As always, it's great to have all of you to consult with during a project.

Photos to follow.

Rich

[terry_208]

I just ran the numbers again, a 292 @ 4000 RPM sucks 338 CFM (at sea level.)  Your carb would support 4588 RPM.  I think the pistons fly out of the engine at 4587 RPM.

Rich

With everything else being equal but with a 302 @ 2800 feet altitude, a 390 CFM carb wouldn't be quite enough carb to get the most out of my engine, would it?

[ROKuberski]

Lets start off with "I am not a combustion engineer."  However, it's really easy to calculate how much air an engine can draw in.  Take the displacement and divide it by 2 (302/2=151.) (In a 4-stroke engine a piston only draws in air every other revolution.)  Then multiply that by the RPM at max HP.  (I don't know what that is for your engine, but lets say 4,500 RPM.)  So, 151 * 4500 = 679,500 (we now have air intake in cubic inches per minute at 4,500 rpm) Divide that by 1,728 to get cubic feet per minute.  393.2 CFM.  Going up in altitude will not make a reduction in the volume of air through the carb, but the air is less dense.  Here where I live at about 5,600', we use .83 to make that correction (a 17% reduction.)    I would say that you would not want to be at 100% of capacity, but I don't know what would be a better number.  Maybe 10% or 20% more would work better.  Another thing to consider is how often do you need to have 100% of your power available?  Are you racing or just want to be first in line at Starbucks?

My EFI unit will make up to 350HP and it's the 2V one.  A stock 292 is 212 HP and I was getting about 17 - 18 MPG on the old engine, I doubt that the new one will be much different.  My 2021 Explorer has a 2.3 liter engine making 310 HP, it weighs about 600 pounds more than the Fairlane and gets about 23.5 MPG with the driving I am doing.  That's 34% better than the Fairlane.  When they say they don't make them like they used to, that's a good thing.

[Ford Blue blood]

Lets start by saying I'm not a combustion expert or engineer.....Only flaw in the calculations is the numbers are "static".  That is they don't take into count things like manifold design, exhaust scavenging, cam shaft profile etc.  Now having said that, those numbers are good for developing a base line.  They will also give you an idea of "over sizing" a carburetor.

A perfect example is the Boss 302 engine.  Came from the factory with a 735 CFM Holly.  Made "290 HP" (really 350 - 360).  Add headers, the 289 Lemans cam and a 850 CFM, timing modifications and HP goes up to well over 400.

So how to size a carb?  For the old shade tree guys like me I now look at (no longer have access to the tools I had when racing) what others have done, exhaust gas sensors and good ol seat of the pants.  IMHO you can't go wrong with a 550 - 650 CFM on a "slightly warm" 312 with stock Thunderbird exhaust manifolds.

Just to add, I fully agree, "they don't build them like they used to" statement!  The 16 F150 I drive with a 5.0, six speed and 3.55 gears gives a solid 20 - 21 MPG running along at 75 MPH.  The Shelby GT500 gives a solid 19 - 20 MPG running along at 75 MPH with a 3.73 rear gear.  That's while making 502 RWHP on the dyno!  My Boss 302 in race trim gave 8 - 9 MPG (on the track) and after returning it to a street configuration (4 speed and 3.91 gears) a good day was 14 - 15.

[hiball3985]

I just ran the numbers again, a 292 @ 4000 RPM sucks 338 CFM (at sea level.)  Your carb would support 4588 RPM.  I think the pistons fly out of the engine at 4587 RPM.

Rich

When I had a tach hooked up I would run to 5200 rpm quite a few times in the lower gears. Only thing not stock is F code valve springs, only concern was bending a push rod. I didn't have a tach the few times I had enough open road to hit 90mph so I don't know what the rpm was..

[ROKuberski]

The 1957 292 w/automatic is rated at 212 bhp (158 kW) at 4,500 rpm.  I would guess you are falling off the peak of the performance curve by going to an even higher rpm.  If there is a published redline, I did not find it.

The stock car with 3.1 diff (no o/d) at 4,500 RPM would be going 115.2 MPH.  You might need a slight breeze behind you to achieve this speed.  Also, a very straight road with no bumps.  On the highway, I keep up with traffic.  It will cruise at 75 all day long.  And, with my new engine that won't burn or leak (I hope) I won't have to check engine oil every time I drive it.  I think I'm wearing out my dip stick.

Rich

[hiball3985]

I'm sure I was over the max hp at that rpm but it doesn't happen often. 99% of the time I'm doing 65-70 on an open road.. In 1967 I had a 58 with a 292 2x4V and hipo cam with 3.25 and 3 spd OD and got clocked at 118 by Hiway Patrol but he only wrote me for 85..

[djfordmanjack]

Thats a lot Jim ! 

clocked at 118

[ROKuberski]

In 1967 I had a 58 with a 292 2x4V and hipo cam with 3.25 and 3 spd OD and got clocked at 118 by Hiway Patrol but he only wrote me for 85..

It's good to have friends when you need them.  In 1970 I was crossing the panhandle of Oklahoma on US 54.  Speed limit was 65 and I was doing 95, about all my little Triumph Spitfire could do.  The cop wrote me for 20 over.  Otherwise, he said he would have to take me to jail.  I had to follow him to a US Post Office mail box and put cash in the envelope and drop it in the box, or put my drivers license in the envelope.  I don't remember what the fine was, but it was a strain on my wallet.

Rich

[hiball3985]

Thats a lot Jim ! 

Luckily the officer was a car guy. He let me off easy because it was at 1:00 am and no traffic..
I told him I wish I had the ticket for 118 so I would have documented proof. He explained that would be speeding and reckless driving and would cause me more problems then it was worth..