My 272 hasn't beenmodified with a cam. I just running rams horn headers and the ECZ intake, '67 9 inch, its not gonna be a racer, but a driver...Yes I want efficiency, I also, don't want to step on the gas and nothing happens...

 

Speedway has a sale on 500 cfm Edelbrocks with manual choke, 279.00. Dont think it is the best choice for a 272, just giving information. Charlie, how did it fare in the comparison testing?

And Low54, you sold a '53 Customline Coup? The reports of them being difficult for a Y conversion abound, but if there was a good one on hand I would have to give it a try. A neighbor has a 53 moredoor that would be a candidate, but he wants WAY too much.

 

An Edelbrock 500 was not tested but a Carter 400cfm was. The 400 is an original equipment carb for '57 312s and is the same basic design. It came dead last. I had offered my Edelbrock 600 for this testing but he said he had a Carter. If I knew it was an older Carter I would have been a little more insistent about sending mine because there are some differences and people are more likely to use a new Edelbrock rather than an old Carter. My personal opinion is to not waste money on the Edelbrock - that's based on experience.

Here's the order that the carbs placed. The test range was 2500 to 5500 rpm. That's street levels. The engine is by no means a race engine.
It is a .060 over 312, ECZ-B intake, ECZ-G heads, cam, headers. The only thing special is the cam, 238@.050, .400" @ the valve, 280 adv. No porting of any kind.
1st Modified Holley 600 L1850 (now 645cfm)
2nd Speed Demon 650
3rd Holley 465 L1848-1
4th Modified Holley 600 L1850 (now 635cfm)
5th Autolite 1.08 (440cfm)
6th Holley 600 L80457
7th Modified L1850 (now 520cfm)
8th Autolite 1.12 (520cfm)
9th Holley 600 L84010 (model 4010 flat top)
10th Holley 410 L1273-1 (another original equipment carb)
11th Holley 750 L84011 (model 4010 flat top)
12th Modified Autolite 1.12 (cfm unknown)
13th Holley 830 w/ Proform contoured center section, no air horn.
14th Holley 750 L3310-2 downsized to 665cfm
15th Holley 600 L1850-3
16th Carter 400

The Holley 465 is already known to be a good carb for these engines. The fact that it placed 3rd confirms that. So for stock to slightly modified Y's, it's probably the best bet.

 

Charlie,


Was the test a dyno test, 1/4 mile or a "seat-of-the-pants" test etc?

I waffled on the Holley 390, 470 and 570 and finally settled on the 390. I'm just putting it on a truck.......and the Holley guys suggested the 390cfm 4160 carb... I hope I didn't make a mistake!! (I'm good at that though!!)

 

That was back to back dyno testing.

 

What were the differences? Worst to best?

 

A scoring system was used, much like the system used in the Engine Masters. This looks at average power and torque, rather than the peaks. The best carb produced the highest average which translates to the best performance regardless of how high it peaked. The worst carb produced the lowest average which translates to the worst performance regardless of the peak. I don't know what the actual power and torque numbers are but I can post the scores.

 

I'm just wondering if the differences are a LOT.

I suspect the differences are probably notable, but if they're only something like 20hp from best to worst and maybe 30 ft-lbs etc..... I probably won't notice much "seat-of-the-pants"!!

 

The score is calculated by adding average torque and average horsepower, dividing by the ci of the engine (322.04) and multiplying by 1000.
Here are the scores:
1st 1572.7
2nd 1557.8
3rd 1541.0
4th 1534.5
5th 1534.2
6th 1531.7
7th 1528.9
8th 1528.0
9th 1509.9
10th 1502.5
11th 1500.3
12th 1500.0
13th 1487.9
14th 1478.9
15th 1466.5
16th 1466.1

The difference between 1st and 16th is 34.3 avg tq+hp.
1st and 5th is 12.4
1st and 10th is 22.6
You will probably notice 5 - 10 ftlbs so you will most certainly notice the difference between 1st and 16th.

And just to add another one, using my butt dynomometer, the Holley 570 Street Avenger is stronger than an Edelbrock 600 when tested back to back.

 

Ok,


Well, I'll stay with the new 390 CFM Holley.

I'll do something bigger on my next one!!


Thanks!


Rick

 

I had a lot of fun with my F100 1955 ford truck, I took out the 239 Y Block, found a 312 eng, rebuilt it, had the cam reground to a Dempsey 280 3/4 dirt track cam specs, Milled the heads .060 , used a Edelbrock 3-2 barrel manifold, 3 stromberg 97 carbs, headers, 2 1/4 " exhaust with 2 1/4" turbo mufflers, cast iron rings, with a 3 speed standard transmission, and stock 390 rear end, with wide low profile tires, it would do high 15s in the quarter mile, not to bad for a 3800LB truck i found all the parts at the swap meet that rebuilt 312 eng lasted for 18 years, eng was still running when i sold the truck.


HOT ROD Y

Stromberg 97 Stromberg 48 81 Stromberg parts carburetors carbs

 

46...I sold my 53 coupe last november, but it had a Flathead in it...I'm using the 272 for my 54 f-100

 

you'll find that a stock 272 is a hole different animal than a highly tuned slitely modified 312. has anyone tryed a spread bore holley. all you need is a four hole adaptor. they have very small primary's for good milage and throtle responce, but have huge secondarys for full throtle acceleration. the good ones have double pumps and daul metering plates for jet changes. i believe your mechanic could have just used a early base plate on your truck carb. they put the idle screws on the secondary side on governed holleys. the 4150's had daul metering blocks while the 4160's just had a metering plate on the secondary side. you'll find that if you use a two bbl to four bbl adaptor that it acts as a venturi and keeps your low end torque and throtle responce and you don't have to waste any money buying a different intake. i've put a 850 double pumper on a 4 cyl opel engine in a garden tractor and it worked fine, of corse it was to much carb but as long as it's jetted right it will work. the fact that i adapted it down to the stock intake helped because of the venturi affect. mabey someone should do a carb dyno test on a stock 272 for everyone running small y's.