Little Mouse

My rich cousin Ron one of his classic cars is a 56 corvette with a two speed power glide and if my memory is right the 283 did not come out till the 57 model yr so its a 265 cu. it has the factory two four setup on it and i'm thinking they might of been 450 cfm factory carbs. Had he not shown me the two fours on it before we rode around the city streets of Wichita Kansas at low speeds i would have never known they were on there.


Like 427 hotrod says if you can tune it will run just as good as anything else.


The first engine masters winner always on speed talk has built engines with the Edelbrock two fours and he uses nothing less then 600 to 750 cfm Edelbrock carbs.

bluedawg

Hi Dwight, I replaced the top end on my l48 before I built the 400". I used the xe262h, Edelbrock rpm heads, 1.6 roller tip rockers, Holley 650 vacuum secondaries, Wieand action plus intake hooker comp headers, 2.5'' dual exhaust and flow master mufflers. it made 260 rwhp and 295 rwtq. I used a .039'' gasket, which in hind sight should have went with a .015'' shim instead to bring the compression ratio up. The vette ran good an pulled to 5500 rpm real well. I replaced the stock converter with a local built 2400 rpm stall and put a shift kit in the turbo 350, which made it more responsive of the line, the compression with the 64cc heads was probably close to 9 to 1, but not quite. I think that it would have ran even better with 3.55 or 3.7 gears.

Replacing the cam with the stock heads will give some gains, but with the 882's it won't be a huge gain. Your intake and carb's although not the best choice in my opinion should function fine.

The things that I would have done differently when I up graded the L48 would be:
1) As mentioned go with a .015" head gasket(shim).
2) rpm intake, went with the Weiand for clearence, but you can get the rpm to fit.
3) All though the edelbrock heads were ok heads, I feel that I left a lot of power on the table with them, I'd either go, AFR or Dart ect. or I'd gone with a set of vortecs, the vortecs would have probably made more power for less money but require other parts that are vortec specific.
4) Went with better mufflers, I love the sound of the flowmasters, but from all that I read and been lead to believe lately they actually don't flow as well as other mufflers such as Magnaflow or Dynomax ect.
5) As mentioned the 3.7 gear for the rear.
6) A roller camshaft instead of the hydraulic flat tappet, the cam when I took it out actually looked fine with 15k miles on it, but the roller camshaft helps power out by allowing faster ramp rates with more time spent at higher lift.

All in all I was happy with it and could out run most of the ricers at the stop light with just shy of 2k$ into the top end not counting the exhaust. Another suggestion I'd make is if you do buy heads, maybe go with 195cc runners, although not optimum for the 350" with that cam, they would be a between size head for future builds. If i'd went with better heads and a roller camshaft, I probably wouldn't have built the 400". Most of us started out adding power to our Vette's by up grading the pathetically under powered L48 and once we got more horse power, it became a sickness leaving us wanting more... Good luck with your project and remeber that it's all in the combination of parts from the carb to the rear gears and tires.

Jebbysan

The Edelbrock C28 low profile intake would never use the Carbs that were bolted on it.....it just does not flow period.
Not to say it could not be made to run around town and work well....
The key is Edelbrocks progressive linkage.....I had the opportunity to play around with one a few years back and they are pretty neat.

Yes it will work. No it is not optimal. Make sure you get the linkage.

Jebby

REELAV8R

The atmosphere pushes the air in as much as the engine sucks it in. It's all about pressure DIFFERENTIAL, not pressure or suction alone on an NA engine. And lets not forget flow capability of all the intake and exhaust components.
Wow 50 year mechanic huh?

roscobbc

Didn't Buick do a Riviera with dual quads? - cfm calculations are not always 100% correct in application - its only a 'formula' not a definitive calculation.
My son runs a '62 TBird with 'warmed' 390, headers, Edelbrock heads and a mild cam. Against all logic (to some anyway) he has installed an early 60's OEM Ford dual quad inlet (ex Cobra?) which is a dual plane rather than single plane configuration. He has used the smallest Holleys he could get (390 cfm) and with some tweaking and work has got it to run fine - with the added bonus of slightly improved mpg, probably down to a high port velocity with its small diameter runners. It can be done

69427

Um, no. I'm an actual automotive engineer. Over the years I've gotten a pretty decent working knowledge of how the laws of physics works in automotive systems. I worked with a lot of talented guys, and I was fortunate to be in a position to learn from their knowledge and experience.

toobroketoretire

What the heck is an "automotive engineer"?

wendellp601

Is that not what happens when the piston retracts while the intake valve is open? Where does manifold vacuum come from?

Another "automotive engineer" here.
I work as an engineer in an automotive manufacturing plant.

diehrd

No point adding anything its all said right there ..

69427

One of the big 3 sent me a check twice a month for several years for the stuff I was assigned to design for them, along with a few years doing engine and chassis dyno work on knock control systems. (And before you mention it, no, I didn't spend any time in the ignition switch engineering group. )

427Hotrod

As has been said....it's not optimum....but it will run fine. I'm not a big Edelbrock carb fan...if nothing else for aesthetics....but if you've got TWO of them they look cool!

A buddy wanted them on his '67 Mustang. He used the 500's. It was literally a junkyard $50 shortblock 302 out of a pickup. Threw some rings in it, a used B303 Hyd roller cam and a set of TFS heads. Obviously a little better package than what you're working with...but they worked great. Now it was a 4 speed with 3.73's in an 8.8 rear...so that helped too.

Side story....he would get real excited when launching and would just blow the tires off it. We spent hours on back roads with a G-Tech meter letting him practice launches on street tires. He'd get it down real good...then we'd go to the track. As soon as he saw the lights counting down his right foot would start going down too and he's end up lighting the tires up again! Eventually we found a little set of 26x8" slicks and I just told him to rev it to the moon and dump it! It ran mid 12's all day long without a whimper.

Anyway....you've got the deck stacked against you a little...and anything you do to help heads, cam, compression it will help....but it can run OK and look awful cool. Oh yeah...they sound incredible at WOT!!

JIM

toobroketoretire

On the down stroke of a piston a void is created and atmospheric pressure fills it. So it's atmospheric pressure that fills the cylinders; not the vacuum. That's why its called a "naturally aspirated" engine. The air/fuel mixture is blown in; not sucked in. Which is why engines produce less torque at high elevations.

gungatim

I used to think gravity did not exist, and it was atmospheric pressure that kept everything on the ground. when I turned 5 and went to kindergarten they explained gravity.

a void filled by atmospheric pressure? I think it was when I was 12 when I learned the definition of vacuum: "vacuum is a void with a gaseous pressure much less than atmospheric pressure".

the principle of equalization is what fills the void...

maybe you were out sick that day in automotive engineering school...

toobroketoretire

And gungatim has now rewritten the laws of physics....................

SH-60B

Too broke is correct about this. The manifold vacuum exists because of lower atmospheric pressure within it. The air is being pushed into the cylinders by 14.7 psi (at sea level). Funny thing is, too broke never pointed this out until I did in a post some months ago, which confirmed to me that he's a fraud.

Solid LT1

Jenkins used the 850 base plates on those 660s with a re profiling of the Venturi taper. I made a set of those back in the 80's for my buddies factory L-89 SS 396 Nova...still feel guilty about what we did so such a rare car but, we were young.

If the OP wants "bling" for car shows, the Edelbrocks will give it to him but, if he's buying a new setup, I would spend my $$ on something else than the proposed combination.

Too Brokes theory of a carb going static is very interesting to a inferior person like me. Maybe Too Broke can explain to all of us how the fuel gets pulled from the float bowls, through the metering circuits into the booster Venturi when his mythical point of equilibrium of air pressure occurs? I'm finding it a difficult concept to grasp myself but, as I have admitted, I'm a mere simpleton compared to the great Too Broke.

gungatim

I guess a certain amount of sarcasm was lost, as was the fact that saying one thing is wrong then stating another is correct, yet the very definition of what he says is wrong is the same as what he states is correct. I guess a more simplistic response would have been NO-DUH!

Les

Dawg,
Nice write up. However, I can't help but to wonder- how's the caribou doing???

StraubTech

Anything can work....but does it "Run". An engine is combination of parts. There are no magic parts. The combination of parts that work together is what makes a good running engine.

bluedawg

his *** is sore, but I think he'll live. nobody but you and 1 other dude on another forum catches on to that...pssshhh, don't tell. I had to laugh when you caught that though.