2 500cfm carbs on a tunnel ram vs a single 4150.

[AMXstocker1]

we are running a class that states 1000cfm max 4150 carb or 1000cfm combined cfm for however many carbs you want to run. would it be worth the trouble to build 2 500cfm holleys or i guess we could do 2 500 cfm edelbrocks on a tunnel ram instead of a 950 or 1000 cfm 4150 on a big single plane? rules also state no dominators. i'm considering this and noticed holley doesn't sell a 500cfm 4150, quickfuel has a 450 slayer carb thats not really what we need but i was thinking if you could copy the venturi and throttle blade size you should be able to come close. I read and watched the intake test on the 470 mopar that andyf did and it seemed to really like the 500cfm edelbrocks on a tunnel ram

[Keith Morganstein]

Two edelbrock 500's on the tunnel ram. Go for it!

[Frankshaft]

Do the tunnel ram. It will be up 40-50hp, easy, likely more. How do the identity the carbs? Based on part numbers? If so, mod a couple of the quick fuels. Probably should be able to get them to go 600 easy. On a basic 396 stroked SBC, that made 535 with a plenum ported super victor, and a hp 950, a weiand street ram, and 2 600 holleys picked it up 50 hp. And that intake isn't even that good. With a good tunnel ram it would likely be more.

[555RAT]

Just remember that 2 barrel and 4 barrel holley carbs are measured in different manners, I don't know the venturii or baseplate size but there might be an advantage or be less airflow that than two 500 4 barrels. That being said I bought a car that had a tunnel ram with a split 1050 dominator, by way of a band saw, that were inline that actually worked really well so there are several options. I do like the 2 500 eddy's though.

Keith

[NormS]

If you used 2 Holley 4412 2 barrel carbs, do your rules restrict what you can do to them? If not, then using 2 modified 4412's could give you 1100-1200 total CFM at 1.5" Hg, the same pressure drop that 4 barrels are rated at.

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Check out the attached pictures. Does this carb interest you? 595 CFM at 1.5"Hg, oval throttle bore.

[427dart]

Now I like that!

[NormS]

With round throttle bores, the flow is 545 CFM at 1.5" Hg. That's using the original Holley baseplate casting, which makes the carb look much closer to stock from the outside. This one uses a venturi size slightly smaller that a Holley HP1000, and the same throttle bore size as the HP 1000. Increasing the venturi size to the same as the HP1000 would add about another 10-15 CFM(at 1.5"Hg).

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[F-BIRD'88]

2x4 500 cfm Edelbrocks are probabily your best bet.
Aparantly the 500's become 600's if/when the primary booster clusters are swapped. > <

You can dyno power and drag test test compare perf against 2x 660 holley center squirters for reference, benchmark.

The bigger the 2x4 carbs the better , on a t ram.

2x 500 2 bbl carbs is not 1000 cfm @ 1.5"

it is only 707 cfm.

[F-BIRD'88]

There are a few airflow management tweeks you can do to the eddy carbs to get more and better flow out of them.

[CamKing]

2
2x 500 2 bbl carbs is not 1000 cfm @ 1.5"

it is only 707 cfm.

You beat me to it.

Why not run 2 Holley NASCAR 390cfm 4bbl's, or 2 Holley 450cfm 4bbl's ?

[CamKing]

we are running a class that states 1000cfm max 4150 carb or 1000cfm combined cfm for however many carbs you want to run. would it be worth the trouble to build 2 500cfm holleys or i guess we could do 2 500 cfm edelbrocks on a tunnel ram instead of a 950 or 1000 cfm 4150 on a big single plane? rules also state no dominators. i'm considering this and noticed holley doesn't sell a 500cfm 4150, quickfuel has a 450 slayer carb thats not really what we need but i was thinking if you could copy the venturi and throttle blade size you should be able to come close. I read and watched the intake test on the 470 mopar that andyf did and it seemed to really like the 500cfm edelbrocks on a tunnel ram

what size engine?
What RPM ?

[F-BIRD'88]

Cause the 2x 500 eddys flow more air and will make more power.. And at a fraction of the $$$.
Very easy to work on too.

[NormS]

Yes, FBird, 2 STOCK 4412's will give 707 CFM at the 4 barrel pressure drop of 1.5"Hg. Those 4412's I showed here are far from stock. I'd like to know how the tech inspectors for this class interpret the rule, and how they enforce the limit of 1000 CFM.

[Old School]

Why not run 1 good QF 950 or 1000 on a good single plane intake. I like tunnel rams but two inferior carbs will not outrun a quality professional built carb.

Pick another brand if you don't like QuickFuel.

[CamKing]

Cause the 2x 500 eddys flow more air and will make more power.. And at a fraction of the $$$.
Very easy to work on too.

No way in hell.
2 NASCAR 390cfm carbs will out-flow the edelbrocks by a ton.