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Carb recommendation. 468 Tunnel ram

General engine tech -- Drag Racing to Circle Track

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cv67
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Carb recommendation. 468 Tunnel ram

Post by cv67 » Wed Oct 09, 2019 10:23 pm

Friend has a 468, 11:1
For now it has some old GM Ovals, single plane, proform 850
Will be freshening it up and adding:
AFR 290s
Edelbrock street ram
Unfortunately no cam specs...its a HFT sounds like its 240 no bigger than 250 with a tight lsa
Might switch to roller havent quite got him talked into it yet.

31 Panel Tubbed , T400 3000 stall
Dont know the gearing that may all be changed

Anyways hes stuck on using the latest Edelbrock carbs, have no idea what would be best for him.

Holley is out for him period.
???

F-BIRD'88
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Re: Carb recommendation. 468 Tunnel ram

Post by F-BIRD'88 » Wed Oct 09, 2019 10:43 pm

So. What's the problem.? The the Eddy carbs work great on a tunnel ram. Don't bother with the 500 cfm's.
2x 750's work great for what you're doing.

ClassAct
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Re: Carb recommendation. 468 Tunnel ram

Post by ClassAct » Wed Oct 09, 2019 11:09 pm

He should just buy another PF 850 and run those.


I don't care who says what, the Carter/Edelbrock carbs do not have the tunability of a Holley or Holley clone. It's that simple. He will be giving up power, and tunability and driveability.

Those are just simple truths.

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Re: Carb recommendation. 468 Tunnel ram

Post by mag2555 » Thu Oct 10, 2019 6:39 am

As posted above if he is willing to do what it takes tuning wise to max out the combo then the tunnel ram will be the way to go with the better flowing heads.
That being said if he's stuck on the Edelbrock Carbs then shows that he does not care to put the effort into maxing things out and to me he is then running the tunnel ram more for the sake of eye Candy and not max performance!

If this is the case then unless he has the tunnel Intake already he would be better off running a single plane Intake and new 950 hp Carb.

One Carb is easier to get right then 2 of them!

cv67
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Re: Carb recommendation. 468 Tunnel ram

Post by cv67 » Thu Oct 10, 2019 11:33 am

he thinks the eddys will be more reliable. Not aware how good the newer holleys are
It sits a lot so has issues occasionally with sticky floats etc...Hes 63. Plans on tracking it, drives it pretty hard

Think hes got ahodge podge of a carb but hes stubborn. So which model/size edelbrock?

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Re: Carb recommendation. 468 Tunnel ram

Post by F-BIRD'88 » Thu Oct 10, 2019 12:08 pm

He is right. The Eddy carbs are much easier to live with in 2x form for this purpose. Yes 2x competition Holley's will make a bit more power. The Eddie's make huge power and are goof proof on a tunnel ramed street motor.
Again don't bother with the small cfm ones.
2x750 is just right.

The cam needs upgrading probably.

A fair size mechanical street roller really gets it done on a 468.

My recommendation is not based on old wives tales.
The eddy carbs are just as tunable. The thing is they don't need that much to get them right for the tunnel ram.
It is the HFT cam that will be the performance limitation.
Depending on the actual goals.
Last edited by F-BIRD'88 on Thu Oct 10, 2019 12:29 pm, edited 1 time in total.

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Re: Carb recommendation. 468 Tunnel ram

Post by ClassAct » Thu Oct 10, 2019 12:24 pm

cv67 wrote:
Thu Oct 10, 2019 11:33 am
he thinks the eddys will be more reliable. Not aware how good the newer holleys are
It sits a lot so has issues occasionally with sticky floats etc...Hes 63. Plans on tracking it, drives it pretty hard

Think hes got ahodge podge of a carb but hes stubborn. So which model/size edelbrock?

I'd say a Holley is no more or less reliable than anything else. The Holley has much more tuning capability than anything else. This nonsense that one carb is more reliable or "bolt on" than another is crazy.

Your friend is going to do what he wants, because he hasn't spent the time to learn. He will keep on doing what he's done because that's the easy way to go.

Again, I don't care who says it, the Holley is more tuneable, will make more power and drive better when all is said and done than an Edelbrock. It's sad that these old wives tales never die.

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Re: Carb recommendation. 468 Tunnel ram

Post by F-BIRD'88 » Thu Oct 10, 2019 12:32 pm

If more people realized how good and simple the Eddy carbs work on tunnel ramed motors a lot more would use a tunnel ram for bracket racing or not fear doing so.
Yes big competition Holley's make a bit more ultimate power on a TR than 2x eddies. But not much.

If I was going to use Holley's I'd use 2x Holley / Pro-form 750HP DP carbs. I build my own using donor carbs and Pro-form parts. You can too.
Don't bother with vs carbs .Don't bother with small cfm carbs.

cv67
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Re: Carb recommendation. 468 Tunnel ram

Post by cv67 » Thu Oct 10, 2019 1:05 pm

Your friend is going to do what he wants, because he hasn't spent the time to learn. He will keep on doing what he's done because that's the easy way to go
I agree, hes not hip to the latest Holleys and a little stuck in his ways.
Yeah part of it is eye candy but cant blame him an old st rod like that is screaming for a TR or blower. Its got attitude for sure.

We are both gonna run our stuff down the 1/4 this fall so I think part of it is him wanting to make sure he makes mince meat outta me. lol

I cant sway him from the eddys so just wanting to know what size/model he should start with. Moneys not the issue if hes not happy he wil switch.

===================================================================================================================
By the way...this TR took a lot of work to port match to the afrs gasket....think I should call it good are the rest of the runners sufficient?
They are blended about 3 inches in.

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Re: Carb recommendation. 468 Tunnel ram

Post by F-BIRD'88 » Thu Oct 10, 2019 1:19 pm

Eddy carbs 2x 750. Eddy#1407 (AFB)

Eddy carbs 2x 800. Eddy #1912 (AVS) (AVS2)
Feature new annular pri boosters
Feature fully adjustable sec air door.

Both will need rejetting on a TR.

He will kick your @$$ once dialed in. Ha ha.😁

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Re: Carb recommendation. 468 Tunnel ram

Post by F-BIRD'88 » Thu Oct 10, 2019 1:38 pm

For street strip use be sure the distributor has vacuum advance.. ya it matters.

Keep the manual cable operated chokes/fast idle
Functional on the Eddy carbs. Keep your options open
Here...

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Re: Carb recommendation. 468 Tunnel ram

Post by cv67 » Thu Oct 10, 2019 1:46 pm

Hes using an HEI no doubt if he can hook/go straight Ill get dusted. HIs car weighs nothing outpowers me bigtime etc.

Time to break something trying, never know! Lightened my steel a body up as much as I can but still its a tank with an overcammed sbc

So 2 750s then? Imagine he will need more pump shot...trying to talk him into an 02 sensor deal, need one myself.

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Re: Carb recommendation. 468 Tunnel ram

Post by Steve K » Thu Oct 10, 2019 9:17 pm

Not sure if a HEI will work with a TR, at least it wont on a SBC. I have two cars with tunnel rams, street driven as often as possible, one is a 406 in the 570 hp range and the other a 427 in the 660 hp range. Both are small blocks. I'm using 1405 eddy's on both cars. Changed the step up springs and went with thinner metering rods and removed the choke plates. Both cars rip with minimal tuning. Throttle response is bang on, no stumble, start easy even when cold with no choke. Bolt them on and go. Have no idea what Holley's would bring to the table but I sure as hell haven't got time to spend tuning carbs...If your looking to get this thing running and have some fun eddy's work well.
79 Cmaro, 427 sbc, Tunnel Ram Dual Quad with Eddy carbs, AFR 210 Race Ready heads, 263-272 @.50 Comp solid roller cam, 4.10's and a faceplated Tremec TKO 600.
65 Beaumont 406 tunnel ram faceplated TKO600

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