302 SBF stumble

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MadBill
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Re: 302 SBF stumble

Post by MadBill » Sun Jun 24, 2018 9:19 pm

Here's a snip from http://www.thecarsource.com re the 1969 factory Trans Am Mustang:
"The Trans-Am engines were provided by Ford's Engine and Foundry group. They were blue printed and balanced, race ready when shipped to Shelby Racing and Bud Moore. Every racing part was heavy duty to stand the rigors of the upcoming season. In the beginning a Cross Boss intake manifold was planned, similar to Chevy's Cross Ram intake. It had two huge 1250 cfm Holley carbs mounted in the front and rear on opposite sides..."
:-k
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Re: 302 SBF stumble

Post by af2 » Sun Jun 24, 2018 10:12 pm

MadBill wrote:
Sun Jun 24, 2018 9:19 pm
Here's a snip from http://www.thecarsource.com re the 1969 factory Trans Am Mustang:
"The Trans-Am engines were provided by Ford's Engine and Foundry group. They were blue printed and balanced, race ready when shipped to Shelby Racing and Bud Moore. Every racing part was heavy duty to stand the rigors of the upcoming season. In the beginning a Cross Boss intake manifold was planned, similar to Chevy's Cross Ram intake. It had two huge 1250 cfm Holley carbs mounted in the front and rear on opposite sides..."
:-k
Yep it would have been faster with a 350 Holley! [-X
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Re: 302 SBF stumble

Post by cjperformance » Sun Jun 24, 2018 10:51 pm

af2 wrote:
Sun Jun 24, 2018 10:12 pm
MadBill wrote:
Sun Jun 24, 2018 9:19 pm
Here's a snip from http://www.thecarsource.com re the 1969 factory Trans Am Mustang:
"The Trans-Am engines were provided by Ford's Engine and Foundry group. They were blue printed and balanced, race ready when shipped to Shelby Racing and Bud Moore. Every racing part was heavy duty to stand the rigors of the upcoming season. In the beginning a Cross Boss intake manifold was planned, similar to Chevy's Cross Ram intake. It had two huge 1250 cfm Holley carbs mounted in the front and rear on opposite sides..."
:-k
Yep it would have been faster with a 350 Holley! [-X
Carter 2 bbl, better air speed!
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Re: 302 SBF stumble

Post by grandsport51 » Sun Jun 24, 2018 11:10 pm

Ford didn’t use a Cross Ram manifold on the ‘69
Trans Ams . They used transverse mounted sand cast
Dominators on an IR Manifold. Supposedly peaky as hell.
9F50566B-1A62-487B-AE34-EBCA1C3DBD56.jpeg
E0BCC879-B835-4C59-98DA-911C1B759F05.jpeg
The Cross Boss manifold developed with the Autolite
Inline Carbs was banned by the SCCA and
The 1970 cars used the Mini-Plenum
FE674D04-15DA-49FB-B155-F7A8CEDE59E0.jpeg
12E4EE93-3F14-4945-B911-B02194A10BFB.jpeg
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Re: 302 SBF stumble

Post by MadBill » Mon Jun 25, 2018 12:11 am

grandsport51 wrote:
Sun Jun 24, 2018 11:10 pm
Ford didn’t use a Cross Ram manifold on the ‘69
Trans Ams . They used transverse mounted sand cast
Dominators on an IR Manifold. Supposedly peaky as hell.
Quite so; hence the quote reads '...was planned...'
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Re: 302 SBF stumble

Post by Geoff2 » Mon Jun 25, 2018 5:42 am

Exactly stat, you just s**t on your own argument: the air valve don't open until the EXTRA air flow is REQUIRED. Which is why those carbs work so well & that there are QJ carbed cars running 10 secs...

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Re: 302 SBF stumble

Post by Geoff2 » Mon Jun 25, 2018 5:59 am

Grandsport, you are exactly right. The extended boosters give it away as the IR version, model #6214, 1150 cfm. So each cylinder of the 302 got 144 cfm.

Reading this Statsystems, 144 cfm, NOT 600+cfm.

CJ Performance [ Craig ], I don't know if it wise to continually bag Carter carbs.

Some of the fastest cars sold in Australia, & road tested by Wheels magazine & other magazines had Carter 2bbl [ & Stromberg ] 2 bbl carbs.

How does 118 mph waaaay back in 1958 for a 318 powered, 2bbl, 1958 Plymouth sound?? Or these comments from Wheels magazine staff: Road Rocket, Blistering Performance. All lavished on 318 Chrysler Poly engined cars with a 2bbl.

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Re: 302 SBF stumble

Post by cjperformance » Mon Jun 25, 2018 7:54 am

:D Geoff im just having a wind up! I actually like Carter, Autolite and Stromberg carbs. Nothing wrong with them at all, single, 2 or 4bbl.
All of the mentioned carbs have their place. TQ up there with my faves.
That previously mentioned 585 holley Ford factory fit carb is a beauty.
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Re: 302 SBF stumble

Post by cjperformance » Mon Jun 25, 2018 7:56 am

I even like SU's ! I dont often admit that ! :lol:
Hitachi or CD strom are better!
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Re: 302 SBF stumble

Post by statsystems » Mon Jun 25, 2018 10:42 am

Geoff2 wrote:
Mon Jun 25, 2018 5:42 am
Exactly stat, you just s**t on your own argument: the air valve don't open until the EXTRA air flow is REQUIRED. Which is why those carbs work so well & that there are QJ carbed cars running 10 secs...



No I didn't. You are mixing your definitions to fit your answer.

You actually made MY argument. By your twisted logic, if the air valve isn't open, then it's still not open! You may have opened the butterflies, but the air valve is shut. You can parse your shit argument any way you want, but it's still a sort of vacuum secondary.

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Re: 302 SBF stumble

Post by statsystems » Mon Jun 25, 2018 10:42 am

Don't know why the lines are in my answer in the above post.

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Re: 302 SBF stumble

Post by MadBill » Mon Jun 25, 2018 10:57 am

There's probably a 'strikeout' option available on this reply box or your keyboard somewhere for highlighting changes/deletions in a text (sort of like the underline tab), which has been accidentally activated. No clue how to switch it off if there is though... :?
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Re: 302 SBF stumble

Post by Geoff2 » Tue Jun 26, 2018 6:16 am

Keep going Stat, you are just showing your ignorance....

A DP works on vacuum. If you knew anything about carbs, you would know this....but you obviously don't.

There is no flow from the boosters of a DP [ or any carb for that matter ] until air speed is high enough through the venturiis to create a depression [ vacuum ] & cause fuel to flow from the boosters.

Craig, sorry if I came on a bit strong. Don't think Carter ever got the credit they deserved. Holley had a much better marketing campaign. Pity their carbs didn't match...

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Re: 302 SBF stumble

Post by cgarb » Tue Jun 26, 2018 8:57 am

I forgot to also include in my response that all of the cylinders would hold air pressure (with both valves shut of course) and no leakage could be heard out of the intake or exhaust ports, so I assume there are no bent valves. That's was my basis for not pulling the heads, I just swapped the springs on the car.

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Re: 302 SBF stumble

Post by 427dart » Tue Jun 26, 2018 9:21 am

Plenty of choices out there for automotive induction systems and we still FREE to make choices which make us happy!
Carb has always functioned based on the speed of air flow. Get the venturi or multiples of them the right size for the application and you will find success. High performance STREET use is always a compromise!

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