Extending intake dividers

[HQM383]

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Larry, do runner extensions this long have any side effects like needing to stagger jet, engine wanting more spacer area or a reduction in reversion pulse dampening that you have seen?

it didn't need any Jet staggering , mostly because 2 Spacer's added Plenum height
causing largest amount of the Mixture to go downward into the top portion of the Runners .
The Manifold picked up TQ and HP everywhere .

from previous experiences , i was not too afraid to Weldup and extend the Runners that far into each other,
in the 1980's i tested and used Epoxy AB Sticks on C/ED Manifolds ,
i made all 4 Runners touch each other in the floor of the Plenum ,
you would think this Divider blockage might mess up Fuel Distribution,
but the C/ED's ran faster back then , and mostly because of 8" Converters , a 7" Converter was not yet available ??? or only a few had them ??
the C/EDs were pretty heavy in weight , mostly 316cid engine sizes , around 1580lbs to 1590lbs .

All very nice work. Is it mig weld with horizontal runs building on each other from the floor up? What wire?

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I was thinking that fuel might need to be encouraged to enter the tops of the runners as much as possible so was thinking it may be spacer sensitive and want plenty of spacer. Only 2” is good.

[steve cowan]

Anybody have pics of their work?

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Impressive work as always Mr Meaux, appreciate you sharing,
I have a couple of questions if you don't mind.
Do you factor the runner extensions in the total length of the runner?
Do you bother cc ing the plenum after welding in extensions and would thinner runners be an advantage?
Would those extensions work in a 4150 plenum?

[Mike Laws]

It must work, here's one that was posted her years ago,
mod 300-25.jpg

This is a cool thread! I welded/ported 20 or so of these in the early 80's, but have no pictures. (The manifold in the picture looks identical and could have been one that we built.) Most were sold to Harry Ranier's team w/Cale Yarborough driving. These manifolds won poles and races at Daytona & Talladega. Cale said the manifold wasn't the best on restarts but couldn't be beat at speed. These manifolds also ran decent at Michigan & Atlanta. We tried 300-25's without the divider extensions and they were awful. The extensions woke it up.

I used tig-rod only on the 1st manifold, then welded 1/4" thick extensions that we pre-shaped and fit for the rest. The extensions were installed and blended after the manifold was ported because you could not properly port with the extensions installed.

[HQM383]

Cale said the manifold wasn't the best on restarts.....

I assume that is when more of the fuel is being drawn from deeper in the plenum at partial throttle?

[Mike Laws]

Cale said the manifold wasn't the best on restarts.....

I assume that is when more of the fuel is being drawn from deeper in the plenum at partial throttle?

I think it had more to do with lower RPM at WOT than part throttle. Engines with these manifolds made less peak tq, but a lot more hp. These manifold runners also had a larger CSA than others at the time and the carburetor pad was higher (runners were more vertical).

[jamie]

Anybody have pics of their work?

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Awesome work Larry! I was hoping you would chime in. Thank you!

[maxracesoftware]

Larry, do runner extensions this long have any side effects like needing to stagger jet, engine wanting more spacer area or a reduction in reversion pulse dampening that you have seen?

it didn't need any Jet staggering , mostly because 2 Spacer's added Plenum height
causing largest amount of the Mixture to go downward into the top portion of the Runners .
The Manifold picked up TQ and HP everywhere .

from previous experiences , i was not too afraid to Weldup and extend the Runners that far into each other,
in the 1980's i tested and used Epoxy AB Sticks on C/ED Manifolds ,
i made all 4 Runners touch each other in the floor of the Plenum ,
you would think this Divider blockage might mess up Fuel Distribution,
but the C/ED's ran faster back then , and mostly because of 8" Converters , a 7" Converter was not yet available ??? or only a few had them ??
the C/EDs were pretty heavy in weight , mostly 316cid engine sizes , around 1580lbs to 1590lbs .

All very nice work. Is it mig weld with horizontal runs building on each other from the floor up? What wire?

42BC4190-F08B-4C04-A991-33DB01B5898F.jpeg

I was thinking that fuel might need to be encouraged to enter the tops of the runners as much as possible so was thinking it may be spacer sensitive and want plenty of spacer. Only 2” is good.

"Is it mig weld with horizontal runs building on each other from the floor up? What wire?"

i don't have a Mig Gun , i just Tig-welded ! .... better control with Tig !
i have a Miller 300 AMP Welding Machine w/foot control
just welded a little at a time , switching around on Runner Dividers

[maxracesoftware]

Anybody have pics of their work?

DSC03108_1280x960.jpg
DSC03114_1280x960.jpg
DSC03116_1280x960.jpg
DSC03127_1280x960.jpg
DSC03140_1280x960.jpg
DSC03142_1280x960.jpg
DSC03143_1280x960.jpg
DSC03144_1280x960.jpg
DSC03147_1280x960.jpg
DSC03148_1280x960.jpg
DSC03154_1280x960.jpg

 

Impressive work as always Mr Meaux, appreciate you sharing,
I have a couple of questions if you don't mind.
Do you factor the runner extensions in the total length of the runner?
Do you bother cc ing the plenum after welding in extensions and would thinner runners be an advantage?
Would those extensions work in a 4150 plenum?

i didn't bother CC'ing Plenum
i just cared a lot about extending the Runner Lengths to make more TQ and HP in the RPM Range i wanted

One important thing or reason :
The Total Induction Length is typically longer all the way on the Roof path , than the Floor path
and so by increasing the Runner Length ( welding ) more on the Floor -to- Middle part of Dividers
you more even out the Total Induction Length .... you decrease Mixture-shearing and gain Flow CFM is what i've noticed !

i first saw this effect with Ford SBC Cleveland with Offenhauser or Weiand Tunnel Ram 2-4's
picked up that Engine over 100 HP with a ton of Welding inside/outside + more Epoxy everywhere
gained around a 11 % percent increase in Flow CFM with Carbs+Manifold bolted on Head on the Flowbench .

Before those Mods , that Tunnel Ram caused Flow CFM to take a giant dive around 0.600" Valve Lift upwards
Flow testing the Cyl Head byitself was OK , it kept on gaining Flow CFM , but bolt on the Tunnel Ram , it was a disaster like it was before Mods !

[SpeierRacingHeads]

Here is a 300-25 I done for a 350/360hp Super Stock engine. It hated it! Ended up pulling it and grinding it all back out while it was still on the dyno.

[steve cowan]

Great information shared by Larry,Chad and Mike on there results,what it does tell me there are no guarantees as Larry and Chad had opposite outcomes on the dyno.
On the 4500 plenum I think the extensions don't hurt area like a 4150 plenum but that is me thinking out loud.
I am working on a 4150 SV at the moment that I welded up runners,I have knocked back a bit of material now as I want to try and get close to the same length which is not easy.
I am looking for a total induction length of around 10.50"
13 :1 comp 383 sbc
Operating rpm of 6500rpm- 8000rpm.
Manifold is a work in progress and viewer discretion advised its not the prettiest thing around lol.
When I dyno this combo I might port another SV and leave the runner lengths standard but work on CSA only and do a back to back.

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[HQM383]

it didn't need any Jet staggering , mostly because 2 Spacer's added Plenum height
causing largest amount of the Mixture to go downward into the top portion of the Runners .
The Manifold picked up TQ and HP everywhere .

from previous experiences , i was not too afraid to Weldup and extend the Runners that far into each other,
in the 1980's i tested and used Epoxy AB Sticks on C/ED Manifolds ,
i made all 4 Runners touch each other in the floor of the Plenum ,
you would think this Divider blockage might mess up Fuel Distribution,
but the C/ED's ran faster back then , and mostly because of 8" Converters , a 7" Converter was not yet available ??? or only a few had them ??
the C/EDs were pretty heavy in weight , mostly 316cid engine sizes , around 1580lbs to 1590lbs .

All very nice work. Is it mig weld with horizontal runs building on each other from the floor up? What wire?

42BC4190-F08B-4C04-A991-33DB01B5898F.jpeg

I was thinking that fuel might need to be encouraged to enter the tops of the runners as much as possible so was thinking it may be spacer sensitive and want plenty of spacer. Only 2” is good.

"Is it mig weld with horizontal runs building on each other from the floor up? What wire?"

i don't have a Mig Gun , i just Tig-welded ! .... better control with Tig !
i have a Miller 300 AMP Welding Machine w/foot control
just welded a little at a time , switching around on Runner Dividers

I was thinking mig due to access.

What tig gun do you use to get down in there? Flexible neck?

5356 or 4043 filler wire?

[jamie]

Larry, what size tungsten did you use? Also, did you need to use your chiller to keep it cool? Thanks

[maxracesoftware]

Here is a 300-25 I done for a 350/360hp Super Stock engine. It hated it! Ended up pulling it and grinding it all back out while it was still on the dyno.

Chad, was that with a Q-Jet Carb ???
its very hard to beat the Edelbrock Victor-E Manifold with a Q-Jet

[maxracesoftware]

Larry, what size tungsten did you use? Also, did you need to use your chiller to keep it cool? Thanks

3/32" tungsten in TIG
i have a brand new water cooled TIG Torch in a box , never opened it, never used it
for that amount of welding , a few times i wanted to hook it up and use it , too lazy to do it
i was stopping for little periods of time + switching areas where i was welding ,
and if i used the water-cooled Torch i think i would have welded longer , might have warped the Manifold

[jamie]

Here is a 300-25 I done for a 350/360hp Super Stock engine. It hated it! Ended up pulling it and grinding it all back out while it was still on the dyno.

Chad,did you or were you allowed to use open spacers on this?