20 replies to this topic

[claysummers]

After advice on this manifold.


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Doesn’t look right. In thinking about ditching the divider and running this:


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[UCSLE]

chop it , the divider is part of a spread bore pattern

 

The red motor type of that Redline manifold never had it

[claysummers]

Thanks Troy.


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[LJ RB30]

The divider is there to essentially reduce flooding of the center cylinders.
The original Cain manifold didn’t have it but later version’s did. This is basically what everyone has copied since. I’ve got a couple of them.
The divider doesn’t go all the way to the floor of the manifold.
Do not remove it or it will not perform at it‘s best.
Most manifold’s have spreadbore & squarebore bolt patterns.
The shape of the opening/divider at the gasket face may not be perfect for a Quadrajet, which I run, so I have blended it to suit some 35+years ago.

[Muzza]

Slightly off topic, if it bogs down , i have a full set of secondary vacuum springs

[claysummers]

Thanks Trevor and Muzza. The divider is quite shallow in fact. I will blend it to the tapered bore spacer I think.


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[yel327]

The divider is there to essentially reduce flooding of the center cylinders.
The original Cain manifold didn’t have it but later version’s did. This is basically what everyone has copied since. I’ve got a couple of them.
The divider doesn’t go all the way to the floor of the manifold.
Do not remove it or it will not perform at it‘s best.
Most manifold’s have spreadbore & squarebore bolt patterns.
The shape of the opening/divider at the gasket face may not be perfect for a Quadrajet, which I run, so I have blended it to suit some 35+years ago.

 

John used to cast some of Redline's manifolds for them. He showed me the patterns years ago. When he shut up shop Hardiman bought them. As you say that intake will be fine for a 390 vacuum secondary Holley.

[claysummers]

I have a nice old Cain manifold with four bores in the mating surface, but it is 9 port. This is going on a black 12 port in wife’s FB sedan.


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Cheers Byron.


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[LXCHEV]

Also, with the spacer you showed above (the super sucker).... sometimes they work, sometimes they don't. Even though we're talking different engines (I tried one years ago on my small block Chev V8) and lost power (back to back tests on the dyno). All depends on the individual combo.

[yel327]

I have a nice old Cain manifold with four bores in the mating surface, but it is 9 port. This is going on a black 12 port in wife’s FB sedan.


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Cheers Byron.


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My old red 6 in my LX had a CAIN 4BBL intake on it with a 390 Holley. It was nothing flash, just a VB block with a blue crank and rods. 40 thou up, all balanced. A simply 30/70 70/30 Waggot cam, not much different really to a VK EFI cam. 186 Yella Terra head with intake port dividers removed, used Allen headed screws for those head bolts. Electronic ignition, manual (Celica 5spd), electric fans. Extractors and 2" exhaust. It pulled about 125hp or thereabouts at the back wheels. Was a very tractable engine. It had a 3.08 A9X Salisbury in it and 245/60/14 rear tyres. Used to easily pull my heavy clinker ski boat and trailer up boat ramps, and was decent around Amaroo on road tyres. I eventually pulled it out of the LX and stuck it into a 1980 WB tonner painted blue and disguised as a blue motor (it was blue in the Torana too), but had a HZ single Stromberg on it and extractors, and a VK Trimatic with 3.08 rear axle. Lots less power without the 390 Holley but it pulled well, had good torque but would have easily dropped peak 25hp with the Stromberg. 

[claysummers]

Also, with the spacer you showed above (the super sucker).... sometimes they work, sometimes they don't. Even though we're talking different engines (I tried one years ago on my small block Chev V8) and lost power (back to back tests on the dyno). All depends on the individual combo.

I didn’t see your comment until after I went and cut out the divider and got the super sucker plus a 1/4” insulator.


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[LXCHEV]

It’ll be good to see how you go with it.

I never had my engine tuned with the super sucker (I simply whacked it on for a club dyno day one year). In hindsight, should have had a tune done with it on to see what we could have extracted with it. Not entirely sure how much jetting would change when playing with spacers.

[claysummers]

Well I got it started, after sorting out a fountain from the secondary vent. Electric fuel pump. No leaks now with pump running, until I start it up. Can’t even see fuel in the sight plug.
It is dribbling from the primary boosters at idle. I will pop the primary bowl off tomorrow.


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[Bruiser]

Nice work
Check the front bowl fuel level before you empty it
Might be too high causing your dribbling

[claysummers]

Checked I a couple times through the sight bung Bruce. Can’t even see fuel.


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[claysummers]

Got the thing going today. Hell yeah! Loads more go off idle and smooth as. That lasted a 15 minute drive, then stalled in drive on a slow corner. Idle low. So adjusted both bowls to spec. Easy to do on these carbs. Now dribbling lots of fuel, but only out one corner primary booster. Lowered the needle and seat one full turn, no difference, still dribbling.

I have a spare carb so I will try the bowl and metering block off that.


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[warrenm]

Got the thing going today. Hell yeah! Loads more go off idle and smooth as. That lasted a 15 minute drive, then stalled in drive on a slow corner. Idle low. So adjusted both bowls to spec. Easy to do on these carbs. Now dribbling lots of fuel, but only out one corner primary booster. Lowered the needle and seat one full turn, no difference, still dribbling.

I have a spare carb so I will try the bowl and metering block off that.


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3 SU's will fix the fuel from primary booster.

[claysummers]

3 SU's will fix the fuel from primary booster.

It is a 12 port head Warren. You couldn’t point me to an SU manifold?


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[Bruiser]

While you’ve got it apart, give every hole and passageway a blast with some carb cleaner,
especially the air bleeds
The inner pair are the ones relating to the main circuit
If one of those was a bit blocked it could siphon fuel when it’s not supposed to
Can even try that with the carb still together.
Got the fuel levels up so it trickles out the sight plug now?

[claysummers]

Thanks Bruce you were on the money. Yank Holley bloke on FB pointed out the offending side idle feed was blocked with this white residue that seems to be on the bowl bolt shanks also. Evidence in both circuits but one side had sort of cleared while the other was still fully blocked. Hence the dribble.

Running sweetly now. Slight ping at a couple spots through the revs top gear WOT. Fuel is a month old and fuel pressure set on 2.5psi as it was when I got the car. Running ok with the 350 2bbl. I advanced initial to 12* on advice, to get a better idle.
Will check for manifold leaks when it cools down. May need to readjust electric choke. I retarded the timing a bit without yet measuring it and bumped the pressure to 3.5psi.
Looks like business.
Happy days!


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[warrenm]

It is a 12 port head Warren. You couldn’t point me to an SU manifold?


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I modified an Armours manifold to suit a 12 port head, it's in storage waiting to go back in the Torana.