RB intake on B block options

[cal30_sniper]

I know it can be done using Stage VI heads. Are there any other available raised port heads that could be modified to allow this?

Looking at the design of the Edelbrock Victor, it has the “spacers” cast directly into the head. My hypothesis is milling the cast in intake flange down ~.850” so it was the same geometry as the Stage VI heads would allow an RB intake to be run. Probably need to measure twice mill once and do some gasket matching, but would this work?

I’ve about settled on a B-block 470 build for my current project. My thought process was to pair good flowing heads with a Weiand “six pack” cross ram intake (RB only intake) converted to throttle body MPFI for a boost in mid-range torque similar to what one would get from a tunnel ram. Motor will be paired with a T56 magnum with a desire for the broadest possible torque curve for street and road racing.

The Victor standard port seemed like it might work here, assuming Chapman Stage VIs have become unicorns by this point. I know I could also start with an RB block, but that’s heavier, I don’t like the geometries as much for a 470 (specifically no RB 3.91 crank), and I have three 400 candidates in the garage.

 

[Outsider]

If you're willing to go to that much trouble and expense, why not just weld together, or have built, a custom aluminum sheet metal intake?

 

[R/T Boy 67]

I admitted my mistake in post 7

 

[cal30_sniper]

Stage 6 heads use a B intake on a RB block, not the other way around.

Maybe it’s early and you’re still working on Sunday morning coffee intake, but this statement is factually incorrect.

Stage VI heads use an RB intake on a B block, or a specially designed wider intake on an RB block. Or you can use ~.850” spacers with whatever intake the engine would have used normally.

 

[cal30_sniper]

If you're willing to go to that much trouble and expense, why not just weld together, or have built, a custom aluminum sheet metal intake?

I thought about that, but it didn’t seem to be in the same league as far as difficult or cost. Milling a head to use an existing intake should be pretty cheap. My understanding of custom sheet metal intakes is they’re quite pricey. As far as the basic mods of adding bungs to an existing intake, I can do Tig work and basic porting at home, so I’m counting that as a zero. I also have to buy heads any way I go, so I’m counting this as a zero as well.

Really just wondering if there’s something native in the Victor head design that would prevent me from having it milled that far. The ports are reportedly raised .650” on the victor, which is only about .1” less than the deck height difference between B and RB. Seems like it would come out real close as far as geometry is concerned.

 

[Curiousyellow71]

Stage 6 heads use a B intake on a RB block, not the other way around.

You have that turned around. A Rb intake fits on B. You have to run spacer to use a rb intake on a rb block with stage vi heads. Or buy the special intake they made for a rb w st vi heads.
We have spacers..the mp special intake is on it now.

 

[R/T Boy 67]

Sorry! My mistake.

 

[Runcharger]

Finding a set of Stage V1's and doing any repairs to them seems to be an easier way home on this deal to me.

 

[Curiousyellow71]

I know it can be done using Stage VI heads. Are there any other available raised port heads that could be modified to allow this?

Looking at the design of the Edelbrock Victor, it has the “spacers” cast directly into the head. My hypothesis is milling the cast in intake flange down ~.850” so it was the same geometry as the Stage VI heads would allow an RB intake to be run. Probably need to measure twice mill once and do some gasket matching, but would this work?

I’ve about settled on a B-block 470 build for my current project. My thought process was to pair good flowing heads with a Weiand “six pack” cross ram intake (RB only intake) converted to throttle body MPFI for a boost in mid-range torque similar to what one would get from a tunnel ram. Motor will be paired with a T56 magnum with a desire for the broadest possible torque curve for street and road racing.

The Victor standard port seemed like it might work here, assuming Chapman Stage VIs have become unicorns by this point. I know I could also start with an RB block, but that’s heavier, I don’t like the geometries as much for a 470 (specifically no RB 3.91 crank), and I have three 400 candidates in the garage.

I would do a bit of research. Although the weiand cross ram six pack looks cool, I am not so sure it is a great performer. Paired w fuel injection sounds like a challenge, not sure what that would do. I think any intake including a Victor rb modified will likely be a epic challenge. Maybe consider a indy mod man.
Not a big fan of the spacers on a rb, but the intake is really tall on a rb with them. Not relevant on a B.

 

[PRHeads]

Maybe a set of Speedmaster Victor clones on a Black Friday deal might make for some suitable guinea pigs.

 

[cal30_sniper]

Finding a set of Stage V1's and doing any repairs to them seems to be an easier way home on this deal to me.

That might work well. I’d love to find a set of the Chapman Stage VIs, but I understand those are unobtainium. Seems the other versions of the Stage VI don’t flow particularly great, that’s kind of why I was thinking Victor.

I would do a bit of research. Although the weiand cross ram six pack looks cool, I am not so sure it is a great performer. Paired w fuel injection sounds like a challenge, not sure what that would do. I think any intake including a Victor rb modified will likely be a epic challenge. Maybe consider a indy mod man.
Not a big fan of the spacers on a rb, but the intake is really tall on a rb with them. Not relevant on a B.

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I think I’ve read just about all that’s out there on them. I haven’t messed with one, but I have messed with a tunnel ram 470, and believe I’d get the same effect of midrange torque boost that a tunnel ram does due to the long equal length runners.

The real drawback of the Weiand (and the similar Edelbrock STRs) seems to be fuel distribution. You can definitely see they aren’t great as a wet manifold. The idea behind EFI would be to use injectors in the runners (sequential MPFI) that should cure the fuel distribution problems. That’s how most of the modern engines get such a nice torque boost from long runner intakes (think Magnum kegger, LS, Gen III HEMI, etc). Dry intakes with long runners.

The Modman seems like the wrong direction from even a basic single plane. Lots of airflow, but almost no runner length.

 

[Curiousyellow71]

The Chapman heads are pretty rare. Stage VIs are less rare, but they aren't easy to find either. It is true out of the box stage VIs were lacking both intake and exhaust (compared to other aftermarket heads). We have a very early set of stage VI heads. They were the first set sold by Ray Barton. He cleaned them up and flowed them in the early 90s. They only flowed about 270 after he cleaned them up. We ran it for several years as is...running high 10s and then decided to find more flow after we got a flow bench. They REALLY respond to making the port taller. We basically ported the intake as deep as we could and the port width stayed the same. Stock port window they can be made 300-330cfm. The limit is the valve springs pockets are really deep in the head and we went as deep as we could go. My understanding that is the big difference on the Chapman's. The heads are similar but Chapman has taller valves allowing for a deeper high flowing port. With some work... I don't see much trouble with stage Vi heads matching up with trick flows 240s or 270s. More work? For sure. The exhaust ports on the stage VI are really good after you open them up.
Not sure how fast you want to go?
It is true on runner length and the modern intakes.. but longer can give up top end power over a short runner. Going with cubic inches will make torque as a substitute for runner length and make hp on top.

 

[Some Car Guy]

I’d search for stage 6s and call it a day. No matter which set you find. Have a guru like Dwayne porter breathe on them. Have the pockets milled on the edge to try and stop the pooling of oil. That was a big issue with these heads. It’s realistically the only way you will pull this off, short of asking somebody like Wilson to do some serious work on your intake to adapt it to anything else.

 

[oldkimmer]

Stage 6 heads use a B intake on a RB block, not the other way around.

Absolutely not. Kim

 

[557hemi]

I’ve also been thinking about a low deck with RB intake and thinking about Chapmans or milling down a set of Victors. I like PRHeads idea of the speedmaster guinea pigs.
Is there a chance of hitting water and or not having enough left in the casting for adequate thread depth ???
Also, will a victor/speedmaster or Stage VI low deck (since the exhaust is only raised about 1/4 inch) end up narrower (exhaust manifold to exhaust manifold) than a standard head RB motor ???

 

[oldkimmer]

PRH has a pic of three heads showing the height difference. I believe stock stage 6 and Victors. Kim. @PRHeads

 

[557hemi]

After seeing this pic it would seem they could be safely milled

 

[dvw]

Milling would be easy enough. Lining the actual intake face to the head face would be easy enough. But the ports are probably in a different location downtream from the original intake flange. They could be lower, openings spread apart further apart from each other, different shape and dimension, bolt holes may not line up. That's where the real work lies. Proably easier to modify the Mod Man. We have done that on a 486" low deck. So far the intial testing is showing some promise. 9.7x@136, 3585lbs
Doug