Holden 9-port Red Engine - 2 questions for our mates down under......

[enigma57]

First of all, thanks to all who have commented here. Many good ideas and points well taken. Your input is much apreciated.

I am searching for a good 292 standard bore block that will clean up with max 0.040" overbore (mine is cracked). And waiting for some hard to locate Weber parts to arrive. Some from the UK, some from Italy and some from Germany. So in the meanwhile, thought I would take a close look at the head and decide how best to set it up.

Here are the notes I have made thus far......

1. Install larger valves. These heads are flow limited and the 1.74" intake and 1.50" exhaust valves should be replaced with larger sizes and bowls reworked. Common practice is to install 1.94" intake and 1.60" exhaust. Standard bore size is same as 283 V-8 (3.875") and I will hold bore to 0.040" oversize (3.915"). So the question here is...... Without moving valve locations, how large can I go without shrouding valves?

2. Rework intake ports. Sissell 12-port aluminum head and corresponding one off intake and exhaust manifolding are beyond the limits of my budget. So will rework an OEM 9-port iron head. The 9-port head has (6) exhaust ports and (3) sets of siamesed intake ports.

a. The largest obstruction to flow is of course the vertical boss cast dead center of each siamesed intake port and through which a head bolt passes. So it must be removed.

b. And unlike the Holden 9-port red engine head...... The floor of the Chevy inlne 6 intake port is flat from manifold flange to bowl. Meaning that the air/fuel mixture must make a 90 degree turn when transitioning from horizontal flow in port to vertical flow at intake valve. So a lump port kit must be installed to give the air/fuel mixture a more gradual radius for this change of direction.

c. Regarding adding a vertical flow vane as was done with the Holden head...... I would like to do this in addition to the lump port if there will be sufficient cross sectional area remaining. I need a minimum of 2.55 sq. inches CSA (1.80" round intake port) without exceeding 300 ft./sec. average velocity at design redline. That is the velocity we sized Dan Miller's ports for at EMC in 2009 - 2010 both with the Webers and the following year, with the EFI setup. My modified Weber intake has 46mm (1.81") round intake ports, so I should be good there.

So the plan is to increase valve sizes as large as possible without shrouding at cylinder wall and to do the lump port mod in order to give the air/fuel mix a more radiused flow path into the bowl. After lump port mod is completed, will measure CSA and see if I have room for vertical flow vanes similar to the ones KnightEngines installed on the reworked Holden head.

Will also look at valve seat angle he suggested. With this type head and 45 or 50 degree seat angle, are there any configurations for bowls that work better?

Again, thanks to all who have posted. Your input is much appreciated.

Harry

[enigma57]

First of all, thanks to all who have commented here. Many good ideas and points well taken. Your input is much appreciated.

I am searching for a good 292 Chevy inline 6 standard bore block that will clean up with max 0.040" overbore (mine is cracked). And waiting for some hard to locate Weber parts to arrive. Some from the UK, some from Italy and some from Germany. So in the meanwhile, thought I would take a close look at the head and decide how best to set it up.

Here are the notes I have made thus far......

1. Install larger valves. These heads are flow limited and the 1.74" intake and 1.50" exhaust valves should be replaced with larger sizes and bowls reworked. Common practice is to install 1.94" intake and 1.60" exhaust. Standard bore size is same as 283 V-8 (3.875") and I will hold bore to 0.040" oversize (3.915"). So the question here is...... Without moving valve locations, how large can I go without shrouding valves?

2. Rework intake ports. Sissell 12-port aluminum head and corresponding one off intake and exhaust manifolding are beyond the limits of my budget. So will rework an OEM 9-port iron head. The 9-port head has (6) exhaust ports and (3) sets of siamesed intake ports.

a. The largest obstruction to flow is of course the vertical boss cast dead center of each siamesed intake port and through which a head bolt passes. So it must be removed.

b. And unlike the Holden 9-port red engine head...... The floor of the Chevy inline 6 intake port is flat from manifold flange to bowl. Meaning that the air/fuel mixture must make a 90 degree turn when transitioning from horizontal flow in port to vertical flow at intake valve. So a lump port kit must be installed to give the air/fuel mixture a more gradual radius for this change of direction.

c. Regarding adding a vertical flow vane as was done with the Holden head...... I would like to do this in addition to the lump port if there will be sufficient cross sectional area remaining. I need a minimum of 2.55 sq. inches CSA (1.80" round intake port) without exceeding 300 ft./sec. average velocity at design redline. That is the velocity we sized Dan Miller's ports for at EMC in 2009 - 2010 both with the Webers and the following year, with the EFI setup. My modified Weber intake has 46mm (1.81") round intake ports, so I should be good there.

So the plan is to increase valve sizes as large as possible without shrouding at cylinder wall and to do the lump port mod in order to give the air/fuel mix a more radiused flow path into the bowl. After lump port mod is completed, will measure CSA and see if I have room for vertical flow vanes similar to the ones KnightEngines installed on the reworked Holden head.

Will also look at valve seat angle he suggested. With this type head and 45 or 50 degree seat angle, are there any configurations for bowls that work better?

Again, thanks to all who have posted. Your input is much appreciated.

Harry

[KnightEngines]

The Holden head does not have enough cross section to support a cylinder on one side of the vane - that's why it is not fully divided, if that was done itd choke.
The idea is to encourage as much flow as the cross section on the side of the vane with the open valve will support to increase intake velocity & inertia ram while still allowing 'top up' flow from the other side to make up the cross section shortfall.

Now I get what a lump port achieves, I have never seen a chev 6 head in person, I didn't realise they had a flat floor.

I can't see a reason why you can't use a vane as well, you'd probably want to be able to achieve 75% of the required cross section per cylinder on each side of the vane.
You could attach the vane to the lump port insert, or weld it directly to the intake manifold - that's how I've done the last 3, much easier than using capscrews through the original bolt hole to locate it!

Being a low rpm torque build I would think you should be able to raise the roof & widen the port enough to work with the vane.

I don't have any more vanes, I carve them by hand from a lump of 10mm thick alloy plate with a die grinder, hacksaw & file, it's a bit of a pita.

[cjperformance]

Yeah, I did that one!
Made 340hp with a 4 barrel holley, he's yet to fit webers.
Back in a bit, morning stuff to do.

That looks like the head i saw on Darrin's flow bench a few years back now, same head?

[cjperformance]

I studied that issue when we were working up the first EFI intake for Dan Miller's early hemi EMC engine in 2010, Geoff. You are spot on. A sharply pointed (knife edged) leading edge will induce shear and turbulence. That is why we went with a symmetrical airfoil shape for all leading edges of divider walls in interiour flow path on that project.

See airfoil shape at bottom......



On the other hand...... We were using the symmetrical airfoil shape on the leading edge of port divider walls at the extreme upper end of very long IR runners.

Whereas the knife edged vertical center vane on the modified Brazilian Opala head that Chevyfreak posted......



Would seem to do a good job of splitting the inflow and directing it towards the 2 valves served by the siamesed Chevy intake port if turbulence at that point of the overall flow path might serve to atomize rather than separate fuel droplets? Not sure, just wondering.

Best regards,

Harry

Similar to aquadynamics , fish knew that shape works long before we did! Rounded front and gently tapering tail.
A pointed leading edge is unstable, is only really suited to mate up to a divided runner intake and when used with an open runner flowing air and fuel toward it is more prone to wetting fuel out along the runner wall due to the almost non existent boundary layer at the start of the divider point.
Funny you mention Dan's Hemi as i was only thinking about that the other day, not long before he passed he had sent some pics and ideas on a Caddy engine and I was wondering what ever became of that.

[Keith Morganstein]

I’d just go with one the lump port kits , 1.94/1.6 valves and the bowl work. There are three different lump port kits along with videos on 12bolt.com. Tom Lowe is on this board as well.

Combine the lump port head, cam, intake, headers and you should reach your goals.

[enigma57]

I’d just go with one the lump port kits , 1.94/1.6 valves and the bowl work. There are three different lump port kits along with videos on 12bolt.com. Tom Lowe is on this board as well.

Combine the lump port head, cam, intake, headers and you should reach your goals.

Thanks, Keith! That's pretty much the plan. Being an old codger and this being my 'last build', just thought I'd explore the possibilities. Very curious as to how this combo will work if I experiment a bit with a vertical vane in each set of siamesed intake runners after the lump port is in place (so long as I can maintain a minimum of 2.55 sq. inches average CSA per port). In fact, I am wondering at this point whether a small brazed lump might help the exhaust side, as well (pretty sure the lumps on exhaust side would be too small to do as bolt-ins, though.).

I suppose how much (if any) a lump on the exhaust side might help would depend on exhaust manifold or header configuration and how that interfaces with the exhaust port at its outlet. This is a road car, so I will be running a set of Tom Langdon's split exhaust manifolds modified with 2-1/2" outlets. Tube headers on a driver are just too much hassle over time dealing with the inevitable leaks, etc. On the other hand, it would be easier to calculate primary header pipe size to provide between 280 and 300 ft./sec. exit velocity (290 ft./sec. would be optimum) at exhaust port and have it coincide with this engine's point of max VE.

Have designed and sized a full length exhaust system to perform same as with open exhaust using David Vizard's calcs for zero sum loss muffled system and what we learned at EMC whilst running Dan's early hemi through the long, muffled system there.

Many moons ago, during the not-so-Cold War years ('75 - '79), I was a shipfitter/brazer and later, an NDT inspector in the Navy. That was a lot different than my priour hitch in the Marine Corps (0311 grunt, '66 - '67). That was supposed to be a 4-year hitch as well, but the NVA had other plans.

Anyway, during my 2nd hitch, I worked off the tender aboard the subs (both diesel boats and nuke fast attack boats in those years). Before moving into inspections, brazed up several large castings, a few exhaust manifolds for friends and silver brazed lots of copper nickle pipe joints. Don't have access to the large ovens now that we used to preheat, maintain in process heating and slowly cool castings after brazing, but I'm sure I could braze lump ports to a cast iron head if I can come up with a small rosebud tip and an oxy-acetylene rig. I would do it by making the lumps from either steel or (more likely) cast-iron. 'Tin' the surfaces of the cast-iron head and of the lumps to be brazed, using yellow brass brazing rod. Then after slow air cooling, clean both 'tinned' surfaces, apply flux, place lumps in ports, fire up the torch and heat the head and lumps evenly. When the brass that was used to 'tin' the cast-iron surfaces of both 'just' becomes molten (about 1,670 degrees Fahrenheit), it will join both surfaces and very little additional brass rod should be needed to hand feed into the joint.

Best regards,

Harry

[enigma57]

Similar to aquadynamics , fish knew that shape works long before we did! Rounded front and gently tapering tail.
A pointed leading edge is unstable, is only really suited to mate up to a divided runner intake and when used with an open runner flowing air and fuel toward it is more prone to wetting fuel out along the runner wall due to the almost non existent boundary layer at the start of the divider point.
Funny you mention Dan's Hemi as i was only thinking about that the other day, not long before he passed he had sent some pics and ideas on a Caddy engine and I was wondering what ever became of that.

Not sure of Dan's plans for the Caddy engine, Craig. I seem to recall his mentioning a Cadillac build once in passing, but not in great detail. Dan and I only discussed the early hemi build for 2009 - 2010. I came on board to help him sort out the 51mm EMPI (Weber IDA clone) carbs that were on loan from a VW racer. The following year (2010), I helped him work out the first EFI unit, as the powers that be at EMC had pretty well outlawed everything we had done to place 3rd overall on carbs the year priour...... Limited number of throttle blades to 4, on carbbed engines...... Limited size of throttle blades (but no size constraints on EFI throttle blades), making EFI the only way to be competitive for 2010, really. Hell, they even outlawed solid lifter cams that year.

Anyway, there were no commercially available EFI setups made for the early hemi that complied with the 2010 EMC rules, so Dan cobbled together an old 4-port Hilborn FI unit using a home brewed adapter plate onto an open plenum Hot Heads intake that looked as if it might have been designed initially to be a blower base the way it was made.

Dan told me that Nick Smithberg had mentioned that he had seen some small engines that utilized a single throttle blade to feed 2 runners and asked if that could be done on the hemi, as well. I ran the numbers and as it happened, each of the 4 throttle blades on the Hilborn unit were exactly twice the surface area required for runners of an IR intake having same displacement and redline RPMs. So I told Dan that it looked feasible. He couldn't make any real power with the huge open plenum below the Hilborn unit, so he contacted the EMC rules guys and they said yes, he could use epoxy or do welding inside the intake so long as the outside remained as-cast (no welding of outside surfaces to allow for enlarging the runners).

So the first version worked out where Dan had used epoxy to form 8 individual runners and he brought those up to the top of the Hot Heads casting, leaving a large open area (plenum) inside the Hilborn unit from the 4 large throttle blades down to the upper end of the individual runners. I sized CSA of all runners to take the hemi 'just' to the EMC mandated redline for the dyno pulls. It worked better than before with the plenum above individual runners, but wasn't as good as we had hoped. So Dan extended a vertical divider wall running front to rear inside the 4-hole Hilborn unit and brought the runners on up to meet it.

This created an IR intake (functionally) once the 4 throttle blades were vertical at WOT. Because of EMC limits on thickness of adapter plates and height of ram tubes/trumpets, we could not get it right on the money, but were able to come within an inch of optimum runner length tuned for the stronger 2nd harmonic per Helmholtz calcs. The hemi ran strong in 2010, but as always was plagued with valvetrain stability issues due to the extreme rocker arm ratios and valve lifts run at EMC.

After Dan passed, I communicated with the team via their facebook page during the tribute build that was run in Dan's remembrance for 2011. Nick Smithberg played a pivotal role in getting the hemi together for the 2011 EMC run. I will always remember the beautifully machined piece he had machined for the airhorn. Dan would have loved it and I'm sure he did as he watched over the team at EMC that year. It was based upon the shape of the airhorn used on many Weber DCNF carbs due to the size and spacing of the throttle blades of the Hilborn 4-hole unit.......





Dan's carburreted engine (placed 3rd overall at EMC in 2009)......



You might contact Dan's partner on the EMC early hemi effort, Gene Adams. Or possibly Nick Smithberg, as Dan may have discussed his plans for the Caddy engine with them. If you'd like to do that, I can send you their E-mail addresses via PM.

Best regards,

Harry

[cjperformance]

Harry, thanks for that write up. Yes if you could PM me Gene and Nicks email that would be great.
Cheers,

[enigma57]

Craig, you have mail!

Best regards,

Harry

[cjperformance]

Craig, you have mail!

Best regards,

Harry

Thankyou !

[BLSTIC]

KnightEngines

Didn't people used to shift the entire head over on Holden 6's to get the intake valve farther away from the cylinder wall?

[Keith Morganstein]

I remembered this thread and found it quick enough with a search.
viewtopic.php?f=1&t=24425

[Fatman]

The Holden head does not have enough cross section to support a cylinder on one side of the vane - that's why it is not fully divided, if that was done itd choke.
The idea is to encourage as much flow as the cross section on the side of the vane with the open valve will support to increase intake velocity & inertia ram while still allowing 'top up' flow from the other side to make up the cross section shortfall.

Now I get what a lump port achieves, I have never seen a chev 6 head in person, I didn't realise they had a flat floor.

I can't see a reason why you can't use a vane as well, you'd probably want to be able to achieve 75% of the required cross section per cylinder on each side of the vane.
You could attach the vane to the lump port insert, or weld it directly to the intake manifold - that's how I've done the last 3, much easier than using capscrews through the original bolt hole to locate it!

Being a low rpm torque build I would think you should be able to raise the roof & widen the port enough to work with the vane.

I don't have any more vanes, I carve them by hand from a lump of 10mm thick alloy plate with a die grinder, hacksaw & file, it's a bit of a pita.

Have you tried removing the bolt boss and not running a vane?
So you have a fully open port with just a short bolt on the floor and a plug at the top.

[KnightEngines]

KnightEngines

Didn't people used to shift the entire head over on Holden 6's to get the intake valve farther away from the cylinder wall?

Did and still do! .060" shift makes a real difference, just have to end mill the bolt holes & plug & shift the dowel holes - or just use offset dowels.