Questions Regarding Siamesed Intake Ports (9 Port Head)

[roc]

Hi Harry, three humble comments:

1) Enjoy and have fun with your 292". I admire you for getting off the V8 beaten path.
2) Don't overthink it.
3) I've never seen an inline-six which firing order isn't 1-5-3-6-2-4 (or equivalent if numbered backwards).

[modok]

I think this could work well!
Let us know how it turns out.

[roc]

Hi Harry, three humble comments:

1) Enjoy and have fun with your 292". I admire you for getting off the V8 beaten path.
2) Don't overthink it.
3) I've never seen an inline-six which firing order isn't 1-5-3-6-2-4 (or equivalent if numbered backwards).

On more comment:
4) I really dig your Engine Racing intake, it looks like a nice piece.

Keep us posted!

[Sir Yun]

8. As to tuned length runners with siamesed intake ports...... At this point, I am thinking that everything within the flow path downstream of throttle blades and upstream of port dividers in each of the 3 groupings of siamesed headports...... Are more akin to plenum volume than anything. However, I might be able to tune what I will call for lack of a better term, 'effective runner length' a bit if I can apply something I learned whilst working with Dan Miller on his and Gene Adams' hemi engine for the 2010 EMC.


Harry

If this port reacts anything like an A series it likes long intakes , and yes it acts like a mini plenum of sorts but 3rd harmonic length carb to valve face seems to work well . The idea is to have a long and pretty large volume intake (a good dose of taper works well too) and have pressure recovery in the 'plenum' . Most of the gains are in the exhaust btw. ( we get pretty good output ( 1.9bhp/cid ish but it buzzes merrily along at >8500 rpm)

[Truckedup]

It's been popular in the USA for 20 years or more to grind out the divider between the ports and raise the port floor with a "lump". Lots of info https://www.google.com/search?q=chevy+2 ... =618&dpr=1

[enigma57]

Thanks, guys! Really appreciate your comments and guidance here.

Other than helping my youngest son put together a small block 350 backed up by a 4th gen. T-56 for his 3rd gen. '92 Camaro, this 292 inline 6 for my '57 Chevy sedan will likely be my last build. I have done the V-8 thing in these cars lots of ways since the '60s. This '57 will be a driver and will pull a trailer from time to time, though. So thought I'd start with a 292 inline 6 truck engine and build it up a bit just for fun. Something different.

I will see if I can work out a way to take advantage of tuned length for 3rd (or possibly even 2nd) harmonic. This will take a very long runner length due to design redline of 5,000 RPMs. Very nearly as long as the runners MOPAR used for their long ram intake for the 413 engine in the 1960 300-F cars and 1961 300-G cars.

Did some trial fitting and preliminary measuring today. This sidedraught intake setup is going to be a challenge to package in my '57 engine bay due to clearance issues with master cylinder and steering column. Especially if I add a spacer between carbs and intake to lengthen runners. I have some ideas, though. Will sleep on it and take another look at it this coming week, as I have to work on taxes this weekend. The car is original thus far and I don't want to butcher it. Want to do the engine swap to larger inline 6 and any other mechanical upgrades in such a way as to retain the original character of the car.

Yes, I am definitely planning on removing center divider in siamesed intake ports and installing lump ports. Was looking at various lump port kits online today and saw that some of these heads have lump ports in exhaust side, as well. Is there any particular type exhaust manifold or headers that lump ports in exhaust work better with than leaving floors of exhaust ports a straight exit path? On exhaust side, I may build tube headers, but hate the inevitable leaks and other hassles on a road car, so I am leaning towards making an old school split exhaust manifold. I have one of the large truck/bus/tractor/combine type manifolds here that has a single 2-1/2" exhaust exit and 3-bolt flange. May braze on a 2nd 2-1/2" exit flange and split the manifold. There is a nice looking store bought split exhaust manifold made for these engines, but it interferes with the stock mechanical clutch linkage in my '57 and the dual 2-1/4" outlets only flow as much as a single 2-1/2" outlet anyway, so no real advantage in flow volume over the single 2-1/2" outlet manifold if running a full length, muffled exhaust system.

Tony! Great to hear from you! Do you still run the 302 GMC in your pickup? Here's a pic taken just before my Grandson left for the Army......



Best regards to all,

Harry

[Truckedup]

Tony! Great to hear from you! Do you still run the 302 GMC in your pickup? Here's a pic taken just before my Grandson left for the Army......



Best regards to all,

Harry

Hey Harry, I sold the GMC 302 powered 37 Chevy truck a few years ago... I'm messing with vintage Triumph bikes again and he's a recent photo of me with the two engine land speed racing Triumph I just finished building...

[enigma57]

Looking good, Tony! Love the Triumph! Have I ever mentioned that the late Burt Munro has long been one of my heroes?

Actually...... One of the ideas I have been playing around with is to blank off 1 port of each of the 3 DCOE flanges on this sidedraught intake and mount 3 Mikuni 45 HSR smooth bore carbs set up for a Twin Cam Harley on this 292 engine.

Best regards,

Harry

[roc]

Tony! Great to hear from you! Do you still run the 302 GMC in your pickup? Here's a pic taken just before my Grandson left for the Army......



Best regards to all,

Harry

Hey Harry, I sold the GMC 302 powered 37 Chevy truck a few years ago... I'm messing with vintage Triumph bikes again and he's a recent photo of me with the two engine land speed racing Triumph I just finished building...

Nice bike Truckedup! I don't remember seeing its picture before, coolest ride for sure!

[Brian P]

Looking good, Tony! Love the Triumph! Have I ever mentioned that the late Burt Munro has long been one of my heroes?

Actually...... One of the ideas I have been playing around with is to blank off 1 port of each of the 3 DCOE flanges on this sidedraught intake and mount 3 Mikuni 45 HSR smooth bore carbs set up for a Twin Cam Harley on this 292 engine.

Best regards,

Harry

Given that the engine itself only has 3 intake ports, a more straightforward way to do this would be to simply make up 3 separate adapters to go from the carb to each port and bolt each one separately to the engine. No manifold needed, and the flow path would be more direct.

[PackardV8]

Given that the engine itself only has 3 intake ports, a more straightforward way to do this would be to simply make up 3 separate adapters to go from the carb to each port and bolt each one separately to the engine. No manifold needed, and the flow path would be more direct.

Three of the 1-3/4" SU carbs from Jaguars would fit and work well.

[Truckedup]

The 42 MM Mikuni flat slide pumper carbs used on Harley's work nicely with fuel pressure limited to about 3 psi...$300 each new but can be found for less at swap meets...

The dual engine Triumph is a race only bike, it was being tested last fall on the rural roads around here when a piston galled up badly from still unknown reasons..Took three months to get the correct forged pistons but it's up and running again....Goes on the dyno in a few weeks... and if it survives, be at the Maine 1-1/2 mile in July to hopefully decimate the Harleys

[wyrmrider]

I mentioned the jag carbs in post 3- the 2" would also work
I used a jag carb on a turbo Corvair- also worked good

[MadBill]

The 42 MM Mikuni flat slide pumper carbs used on Harley's work nicely with fuel pressure limited to about 3 psi...$300 each new but can be found for less at swap meets...

The dual engine Triumph is a race only bike, it was being tested last fall on the rural roads around here when a piston galled up badly from still unknown reasons.Took three months to get the correct forged pistons but it's up and running again....Goes on the dyno in a few weeks... and if it survives, be at the Maine 1-1/2 mile in July to hopefully decimate the Harleys

A brief O/T excursion: I forget; was piston coating discussed in the thread on this incident? Line2Line coated crowns and skirts could be a peace of mind as well as a power move... Keep us posted on the other thread.

[pamotorman]

Tony! Great to hear from you! Do you still run the 302 GMC in your pickup? Here's a pic taken just before my Grandson left for the Army......



Best regards to all,

Harry

Hey Harry, I sold the GMC 302 powered 37 Chevy truck a few years ago... I'm messing with vintage Triumph bikes again and he's a recent photo of me with the two engine land speed racing Triumph I just finished building...

Nice bike Truckedup! I don't remember seeing its picture before, coolest ride for sure!

how does the second engine cool because it is seeing all the heated air from the front engine ??