If/When you go to siamesed Intakes?
 

In a conversation on Sunday, One of the evil influences, which shall nameless("ZZZZZR1") started talking about siamesed intake ports for a 385 cube engine. It got me wondering, when & what parameters to use this method. I do comprehend the concept of drawing from 2 ports. I am sure RPM & Engine Size dictates use, just curious when. And, if cylinder porting would be different. I doubt I would ever do, just curious how it is used. Thanks, Tim

Re: If/When you go to siamesed Intakes?
 

I have one on my 350 w/cams.....have not been to the dyno but trust me no loss in torque.....pete drove it as well and came to the same conclusion. In fact, someone put it on a lift and checked the revolutions because they thought it has a 4.10 gear.

Re: If/When you go to siamesed Intakes?
 

Now why would he go and do that?? ;)

Lee,

The set up on the 90 you did is pretty much where I want to go eventually. Good gains for the amount of work IMHO.

-Daniel

Re: If/When you go to siamesed Intakes?
 

Siamesed and dropped plenum on a 385 is sexy. We need to meet up soon

Re: If/When you go to siamesed Intakes?
 

Pic after rough porting was done:

http://i134.photobucket.com/albums/q115/lgaff/156.jpg

Stock:

http://i134.photobucket.com/albums/q115/lgaff/152-2.jpg

Re: If/When you go to siamesed Intakes?
 

WANT!

Re: If/When you go to siamesed Intakes?
 

Anyone done a bench flow test on this?

Re: If/When you go to siamesed Intakes?
 

You are correct sir! Beware of the pretenders, unless it looks like this it's not a true siamesed plenum... This is my 93'

http://i1132.photobucket.com/albums/...an/SiaPlen.jpg

Re: If/When you go to siamesed Intakes?
 

you aint kiddin ron

http://i1181.photobucket.com/albums/...pse4fd688c.jpg

Re: If/When you go to siamesed Intakes?
 

Ron, I would say this is more of a monorunner than siamesed.......they actually cut the runner out and reweld.....

Re: If/When you go to siamesed Intakes?
 

Ya Lee, that's a common mistake. No such thing as a mono-runner. The plenums pictured are referred to as Siamese’d. The plenums that have been joined internally only are referred to as a fully ported. Lot's of differance in flow and price...

Cheers,

Re: If/When you go to siamesed Intakes?
 

TQ is still good on my 368

http://i1132.photobucket.com/albums/...ynoSheetlg.jpg

Re: If/When you go to siamesed Intakes?
 

Ron, You wouldn't have port pics, would you? Wow, lots more to know!

Re: If/When you go to siamesed Intakes?
 

I like to think of them as full siamesed or partial (figure 8) siamesed.... and then there is my B-port siamese :D

http://i418.photobucket.com/albums/p...g/P7120021.jpg

http://i418.photobucket.com/albums/p...g/P7120036.jpg

Re: If/When you go to siamesed Intakes?
 

The Siamese port actually started with Gulstrand and then TPIS who both made a siamesed TPI runner....TPIS version was more like the one Locobob and I did.....

Re: If/When you go to siamesed Intakes?
 

I will call it an infiniti port.........

Re: If/When you go to siamesed Intakes?
 

If it's mine, I'll call it what I want.

If it's yours, I'll call it what I want.

...................http://www.xnormal.net/Images/bananaDanceInverted.gif...


...

Re: If/When you go to siamesed Intakes?
 

Re: If/When you go to siamesed Intakes?
 

I would think the separation between runners would become important with respect to cam timing of the two valves - do they open in unison (stock cam) or is there a difference in cam timing?

- Jeff the curious, who will wind up with exactly one chance to get it right and still meet class rules....

Re: If/When you go to siamesed Intakes?
 

I believe the stockers have some offset timing and lift, my regrinds have different lift and cam duration for primaries and secondaries...there is also a dog leg to one port that acts as a swirl generator

Re: If/When you go to siamesed Intakes?
 

650 rwhp and the inj housings are still divided on mine, and only 35mm ports. The plenum runners are the figure eight style like Bob posted. Definitely not the welded mono style.

Different ways to skin the cat, bigger isn't always necessary. LPE got good power for the times with the mono plenum runners. However, if you've seen pics of their inj housings they were not siamesed either. Either "D" port on the secondary, or "double D" ports, from what I've seen.

Todd

Re: If/When you go to siamesed Intakes?
 

This is a good question - the reason I asked if anyone has done flow test on the bench OR IN A LAB.

Airflow through the tubes - just like water flow - has dynamics - AEROdynamics. The column of air has LAMINAR flow - momentum, going through the tubes.

Introduction of turbulence can create eddies. But, DEPENDING on where it is in the intake mechanics, it can be good (think of GM's VORTEC induction), OR, it can be 'not beneficial'.

And I say 'not beneficial', as opposed to BAD, conditionally; with some reservation here.

Making a bigger hole WILL allow more air, which without question, will benefit an engine with the hammer on the floor.

But what about mid-range? And low end?

Best example that I can think of, is L98's intake manifold. Flow characteristics of L98 intake are 'templated' on flow characteristics of an LB9. L98 loses out top end, NOT because of the VOLUME THAT THE INTAKE ALLOWS, BUT BECAUSE OF FLOW DYNAMICS.

Another example came from another forum board - discussion of the 'Foil', on the throttle body. After thinking on it - how it would stop air from 'bouncing' (turbulence), off of the OEM TB divider (of the 2 TB openings), made me think further on it's benefits. Throw a rock in a pond, and watch the waves 'bounce', AND COME BACKWARD EVEN, WHEN THE WAVES HIT THE "No Fishing" sign. Then I posted that in a forced air induction system, it should REALLY be beneficial, to reduce the 'bounce'. User 'Joe', whom some of you probably know, after lurking about, posted up 'Bingo', on the forced air induction/ benefits.

A true MONOrunner plenum has dynamics already considered.

So I'm asking again here; has anyone done flow dynamics tests, of any sort, on OEM vs 'siamese-d' tubes? Or even, Before and After TQ/HP numbers???

Re: If/When you go to siamesed Intakes?
 

i'd like to see down into the IH of Mark H's 385. with that dropped plenum I'd like to see what LPE did there

Re: If/When you go to siamesed Intakes?
 

Really what I would like to do it

Divide the plenum in two to create a helmholtz resonator
Create a air horn/veolicty stack entry into each set of runners

Re: If/When you go to siamesed Intakes?
 

Lee, I have to recover some brain cells lost at BG this past year however I ran into a guy that told me about the first true Siamese and it wasn't for Gulstrand. I believe it was for LPE or Jeal. I'll do some research and get back with you. You know, it might have been Graham telling me?? Guess I'll have to give him a call... Billy K comes to mind but again, those brain cells are dead...

Cheers,

Re: If/When you go to siamesed Intakes?
 

i remember the sheet metal intake that billy k made for his car.

Re: If/When you go to siamesed Intakes?
 

I am talking about the TPI stiff Ron, TPIS/Gulstrand did siamese with TPI runners...which is were I think the term was first used......you are correct on the LT-5....I was just speaking to the way it was done on those...some combined with no center ridge, some did not

Re: If/When you go to siamesed Intakes?
 

Copy, your talking L98 then. I wasn't sure because of the 1990's having TPI on the side ;)

Re: If/When you go to siamesed Intakes?
 

I thought this thing was cool looking. You could see the top flex when he revved her up... Probably needed a little more volume and some stiffeners.

Re: If/When you go to siamesed Intakes?
 

Actaully Ron, the first Siamese was the snakeskinner car......from sports car illustrated:

"The secondary throttles have been removed, so the engine is always drawing air through both runners. The intake runners have been siamesed along part of their length by cutting out the wall separating them. The cams are stock......."

This car ran 11.83@123 .....launching at 1600 RPM

This is from May 1992 mag...the 1989 Snakeskinner 1

Re: If/When you go to siamesed Intakes?
 

Yep but who did the work? I cannot remember... I guess JVD would know unless you do...

Re: If/When you go to siamesed Intakes?
 

since that was a gm project i'd have thought mercruiser did it

Re: If/When you go to siamesed Intakes?
 

Ron this is the GM test car.......I am guessing either Mercury or Scott Leon at GM

Re: If/When you go to siamesed Intakes?
 

If you go down this road to Siamese , make sure you have someone who know what they are doing........ this thing cost me major $$$ for the plenum, work done, then GVD to fix it...

http://i7.photobucket.com/albums/y292/kpie/DSC07909.jpg

Hey Todd

Sure would like to see those double DD's ;)

I have only seen the single D

http://i7.photobucket.com/albums/y292/kpie/lt-5006.jpg

Re: If/When you go to siamesed Intakes?
 

You know, GVD was probably the guy...

Re: If/When you go to siamesed Intakes?
 

what's warped the plenum or I/H ?

AL.

Re: If/When you go to siamesed Intakes?
 

GVD was certainly involved in some interesting testing but I don't recall him ever mentioning working on the SS motor...... hmmm

Re: If/When you go to siamesed Intakes?
 

Hey Al

It was both that Greg had mill flat.
I bought all new plenum, and housings, sent out for siamese runners got back a wrapped used mess from Kirchhofer. I sat on it for a few years then had Greg Van Deventer port it and mill it all flat. So I bought new parts, got used parts back that would not seal, then Had the right Guy fix it.... This is why I say " go to the right guy first ".

http://i7.photobucket.com/albums/y292/kpie/DSC08640.jpg

Re: If/When you go to siamesed Intakes?
 

I've never heard or read of anyone doing a flow dynamics study on
the LT5 intake. I'd like to hear more about how this would be done.
(specifics)
As for before and after TQ & HP numbers, yes I've seen them years
back on a HI car called the Pineapple Express. They were posted on the list server (mail list). I can't promise to find them, but I'll look. As for the stock numbers. They're out there in spades.

Re: If/When you go to siamesed Intakes?
 

[QUOTE=Polo-1;182755]Hey Al

It was both that Greg had mill flat.
I bought all new plenum, and housings, sent out for siamese runners got back a wrapped used mess from Kirchhofer. I sat on it for a few years then had Greg Van Deventer port it and mill it all flat. So I bought new parts, got used parts back that would not seal, then Had the right Guy fix it.... This is why I say " go to the right guy first ".

http://i7.photobucket.com/albums/y292/kpie/DSC08640.jpg[/QUOTE.

Typical of him to pull shiit like that,I know exactly how you feel.



AL.