Tubing based MPFI intake for Scout?

[Hoplee]

I can't weld because of a medical condition, so...

Anyone interested in aiding in the design/construction of an MPFI capable, grass-roots budget, intake manifold for a v8 engine? The only reason this is interesting is because this engine, an International SV 304 v8, was never offered with MPFI...

I like to think of it as a geas, but it IS attainable with a megasquirt and a few junkyard sensors...

I think the easiest thing would be to machine intake flanges based on a set of OEM metal gaskets. Make the flanges 0.250" thick and weld brass/aluminum/steel/unobtainium tubing to it as 8 individual throttle bodies OR connect each intake runner to a sheet-metal box fed by a big three original equipment throttle body...

C'mon, somebody besides me is feeling crazy, right?

[Bad One]

It'll be some coin, but look here.
No MPFI one yet, but they're supposidly working on it...

Oh, and the Binder Bulletin (well, Binder Planet now) is back up.

[Drift2XL]

I got some free lunch time. But no real way to mandrel bend tube.    Or supplies for aluminum.    My shop specializes in Stainless. And my area is nothing but.

I guess this could be a great warm up. I'm planning a MP-EFI mani for a Clevor.

Need to figure out optimum runner length and cross area. I figure you want to trade a little bit of grunt for some more top end. Mani is a good start, but the heads are where the big gains would be.

With some schematics, I might ..... I said might, be able to squeeze some laser time on some drop pieces. Yeah a 4 MW laser. Cuts up to 1" thick. But at that thickness, it would leave the same rough edge as the HD-Plasma. Quarter inch should be good for flanges.

No, not TV plasma.

[Hoplee]

Luckily, I know someone who has already taken a stab at optimal runner length for the 304 and the number he came up with is about 15" IIRC.

However, I was reading recently about a monster twin turbo factory v8 that GM built off the latest LS-X series engine. Let me see if I can post a pic... or better yet a dyno run producing a confirmed 2,000hp from 400 cubic inches of American FURY!!!

http://videos.streetfire.net/video/LSX-Block-makes-2000HP-on_168394.htm

Notice that the runners are extremely short and entirely straight, from each intake port to the sheet metal "box" below the twin throttle bodies mounted on top. The injectors are mounted at the base of each runner to avoid pooling and improve atomization at the valve/combustion chamber. How does THAT grind your gears? Sure makes things LOOK simple as far as basic construction goes, and may eliminate the desire/need for mandrel bends? There are going to be tradeoffs in the power band going with such short runners, but we could always fix that later with the right forced induction setup...

Personally, I think we should design something that could accept a turbo at a later date...

[bimmerlovere39]

[bimmerlovere39]

Some engine porn for ya (the 2000hp LSX)


Don't turbocharged engines have different needs/wants when it comes to runner length, due to the pressurized intake?

[fndrbndr]

Dear God, that thing was awesome.  I have to ask, though...where, outside of drag racing, could anyone use 2000 hp in a "normal" car?  I mean, doesn't the Bugatti Veyron have AWD and a TCS that costs more than my car to manage roughly half that?  I know you want to spin the wheels more in rally driving, but doesn't some power have to get to the ground eventually?

[bimmerlovere39]

Oh, the Veyron has more in it, there's just a lack of transmissions that can take it 

[Drift2XL]

Yeah, I was about to ask how about a tunnel ram style. I figure you got plenty of hood clearance. I can do that easier. Just brake up two channels and weld together. Keeps the better (for torque) square port design.

I'll get with you tomorrow Hop. Evidently, I got to go shopping tonight

[Hoplee]

First, let me say that between 3 and 5 psi of boost is about all I'd think would be useful on an approximately 5.0L v8 using a rebuilt mechanical wet-sump oil pump in a 100" WB chassis. However, the stock CR is LOW , so it might be fun to try 10 psi someday when I'm really feeling the Wheaties. Cause, you'd better eat yo Wheaties!

Now, on to the explanation of why the flanges/runners need extra material for machining & grinding!

1) OEM, International SV v8 engines used "steel shim type" intake and head gaskets, instead of the composite head and intake gaskets included with any complete FelPro engine gasket set. The compressed thickness is different by an average of 0.5mm (0.020") or so. This lowers the compression ratio by increasing the volume of the combustion chamber, leading us to "2)"...

2) Almost all experienced rebuilders of International SV engines will deck the block by 1.5 to 2mm (0.060 to 0.080") or more, and furthermore machine about 0.5mm (0.020") off the heads. They do this to raise the compression ratio up from the OEM nominal of about 8.1:1.

BREAK FOR RANDOM OLD ENGINE TRIVIA!
The rotating assembly is forged and won't break a sweat running 5,500 to 6,000 RPMs or so. (even though they're usually making their best power between 2,400RPM (max torque RPM stock) and 4,000RPM (max hp RPM stock)

The first limitation that you'll actually run into when building these for RPM/hp (they gots the TORQUE already!) is that the OEM valve springs are too soft to avoid floating over 5,000 RPM, but these can be replaced with BB Chebby springs, raising the effective redline over 6,000 RPM without much issue.

Of course, the right gearing makes RPMs muuuch less critical, and it's not much $$$ to swap the ring and pinion on a SII Dana 44 to just about anything you'd want. Parts cost would be $100 or so IIRC.

If one gets really creative, those IH rods and the crank can be lightened by at least 20% without hurting reliability. The block is also a stout, deep skirt & high-nickel piece that can be bored out quite a bit to accept a more modern piston assembly.* If you've got really deep pockets and a serious desire to punish others with an orphaned engine family, I might have an extra engine with a bad rod that you can have for free, IF you can move it...

I personally did NOT machine or deck anything, am using stock springs, and I'm using standard style composite Fel-Pro gaskets, which is probably why my intake leaks a little!  I'm not worried about my effective 8:0 CR because a turbo is a more efficient compressor than a piston... 

* The reason why everything has extra material on it is partially that the engine was designed to produce max power for 1,000 hrs continuous. Heavier rods help with low end torque, etc, etc, etc. Low RPMs is the best way to keep an engine alive, no matter who made it or when, and the SV series engine is a perfect example. "It just... don't... DIE!"
BACK TO OUR INTAKE!

Put "1)" and "2)" together and think about the geometry. Thicker head gaskets move the heads UP and OUT. Thicker intake gaskets move the intake UP and IN. Machining the deck moves the heads DOWN and IN relative to the ground. Machining the bottom of the heads also moves their mating surfaces for the intake DOWN and IN. This means that if you rebuilt your SV for improved compression, you'll need enough extra flange material to adjust for side to side variation. It also means that a thicker runner would be helpful for any port matching you might try with a die-grinder after the first test-fit, because the intake moves vertically due to gasket material, machining, and our old friend: Tolerance Stack-Up. 

!HARE-BRAINED IDEA!
This extra machining can be avoided by making the inlet portions separable for each bank. One of my hare-brained ideas is actually to make thick flanges that act as adapters for the upper portion of a more modern intake that already has a throttle body assembly ready to go, like half of a junkyard Ford 5.0L two-piece plenum (5.0L is darned close to 304 cubic inches ) An even crazier idea is to use 2x modern 4 cylinder intakes, again using thick flanges as adapters. If the flanges are thick enough, they can be used for injector bungs, simplifying the requirements of any upper plenum assembly. It could wind up looking like an old Weber or Hillborn setup, or it could look like two honda motorcycle intakes bolted on top of a 30 year old v8! 

I'd tell you the reasons why this is more hare-brained than it sounds, but it's more fun if you try to guess!

Scared? I make it sound worse than it is. In the end, any intake is just a hunk of something with holes in it! it doesn't have to be perfect, it just shouldn't LEAK! 

[bimmerlovere39]

hm.... a couple of 4 cylinder intakes...that might work...

Perhaps you might "just" need to go junkyard hunting... and get an adapter plate or two, rather than a full intake?

[Hoplee]

Important Design Notes:

a) The OEM cast iron SIXTY POUND intake is the equivalent of a aftermarket v8 carbureted "dual-plane" air gap 2bbl intake.

b) The intake runners are approximately equally spaced at the heads.

c) There is a small exhaust cross-over going straight through the center of every thing, from one cylinder bank to the other.

d) Coolant Return
-dI. The thermostat is mounted to the front of the intake, right next to the distributor.
-dII. There are two passages for water coming out of each head, one each between two intake runners (the center of the 3 spaces available between the intake runners  is used for "c)", the exhaust cross-over.) The coolant returns connect to each other and then to a reservoir/void underneath the thermostat housing at the front.

- Notes for PROTO-

Pa) The coolant return passages don't even need to be rigid or cast/machined material, they just need to stay lower than the thermostat. There's not much pressure and they don't see much over 165 to 185 degrees F unless you're really pushing it. As long as the thermostat housing is locked down, simply using the correct length of braided hose (or similar) would keep the returns in position. They don't really even need to be joined to each other as long as they're all about level horizontally. Fabricate a "jug" shaped piece about the size of a can of campbell's soup to hold the thermostat at the right place and then run all four coolant returns straight into the bottom of it, problem solved.

Pb) The exhaust cross-over needs to be considered for any turbo application. If blocked off, the exhaust ports can't be opened up enough to compensate. Still, it's kinda cool to have an "H" pipe / pressure equalizer that's RIGHT THERE at the heads! I think it needs to be a high pressure/ high temp piece, but I'd like it to be a separate component from the intake runners to isolate heat transfer and potential cracking/thermal expansion issues. Any exhaust cross-over shouldn't need to be connected to anything other than itself, even in a potential turbo install IMHO. How about cast iron with pipe fittings? Seriously!

[Hoplee]

hm.... a couple of 4 cylinder intakes...that might work...

Perhaps you might "just" need to go junkyard hunting... and get an adapter plate or two, rather than a full intake?

I actually think that adapting something off another car would be just as much work as a crude but effective prototype intake, with the added drawbacks of dealing with any proprietary systems or annoying linkage/connections/controls piggy-backed onto half someone else's manifold assembly.

Besides, two four cylinder intakes would mean two separate throttle body assemblies and controls...or trying to convince them to be happy sharing one...ugh

See also, my notes previous re: coolant return and exhaust cross-over!

AND it's not as cool.

I seriously don't think making a crude but effective intake for this thing would be impossible. I need to spend time thinking about what kind of cheap throttle body & fuel system to use, and those parts would probably have to come from the junkpile.

[Hoplee]

Talked to Drift last night and outlined my best concepts for prototyping. Here's a short summary:

*Valley Pan is a separate piece on the IH SV v8 engine and need not be considered for the prototype
*Runners can be relatively short & square/rectangular in cross-section. I'm picturing 3 or 4 inches straight out from the head with injector bungs mounted at the base of each runner.
*Runners need only be rigidly attached to flange at head, Runners can be connected to a separate plenum/throttle body assembly using short sections of silicon hose, much like a typical after-market inter-cooler hose connection
*0.250" thick flanges adequate, stainless mat'l OK
*flexible lines OK for coolant return linked to reservoir/thermostat mount
*an exhaust cross-over with threaded ends, one right and one left hand to adjust assembled length 

Given the concepts presented by the above summary, we can consider this version to have solved several issues re: function and fitment. For example,

1) NO extra mat'l would be required for the intake manifold flange & runner assembly due to previously mentioned tolerance stack-up, or even block/head modification -IF exhaust cross over is threaded to adjust it's length AND the plenum used is NOT rigidly fixed to the runners!
2) latest prototype concept requires no complicated machining. The flange is the most complicated part, but once you get that out of the way, you can make runners from square stock or by welding together two C-channels. A little more welding for the bungs and you're basically done with fabrication other than some standard hose fittings.
3) latest prototype concept would be easily adapted to any motor configuration by simply tracing the profile of a head gasket! The proposed separate plenum makes the fundamental design VERY adaptable.

 

[Hoplee]

Fun Fact!

The TBI system from a 5.0L Ford v8 will bolt right up to the International SV manifold WITHOUT AN ADAPTER!!

Nifty!