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FE Power Forums => Non-FE Discussion Forum => Topic started by: FrozenMerc on September 27, 2021, 02:24:06 PM

Title: Intake Manifold Design - Forced Induction (MEL)
Post by: FrozenMerc on September 27, 2021, 02:24:06 PM
A bit off topic, but I would like some opinions from the brain trust on here.  4 or 5 years ago, I got my hands on a 430 MEL core, a 6-71 blower, and an old Weiand Intake manifold to pair the two together.  However, it quickly became obvious the Weiand intake was a race only piece that would require things such as a remote thermostat, relocation of the distributor, and crank breather.  It only had minimal provisions for coolant passages that I felt would not work well on a street motor, and to be clear, my intention was for the motor to be 100% street functional (idling in traffic, 75 mph sustained interstates, etc.).  After researching relocating the distributor and doing the other modifications that it would require to make the Weiand work, I came to the conclusion that it would likely be easier to build the intake manifold I needed instead.

Excuse the dirty engine...
(https://live.staticflickr.com/4851/31329607407_eab901b288_b.jpg)

Being the good little engineer that I am, I took the Weiand and made a CAD model of it in UG.  I then started another model that had all the features I wanted, including clearance for the stock distributor, the thermostat in the stock location, better water passages, relocation of blow-off valve, etc.  I have an image of that model below.

(https://live.staticflickr.com/4862/44347857900_bd9eb8fb61_h.jpg)

Well, that was about 3.5 years ago, life happened, new job, moved across the country, couldn't sell the old house and shop, blah, blah, blah.  Long story short, I am ready to get back on this project by getting a 3D printed plastic model made for fit-up, flow testing, etc.  But before I do, the design of the plenum has been bugging me.  The Weiand was completely open in the center (see cross section of the CAD model below), resulting a very large plenum.  I think this probably worked fine on a drag car that was either idling or at WOT with a healthy amount of boost, but I am concerned that at part throttle operation low boost (or no boost), this is less than optimal. 

(https://live.staticflickr.com/65535/51524888928_5f0fd8339f_h.jpg)

What do you guys that have played with forced induction applications think?  My thoughts are leaning towards redesigning it so the plenum is no wider than the opening in the bottom of the 6-71.  This would increase the individual cylinder runner length significantly, and hopefully smooth out the flow.  More along the lines of an FE 6-71 intake.

(https://www.jegs.com/images/photos/700/746/746-1-149-001.jpg)

Not that it matters as I want this to be somewhat universal for any street driven application, but the plan / specs for this motor are as follows.

1958 430 MEL
Offset ground crank to BBC journal size.  4.1" stroke (or as close as possible)
4.35" bore
6-71 Blower, up to 12 psi boost
8:1 compression (most likely custom pistons, although 427 BBC flat-tops will get me close)
Should be right around 485 ci all said and done.  Street friendly tune concentrating on a big, broad torque curve.
I am not sure what it is going in, but most likely something big and heavy.

Finally, The Weiand's intended purpose...
(http://2.bp.blogspot.com/_i_AovfzNXgQ/Rls6wXnjuxI/AAAAAAAACPc/ZxmeNRJiKMc/s400/DSC06583.jpg)
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: TomP on September 27, 2021, 10:51:27 PM
Very rare intake there don't cut it up. Longer runners would be better, for a lower height they used a big box with one large hole in the top and eight smaller holes in the sides.
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: jayb on September 28, 2021, 10:03:00 AM
+1, no runner length will kill low end torque.  It will be bad enough with the short runners you are stuck with when leaving the center of the manifold open for the blower.  Hopefully it will come up on boost fast and you won't notice the issue.  In the drag car you'd never notice the issue because you would leave the line under boost, but on the street it may be a different story.
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: cjshaker on September 28, 2021, 11:21:55 AM
You could enlarge the ports on that Weiand, then slide tubes up inside the plenum and have them welded in, essentially making the runners that you need. Or you could "notch" the opening, have the ports flanged, and simply sandwiched between the head and intake. It wouldn't require any changes or cutting to the outside, and nothing would look different. Just an idea.

As for the water ports, they would flow much better with better fittings, or you could enlarge the port holes. Not sure if there's enough meat there to do that or not. You'd be surprised how much water would flow when you have 2 ports flowing. Seen lots of big HP cars on Drag Week doing exactly that, and they seem to work fine with a good pump.

Cool piece though. Royce needs that for his FED.
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: FrozenMerc on September 28, 2021, 12:21:19 PM
I am definitely not going to cut up or really even touch the Weiand.  That is too rare and too nice of a piece to mess with.  Tom and Jay, you confirmed what I was thinking.  Time to go back to the CAD board and draw something up with longer runners and a smaller center plenum.  I don't think it will be too difficult, just take a few hours.  Thanks for the insight, everyone.  If there is interest, I will keep this updated as things progress.  I have got to put this Corn Binder back together first and then it is on to the MEL.

(https://live.staticflickr.com/65535/51528804565_da6dae4ed0_c.jpg)
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: Dumpling on September 28, 2021, 01:24:46 PM
Did they ever make a 2x4 intake for the MEL?
If there's one available, make an adapter to mount on top of it, open plenum under the blower feeding into the carb openings.  That would give you the runner length and probably address the water and distributor issue too. Would end up setting the blower higher though.
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: 67xr7cat on September 28, 2021, 11:14:17 PM
The MEL and 385 series (429/460) both have a 4.9" bore spacing.  Guys have adapted intakes from a 460 to the MEL. Was common back in the day when putting a blower on a 460 to use a tunnel ram intake with a plate fashioned to attach the blower. Made for a bit high deal, but cleared the dizzy just fine.  Also the MEL and 460 cranks are pretty close.  Guys have used the stroker 460 cranks in the MEL.  Offset grinding the MEL crank is fine, but if you want a bigger stroke or a forged crank doing the mods to make the 460 crank work is the way to go.
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: FrozenMerc on September 29, 2021, 01:43:55 PM
Did they ever make a 2x4 intake for the MEL?
If there's one available, make an adapter to mount on top of it, open plenum under the blower feeding into the carb openings.  That would give you the runner length and probably address the water and distributor issue too. Would end up setting the blower higher though.

As far as I know, there was never a 2x4 intake for the MEL.  3x2 and 1x4 from the factory (all cast iron), and a few aftermarket oddities such as the Weiand blower intake and 6x2 and 8x2 log set ups.

The MEL and 385 series (429/460) both have a 4.9" bore spacing.  Guys have adapted intakes from a 460 to the MEL. Was common back in the day when putting a blower on a 460 to use a tunnel ram intake with a plate fashioned to attach the blower. Made for a bit high deal, but cleared the dizzy just fine.  Also the MEL and 460 cranks are pretty close.  Guys have used the stroker 460 cranks in the MEL.  Offset grinding the MEL crank is fine, but if you want a bigger stroke or a forged crank doing the mods to make the 460 crank work is the way to go.

I initially looked into 385 compatibility.  Supposedly someone was making a set of adaptors to go from the MEL to 385 series intake about 10 or 12 years ago.  The photos I could find led to questions that did not have a good solution.  Mainly dealing with the port shape (oval - 385, rectangle - MEL), and the coolant cross over (front on the 385, rear on MEL).  In the end, I just liked the thought of doing my own intake better.  More issues could be resolved in one package rather then solving 2 and creating 4 more, even if it cost more.

I also thought about the 460 crank, Kasse and Royce obviously did it quite effectively on the Engine Masters MEL.   However, I would still have to buy a 460 crank (aftermarket or otherwise) and have it machined.  I already have the MEL crank and it still needs to be machined.  I figured the machining cost was going to be a wash between the two cranks, so I decided I would start out with what I already have. 
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: Royce on September 29, 2021, 03:57:42 PM
Jay can fix you up with adapter to put a 460 intake on a MEL. He has one on a CNC program.  It requires some re-plumbing  of the coolant but nothing too radical 

Up to about 5500 - 6000 I would trust the Stock MEL crank. I offset ground mine to 4.124 on a 524 inch and on a 475 inch, offset to 4".   The 475 never gave any trouble , but I am limiting the long stroke to 5500. I did these before the 460 crank idea came along..

 All MEL stock intakes suck.. Even the Super Marauder
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: pbf777 on September 29, 2021, 04:29:55 PM
.............3x2 and 1x4 from the factory (all cast iron),.............

     Just a note: the 3x2 factory "Super Marauder" intake was aluminum.    ;)

     There also is the aluminum Edelbrock L300 3x2, but vs. the Holley 2300's as on the S.M. version, I've seen them drilled for either the 4-bolt small-base 2V Rockchesters or the 3-bolt Holley 2100's & Stromberg 94/97's.

     This intake presents good runner lengths, and could be converted into a blower intake in the typical process of the addition of an adapter plate with machining and welding, though the blower, without intentional spacing would be quite low perhaps complicating the distributor fixturing; but does have the advantages of being flat in the plenum presentation which aids in the endeavor vs. with a rake angle, and does exhibit the water passage from the rear. 

     Scott.   
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: frnkeore on September 30, 2021, 02:17:13 AM
You may be over thinking this, a little.

I have some personal experience with old blower manifolds and street driving. My best friend had this car and he and I did all the work on it, frame body, drive train and engine. It was a 326 Olds, with Herbert roller cam and a 471 with dual AFB's. There weren't any dividers for the ports, just a open hole, for each pair of ports but, because the heads aren't as far a part as the MEL, the plenum was a little smaller.

It weighed about 2200 and with the smaller engine, it no flat spots and a smooth transition from idle to any speed, part throttle or WOT. Instant torque! It actually got good gas mileage, too. I think that was because the rotors helped with atomization of the fuel.

Now, at part throttle, on a dyno, you might be able to see a difference, with a well designed manifold but, on the street, I believe you would be hard pressed to tell in by the seat of your pants. Once the plenum becomes pressurized, at any level (and that does not take long), the A/F is at the valve, ready to serve the cylinder. Remember a pressurized vessel, has equal pressure in all directions.

I would agree that the water ports are small and look like 3/8 pipe, to me but, it looks like there is enough room on the boss to take them to 1/2 pipe. I think 1/2 would work for anything but sustain HARD pulls. Back in the 60's and early 70's, there were street driven cars with 671, that ran with a pair of Jabsco 12V water pumps (like for RV water systems). They seemed to run ok at street level driving, in SoCal but, I wasn't associated with them so, I can't confirm that they were trouble free. Georges coupe had the std Olds pump.

The biggest thing, as I see it, is making a 90° or a offset drive, for the dist.
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: cjshaker on September 30, 2021, 06:44:15 AM
Frank, that had to be the bitchinist car in the valley!

Sorry, I couldn't resist the obvious Milner comparison.  ;)
Cool car.
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: frnkeore on September 30, 2021, 11:44:53 AM
It was and we were almost, always stopped by the cops when we took it out. The HR picture, was in the Nov '64 issue and a preview for the Orange County Car and Boat Show, held that Nov.

Although I don't have any pictures of it with my 427, it is the the car that I put my LR in, before he sold it and I went formula car racing. He put the Olds in a flat bottom boat.
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: 1964Fastback on September 30, 2021, 12:38:56 PM
A bunch of us were talking about American Graffiti the day after it was shown on TV for the first time, before class.  A friend of mine, laid back and a bit of a stoner said, "Man, a deuce coupe and a '55 Chevy drag racing at dawn!  I was just born too late!"  At the time, anyway, I had to agree with him.  :)

Pat
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: pbf777 on September 30, 2021, 12:40:23 PM
What do you guys that have played with forced induction applications think?  My thoughts are leaning towards redesigning it so the plenum is no wider than the opening in the bottom of the 6-71.  This would increase the individual cylinder runner length significantly, and hopefully smooth out the flow.  More along the lines of an FE 6-71 intake.

(https://www.jegs.com/images/photos/700/746/746-1-149-001.jpg)

     Backing up a little; if the intention is to manufacture an intake of your own design, then yes, I would incorporate similar under blower plenum to port runner transition as presented in the photo of the FE example.    :)

     But I'm not so sure that with the longer port runners torque increases would truly be the greatest benefit, as stated by another previously this is a positive displacement blower geared to the crank, so boost will come-up rather quickly with throttle opening even at lower revolutions; but rather I think the greater value would be to aid in the control of fuel drop-out, this being promoted due to the otherwise rather large box plenum area, that although the fuel may have been well mixed as passing thru the blower, without better directional coercement and considering the necessity to operate with a generally otherwise considered overly rich mixture, excessive unappreciated fuel puddling at the lower velocities is likely.    :(

     Also while engineering your manifold realize that typically over the decades it has been noted that there is a tendency for the fuel charge to present leaner mixtures toward the front and getting progressively richer as approaching the rear; this generally being attributed to the helix twist in the rotors resulting in their progressive displacement of area in their length. Remember, this was not a concern by Detroit Diesel in the original application as no fuel (diesel) was intended to pass thru the blower (direct in cylinder injection) not to mention the convoluted pathway from the blower discharge to the air box position on the side of the block to feed the cylinders port openings (two-stroke!   :o  ) negated any such considerations; though still, due to reversion effects the air boxes were fitted with drains to remove the accumulation of oil and fuel liquid. The simplest solution to attempt to equalize the cylinder to cylinder fuel mixtures has generally been to move the blowers' mounting forward on the engine, when and if other concerns (what distributor?    ::)  ) in the fitment permit such; this somewhat akin to the adjustable/sliding carburetor spacer plates this allowing the carburetor to be moved forward & back to find the position providing the best performance.   ???

     As a side note: if one were going to have a billet crankshaft made for their MEL or Lima 385 motor, for an aggressive blower application, consider looking at the 1967-'68 front timing covers (for seal application) with the crankshaft snout mounted power steering pumps (just mimic the P.S. assembly's drive hub O.D.), as this engineering would permit a quite greater diameter crank-snout providing better support particularly considering the length in these engine applications!    8)

     Scott.

Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: FrozenMerc on September 30, 2021, 12:47:18 PM
Jay can fix you up with adapter to put a 460 intake on a MEL. He has one on a CNC program.  It requires some re-plumbing  of the coolant but nothing too radical 

Up to about 5500 - 6000 I would trust the Stock MEL crank. I offset ground mine to 4.124 on a 524 inch and on a 475 inch, offset to 4".   The 475 never gave any trouble , but I am limiting the long stroke to 5500. I did these before the 460 crank idea came along..

 All MEL stock intakes suck.. Even the Super Marauder

I have no plans to exceed 6000 rpms.  No intention to build an all out max horsepower effort.  The goal is for a reliable bruiser.  I know there are much easier ways to do that (445 FE, 460 based  whatever, Cummins, etc.), but I like taking the road less travelled.
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: FrozenMerc on September 30, 2021, 12:56:18 PM
You may be over thinking this, a little.

The biggest thing, as I see it, is making a 90° or a offset drive, for the dist.

Your not the first to accuse me of such.  Something about not being able to find a tree since this damn forest keeps getting in the way.

I did alot of research on offset or 90 deg drive distributors.  Honestly, going to a remote electric water pump, and adapting a flathead crab style distributor to the timing cover would probably be the simplest.  Blower Drive belt clearance could be interesting, but I think doable.

Very Cool car, Thanks for the insight and experience with a similar setup.

(https://content.speedwaymotors.com/ProductImages/5478353_L_afd41bde-0ed3-47e8-8ecb-14cf8795f713.jpg)
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: FrozenMerc on September 30, 2021, 01:13:46 PM
     Backing up a little; if the intention is to manufacture an intake of your own design, then yes, I would incorporate similar under blower plenum to port runner transition as presented in the photo of the FE example.    :)

     But I'm not so sure that with the longer port runners torque increases would truly be the greatest benefit, as stated by another previously this is a positive displacement blower geared to the crank, so boost will come-up rather quickly with throttle opening even at lower revolutions; but rather I think the greater value would be to aid in the control of fuel drop-out, this being promoted due to the otherwise rather large box plenum area, that although the fuel may have been well mixed as passing thru the blower, without better directional coercement and considering the necessity to operate with a generally otherwise considered overly rich mixture, excessive unappreciated fuel puddling at the lower velocities is likely.    :(

     Also while engineering your manifold realize that typically over the decades it has been noted that there is a tendency for the fuel charge to present leaner mixtures toward the front and getting progressively richer as approaching the rear; this generally being attributed to the helix twist in the rotors resulting in their progressive displacement of area in their length. Remember, this was not a concern by Detroit Diesel in the original application as no fuel (diesel) was intended to pass thru the blower (direct in cylinder injection) not to mention the convoluted pathway from the blower discharge to the air box position on the side of the block to feed the cylinders port openings (two-stroke!   :o  ) negated any such considerations; though still, due to reversion effects the air boxes were fitted with drains to remove the accumulation of oil and fuel liquid. The simplest solution to attempt to equalize the cylinder to cylinder fuel mixtures has generally been to move the blowers' mounting forward on the engine, when and if other concerns (what distributor?    ::)  ) in the fitment permit such; this somewhat akin to the adjustable/sliding carburetor spacer plates this allowing the carburetor to be moved forward & back to find the position providing the best performance.   ???

     As a side note: if one were going to have a billet crankshaft made for their MEL or Lima 385 motor, for an aggressive blower application, consider looking at the 1967-'68 front timing covers (for seal application) with the crankshaft snout mounted power steering pumps (just mimic the P.S. assembly's drive hub O.D.), as this engineering would permit a quite greater diameter crank-snout providing better support particularly considering the length in these engine applications!    8)

     Scott.

All Valid points, Scott.  I was concerned about fuel puddling, and equal fuel distribution to the front cylinders.  That is part of what made me hesitate on just copying the Weiand design and ask for opinions on here.  Even in my initial design, the front cylinder port was somewhat blocked by the thermostat housing, and I am especially concerned with that one going lean, not a good thing in a boosted application.

All told, the easy thing to do would be to stick with the stock 4 barrel manifold, add a throttle body injection unit, and go with a belt driven centrifugal supercharger.  But that didn't sound like as much fun.... :o
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: Dumpling on September 30, 2021, 03:15:02 PM
This all seems overly complicated.
Latham blowers fed the engine through basically a 2V intake. Paxtons through 4V intakes.
Can't you just funnel down from the base of the Roots blower into a 4V intake of your choice. The funnel would probably raise the blower high enough to give you distributor clearance.

http://fepower.net/Photos/Posts/latham3.jpg
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: pbf777 on September 30, 2021, 05:11:16 PM

I did alot of research on offset or 90 deg drive distributors.  Honestly, going to a remote electric water pump, and adapting a flathead crab style distributor to the timing cover would probably be the simplest.

(https://content.speedwaymotors.com/ProductImages/5478353_L_afd41bde-0ed3-47e8-8ecb-14cf8795f713.jpg)

     For engines of relatively short duration operation where the engine is basically acting as a heat-sink such as a drag car the electric water pumps work fine; but longer duration operation requires significant consideration for how these engines (American V8's) were designed and intended to be cooled vs. what one may reap from something else.       :-\

     The front cover mounted direct-drive off the cam distributor is a fine installation except the water pump must move, and greater belt clearance is had by mounting the distributor body out of line of the blower belt.  In the past we made some remote belt-driven distributor heads which were mounted as one mounts a belt-driven fuel pump, these worked with good success in even extended road course race applications.    8)

     And yes, it always gets complicated, but then although I think the Lathams were cool (they supposedly created a kit for the MEL's, but I haven't seen one!   :(  ) they really didn't do so well, and I always attributed some of this to the often very poor intake manifolds supplied; and not that I have ever tested such, but the funnel program except to be able to say one successfully mounted a blower on their engine, I just don't think we could say it was a very successfully efficient installation, this perhaps being similar in effect to the Dominator carburetor to std. Holley pattern intake manifold adapters (funnels!  ::)  ) which most often kinda suffer, but it would be on there!    :-\

     Scott.

   
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: Dumpling on October 01, 2021, 07:52:28 AM
Latham's didn't do so well simply because they didn't actually pump much air, or much air enough air for some of the engines they were mounted to.

It wasn't the intake.

Why not DIS? Coil packs with a crank trigger. End of distributor clearance issues.

The FE needs a sub-shaft if the distributor is moved or eliminated; is the MEL the same?
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: pbf777 on October 01, 2021, 12:01:16 PM
The FE needs a sub-shaft if the distributor is moved or eliminated; is the MEL the same?

     Yes, a distributor "stub-shaft", if you're going to drive the in the pan oil pump.  We have made these by simply cutting down std. distributor bodies & shafts, and fixturing a ball-bearing assy. in the top of the newly created short assy. with a cap fastened.    ;)

     Scott.
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: FrozenMerc on October 01, 2021, 02:31:56 PM
I don't think choking the 6-71 through any more of a funnel than absolutely necessary is wise.  Roots blowers are positive displacement type blowers that create air flow only, and rely on downstream restrictions to create the manifold pressure.  Having a major restriction between the manifold and blower seems like a recipe to make an already in-efficient air pump even worse, and do nothing to increase the charge air density, which is what we are after in the long run.  Part of the reason why I am leaning towards a new manifold, rather than trying to modify an existing one.

No doubt a centrifugal supercharger would be easier, and probably better for max power efforts, especially if an intercooler could be deployed, but I also am going for a specific look.  Even though there a few examples of some damn good looking Paxton / McCullochs on MEL's out there.

(https://fox-kraft.com/WEBSTUFF/GNRS15/P1230050.JPG)   
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: Tommy-T on October 02, 2021, 04:27:59 PM
I've got nothing to add to the technical portion of this thread except that on my 8-71 454 FE I used a Blue Thunder intake and ran a Electromotive HPV1 crank trigger with no distributor to mess with.
I ran the 8-71 deal for about 10 years. I got a good chuckle when it was mentioned that intake manifold runner length would have a significant impact on torque production. Maybe it would but I can tell you matter-of factly...from a 10 mile an hour roll, manual valve body C6 in 3rd gear, you could roast 19X33 M/T Sportsmans as far as you wanted and be up on 6K RPM VERY quickly.

Roots blowers are very cool...but detonation is NOT. The learning curve is VERY steep and EXPENSIVE.
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: Royce on October 04, 2021, 09:20:01 AM
Why not use the 460 blower intake and the MEL intake adapters,,Distributor off the cam and a high flow electric water pump  Jay uses one on his drag week cars with good success..
Title: Re: Intake Manifold Design - Forced Induction (MEL)
Post by: pbf777 on October 04, 2021, 10:45:49 AM
I got a good chuckle when it was mentioned that intake manifold runner length would have a significant impact on torque production. Maybe it would but I can tell you matter-of factly...

     Yes, blowers (and other forms of forced induction) do work well to improve the filling of the cylinder(s), hence the improved performance.  But unfortunately they have often encompassed induction pathways of less than ideal design, and this deficit should not be ignored as so it has often been, for some capability is lost to this practice.  But one easily understands how this has come to be, as if the addition of a blower, even if mounted on a poor manifold, results in just spinning of the tires, who's looking for more!    ::)

     But as I stated previously, and which I don't completely disagree with the above statement, but I'm also really not so sure if as presented as a concern by the O.P. torque production (under-the-boost?) is what one might really be chasing in this type of forced induction apparatus in attempting to 'better' the inlet manifold.     :)

     Scott.