Intake Manifold Design - Forced Induction (MEL)

[FrozenMerc]

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.

[FrozenMerc]

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.

[FrozenMerc]

     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!     ) 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!   

     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....

[Dumpling]

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

[pbf777]

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.

     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.   

     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.

   

[Dumpling]

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?

[pbf777]

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.

[FrozenMerc]

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.

   

[Tommy-T]

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.

[Royce]

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..

[pbf777]

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.