Build Thread 1978 Mercury Cyclone. The pig is in the pen.

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#7,381
I started another thread to try and get opinions that would not otherwise get offered on my daily beast here.

Seems a few folks believe that I'll suffer from reversion,..and fuel standoff back spray out into the air plenum/filter/atmosphere with this system.And that low speed port velocity will be non-existent due to the total surface area that opens, and closes at the same time...

I'm betting against that...The engine that these TB's came off of did not suffer from any of the drivability concerns.

It makes sense to me That: The commensurate amount of fuel required to cover the air gap is gonna happen as a result of throttle percentage when/if I convert to Alpha N, and that's gonna be totally dependent on whether or not the speed density system goes to hell when I build this vacuum reservoir/ remote plenum that all six tb's will be plumbed into.

when the throttle blade cracks open, it's only gonna take a fraction of the pedal travel to create the same amount of throttle opening that would've had to happen with the old single TB...the issue may be that the engine would be too slow to respond RPM wise to a quick snap open of the throttle, and that would result in a bog..

I've never seen a BMW M three bog.
 

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#7,382
Understood about the BMW. Just remember that the BMW has a DOHC head. Your push rod engine has a much smaller port cross section and much smaller intake valve curtain area. I'm not here to go round and round with you Mike, I really respect what you do and have always enjoyed your posts. I know you are going to build it I'm sure it will run, I'm just pointing out my concerns.
 
#7,383
I think some of that concern can be worked around Mike. Not sure how you plan to do the linkage but if it is a cable you can do something with a large radius that decreases with throttle movement, this way the blades have a very slow open speed in relation to the pedal movement until the radius decreases nearing WOT. I think done right this could work well.

as for throttle crispness i think i can help tune that nicely.
 
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#7,384
Ok then,...learning about what kind of CFM is required to support a certain horsepower goal.

A 250 c.i. Engine that will service 6000 RPM only needs 250 CFM to make 300 WHP.

The next hurdle to clear is how restrictive one of the little filters are, or conversely, how much CFM each one of them will pass.

250/6= 42 CFM....Each throttle body only needs to flow 42 CFM to support that power...

These four filters together will flow 600 CFM.....

599-rc-2334.jpg

Obviously, ill need 6 of the things, but at 164 CFM each...together they'll flow more than enough to go way beyond the horsepower that this engine will ever see.

But,...it's a commitment...6 of these things wil be over 200 bucks...If I go this route, it's over,..I'm not building anything else to filter/provide air to the TB's..

As much of an effort it will be to build the box.....with, or without a clear cover..putting six little hats like these on the TB's solve several issues...and save a butt load of work..in the end, 200.00 will be well worth it in contrast.
 
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#7,386
CarMichael Angelo said:
Ok then,...learning about what kind of CFM is required to support a certain horsepower goal.

A 250 c.i. Engine that will service 6000 RPM only needs 250 CFM to make 300 WHP.

The next hurdle to clear is how restrictive one of the little filters are, or conversely, how much CFM each one of them will pass.

250/6= 42 CFM....Each throttle body only needs to flow 42 CFM to support that power...

These four filters together will flow 600 CFM.....

599-rc-2334.jpg

Obviously, ill need 6 of the things, but at 164 CFM each...together they'll flow more than enough to go way beyond the horsepower that this engine will ever see.

But,...it's a commitment...6 of these things wil be over 200 bucks...If I go this route, it's over,..I'm not building anything else to filter/provide air to the TB's..

As much of an effort it will be to build the box.....with, or without a clear cover..putting six little hats like these on the TB's solve several issues...and save a butt load of work..in the end, 200.00 will be well worth it in contrast.
Click to expand...
I like this plan. Was not a fan of the box ideas :confused:
 
#7,387
The big Samll block "stroker" gospel means the low hanging fruit is cubic inches, not ITB's.

N Alpha is just wonderfull. Its what makes a Hillbourne Mechanical system work even better when electronic. Making a barrel valve Mechnical injection, or Rochester Mechncial Injection system work is not quite an ITB art form, but it uses the same kind of kit.


Reversion happens, and it and fuel standoff is what makes an ITB system work, as the fuel delivery from the injector often gets pulse tunned with slugs from a forwards and backwards movement of air fuel mix. ITB fuel delivery is just like alternating current, or playing with a backdraft in an advanced fire drill.


USA isn't anti Independent Runner,
its anti cost,
anti uncompetitive atvantage.

The Australians have used it in situations here the US Super speedways would then incur the need for other restrictions.

Aint nothing you can't chew at 8.2 (thousand rpm)

View: https://www.youtube.com/watch?time_continue=10&v=0OrKoQ6aCns



America didn't need to scew around with pulse tuning on its 6 or 8 barrel V8's untill the Bendix fuel injection era of the Cosworth Vega. As soon as those little pip squeeks started making a race debut, GM and Ford decided that Electronic Bosch D and L jetronic type injection had to be made in the USA without Bosch patents, and it kept away from ITB's until

On above 289 cubic inch Ford's, the design teams always got better results with a staged dual quad FE 427 or 428 when compared to 4 2-bbl IDA's because ITB tuning is actually a very fine art, with a very narrow band required to be sucessfull. For Ford, it was a huge cost and development issues, especailly when FIA went back to a 5 liter, 305 cubic inch capacity limit for 1968.


Stock, the basic engine used on the 31 road car 289 GT40's started off as the 271 or 306 hp K code engine from Mustangs or GT350'S. The C6FE engine with 289 GT40 C6FE-6090A heads, based on the 10.5:1 306bhp @ 6000rpm 329lb ft @ 4200rpm Shelby 289 HI Po K code engine as its base. The Big Valve GT350 "R" got a nominal 350 hp gross @ 6500 rpm.

On the British GT40's the Hi Po K 289's then got very special headers and either "Dual Quad" twin 585 Holley's, or the Quad IDA Webers. They had were neck and neck.

With Quad Webers added, it was listed as 380, 375, 350 or 335 hp, the first two figures SAE Gross at 6800 rpm, the rest earlier developement SAE Gross.. The four factory ratings around were in addition to the base factory 306 SAE Gross hp rating for the street GT350.

380hp was the accepted SAE Gross figure and the 326 lb-ft torque, but 350 and 335 bhp SAE net at 6250 rpm were also claimed.

Jeremy Diamond goes into it in Panics Mopar section in "http://victorylibrary.com/main_menu.htm"website. I endorse it with everything I've got. He nails the Independent Runner sizings perfectly.

Spit back is fuel stand off that isn't fully contained, it is what makes a car stall or pig root from curb idle to wide open throttle.

Reversion is more likely to happen in an old Y block.


There is a reason Fords Hot Rodders used triple carbs in them rather than dual fours, they thought less carb area would help , um, pick-up to a T.

?format=1000w.jpg


It happens classically in the old infamous RHS steel Y block dual quad intakes people made down here in the Antipodes, essentially an independent runner 8 bbl 272-292-312 V8 that didn't work in on and off throttle because of very bad Idle Air Bleed and Power valve channels and a lack of understanding about what happens to the well tubes on a couple of 465 or 600 Holley's when popped on a trap door Y block intake.


Somwhere I have a picture of the late Dave Johnston, an Alfa Laval heat exhachager techncician whos Ford Y and FE block loving 8 bbl concoctions made fuel spit back an art form

Reversion, spit back, fuel standoff, you can tune through it without closed loop, and its easy when you can play with the ignition tip ins. The US masters this as well.
 
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#7,388
a91what said:
I think some of that concern can be worked around Mike. Not sure how you plan to do the linkage but if it is a cable you can do something with a large radius that decreases with throttle movement, this way the blades have a very slow open speed in relation to the pedal movement until the radius decreases nearing WOT. I think done right this could work well.

as for throttle crispness i think i can help tune that nicely.
Click to expand...
The linkage is gonna be fairly basic. an L bracket w/ a socket ball attached so that my accel linkage can snap on it.The length of the bracket was all I was gonna mess with to make actuation easier for the throttle cable.
 
#7,390
95BlueStallion said:
So now that you know you only need to flow 40-something CFM per TB, do you think these cooler looking velocity stacks would be suffient? You pop the filters off the end at the car show, and they look quite a bit better than those conical filters. Suppose the supplier has flow tested them?
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Oh I'm thinking that the v stacks will probably flow that much air minimally...but in the long run, I'd be relying on a screen instead of a filter to clean the incoming air.

And when you look up close, you can see the large step that they make to create the clamp flange....I'm pretty sure that it necks down much smaller than the actual throttle bore diameter.

The red filters won't look as good admittedly....but they'll do a much better job of keeping crap out of the engine w/o plugging up. Have you seen how cars turn green in the spring down here?...that dust floats in the air for about a month......
llen-has-covered-parts-of-the-boston-area-like-fallen-snow-a-volvo-picture-id145487430?s=612x612.jpg

It starts in March....just about the time that the Monster will be out playing again.
 
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#7,394
I used those on my Diesel LD28 Falcon sedan. One filter flows enough to liberate 91 seat frame bending horsepower for a 2.8 liter Nissan engine.

6 x 91 = 546 hp.

If its mounted far enough away, it will hold fuel stand off, and add power.


Getting back to it all, the reason NASCAR moved away from these kind of systems was due to fires from fuel loads. The GT40 small blocks were fire risks, the big blocks, less so. Fuel loads with Independent runner systems go into driver safety issues depending on how much cam overlap and fuel standoff you have. 630 horsepower is certain to make it an issue in any ITB passenger car, which sends evaporative emissions into the stratsophere. In 1980, all Weber or Dell Orto Ferrari, Alfa Romeo, Lamborghini and Aston Martins failed the CA over nigh test, and the operational Evap hydrocarbon test, and the EPA said either curtail production per year to less than 40 imports, or run the Spica, or Bosch K, L, or D injection. Having a throttle body upstream ensures you met evapaortive emissions, and it helps remove any engine to driver fumes.

K&N Cotton is not a flame arrestor unless it has a container to hold the back draft.

Smell and fumes wise, the mini air cleaners won't help at all.

This is not a vote against your kind of fliter, just info. 400 hp at the flywheel will be enough to start the fumes, and in Ford GT40's, ITB's became instant fire and fumes risks.


Normally, a brace of 6 barrels of Holley style carb will be a lot safer, but its all about how to the cover them with a function filter or filters.


Three Cow Bells like the one providing air flow to this 390 cfm 4-bbl in a 24 Oz would do nicely.

You can see why BMW and Nissan slanted the engine...brake booster clearance.


1971_Datsun_240Z_SCCA_Race_Car_For_Sale_Engine_resize.jpg


New%20390cfm%20holley%205.jpg



The air cleaner solution you'll work through in your own way. I'd personally find something that can operate as a flame arrester.


The ITB system is like natures Bug communities diffusion breathing. Yeah, bugs have ITB's.

Air_enters_the_tubes_through_a_row_of_holes_along_a_bugs_abdomen.jpg


Air enters the tubes through a row of holes along a bugs abdomen. In the same way, there is no deep breathing with ITB's, the air speed is stalled right down to less than from the 250 to 405 feet per second in a Holley 4 or 2-bbl. That's with engines that are practically a NASCAR restrictor plate engine.

A really hot restrictor plate race 289 with a 500 cfm Holley flows 352 hp, and consumes 500 cfm at 405 feet per second.

A 352 hp 351 Cleveland at 6500 rpm with a nice big 5.936 sq inch venturi 3310 780 cfm carb takes air speed down to around 212 feet per second tops.

An in line 250 cube six with ITB's at 14 cubic inches of engine per square inch of venturi area, reving to 6500 rpm, its down to 470 cfm of flow.

At that rate, a 465 cfm carb does 265 feet per second for an average venturi area of about 5.09 sq inches, but with 14 sq inches of ITB, air speed is less than 93 feet per second.

On a Lamborghini V12 reving to 8000 rpm, it needs less than 550 cfm of air, and its air speed is down to 63 feet per second via 12 ITB's. 21 sq inches of carb venturi area on a little 239 cube 375 HP V12.

From restricted traditional 2-bbl to unrestricted, there is a real slow quarter the speed flow rate.
 
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#7,395
@xecute:
I really enjoy reading all your fact based gobbledygoop, I can even understand some of it ( not really but the pictures are cool 'cept for the bug thing) my question for you is:
Do ya think mike's new 'monster motor makeover' is gonna work ok?
Please, 500 words or less. :stick:
 
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#7,398
karthief said:
@xecute:
I really enjoy reading all your fact based gobbledygoop, I can even understand some of it ( not really but the pictures are cool 'cept for the bug thing) my question for you is:
Do ya think mike's new 'monster motor makeover' is gonna work ok?
Please, 500 words or less. :stick:
Click to expand...
For once,...I'm with you. Equally confused by my Man from U.n.d.e.r.'s @xecute 's last post.

Every other thing I've read from him about the decision to convert to ITB has been "Hell Yeah!".....

But after the last one...To a person far below his degree(s) of technological speak, It looks like I'll have a sluggish, potential fire hazard, that indicates to me that he wants me to put Cowbells on the throttle bodies, and name the engine Elsie..:shrug:

And now....an insect is in the pictures ..How do we even get to bug guts when comparing things here?:nonono:
 
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#7,400
It is encouraging to see the other bangers making my power objectives though...That 265 Hemi with the webers made over 337 HP at the rear wheels w/ a cast iron head, and a flat tappet cam....I'll take that every single day.
 
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