what all are the differances? will a boss bold up to the transmission the same as a regular 429? thanks, dave

 

Ah yes the Twisted Hemi.

Used aluminium heads, that have a hemipherical combustion chamber it is actually a cresent shape. with swirl intake porting they produce massive amounts of power, typical of any hemi, and i believe the efficiency coefficient was something like 115%, they four bolt mains, and a different intake, uses a the same bell pattern as any other 385 series motor. And thats all i know. Wish i could find a set. but nobody remans them anymore.

F-250 now 350 4x4 ext cab SB Green Monster (Used to have)205000 miles, Mass air 460 w/ performance heads, E40d to 5spd conversion, 205 T-case, 4.11 gears, Power-Lok equipt dana 60 front, Doug Thorleys and swapped in EFI 33 gallon bronco rear tank. 33's on 16x8" Outlaw II's, Truck is destined to be a 5.9L cummins diesel 5spd.

 

>Ah yes the Twisted Hemi.
>
>Used aluminium heads, that have a hemipherical combustion
>chamber it is actually a cresent shape. with swirl intake
>porting they produce massive amounts of power, typical of
>any hemi, and i believe the efficiency coefficient was
>something like 115%, they four bolt mains, and a different
>intake, uses a the same bell pattern as any other 385 series
>motor. And thats all i know. Wish i could find a set. but
>nobody remans them anymore.
>
>F-250 now 350 4x4 ext cab SB Green Monster (Used to
>have)205000 miles, Mass air 460 w/ performance heads, E40d
>to 5spd conversion, 205 T-case, 4.11 gears, Power-Lok equipt
>dana 60 front, Doug Thorleys and swapped in EFI 33 gallon
>bronco rear tank. 33's on 16x8" Outlaw II's, Truck is
>destined to be a 5.9L cummins diesel 5spd.




Even Though Ford sometimes calls 'em a hemi, they are not TRUE hemis because of the crescent shape which helps make a tad more compression without resorting to real weird piston shapes 'ala a true hemispherical chamber.

Repro heads are still available through Ford. Part # M-6049-B441. I guess they're distributed by "Raceceparts Dist." @ 704-892-8688

As learned through pro-stock, A good wedge when normally aspirated will out run a hemi or semi hemi(Boss). Forced induction is a whole 'nother ball game.

 

lvstang,

I beg to differ with you on your last comment. A hemi head is designed to flow much better than the wedge design. In a hemi the valves are directly across from each other, the chamber is symmetrical, the spark plug is in the middle and the flow is even downhill so you get a little gravity working for you.

With the wedge you have valves sitting next to each other, the chamber is not symmetrical and the spark plug is off to the side, a huge amout of turbulence is created with this design. From what I have seen a Hemi will beat the living crap out of a wedge shaped head any day of the week if built correctly. Correct me if im wrong. Anybody else share my opinion here??

Nitro

 

Thats right the hemi's (at least dodge's) are designed to get the fuel in and out as quick as possible, better flow.

 

Boss 429 Engine specs:


Hp = 375 x 5200 Rpm
Torque = 450lbs x 3400 Rpm
Block =High nickel content & 4 Bolt mains
Camshaft = Hyd >Mech.
Ignition = Dual point > Dual vacuum advance
Exh Manifold = Free flowing cast iron
Heads = Aluminium w/Huge valves & Ports
Intake Manifold = Alumnium Dual-Plane
Con.Rods = Two different for Engine code or "T" & "S"

Dennis
Please Don't Ask Me Any Tough Questions As:
"I'm Saving Up MY Memory For When I Develop Alzheimer's"







78 F-150 429CJ C6 ,Silver w/Explorer Pkge
641/2 Mustang,Pre-World's Fair Car #8092
64 Fairlane S/C waiting for a 390-4spd.
68-Mustang.Sunlit Gold 80,000 miles

 

>lvstang,
>
>I beg to differ with you on your last comment. A hemi head
>is designed to flow much better than the wedge design. In a
>hemi the valves are directly across from each other, the
>chamber is symmetrical, the spark plug is in the middle and
>the flow is even downhill so you get a little gravity
>working for you.
>
>With the wedge you have valves sitting next to each other,
>the chamber is not symmetrical and the spark plug is off to
>the side, a huge amout of turbulence is created with this
>design. From what I have seen a Hemi will beat the living
>crap out of a wedge shaped head any day of the week if built
>correctly. Correct me if im wrong. Anybody else share my
>opinion here??
>
>Nitro



In theory you're absolutely correct. But here's the problem: The hemi dome allows very large valve sizes which ultimately hurt low end torque. The dome also means to get any compression the piston has to be a weird shape which causes flame travel problems(witness the dual plug heads on top fuel dragsters) Also realize that turbulence is a GOOD thing when talking about air/fuel mixture. There's even snake oil salesman trying to sell crap to put in your intake to "cause high swirl"!!!

It's not all about how much air gets in and out(although very important) it's the velocity that the air gets in and out at. This is where the hemi suffers in normally aspirated form. The pentproof chamber on most modern 4 valve heads also puts the plug in the middle and has a cross flow design. But the chambers are much smaller and flatter so the piston shape stays flat. Also realize that a 4 valve head usually has a VVT or VI to cut off air flow at lower engine speeds.


Bob Glidden gave up on the Boss semi-Hemi in Pro Stock and was going back to a wedge when Ford pulled the plug. The wedges like the CJ 429/460, BBC and the Pro Stock Pontiac big chief heads were/are faster normally aspirated. They all use a form of canted valve which seems to be a good compromise for a 2 valve normally aspirated head, If the larger valve sizes can be utilized. Realize you can have too big of a valve.


I think it was HOT ROD magazine who did a Buick 455 G/N vs. hemi shootout a few years back and the weaker on paper buicks cleaned up. Better low end torque was the main reason.

Now, throw a blower on and all bets are off!!!!

 

Just for the sake of adding to this conversation....
I have heard both arguments on wedges and hemis, I run a 57 354 10:1 hemi in my 69 CJ-5 it was dynoed at 361hp (numbers have never mattered much, it how she runs in the end), runs a .418 lift cam, it was a 2 ton truck motor before being donated to my jeep and it gets 16 mpg without much foot control, granted it is a lighter vehicle but there is an increase in efficiency from the 350 %$#@^ i ran before.
The one thing i have knowticed in it and in vehicles i have driven with the hemi's both the 426 (storage for now) and the small blocks has been that in the higher RPMs they maintain thier power where the wedge seems to begin loosing power. I have been told by local racers that the reason is as is stated above the hemi has more efficient
flow coefficients, more efficient above 5-6k. The Hemis work less to relieve themselves of spent fuel at higher RPMs. I have also been told that the centered sparkplug even on a wedge design offered supperior burn characteristics.
I am partial to hemi's that is why i play with them, they have a mystique that clings to them. But with modern technologies for the wedge motor, design improvements have been made to make them far more powerful than they were in the hay day of hemis when Mopus ruled the track. There is a reason GM & %^&%$ chased Ford and Mopus and thier Hemi's and 427 SOHC (hemi), 429 BOSS motors off the NASCAR tracks. But we will never know what the ultimate potential of these revolutionary designs were. Instead we are stuck with a design that thirty years ago they tried to evolve out of and somebody had to cry out that they couldnt compete technology wise anymore (remember the proposed 396 cui guideline).



As an after though just to disagree a little:
The comparison of the hemi and the 455 buick was not exactly a perfect comparison. I enjoy comparisons where cam specs and engine displacement are more in a similar area. If both engines were designed for 1000-6000 rpm power ranges, .500 lift in the buick or so and both had long strokes then maybe it might have been more accurate or at least fair IN MY OPINION (some people get sensitive when i voice odd thoughts).
There is no substitute for cubes right.... but the 455 has always been a torque monster built to get a 6000lbs land boat moving. That would be like comparing a 429 to a 460, or in the case of the article a 426 to a 455. The 455 is built with a low end cam and a long stroke vs the 426 which was using the factory street/race cam designed for higher rpms and has the shorter stroke. The 455 as been noted to blow the doors off the old HPerformance 454's of that era, which also had better numbers than the 455.
Like the 429, the 426 was designed to esentially be a race motor that fell under the NASCAR guidelines so the shorter stroke was necessary. Also i was thinking that on the tracks the Hemis always lost in the short runs (lack of low end and ability to get going like you said) it wasnt until further down the track that they used to come alive and pull back in. Would have been neat if they would have run them on a circle track constant mid and upper RPMs. Im just biased and i know it but i figured id throw a little mumble jumble in to add to the confussion.

Hey guys i like this string its a really neat comparison since so few of us deal with these odd ***** anymore. I know some of my text is really controversial but i like to at least voice a little before it these are completely forgotten.


Dusty

F-250 now 350 4x4 ext cab SB Green Monster (Used to have)205000 miles, Mass air 460 w/ performance heads, E40d to 5spd conversion, 205 T-case, 4.11 gears, Power-Lok equipt dana 60 front, Doug Thorleys and swapped in EFI 33 gallon bronco rear tank. 33's on 16x8" Outlaw II's, Truck is destined to be a 5.9L cummins diesel 5spd.

 

And just a comment about Bob Glidden and why he gave up on the hemi.....at 500 cubes....he was having a tuff time getting the compression ratio to a respectible level of like 14-16 to one where as with a wedge design you can do it very easy. Now, let's flip over to IHRA a moment, look at the stats and see how many 'hemi' Fords have won over there where they can run engines larger than 800 cubes. The larger the cubes, the easier it is to make a higher compression ratio.

 

Dusty, excellent post. I THINK we both agree that just because something is a hemi it isn't magically going to make more power or torque.

You brought up a good point about "what if" I think maybe the hemi wouldn't of died so quickly if fuel quality weren't such an issue. The hemi and to a lesser extent Clevelands need to rev to take advantage of their superiour flow capabilities. Without the fuel to back high compression, what's the use.

The Chrysler Hemi and even the Boss Ford didn't need to die just because GM cried foul at the NASCAR level. The fact was that the 440/429/460 were better large car/truck motors in the state of tune needed for everyday driving. I remember a 426 W vs. hemi camparo(also in HOT ROD) in the same body(forgot what it was) where the hemi was a few 10ths faster but was in a much higher state of tune. It didn't idle as well and there were a few other issues where the writers perferred the W as an everyday car.

You said it best though when you mentioned the "mystique" of the hemi!

 

>And just a comment about Bob Glidden and why he gave up on
>the hemi.....at 500 cubes....he was having a tuff time
>getting the compression ratio to a respectible level of like
>14-16 to one where as with a wedge design you can do it very
>easy. Now, let's flip over to IHRA a moment, look at the
>stats and see how many 'hemi' Fords have won over there
>where they can run engines larger than 800 cubes. The larger
>the cubes, the easier it is to make a higher compression
>ratio.

I remember Glidden eating pistons left and right due to detonation.

Do you have any info on the IHRA mountain motors??? Do they squeeze 'em?? I'm sure Jon Kaase is in there somewhere!!!

Glad to see Ford winning!!!

 

Thanks, I just enjoy thinking that each motor has its place for someone, some diehards enjoy playing with the old and i thought that it needed to be said. Sometimes these engines can be forgotten or overlooked Its good to learn from them. I love Keepin Old Cast Iron designs alive and it is part of the hot rod game.

Bringin em back to runnin
Dusty


F-250 now 350 4x4 ext cab SB Green Monster (Used to have)205000 miles, Mass air 460 w/ performance heads, E40d to 5spd conversion, 205 T-case, 4.11 gears, Power-Lok equipt dana 60 front, Doug Thorleys and swapped in EFI 33 gallon bronco rear tank. 33's on 16x8" Outlaw II's, Truck is soon to be a 284HP 703lb/ft flywheel rated 5.9L cummins diesel w/ NV4500 5spd and NP205.
My other toy is a '69 CJ-5 354 Hemi 4 spd 4.88's 32x12.50 MThompsons w/ power-lok 44 rear

 

Did anybody ever find a supplier still selling the boss/ hemi heads for use on a 460 or 429? just curious.


Why Buy new when you can build and tailor it cheaper?
F-350 4x4 ext cab Short Bed Green Monster, it is now Sporting a 300HP 715lb/ft Dyno rated 5.9L 12v Cummins diesel w/ NV4500 5spd and custom NP205 ford T-case w/ rear spicer 1410 yoke, Converted to Sterling 10.5 gears w/3.73 gears using the 41 spline pinion and 1410 U-Joints, Power-Lok equipt Dana 60 front, 33's on 16x8" Outlaw II's. (Used to have)205000 miles, Mass air 460 w/ performance heads and a E40d to 5spd conversion and Doug Thorleys. Old EFI 460 @10 MPG to the 12 V @ 23.2 MPG @ 75 MPH and loving it.
My other toy is a '69 CJ-5 354 Hemi 4 spd 4.88's 32x12.50 MThompsons w/ power-lok 44 rear.

 

When at the Columbus, OH Flea/Parts swap this past 6-7 April, I saw dozens of B9 heads for sale...and all the related valve train parts for them. One guy even had 5-6 B9 short blocks that needed rebuilt.

 

>Did anybody ever find a supplier still selling the boss/
>hemi heads for use on a 460 or 429? just curious.
>
>
>Why Buy new when you can build and tailor it cheaper?
>F-350 4x4 ext cab Short Bed Green Monster, it is now
>Sporting a 300HP 715lb/ft Dyno rated 5.9L 12v Cummins diesel
>w/ NV4500 5spd and custom NP205 ford T-case w/ rear spicer
>1410 yoke, Converted to Sterling 10.5 gears w/3.73 gears
>using the 41 spline pinion and 1410 U-Joints, Power-Lok
>equipt Dana 60 front, 33's on 16x8" Outlaw II's. (Used to
>have)205000 miles, Mass air 460 w/ performance heads and a
>E40d to 5spd conversion and Doug Thorleys. Old EFI 460 @10
>MPG to the 12 V @ 23.2 MPG @ 75 MPH and loving it.
>My other toy is a '69 CJ-5 354 Hemi 4 spd 4.88's 32x12.50
>MThompsons w/ power-lok 44 rear.




Repro heads are still available through Ford. Part # M-6049-B441. I guess they're distributed by "Raceceparts Dist." @ 704-892-8688