Comments on: 4 Valve Hemi Heads for Harley Big Twin Engines http://thekneeslider.com/archives/2008/02/26/4-valve-hemi-heads-for-harley-big-twin-engines/ Motorcycle News for Positive People Sun, 12 Feb 2012 09:09:53 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Casey http://thekneeslider.com/archives/2008/02/26/4-valve-hemi-heads-for-harley-big-twin-engines/#comment-270615 Casey Sat, 13 Feb 2010 22:37:14 +0000 http://thekneeslider.com/archives/2008/02/26/4-valve-hemi-heads-for-harley-big-twin-engines/#comment-270615 What is a used set of the 4 valve heads worth, evo? What is a used set of the 4 valve heads worth, evo?

]]> By: Kazoom http://thekneeslider.com/archives/2008/02/26/4-valve-hemi-heads-for-harley-big-twin-engines/#comment-268306 Kazoom Sun, 03 Jan 2010 22:35:15 +0000 http://thekneeslider.com/archives/2008/02/26/4-valve-hemi-heads-for-harley-big-twin-engines/#comment-268306 Warning... for those interested in these heads, in the posts above... (jurneyman/john mansell).... this guy has had my money since July 2008 and I still dont have my heads or my 2 pistons I sent him over a year ago for a one hour job to cut valve reliefs. It is now january 2010. I have had nothing but problems and bs with this guy as soon as he got my money ($3187cnd). For anyone that needs more info... vascarperf@hotmail.com Warning… for those interested in these heads, in the posts above… (jurneyman/john mansell)…. this guy has had my money since July 2008 and I still dont have my heads or my 2 pistons I sent him over a year ago for a one hour job to cut valve reliefs. It is now january 2010. I have had nothing but problems and bs with this guy as soon as he got my money ($3187cnd). For anyone that needs more info… vascarperf@hotmail.com

]]> By: Bill http://thekneeslider.com/archives/2008/02/26/4-valve-hemi-heads-for-harley-big-twin-engines/#comment-267622 Bill Thu, 10 Dec 2009 04:16:04 +0000 http://thekneeslider.com/archives/2008/02/26/4-valve-hemi-heads-for-harley-big-twin-engines/#comment-267622 It is correct to state that “RPM”’s use of the word “Hemi” in its advertising is indeed erroneous (a ploy). RPM’s heads are the exact items that Jim Fuelling engineered back in the late 80’s ~ early 90’s and are in fact a pentroof design and not a “Hemi” ( I considered buying the stage I kit for my FXRSSE in the early 90’s but found them too expensive). I simply disagree with the use of the word “ploy” when referencing the Chrysler Corporation (R.I.P.) as this insinuates a dishonest act (the Cambridge dictionary defines a ploy as “something that is done or said in order to get an advantage, often dishonestly”). While one is correct in stating that Chryslers new Hemi is not truly a “hemi” (its combustion chamber is a shallow hemispherical chamber with the addition of two squish bands perpendicular to the intake and exhaust valves), it still employs the basic elements of a hemispherical combustion chamber (a semi-hemi) and ties in with Chryslers well earned reputation and history (DNA) with this engineering design. Hence, it is deserving of the use of the word “Hemi” in its advertising as it is well desreved (“Hemi” is a registered trademark of the Chrysler Corporation). It is correct to state that “RPM”’s use of the word “Hemi” in its advertising is indeed erroneous (a ploy). RPM’s heads are the exact items that Jim Fuelling engineered back in the late 80’s ~ early 90’s and are in fact a pentroof design and not a “Hemi” ( I considered buying the stage I kit for my FXRSSE in the early 90’s but found them too expensive). I simply disagree with the use of the word “ploy” when referencing the Chrysler Corporation (R.I.P.) as this insinuates a dishonest act (the Cambridge dictionary defines a ploy as “something that is done or said in order to get an advantage, often dishonestly”). While one is correct in stating that Chryslers new Hemi is not truly a “hemi” (its combustion chamber is a shallow hemispherical chamber with the addition of two squish bands perpendicular to the intake and exhaust valves), it still employs the basic elements of a hemispherical combustion chamber (a semi-hemi) and ties in with Chryslers well earned reputation and history (DNA) with this engineering design. Hence, it is deserving of the use of the word “Hemi” in its advertising as it is well desreved (“Hemi” is a registered trademark of the Chrysler Corporation).

]]> By: todd http://thekneeslider.com/archives/2008/02/26/4-valve-hemi-heads-for-harley-big-twin-engines/#comment-267220 todd Wed, 25 Nov 2009 20:28:05 +0000 http://thekneeslider.com/archives/2008/02/26/4-valve-hemi-heads-for-harley-big-twin-engines/#comment-267220 The point is that RPM's use of the term "HEMI" is misleading marketing. These are pent -roof heads. The valves are parallel. Plain and simple. In order to achieve a true hemishperical combustion chamber with four valves is to arrange the valves hemispherically. The Honda RFVC single is the only true 4-valve hemi I've ever heard of (got one in my GB500 and XR650L). Honda was able to accomplish this with 8 rocker arms. The point of Chrysler using it as a marketing hype is the fact that, as you state, they (and Desoto) had "hemis" long before they ever marketed the "HEMI". Now that nearly every 2-valve motor has a hemi head they are using it primarily as a marketing ploy. After all, they deserve it. -todd The point is that RPM’s use of the term “HEMI” is misleading marketing. These are pent -roof heads. The valves are parallel. Plain and simple. In order to achieve a true hemishperical combustion chamber with four valves is to arrange the valves hemispherically. The Honda RFVC single is the only true 4-valve hemi I’ve ever heard of (got one in my GB500 and XR650L). Honda was able to accomplish this with 8 rocker arms.

The point of Chrysler using it as a marketing hype is the fact that, as you state, they (and Desoto) had “hemis” long before they ever marketed the “HEMI”. Now that nearly every 2-valve motor has a hemi head they are using it primarily as a marketing ploy. After all, they deserve it.

-todd

]]> By: Bill http://thekneeslider.com/archives/2008/02/26/4-valve-hemi-heads-for-harley-big-twin-engines/#comment-267217 Bill Wed, 25 Nov 2009 14:59:55 +0000 http://thekneeslider.com/archives/2008/02/26/4-valve-hemi-heads-for-harley-big-twin-engines/#comment-267217 With all due respect, Chryslers use of the word “Hemi” is not a marketing ploy but a literal use of an engineering design in which the combustion chamber utilizes a hemispherical shape (hemi means half, spherical means round, thus one-half of a round shape). Chrysler did a tremendous amount of R&D work on this design in WWII and found it to be highly efficient (it utilized this design when re-engineering the engines used on the B-29 Superfortress which initially had high failure rates). Chrysler first introduced its Hemi V8 in the early 50’s as a 331 c.i.; it grew to 354 (which was the first production V8 to produce more than 1 hp per cubic inch) than to finish as a 392 in the late 50’s. It broke practically every major record in competed in be it land, air or sea. It was reintroduced in 1964 as the 426 hemi and (to this day) holds more speed records than any other internal combustion engine in recorded history. In drag racing, ALL top fuel drag racers and well as funny cars (irregardless of the body which lies upon the frame) use a variation of the spendid Chrysler 426 Hemi, as no other compares. With all due respect, Chryslers use of the word “Hemi” is not a marketing ploy but a literal use of an engineering design in which the combustion chamber utilizes a hemispherical shape (hemi means half, spherical means round, thus one-half of a round shape). Chrysler did a tremendous amount of R&D work on this design in WWII and found it to be highly efficient (it utilized this design when re-engineering the engines used on the B-29 Superfortress which initially had high failure rates). Chrysler first introduced its Hemi V8 in the early 50’s as a 331 c.i.; it grew to 354 (which was the first production V8 to produce more than 1 hp per cubic inch) than to finish as a 392 in the late 50’s. It broke practically every major record in competed in be it land, air or sea. It was reintroduced in 1964 as the 426 hemi and (to this day) holds more speed records than any other internal combustion engine in recorded history. In drag racing, ALL top fuel drag racers and well as funny cars (irregardless of the body which lies upon the frame) use a variation of the spendid Chrysler 426 Hemi, as no other compares.

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