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HEMI in NHRA T/F,F/C,TAD,TAFC

Posted By: Moe

HEMI in NHRA T/F,F/C,TAD,TAFC - 11/05/11 03:11 AM

HEMI in NHRA T/F,F/C,TAD,TAFC.

What is the reason why the HEMI is the choice of engines.

It will stay together @ 8000 Hp?

It has superior dentonation characteristics?

Ford & GM won't work in these applications?

Need a good detailed answer for the guys at work.

"Google"
Won't give me an answer.



THANKS!
Posted By: slantzilla

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/05/11 11:28 AM

Because it is the only engine allowed by the NHRA.
Posted By: Challenger 1

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/05/11 01:51 PM

Because it looks cool?

Posted By: rdrnr6970

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/05/11 02:18 PM

because years ago the hemis were beating everybody...they had the most horsepower,when placed in vehicles they were the fastest.racers found out the hemispherical combustion chambers,the motor set up, in these mosters couldnt be beat!
Posted By: rdrnr6970

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/05/11 02:19 PM

amd YES...HEMI motors look cool!
Posted By: dennismopar73

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/05/11 02:33 PM

I was going to say something like ,, no-one designs motors here anymore!
now its built on someones computor in japan or china.
same as the cars platform ,
car makers used to have designers, now they leave that to the jackets they wear
Posted By: Challenger 1

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/05/11 02:52 PM

I think it's because of the huge port design of the hemi, epecially with aftermarket heads like these. Combine that with 60 pounds of boost like this engine sees=3000hp on alcohol!!



Posted By: rdrnr6970

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/05/11 03:21 PM

Posted By: dennismopar73

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/05/11 03:26 PM

We all know what the Hemi does,, but why hasn't Ford,,, Chevy,,,
tried to put some type of engine that would at least compete with the Hemi??
The Hemi that is being used , is just a distant relative of the original Hemi.

Posted By: rdrnr6970

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/05/11 03:44 PM

ford did try in 69 with the BOSS 429,hemi configuration.limited sales,and the expense of the motor and its development,prob led to its demise.chevy tried too,their was a smokey yunik built( i think)302?or 307?cross ram hemi,that was put in a 68/69 camaro,but never worked out.
Posted By: HemiRick

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/05/11 05:08 PM

The reason why Hemis dominate the Nitro classes is because they are the only engine with a port design good enough to keep the exhaust valves from melting. During the overlap period enough air goes thru them to cool the exhaust valve for the next stroke.
Posted By: Prostock

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/05/11 07:38 PM

Quote:

Because it is the only engine allowed by the NHRA.





No other engines are permitted.
Posted By: MoparDan

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/06/11 04:00 AM

In the 60's and 70's TF and FC ran motors of all makes...The 392H (& Donovan 417) and later 426H proved to BE the motors to lead the pack for several reasons: as mentioned, with more and more nitro being used in the 60's/70's they stayed together better/longer than the others; the chrysler hemispherical combustion chamber design was the best, particularly in blower application. As side note- the hemi was competitive in the early years of PS, but later with rpms above 8500 and in normally aspirated motors... in PS the Hemi was inefficent. BUT with a blower attached- NOTHING could touch the Hemi and it's combustion design. Fast forward 10 or so years when no other motor would would even try to compete in FT/FC, NHRA deemed the Hemi was king! and made it the standard.
Posted By: 70AARcuda

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/06/11 04:37 AM

NHRA killed the hemi in pro stock by assigning it a very uncompetitive weight break..

so with the swipe of a pen the 426 hemi was dead in pro stock...after several years of trying..all further development on the PS hemi was stopped..
Posted By: slantzilla

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/06/11 04:53 AM

Quote:

NHRA killed the hemi in pro stock by assigning it a very uncompetitive weight break..

so with the swipe of a pen the 426 hemi was dead in pro stock...after several years of trying..all further development on the PS hemi was stopped..



Not completely true. NHRA went to 500ci for everyone and the Hemi just could not compete with the wedges. Jeff Wick kept trying until the late '90's. Even Bob Glidden had to give up on the Shotgun motor.
Posted By: 70AARcuda

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/06/11 05:14 AM

Quote:

Quote:

NHRA killed the hemi in pro stock by assigning it a very uncompetitive weight break..

so with the swipe of a pen the 426 hemi was dead in pro stock...after several years of trying..all further development on the PS hemi was stopped..



Not completely true. NHRA went to 500ci for everyone and the Hemi just could not compete with the wedges. Jeff Wick kept trying until the late '90's. Even Bob Glidden had to give up on the Shotgun motor.




NHRA instituted the ps weight breaks in 1972...chrysler pulled the plug on the hemi a couple years later....nhra went to 500 inch motors in 1982...

yes a few people continue to run the hemi...but once the factory money stopped...no one was doing any R&D...

a SS/HA hemi today turns over 9000 rpm with the new valvetrain that has been developed..
Posted By: 383man

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/06/11 05:51 AM

Quote:

Quote:

Quote:

NHRA killed the hemi in pro stock by assigning it a very uncompetitive weight break..

so with the swipe of a pen the 426 hemi was dead in pro stock...after several years of trying..all further development on the PS hemi was stopped..



Not completely true. NHRA went to 500ci for everyone and the Hemi just could not compete with the wedges. Jeff Wick kept trying until the late '90's. Even Bob Glidden had to give up on the Shotgun motor.




NHRA instituted the ps weight breaks in 1972...chrysler pulled the plug on the hemi a couple years later....nhra went to 500 inch motors in 1982...

yes a few people continue to run the hemi...but once the factory money stopped...no one was doing any R&D...

a SS/HA hemi today turns over 9000 rpm with the new valvetrain that has been developed..



That is so true as the Hemi Dominated Pro Stock in the 70 to 72 Era. The added weight in 72 slowed them down and Wally Parks of NHRA even told some of the racers they wanted more GM and Fords to win and not the Mopars all the time so they made the Hemi's run heavier cars then GM and Ford. So politics is even in racing. Then Bill Jenkins was allowed to run his tube frame Vega at the 72 Winter Nationals and everything Changed in Pro Stock.

On a side note the best eng that ran as good as the Mopar Hemi was the SOHC 427 Ford eng. But they never put it in a production car and it did not stay together as well as the Hemi. When Don Nicholson had his 427 SOHC eng Maverick in the 70 to 72 Pro Stock era running good it could run with the 426 Hemi but it was hard to keep it running great and parts were scarce for it since it was never a production eng. And Mickey Thompson had the 427 SOHC in his Funny Car Mustang in 69 and 70 and it ran as good as the Hemi when it ran right. It had overhead cams and it was a Hemi and it could rev good with the overhead cams. Also NASCAR would not let Ford use it so thats why Ford went to the Boss 429 pushrod semi Hemi eng. Ron
Posted By: bobby66

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/06/11 01:57 PM

I remember seeing a 427SOHC in a F/C many years ago. What a cool looking engine!
Posted By: John_Kunkel

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/06/11 07:12 PM

Quote:

HEMI in NHRA T/F,F/C,TAD,TAFC.

What is the reason why the HEMI is the choice of engines.




The Hemi is easier than others to maintain, other designs require too much time to teardown/reassemble between rounds.
Posted By: B5 Bee

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/06/11 07:33 PM

By 1990, the 426 Hemi type motors were the only motor being used in the nitro classes for reasons given above (ease of maintainence and performance using a blower and nitro).
The 426 Hemi rule came not long after Bernstein invested in and was testing the McGee 4valve OHC motor. The Hemi only rule was to slow the rising costs of running in the nitro classes.

Best I recall, the last TF car that won a National event (Springs I think) that wasn't 392 or 426 based, was Jim Bucher's Chevy. He was an underdog favorite, ran 3 or 4 years in the early '70s on a small budget, a Chevy motor and still managed to win some rounds.
Posted By: hemicop

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/06/11 10:49 PM

Port size & design, valve placement, stronger bottom end all translated into better durability in the 3-4k hp (for the time) range that kept the Hemis reputation up. That coupled with the fact Mopar actually produced an iron block back then for the guys that wanted to run a "budget" (?) fuel car that was actually affordable.
The SOHC motor was a good contender but parts availibility along with its timing change caused issues even in the "low" hp ranks of P/S.
You can dig up lots of old magizines & find Chevy powered F/Cs & T/Fers but the fact is given the quality of the parts & inherent designs of those motors back then (remember there were few if any aftermarket manufacturers) neither Ford nor GM could stay with the Hemi........
Posted By: Moe

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/09/11 05:07 PM

Quote:

Because it is the only engine allowed by the NHRA.



Where can I find this in black & white?
Posted By: Challenger 1

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/09/11 05:10 PM

NHRA rule book, they send out new one's every year.
Posted By: Moe

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/09/11 05:11 PM

Is it true that Bob Glidden put a 340 in a Plymouth Arrow or Dodge Colt in Pro-Stock, and they [NHRA] re-wrote the rule book in that category ?
Posted By: Moe

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/09/11 05:13 PM

Quote:

NHRA rule book, they send out new one's every year.



Thanks, I will get one!
Posted By: John_Kunkel

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/09/11 07:36 PM


Quote:

Is it true that Bob Glidden put a 340 in a Plymouth Arrow or Dodge Colt in Pro-Stock, and they [NHRA] re-wrote the rule book in that category ?



During that period in history the NHRA re-wrote the Pro Stock rules about every 90 days. It was called "factoring".

In Glidden's case he had milled the entire valley out of the 340 block and rebuilt it with welded-in chrome moly to change the lifter angle.
Posted By: Moparnut426

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/09/11 08:30 PM

I have also heard the Rockers on a ball stud design head is too time consuming for the quick turn arounds required is some racing.

also a string deep skirt block, the crank is set deep in the block so there is a lot of meet around the mains for support.



Kasey
Posted By: slantzilla

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/09/11 11:46 PM

Quote:

Is it true that Bob Glidden put a 340 in a Plymouth Arrow or Dodge Colt in Pro-Stock, and they [NHRA] re-wrote the rule book in that category ?



Actually Glidden gave up on the Arrow because Chrysler ran out of money.
Posted By: Challenger 1

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/10/11 01:24 AM

Quote:

Quote:

Because it is the only engine allowed by the NHRA.



Where can I find this in black & white?



Your right, you won't.

I just looked at a rule book for top fuel, Any engine is permitted with some restrictions.
Posted By: slantzilla

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 11/10/11 01:27 AM

Quote:

Quote:

Quote:

Because it is the only engine allowed by the NHRA.



Where can I find this in black & white?



Your right, you won't.

I just looked at a rule book for top fuel, Any engine is permitted with some restrictions.




Well, any engine as long as the block and crank specs match a Hemi.
Posted By: Moe

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 12/03/11 03:51 AM

Hey, If you guys have time. The Super Stock '68 HEMI darts and 'Cuda's (SS/AA) have to follow certain rules. I need these specs for the guys @ work. so far I have;

Must use OE cast iron cylinder heads.
Must use OEM heavy K-member and & control arms.
Must not be over 426 c.i
Must use OEM size carbs.

What else am I missing?
Posted By: 72N96RR

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 12/03/11 04:25 AM

Why is it in modern day Pro Stock the Hemi isnt getting it done...??

Those obsolete Pontiac drivers are still whooping Mopars butt in this class...

I would love an explaination for this one from you experienced racers out there..

This is an original pro stock block and aluminum heads developed by Warren Johnson in 1983...Its never been in a car..It can be built between 350 and 650 cubic inches and handle 1400 hp...I stumbled upon it and snagged it for a great price...

I would love to have an 83 Hurst Olds car..Kind of a tribute car to race in NPS class..A tribute to ol WJ himself..

Attached picture 6947961-!B)MOS,QCGk~$(KGrHqQOKnUEvyFrmU+(BMMcqnyOqQ~~_3.jpg
Posted By: 72N96RR

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 12/03/11 04:26 AM

The car for it!!!

Attached picture 6947963-mw9211.jpg
Posted By: hemicop

Re: HEMI in NHRA T/F,F/C,TAD,TAFC - 12/03/11 06:11 PM

Quote:

Hey, If you guys have time. The Super Stock '68 HEMI darts and 'Cuda's (SS/AA) have to follow certain rules. I need these specs for the guys @ work. so far I have;

Must use OE cast iron cylinder heads.
Must use OEM heavy K-member and & control arms.
Must not be over 426 c.i
Must use OEM size carbs.

What else am I missing?



Among other things, carbs must be stock, inake manifold must be of original design (that gets tricky!), crank, rods & pistons (I believe) must be stock weight, valve angles can't change, car must have interior--no gutting, no "cross-breeding" of engine/trans (but oddly, you can use a different rear ). Imagine a 20-30yrear old Comp engine & that's what the S/S motors have evolved into.
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