What Made the Original Yamaha Design 300HP?

[aaronsbiza]

I have heard many people on this forum state that Yamaha originaly designed the engine to put out 300HP, so where did the other 80 hp go? What did ford cut back? Is there any shop or any specific set of performance parts in production to restore Yamaha's original design?

 

[Deaks2]

From what I have ascertained these are some of the differences:

Cams
Compression ratio
Restrictive intake/exhaust
Use of something other than Ford EEC-IV to control the thing wink

 

[flosho]

Lots of people say that there was NO 300 horsepower Yamaha design... Chew on that for a while wink

 

[edmontonsho]

If it was possible somebody would have figured it out by now. Think about it, SHO enthuisists have had almost 15 years to try and figure it out, if it was true somebody would have figured it out.

 

[Mike Kopstain]

edmontonsho:
If it was possible somebody would have figured it out by now. Think about it, SHO enthuisists have had almost 15 years to try and figure it out, if it was true somebody would have figured it out.

Exactly. If it was that easy, we would all be trolling around in 300hp SHOs.

Instead, we sit here, wondering why some popular mods actually make us lose horsepower.

 

[Mr Anonymous]

Where is all this mythical 300HP discussion coming from lately??? It seems like every day there's someone new mentioning it. Ah, the bliss of living in make-believe!

 

[jthomas68]

The 300hp SHO motor is an old wives tale,it`s a crock.Mike Wesley had a motor direct from Yamaha with more agressive specs and even it wasn`t near 300hp.Wasn`t this tall tale started somewhere on shotimes.com?

 

[Toneboski]

Yeah i remember seeing that on shotimes.com. I wish it were true, but it ain't. frown

 

[E1]

jthomas68:
Wasn`t this tall tale started somewhere on shotimes.com?

It sounds like one of the Army Camo wearing, Pimple-faced 17yr olds on TCCA to me. Never heard sooo many 13 second taurus's in my life. oh_my

 

[rangerj]

Gentlemen, and ladies!

There are 3.0 Liter v-6 Yamaha engines that produce 300 + HP, and much more. The question is did the Yamaha engine produced for Ford (for the SHO) originally produce 300HP by design.

Ford has never officially responded to this question. The unconfirmed rumor, one of many, has it that the original bunch of engines sent to Ford for testing did indeed produce 300+ HP.

The production engines were made less powerful for fuel economy, pollution, liability, warranty, and insurability, reasons.

Some folks familiar with the auto industry have speculated that Ford marketing people did not want any other Ford product competing with the Mustang's high performance niche.

This whole controversy supposedly started with an article in an industry magazine about the testing of the engines for use in the Taurus. The article referred to the engine as having 300HP. I have been looking for the article for five years. Keep in mind that most industry magazines are not made available to the public.

If there is a factory installed 300HP SHO engine out there, I sure have not found it. Does that mean it is not possible?

Back in 1967 there was a rumor about some 550HP Corvettes with all aluminum 427CID engines. The general opinion at the time was B. S. Well, 12 of these Vettes have been documented. Perry, there is one of them up by you in Toledo. I think the place is called Napolian.

I believe there are 300 HP Yamaha V-6s. I do not believe that any of them ever got put into a production automobile for sale to the public. FWIW

If you think about it, it is one more thing that is special about the SHO. It has it's own folk lore! rangerj

 

[RJ-92]

rangerj:

Back in 1967 there was a rumor about some 550HP Corvettes with all aluminum 427CID engines. The general opinion at the time was B. S. Well, 12 of these Vettes have been documented. Perry, there is one of them up by you in Toledo. I think the place is called Napolian.

Wrong! It was 1969 and it was called the ZL1. 2 Corvettes were built with this motor(hand-buit, 600+HP) along with a handful of Camaros, 49 if I remember correctly. One of the Vetes is in Otis Chandler's museum which was bought at an auction for ~$400k nearly 5 years ago. The other has not surfaced. There were a few Vettes that people had put the enging in themselves, brand new. That number is near 3. One was stolen from the factory less than a month after its inception.

You must be refering to the L88 (also hand-built) This was the iron block with aluminum heads. 20 were built in 1967. I believe 12 still can be documented.

<small>[ February 26, 2003, 06:44 PM: Message edited by: RJ-92 ]</small>

 

[rangerj]

RJ,

Your right, I got pieces of it wrong. The L-88s were in fact 20 in number with 12 accounted for.

I was reffering to the L-89 Corvette for 1967, of which 16 were built. It had an iron block with aluminum heads and aluminum intake with three 2bbl carbs, and the K-66 transister ignition upgrade.

Chevy listed it at 435HP, but it actually dynoed at "well over 500HP". The source of the information is an article in Auto Enthusiast Magazine for Dec. 2001.

The author got his reference materials for the article from the National Corvette Restorers Society, The Corvette Black Book, by Mike Antonic, and a few others.

One of these Vettes is listed as being in a collection in Napolean, Ohio (near Toledo).

If I remember right, didn't Yenko Chevrolet in PA drop a few 427s in Camaros, Chevelles, and Novas in 69? From now on I'll deffer any Vette questions or comments to you. thumbs_u rangerj

PS the point of my post was that every now and then the manufacturers do put out a wild machine in small numbers. So, a few 300HP SHOs is not impossible!

 

[Levand16]

rangerj:
RJ,

Your right, I got pieces of it wrong. The L-88s were in fact 20 in number with 12 accounted for.

I was reffering to the L-89 Corvette for 1967, of which 16 were built. It had an iron block with aluminum heads and aluminum intake with three 2bbl carbs, and the K-66 transister ignition upgrade.

Chevy listed it at 435HP, but it actually dynoed at "well over 500HP". The source of the information is an article in Auto Enthusiast Magazine for Dec. 2001.

The author got his reference materials for the article from the National Corvette Restorers Society, The Corvette Black Book, by Mike Antonic, and a few others.

One of these Vettes is listed as being in a collection in Napolean, Ohio (near Toledo).

My dad was talking about those the other day. He has a 95 Corvette and he always reads anything he can about corvettes or Camaros. He used to have a RS/SS but sold it before he knew what it was. We found out something pretty cool on his vette, and it's kinda rare. It has the "spare tire delete" option. Instead of a spare there is a aluminum bar welded in, It's said that chevy thought it would make the frame stronger shrug
The car also has run flat tires and a second low tire pressure warning system that just reads "flat tire". I've never seen another one with this option, my dad knows how many were made like this but I can't remember. I know it wasn't very many!

 

[rendyx]

Do you believe in 300HP+ Yamaha SHO's?

I've heard that Ford sent a motor to Yamaha, and wanted them to modify the top section to make 300HP. They couldn't, so they made the SHO motor we know from scratch, and it produced 220HP. I don't know if that's true or now, however. I'd also guess there were high HP experimental ones. Rangerj said they may have had to tone it down for a few reasons, and I'd agree. I've also heard that Ford wanted it weaker so as not to conquer the 5.0 in performance. Of course some seem to have had success in that task...

 

[SolidState]

sorry, but could you imagine the torque steer out of the factory on an Taurus with 300hp in 89!?

 

[X-15 SHO]

Wow...there's a lot of different thoery's here and explainations. I've heard are motors can do it right NOW, but we can't Something about our accessories can't withstand the high rpms and that the 300 hp came from the revs being around 11.5k - 12.5k rpms. shrug Who will ever know. Could that be for the rev limiter? I know those **** are raised to make the most out of the littlest and 3.0 was enough. thumbs_u

 

[Leon]

hey everyone...here`s something to think about...Yamaha has snow machines that make 150HP from N/A engines just over one quarter of the size of our SHO`s!...i have a Skidoo MACH Z that is 780cc and is 150 hp...SHO`S of course,are 3000 to 3200cc`s...gotta be lots of room for N/A improvement somewhere!

 

[KentuckySHOoff]

rangerj:



The production engines were made less powerful for fuel economy, pollution, liability, warranty, and insurability, reasons.

Hmmmm. maybe they should follow me around...

 

[revhardSHO]

hey everyone...here`s something to think about...Yamaha has snow machines that make 150HP from N/A engines just over one quarter of the size of our SHO`s!...i have a Skidoo MACH Z that is 780cc and is 150 hp...SHO`S of course,are 3000 to 3200cc`s...gotta be lots of room for N/A improvement somewhere!

You can compare those little two strokes to our [larger] DOHC 4 stroke. Completly different animal. Those things make there power extremly high up in the throttle range, most around 9 to 10K rpm. Yes our SHO's make there power up high also (~6200rpm), but comparing them is like comparing apples and oranges.

silas

 

[BlackMagik]

My 1.3L Suzuki makes 175 crank HP completely stock...not including ram boost at speed. Kevin Cameron's formulas indicate this engine makes close to 200 crank HP at 194 mph!

I'll look through some engineering formulas to see if I can calculate a new HP for the 3.2 SHO at a higher RPM. What do you think?