Oldsmobile's Hemi?

[moparcanuck]

Hard to believe: http://www.streetlegaltv.com/news/insanely-rare-w-43-455ci-oldsmobile-hemi-engine-up-for-sale/

 

[1966Christine]

that's
pretty cool

 

[Meep-Meep]

That would be really cool in my Olds powered jet boat!

What's ironic is the 4 valve pentroof chamber goes a long way towards efficiency and low fuel consumption. And to feed less cubes they could have thrown that together on a short deck 350 motor. Then add port injection, etc.. American ingenuity like this could have kept the Japanese out of the car business.

 

[barnfind]

Ive never heard of that one. Seems like a lot of manufacturers were duplicating "Hemi" type engines after mopar. Cool find thanks for sharing that.

 

[Meep-Meep]

Actually, the Europeans were building hemi's long before Chrysler got int he game.

 

[krowbar]

Damned govt regulations and gas prices put a stop to that and all the other POWER engines. HP numbers are coming back though in New vehicles. The torque seems to be alot less now. All the new computer management is a killer to the average guy( cost wise ) trying to low buck high HP.

 

[barnfind]

Actually, the Europeans were building hemi's long before Chrysler got int he game.

sounds like some more research. Personally Ive never had a hemi car (been close though) I have had 455 cars there great torque monsters. Makes me wonder how the head design would affect it.

 

[Budnicks]

That was a cool read, interesting I knew about the Pontiac M/T Hemi but not the Olds...

 

[bigaadams]

appears single lifter per "set" of vales..that would be brutal punishment on the camshaft/lifter faces as the spring pressure from two valves of any performance quality whatsoever would be quite high...would suspect cam life to be short if car idled much in street application and if springs were compromised for the street..then do not think any serious high end would have resulted without floating..may wellhave been squashed to prevent future embarrassment..though GM has a goodly number of embarrassments as it is..

 

[Photon440]

appears single lifter per "set" of vales..that would be brutal punishment on the camshaft/lifter faces as the spring pressure from two valves of any performance quality whatsoever would be quite high...would suspect cam life to be short if car idled much in street application and if springs were compromised for the street..then do not think any serious high end would have resulted without floating..may wellhave been squashed to prevent future embarrassment..though GM has a goodly number of embarrassments as it is..

BUT, using more valves likely also means that they're smaller and lighter, reducing some of the load on springs and the lifters.

 

[bigaadams]

Evidently you did not look at the valves on the head in the picture...good idea with poor execution is still my opinion..

 

[kb67mopar]

Evidently you did not look at the valves on the head in the picture...good idea with poor execution is still my opinion..

It partially depends on the stage of development. Obviously this was not a production engine and may have been the theory proving test in which case longevity is not a concern. If you prove the head design makes a huge improvement of the original head then you would move into a phase of designing a reliable cam/lifter arrangement and revise the block to match.

If you have an idea, rarely do you go into full start over design phase without proving a benefit.

 

[bigaadams]

therein lies just one of who knows how many design flaws that kept it from production...

 

[Richard Cranium]

appears single lifter per "set" of vales..that would be brutal punishment on the camshaft/lifter faces as the spring pressure from two valves of any performance quality whatsoever would be quite high.

Also, carefully check out the picture below. You can see where the pushrods are actually the rockers themselves.....on the side, not the middle. My gut instinct tells me that rockers and shafts would be a high wear area.

 

[snakeoil24]

Looks alot like an old 354 Hemi Head. I can tell you for sure, i raced my share of 455 olds and GS Buicks they where very hard to beat. Took all of the track in stock form before Hemi woke up and scragged those big strokers.

 

[Photon440]

Evidently you did not look at the valves on the head in the picture...good idea with poor execution is still my opinion..

I don't understand what you're getting at...sorry. What's to look at as to the valves on the head in the picture?

Valve sizes were: Intake 1.75" and Exhaust 1.375". Not the largest in the world...

By the way, there was an aluminum version of this engine developed for CAN-AM racing that actually ran and made it to the Lansing dyno rooms. With Weber carbs it made 700 hp. at 6800 rpm. The redline was 8500 rpm.

-=Photon440=-

 

[bigaadams]

I don't understand what you're getting at...sorry. What's to look at as to the valves on the head in the picture?

Valve sizes were: Intake 1.75" and Exhaust 1.375". Not the largest in the world...

By the way, there was an aluminum version of this engine developed for CAN-AM racing that actually ran and made it to the Lansing dyno rooms. With Weber carbs it made 700 hp. at 6800 rpm. The redline was 8500 rpm.

-=Photon440=-

You only continue to make my very point..size of valves, strength of spring and rated max RPM redline of 8500

IT is a far cry from getting one made with aluminum heads, designed for does not a successful engine make...getting all the way to a dyno is a far cry from hitting the street much less having any kind of lifespan in daily use..there were many many engine designs worked with over the years..the successful did make it to production...had this engine any reliably factors built in I have no doubt it would have been placed in production as they needed a competitive edge...I am not knocking their venture and love to see prototype work myself...but the obvious is still the obvious..I recall well GM's first quad valve full production engine..the set up was very noisy due to the cam chains instead of the typical belt driven OHV designs..but knowing that the interference fit engine (the only reason it has any power) was a handgrenade with the pin already pulled...the new wore off within the first year of so in use when these very concerns arose from the ownership...after a number of redesigns here and there that still did not address all issues.....the engine got canned.

PS...Vega was a Cosworth design, English so does not apply as a GM first..

 

[Photon440]

I wonder why GM would have selected noisy cam chains? It would have been more logical to select the nearly silent cam chains that other manufacturers (BMW, Mercedes, some Lexus, Fiat, Honda and Jaguar, plus GM's own Cadillac) use without issues.

At any rate, more info on Oldsmobile's engine designs here:
http://www.streetlegaltv.com/news/the-w43-oldsmobiles-dohc-455-v8-that-never-was/

 

[Tempest 455]

Actually a Buick has a fairly short stroke for a 455 engine (shortest of GM) with a larger bore than most. Many mfg's played w/ HEMI heads (Chrysler was most successful in production). Pontiac also had Mickey Thompson HEMI heads which were used on 421's in A/FX cars.