rons 00z

iTrader: (10)

please explain

Another_User

It would have been done on a production vehicle before if it made any sense at all. Why introduce extra moving parts to do what could be done with the same as we have now? I mean, it may help, IF you had 16 runners and closed half off. But that is a LOT of crap to break in your intake. And the valvetrain does not look stable on those GM 3-valve heads. I don't think it would be too unrealistic to expect that extra pushrod to go flying through the valve cover in the event that you encounter valve float. Regular pushrods are not going to do anything like that because there is plenty in place to hold them from moving. If they were to ever put anything like that in production you would need a driveshaft loop kind of thing to try and help make sure the extra pushrod didn't come out. It is a poor design built on old technology. And without a ton of extra worthless parts it would not net much of a gain. I would not be half surprised if those heads were not scrapped because of:
1) reliability
2) safety
3) high production cost
4) lack of power gain over equally flowing 2-valve heads without additional (and expensive) parts in the intake, which would also need good R&D to be reliable.

It's crap. Really. A gimmick to get people's attention.

Big-DEN

Turbulence part was if the 2 intake valves where "inline" with the port.

Most dual intake valve setups the intake valves are side by side and have potential
for having independant runners feeding em.

ChucksZ06

iTrader: (9)

This has been a great thread. Multivalve heads are nothing new to auto engines and were used on engines 60 years ago. The thing thant has not changed is well designed 2 valve engines can equal or come very close to the multivalve with less weight and much better reliability not to mention lower manufacturing costs. The new z06 is going to be lighter than any mass produced, fully optioned supercar in the world.

chuntington101

Chuck the Spitfier's Merline and Griffin engines both had 4 valves per cylinder back in the 30s/40s and the same engine (the merlin) was used in the (very good) P51!

as for supercars, well, have you ever heard a Lambo V10 at WTO doing about 7-8K? trust me it sounds ace. and thats not even a V12!!!!! back to the point. supercar manufactures use multivalve designs because it enables the compaines to exstract more power per CC.

personaly i think they are def the way forward, its just some people will always say no to anything that means change. and what is the point of enginerring if it is not to solve problems, not just keep reproducing the same old stuff with a new tag on it. what would you guys think if the next GM was a V10???????????

thanks Chris.

gen 3 bu

iTrader: (2)

there is one in the works and it is ls1 based. saw some proto-type pics of the 5 cylinder ls1 type heads on here a couple of months ago. dont know when it will be available though.

chuntington101

SWEET! now that could be realllllllly nice. and it would be just over 7.0 ltr to (if used same cylinder dymensions as the ls1! now that with a 4 valve heads on would be amazing.

thanks Chris.

zamboxl

iTrader: (1)

any links to those pics there man.

ChucksZ06

iTrader: (9)

I am all about change, but not change to more complexity when there are simpler designs that save money, time, and are more reliable. Every example that is given for fast powerful multivalve power cars are examples of cars that are too expensive for all but the ultrarich. I love the sound of F1 cars turning 16,000 rpms but it has nothing to do with what anyone will drive on the street. Look at the new porsche sports car. It is 5.7 liters and it doesn't put out any more rwhp than Tony Mamo's vette. An that car has a reciprocating mass so light that you can barely launch the car from a dead stop. It costs over 500,000 dollars. You know what? A mildly tuned 05 Z06 will beat that car in any way you want to talk about. That is real world when a mass produced auto that sells for 70,000 can equal and excede a hand made car by some of the best engine people in the world.

Another_User

3 valve heads are the best idea ever.

April fools. They are still crap.

DavidNJ

I believe every manufacturer, worldwide, including GM, is using DOHC 4-valve engines for their passenger cars. Pushrod motors are still there for trucks and high performance sports cars that put the high power/high torque truck engines in a light chassis. The pushrod motors are just a different point on the power/cost/refinement scale (high power at a low price with a loss of refinement).

The variable cam timing has given some extra push behind DOHC engines. However the difference isn't one is better than the other...just different.

Sharpe

iTrader: (7)

What were the LT5 heads?

Phoenix 5.7

iTrader: (7)

one other issue with OHC is the extra size of the head, especially a DOHC. OHCs are good for really high revving engines like the S2K. no valve float. i like the simplicity of our pushrod design. i was talking to a mach 1 owner who jsut finished putting in his cams, and he said it was a major PITA to get them all corretly aligned. isn't the new mustang 4.6 supposed to run on 87 octane?

gen 3 bu

iTrader: (2)

the lt5 heads were 4 valves per cylinder, BUT they were dohc. the heads we are discussing are multi-valve heaads that use the factory located cam.

gen 3 bu

iTrader: (2)

https://ls1tech.com/forums/showthrea...light=v10+head
this is were it used to be. sorry.
kevin

chuntington101

David i agree with you 100% on that. 2 diffrent ways of doing the same thing.

Chuck. how about putting one of these high HP vettes up agains a GT (thats Porsche not ford) around the 'ring in Germany? the track is used by all sorts of companies (from race to road cars) for set up and testing. and is also one of the most difficult tracks in the world. i know where my money is. and if you do beat the GT, then come and have a word with a samll british company called radical and see how they do against their SR3 Turbo

thanks Chris.

PS. no hard feelings Chuck, just saying there is a lot more that goes into the GT than just power.

technical

That's why they make cam holders. At least there exists a "special" factory tool per manufacturer for holding cams in place while timing them. The first time replacing overhead cams feels odd or a pita when your used to pushrod motors. Excluding space contraints in the engine bay, I think replacing OHC's is easier.

zamboxl

iTrader: (1)

dude come one now how much is that new porsche gt super car, the vette is less than half, and is a production car not to say that the gt aint but is a very very very low volume hand made super car ok and that little british company hell i'll tell them to go check out a little american company called Panoz . The whole argument of the z06 is that i'll blow away anything in its price range and i would say not till you get into the $100 000 is there somthing that will match it's performance. While i do agree with you that the gt is more than just power and i know the z06 is not match for the gt it will spank any other porsche out there, be it carrera the gt2, gt3, 911, 911 turbo what ever it be it will spank it and cost less money than they do.

ChucksZ06

iTrader: (9)

Apparentley you do not know where the c5, c6, and CTS v suspensions have been developed the past few years...yes the "ring". In fact GM recentley built a brand new road test course that duplicates the demanding corners and elevation changes that occurr on the famous german track. You really do not know how trick a car the new vettes (zo 6s are). I have no hard feelings I am just trying to educate with a little truth here. Go to a ALMs race and watch all the cars chasing the c5/c6r s around the road courses. Only the factory turbocharged audi's consistently beat the factory vettes and they are one off unlimited lemans cars. I outcorner $150,000 tricked out porches all the time with my stock 02 Z06 at Portland. If you open your mind a little and read about the 10 cylinder, half million dollar porsche, see how much it weighs the horsepower and torque levels, the cornering force, the brakeing distance...Car and Driver tested one and it is an awesome car for the track but not for my money...you have to be careful not to be impressed just because of the mystique of the name or the amount of money it costs. Look at the specs...the porsche is tweaked so high that you have to burn the clutch to start out. The guys that buy those things never take them to a track or race anyone because they are afraid of dings and mostly that some low class american iron is going to kick euro ***.

chuntington101

Panoz is a race car the SR3 is a road car, ok well a race car for the road, but its still legal on the road (just). and soory for being stupid on the 'ring thing. i should have thought twice before thinking about having a go on something i was not 100% sure of. again sorry. as for the pace of a GT3 vs a vette thing i will have to agree to disagree. i think the GT3 would win (cant remamber what time it set). what did the z06 lap in? be nice to compare numbers.

thansk Chris.

PS did i say sorry for being such a t**t had a bad day!