GM 3 valve cylinder design
GM doesn't make a 3V head for LSx. I think Lingenfelter or Elderbrock was working on one but I can't remmenber which one for sure. I think I saw a discussion about it acouple months ago on this board.
We are still doing work on the prototype castings. GM stopped by the other day to get another set of heads rockers and transfer arms for more testing.So the project is far from dead.
TECH Addict
Joined: Feb 2004
Posts: 2,826
Likes: 0
Originally Posted by pman
We are still doing work on the prototype castings. GM stopped by the other day to get another set of heads rockers and transfer arms for more testing.So the project is far from dead.
Trending Topics
Thread Starter
11 Second Club
iTrader: (6)
Joined: Feb 2003
Posts: 463
Likes: 0
From: Oklahoma City, OK
only reason I asked was because this thread
http://turbobuicks.com/forums/showth...t=page=1&pp=15
You will have to read a wya into it where I said that GM was making the same or damn near same power as Ford was but GM using 2 valves per cyl and ford 4 and GM N/A vs Ford S/C. Well a guy came back adn said GM LS2 and LS7 are 3 valve, since I had sold my 01 Z last year I got out of the LSx scene for awhile and now that I have another LS1 Z I got back in and was not sure if GM went on with the LS2 LS7 3 valve design
http://turbobuicks.com/forums/showth...t=page=1&pp=15
You will have to read a wya into it where I said that GM was making the same or damn near same power as Ford was but GM using 2 valves per cyl and ford 4 and GM N/A vs Ford S/C. Well a guy came back adn said GM LS2 and LS7 are 3 valve, since I had sold my 01 Z last year I got out of the LSx scene for awhile and now that I have another LS1 Z I got back in and was not sure if GM went on with the LS2 LS7 3 valve design
Last edited by 89ws6formula50; Apr 29, 2005 at 09:49 PM.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo TECH Addict
Joined: Feb 2004
Posts: 2,826
Likes: 0
Originally Posted by 89ws6formula50
only reason I asked was because this thread
http://turbobuicks.com/forums/showth...4&page=1&pp=15
You will have to read a wya into it where I said that GM was making the same or damn near same power as Ford was but GM using 2 valves per cyl and ford 4 and GM N/A vs Ford S/C. Well a guy came back adn said GM LS2 and LS7 are 3 valve, since I had sold my 01 Z last year I got out of the LSx scene for awhile and now that I have another LS1 Z I got back in and was not sure if GM went on with the LS2 LS7 3 valve design
http://turbobuicks.com/forums/showth...4&page=1&pp=15
You will have to read a wya into it where I said that GM was making the same or damn near same power as Ford was but GM using 2 valves per cyl and ford 4 and GM N/A vs Ford S/C. Well a guy came back adn said GM LS2 and LS7 are 3 valve, since I had sold my 01 Z last year I got out of the LSx scene for awhile and now that I have another LS1 Z I got back in and was not sure if GM went on with the LS2 LS7 3 valve design
GM pays us to do the machine work...how does that suck? I never really read the other threads about the 3 valve heads, but you seem to have all the first hand info on them? Am i right on this guess or do you just have something against them? Not looking for an argurment here just want to compare your info with what we hear from the guys testing and developing them. TECH Addict
Joined: Feb 2004
Posts: 2,826
Likes: 0
Originally Posted by pman
GM pays us to do the machine work...how does that suck? I never really read the other threads about the 3 valve heads, but you seem to have all the first hand info on them? Am i right on this guess or do you just have something against them? Not looking for an argurment here just want to compare your info with what we hear from the guys testing and developing them.
Originally Posted by Another_User
I just have something against them. It is not even logical that the valvetrain design could hold up to normal wear and tear, let alone high-rpm abuse. Plus, if you want to add more valvetrain weight and valves, GM should at least give us DOHC, and some variable cam timing technology. Not just some crappy gimmick. If it were some useful magical technology, other car companies would have gone, "Oh wow, three valves on a pushrod engine, with both valves opening at the same time, what a great idea! Oh wait, we can just make the intake valve bigger and accomplish the same thing with less turbulence, or better yet, lets actually do something useful and use OHC technology that has been out for years, and now we can actually rev the **** out of the engine, vary cam timing, and do something GM didn't think of....making more horsepower!" GM wastes money like it is water. That is their problem.
TECH Addict
Joined: Feb 2004
Posts: 2,826
Likes: 0
Originally Posted by 8KickassRS9
sohc is crap, its more gimmicky than the pushrod 3 valve heads. a comparable motor to the same year ls1 makes what? up to 70hp less than the good ole pushrod ls1 heads? then u come to the redline, with the right setup you could rev the ls1 jus as far if not further. if nething gm should slap a blower on the LSx cars and jus give ford the big ole finger once again. hell its evident wht the blowers would do, look at the joe gibbs trucks. they outrun there competition the blown lightings stock for stock at a 1/10th leiter(sp) less.
On The Tree
Joined: Sep 2004
Posts: 143
Likes: 0
From: Naperville
My guess would be that size and weight are the two factors of why gm doesn't waste their time with ohc v-type motors. Fwiw a ford dohc v8 is about the same size as a big block motor. The other factor is the additional cost of using ohc motors. I've said it before and i will say it again it's a popular misconception that gm's pushrod technology is outdated, they know exactly what they're doing.
For instance take fords dohc v8's, though they make a very little bit more hp per liter, go and compare power per pound of motor. You will find out that gms old pushrod technology is much more efficient than the current ohc technology ford is using. Also not only does an ohc motor add more weight in the front of a car that already has a heavy front weight bias, it also adds the weight to the top of the motor which increases the center of gravity which also hurts handeling. Also if gm used ohc's in their motors you'd have less sleek cars with much more bulky front ends, take the corvette for instance. If gm decided to use an ohc type v8 in the vette they'd have to raise the hood line a few inches, car would look like garbage imo if that were to happen.
For instance take fords dohc v8's, though they make a very little bit more hp per liter, go and compare power per pound of motor. You will find out that gms old pushrod technology is much more efficient than the current ohc technology ford is using. Also not only does an ohc motor add more weight in the front of a car that already has a heavy front weight bias, it also adds the weight to the top of the motor which increases the center of gravity which also hurts handeling. Also if gm used ohc's in their motors you'd have less sleek cars with much more bulky front ends, take the corvette for instance. If gm decided to use an ohc type v8 in the vette they'd have to raise the hood line a few inches, car would look like garbage imo if that were to happen.
Last edited by stik6shift93; May 1, 2005 at 12:28 AM.
Teching In
Joined: Aug 2004
Posts: 7
Likes: 0
Originally Posted by pman
we also are machining the 3 valve V10 and V6 proto work 
pman,
Have you seen any indication that there are versions of these heads
which have provisions for side- or central direct-injection?? Do you have
any idea of the valve sizes (diameters)?? What bore sizes are these heads
designed for?? Has anyone given you any hints as to the flow rates of these
heads? Is the first application of these heads to truck or cars? I assume V8's
will appear before the V6's and V10's. Do intake manifolds for these heads
look anything like either the LS2 or LS7 intake manifolds? Are the heads much
heavier than 2V heads. What is the valve angle on these heads? Are there many
different versions of the heads??
Any thoughts would be appreciated. Don't get yourself fired!
TECH Regular
Joined: Jan 2005
Posts: 476
Likes: 0
From: Pleasanton, CA
I agree with stik 100%. One of the biggest differences in the GM cars and Fords or most other OHC v-8's is that the GM pushrod cars are more aerodynamic(front engine mount, excluding mid mounted cars). The front of the mustangs look like bricks in the wind, also my opinion, but they definately arent as aerodynamic. I also like the old saying "keep it simple, stupid." And that is what GM has been doing and doing it well. Pushrod engines are a simple design that just plain works. Im not gonna say it works better than OHC, but for what GM and most of there buyers want, it is a better suited engine. I also dont see any real benefits from OHC engines. The pushrod engines and heads are capable of making the same power. Sure it takes bigger valves, but power is power, no matter how it is made. As far as ive seen the LS series heads flow just as good as the OHC heads flow, and the LS engines can rev just as high as other OHC V-8. I would imagine that they would be able to rev higher seeing as they are using less moving parts and therefore moving less mass during revving. That is just an educated guess, no facts to support that.
I could see why an engineer would flirt with the idea of an OHC engine, however in GM's case when they owned lotus cars, the LT5 (great motor indeed) was a vehicle with one heck of a price tag, not to mention that it was one heck of a heavy and large engine. Even though skeptics would like to believe that the LSx engine is pushing the pushrod design too far, I like to think that what it doesn't push too far is the price tag.
Lack of variable valve tech is for sure, but lack of power for the price? Good question. I would like to know how that 3v design will work myself, because the exhaust valve arrangement looks a bit awkward. I couldn't see why it couldn't work, just looks like a proprietary design that might need much r&d before it can work better than GM's 2v OHV design. If my memory doesn't fail me, I believe that there was a company called dominion that had a retrofit design for a 4v OHV. don't remember what ever happened with it.
Lack of variable valve tech is for sure, but lack of power for the price? Good question. I would like to know how that 3v design will work myself, because the exhaust valve arrangement looks a bit awkward. I couldn't see why it couldn't work, just looks like a proprietary design that might need much r&d before it can work better than GM's 2v OHV design. If my memory doesn't fail me, I believe that there was a company called dominion that had a retrofit design for a 4v OHV. don't remember what ever happened with it.