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4-Valve LS Heads at SEMA?
4-Valve LS Heads at SEMA? Has anyone heard more about these heads and this setup? Seems pretty interesting. Supposedly it's outrageously expensive. I didn't see anything through searching on here, so if it has already been talked about, then I apologize in advance.
http://www.hotrod.com/events/mercury...-at-sema-2014/
http://www.hotrod.com/events/mercury...-at-sema-2014/
Normally you would be refferring to aeroheads I think...which long ago were dominion heads. I ran dominion heads On a 396 lt1 in the 90's. I ve seen there 4 valve ls heads at sema....but I did not see them this year, but they could have been there.
I did see mercruiser though....with dual over head valve 4 valve heads on an ls.
No price (Id gues 6000 area) and they look cool as hell, I posted a pic in another thread in forced induction. I did find it strange that they had them displayed with NO flow numbers.......The aero 4 valve heads are in the 400 + cfm area.....awesome heads, but no one ever uses them primarely because all the class rules say 2 valve heads.....most sanctioning bodies dont allow 4 valve heads on an original 2 valve engine......so who is gonna spend 60004 on heads for the cool factor only....no racers can really use em and thats the market
I did see mercruiser though....with dual over head valve 4 valve heads on an ls.
No price (Id gues 6000 area) and they look cool as hell, I posted a pic in another thread in forced induction. I did find it strange that they had them displayed with NO flow numbers.......The aero 4 valve heads are in the 400 + cfm area.....awesome heads, but no one ever uses them primarely because all the class rules say 2 valve heads.....most sanctioning bodies dont allow 4 valve heads on an original 2 valve engine......so who is gonna spend 60004 on heads for the cool factor only....no racers can really use em and thats the market
I think mercuiser is what my friend saw. He was sending me pictures of the heads. He was curious to why they didn't have any flow numbers as well, but the article I posted said it should be in the 400 cfm area. It also said they haven't done extensive durability testing on them yet.
I was just trying to learn more about them and maybe find a comparison on the DOHC versus the normal single cam LS's.
I was just trying to learn more about them and maybe find a comparison on the DOHC versus the normal single cam LS's.
I think mercuiser is what my friend saw. He was sending me pictures of the heads. He was curious to why they didn't have any flow numbers as well, but the article I posted said it should be in the 400 cfm area. It also said they haven't done extensive durability testing on them yet.
I was just trying to learn more about them and maybe find a comparison on the DOHC versus the normal single cam LS's.
I was just trying to learn more about them and maybe find a comparison on the DOHC versus the normal single cam LS's.
Ok I guess technically not a DOHC, but it uses one cam per head, so two cams. That's more what I meant. From previously stated, not many people use them, but does anyone have results from these heads? Dyno numbers and graphs?
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4 valve heads Over the years I have heard and seen attempts at DOHC heads on a Chevy small block. One problem that kept coming up was the head bolts/studs were in the wrong place.
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From what I gather looking at the various off shore sites, I think these will make their way into boats more often that not. Lots of people want to stuff LS engines into their boats, but it's hard to beat the al over torque of a BBC. The article states that the flow numbers are well north of 400 as cast. And if you look closely, there are two cams per head, so it is a DOHC setup.
I am sure more testing will come along. Based on the price of a normal Mercury Racing engine, I am sure they will not be cheap. I have had my hands on a couple of their engines that are WELL into the 6 digit territory. Only time will tell.
I am sure more testing will come along. Based on the price of a normal Mercury Racing engine, I am sure they will not be cheap. I have had my hands on a couple of their engines that are WELL into the 6 digit territory. Only time will tell. 
Staging Lane
Joined: Jul 2005
Posts: 61
Likes: 1
From: Shreveport, LA
You screwed that way up lol.
The in block cam is swapped to a blank, not the ones in the heads. Wtf? What would even be the point of using them if the cams were blanks and didn't control the valves? Did you even think about what you were saying?
It has 2 cams per cylinder head, hence the DOHC. Dual cams over each head. Just as SOHC means a single cam over each head.
Going by your logic, DOHC means 2 cams, one over each head. Which is wrong. So SOHC would mean only one cam shared by both heads, and somehow still mounted above both heads and controlling the valvetrain. Smh.
No. Just no.
DOHC means 2 cams over each head. 4 total.
SOHC means 1 cam over each head. 2 total.
OHV means valves mounted overhead of the single cam, which is in the block.
So you "built drag Hondas for years" but you don't know what DOHC AND SOHC means? And can't identify what you're even looking at? I call
Last edited by midnightbluS10; Dec 11, 2014 at 08:39 AM.
You screwed that way up lol.
The in block cam is swapped to a blank, not the ones in the heads. Wtf? What would even be the point of using them if the cams were blanks and didn't control the valves? Did you even think about what you were saying?
It has 2 cams per cylinder head, hence the DOHC. Dual cams over each head. Just as SOHC means a single cam over each head.
Going by your logic, DOHC means 2 cams, one over each head. Which is wrong. So SOHC would mean only one cam shared by both heads, and somehow still mounted above both heads and controlling the valvetrain. Smh.
No. Just no.
DOHC means 2 cams over each head. 4 total.
SOHC means 1 cam over each head. 2 total.
OHV means valves mounted overhead of the single cam, which is in the block.
So you "built drag Hondas for years" but you don't know what DOHC AND SOHC means? And can't identify what you're even looking at? I call
The in block cam is swapped to a blank, not the ones in the heads. Wtf? What would even be the point of using them if the cams were blanks and didn't control the valves? Did you even think about what you were saying?
It has 2 cams per cylinder head, hence the DOHC. Dual cams over each head. Just as SOHC means a single cam over each head.
Going by your logic, DOHC means 2 cams, one over each head. Which is wrong. So SOHC would mean only one cam shared by both heads, and somehow still mounted above both heads and controlling the valvetrain. Smh.
No. Just no.
DOHC means 2 cams over each head. 4 total.
SOHC means 1 cam over each head. 2 total.
OHV means valves mounted overhead of the single cam, which is in the block.
So you "built drag Hondas for years" but you don't know what DOHC AND SOHC means? And can't identify what you're even looking at? I call
You screwed that way up lol.
OHV means valves mounted in the cylinder head. Example, the flathead Ford(and many other flathead engines) had the valves mounted "overhead of the single cam" as you described but the valves were in the engine block, hence the name 'Flathead'. Be careful before you wave the BS flag around because you just got hit with it!
TECH Enthusiast
Joined: Mar 2013
Posts: 503
Likes: 39
You screwed that way up lol.
OHV means valves mounted in the cylinder head. Example, the flathead Ford(and many other flathead engines) had the valves mounted "overhead of the single cam" as you described but the valves were in the engine block, hence the name 'Flathead'. Be careful before you wave the BS flag around because you just got hit with it!
OHV means valves mounted in the cylinder head. Example, the flathead Ford(and many other flathead engines) had the valves mounted "overhead of the single cam" as you described but the valves were in the engine block, hence the name 'Flathead'. Be careful before you wave the BS flag around because you just got hit with it!