Real Fiero Tech

http://www.hotrod.com/events/mercury-ra ... sema-2014/

Seems mercury is attempting the same thing GM did with the 3.4 Install a blank cam to drive the quad cams and voila, 4 cam LS. I like this better being all aluminum but I imagine it's also a large engine. Maybe being all aluminum will keep it the same weight as the 3.4

There are two things that really hurt the 3.4 in terms of weight.

-Separate heads and cam carriers. BMW lost the cam carriers when they designed the S54 and dropped 29 POUNDS (!) out of the fully assembled cylinder head vs. the previous design (M50 through S52)

-Cams install from the end instead of being retained by saddles; this adds several pounds of iron to the weight of each cam

It looks like Mercury avoided both of those pitfalls.

However, I'll reserve judgement on the OHC conversion until I see airflow numbers. The production CNC'd LS9/LS7 heads, the as cast LS3/L92 heads and aftermarket MAST Motorsports and similar heads already have stoopid, stoopid flow numbers... 350 CFM and up. That's enough that a 7.0 has to turn to and beyond 7,000 RPM to really fulfill the potential in the heads. At that point, the cost of the valvetrain that can handle the necessary lift (0.700+!) with the huge intake valve at that RPM and still last rises dramatically.

I don't think the 4V heads will significantly exceed the airflow of the 2V heads, but may offer something that's cost competitive if the redline RPM is in the 7500-8000 range.

Also, there can be some interesting packaging tradeoffs in OHC valvetrain design. The larger the base circle, the better the valve events can be managed and the higher the lobe lift can be. The base circles on those cams don't look particularly large.

Also, anything that doesn't support DI is behind the times. I hope there are injector bosses in those heads AND space between the intake valves for an injector well.

That's neat, but I agree with Will, its solving a problem that never really existed, not a whole lot of people have outrun the flow of existing LS head options. It'll be a $10,000 solution to a problem no-one has.

My thing is who cares if the heads do outflow LSX heads? We aren't in a displacement limited class. Until the 32v engines can make the power of an LSX, whill weighing less and being physically smaller, it's not in competition.

The LSX tops at 505hp without a blower, 638 with one. And the thing fits into a Miata, comfortably.

the article says the heads flow "north of 400 CFM" I don't car who you are, that's a ton of air. I wonder how the heads flow at low lift, and I wonder how low speed torque does with heads flowing in excess of 400 cfm.

Arao has had 4 valve LS heads for years (with pushrods, not a belt drive), but I have never come across them at the LS Fest. I doubt they are much better than current head options that can be had at half the cost.

http://www.araoengineering.com/lsx.htm

fieroguru wrote:Arao has had 4 valve LS heads for years (with pushrods, not a belt drive), but I have never come across them at the LS Fest. I doubt they are much better than current head options that can be had at half the cost.

http://www.araoengineering.com/lsx.htm

Me and my buddy used to salivate over those heads back in the day.

you guys see the 550 cubic inch version?

http://features.boats.com/boat-content/ ... e-project/

ericjon262 wrote:you guys see the 550 cubic inch version?

http://features.boats.com/boat-content/ ... e-project/

That's Mercury's bespoke engine architecture and not an adaptation to the LS...

Bad ass engine, of course, but also huge.

The Dark Side of Will wrote:

ericjon262 wrote:you guys see the 550 cubic inch version?

http://features.boats.com/boat-content/ ... e-project/

That's Mercury's bespoke engine architecture and not an adaptation to the LS...

Bad ass engine, of course, but also huge.

I know it's not adaptable, but I bet it's got a chevy bellhousing flange....

If you have a 4-1/2 angle grinder and a MIG welder, don't let anyone tell you something isn't possible.

FieroWanaBe1 wrote:If you have a 4-1/2 angle grinder and a MIG welder, don't let anyone tell you something isn't possible.

lol, I almost said this exact phrase earlier...