Getting my 1st 300R V8 this week.

[engineermike]

The intake manifold and camshafts are different.

[madmatic]

both should be easily changed, the cam shaft will be right under the valve covers and easily changed out. How about the aftermarket/ custom cam companies? I loved the custom grind I had lunati make for an old 636ci. I'm sure if we throw away the emissions rating, port/shave the heads for 91octane and get some good breathing cams these engines will approach the 400+ mark

[engineermike]

I think we're going to find that mechanical changes are the easy part. On modern engines, without someone who can and has indepth knowledge of electronic engine controls, mechanical changes are all but moot.

[JPEROG]

I think we're going to find that mechanical changes are the easy part. On modern engines, without someone who can and has indepth knowledge of electronic engine controls, mechanical changes are all but moot.

I agree, it will take an aftermarket ecu more then likely. Mercury is not going to pay warranty claims for some "Joey with a laptop" being able to go and access a tune change that ends up being detrimental to the motor. But if someone qualified invest the resources into a plug and play aftermarket ecu, you can bet that a bump in compression, valve timing change and tune will extract over 100 hp per. 1000CC. Its been proven on all of the car motors now. The question is will there be enough market interest for this to happen. There are thousands of LS and Coyotes out there but there will only be hundreds of 4.6 300R motors. Then there will only be a small percentage of the guys willing to pay for the additional changes-I don't think its going to make anyone rich.

Joe

[madmatic]

Yes but there are are a ton of 4.6l 32v cobra motors that look strikingly similar.. do we know if the fuel curve is open loop or closed loop? Meaning will the ecu make proper corrections to a/f or is it relying on the tps to regulate fuel. the link below is a 485hp pump gas 4.6l I'm going to look into the cam specs to see if reversion would be an issue. http://www.mustangandfords.com/how-t...gine-upgrades/

[mach351]

Mike is right. Mercury isn’t going to let anyone in the programming that will threaten their multi million dollar investments. It just ain’t gunna happen. If you want more power out of that V8 you’re just going to have to wait till Mother Merc gives it to you - it’s coming, don’t worry.

[JPEROG]

Yes but there are are a ton of 4.6l 32v cobra motors that look strikingly similar.. do we know if the fuel curve is open loop or closed loop? Meaning will the ecu make proper corrections to a/f or is it relying on the tps to regulate fuel. the link below is a 485hp pump gas 4.6l I'm going to look into the cam specs to see if reversion would be an issue. http://www.mustangandfords.com/how-t...gine-upgrades/

Its a closed loop system. Like I said before, we will have to wait and see if someone with the proper resources comes out with an aftermarket ecu. Mercury did an awfully good job of maxing out the 300XS two stroke platform (not really any room for real world gains that I ever witnessed). But four stroke, variable valve timing technology is another deal as proven by today's automotive applications. There are also some Yamaha SHO motors without forced induction that have seen significant "real world" performance gains via. tune changes. This motor definitely has big displacement on its side.

Joe

[vnemous]

Inline verado 6 platform is easily upgraded from 200 hp to 340 with just an $800 computer upgrade from Whipple. Reflash the computer and 93 octane and wala 340 hp. Best bang for the buck.

[JPEROG]

[QUOTE=vnemous;3059281]Inline verado 6 platform is easily upgraded from 200 hp to 340 with just an $800 computer upgrade from Whipple. Reflash the computer and 93 octane and wala 340 hp. Best bang for the buck.[/QUOTE

Built in software protection has advanced light years over the past 11 years since the verado first came out but we will see if its going to be something that simple. What kind of real world speed gains have you guys experienced on a whipple reflash? what hull? just curious, I have no Verados personally.

Joe

[deckofficer]

I'm new here, only joined the forum 6 years ago and 21 posts total. I'd like to give a perspective of being and old hot rodder and the direction I think Mercury might be headed. With the liability laws the way they are I believe the days of 375 lb modded 2.8 2 strokes clamped on the transom of some 350 lb kevlar laid up 18' tunnel are over. That is too bad because hole shot and top speed is obtained for this favorable power to weight ratio air entrapment hull. But some people (like me) still want this and in the near future I believe Mercury will address this with a 600 hp supercharged (hopefully by Eaton) innercooled version of this 4.2 L 300R V8. Mercury was caught off guard with the success of the Seven outboards producing 626 hp but at a weight of 1094 lbs. I believe Mercury could get 600 hp with just the addition of the positive displacement forced induction on this motor at a weight increase of around 40~50 lbs. Now back to product liability. This motor would be embraced by the 20'~25' tunnel boaters, which as everyone knows can be piloted by grandma vs the skill set required to safely drive an 18' STV with 300 hp. I have in my stable of cars two that can go 200 mph. One being like a STV boat equivalent. The other more like the much heavier 25' tunnel with a 626 hp Seven outboard. I've never had either much above 160 mph but I can assure you the Detroit designed and built one at 4200 lbs is so much safer at those speeds than my home built rod weighing just 1790 lbs. My bet is Mercury will satisfy the hot boat market and at the same time deal a crushing blow to Seven Outboards. Which would you rather have, a 550 lb 600 hp outboard or a 1094 lb 626 hp outboard at twice the price?

[mjw930]

Inline verado 6 platform is easily upgraded from 200 hp to 340 with just an $800 computer upgrade from Whipple. Reflash the computer and 93 octane and wala 340 hp. Best bang for the buck.

As long as you factor in the loss of warranty and the weight penalty but it’s moot, that motor doesn’t exist anymore. The only I6 Verados left are the 350 and the 400R from what I can see on the mercury site.

[Whaaaaat]

Not one bit of this matters if your looking to repower that stv though. It's still to heavy/ top heavy to matter, even if it had a million horse power.

[engineermike]

Inline verado 6 platform is easily upgraded from 200 hp to 340 with just an $800 computer upgrade from Whipple. Reflash the computer and 93 octane and wala 340 hp. Best bang for the buck.

I believe the 200-275 hp verados were all mechanically identical, with the cal determining the final power output. I know some of the lower hp range experienced real gains with a reflash....not sure about the 275's. This is becoming more and more common because they can get one design engineered, tested, emissions certified, and mass produced for multiple applications much cheaper than several designs. The seadoo spark 60 and 90 hp versions are mechanically the same as well.

We do know the 300r is mechanically different from the other 300 v8's. That tells me they aren't electronically limiting the 300's, unless it's for some other reason like gearcase protection, emissions, or octane. Only time and research will tell if the 250's and 225's are mechanically the same as the regular 300's, which could be remedied with a new cal. Another thought is that the V6's may be mechanically the same.

[engineermike]

Not one bit of this matters if your looking to repower that stv though. It's still to heavy/ top heavy to matter, even if it had a million horse power.

Do stv's not work well with a 300xs? I honestly don't have experience with them.

[madmatic]

When you see the seven marine engine and the verado 400 it blows my mind that Yamaha put out a 5.6l 950lb dry 425.. either way Mercury is going to do great with this platform. Any one know the bore and stroke to see if it is square?