300R vs 300X

[JPEROG]

It will be aftermarket ecus that come into play no different then the automotive world. And yes, they have a much broader torque band then a two stroke. I ran a prop on the 300r that my 300X wouldn't allow to get on plane. There is a big difference. 135-140 mph small tunnels will be out there soon "not that this is a good thing" but it will be available.

It was just documented on video (25 liberator with a "center pod" and 400Rs with 1.75s running 125 with crazy acceleration getting there) now take 400 pounds out of the picture and add a 1.60 back into the picture=crazy speeds and accel. These motors are changing performance boating and will be worked and modified for the next decade to come.

Joe

[PRE-Z06]

so you get you carby OMC 200, take it apart and grind on it and you have 300 with the cost of a gasket set
hows the 4 stroke cost compare with that to add 50% or 100HP?

The 200hp Pro XS V8 only needs the larger throttle body and tune to be turned into the 300hp Pro XS V8. Technically I think that’s only a 70hp gain based on the carb report numbers. I’ve been wanting to know if Simon is actually tuning the engines or just flashing them with the higher hp factory tunes. A 200 sho will pick up ~120hp from just a software change from Wayne.

[New Canoe]

21’ Cougar MTR ...300X ...372 HP / 365 torque

21’ Liberator w/ 300R

Cougar best : 122 mph w/ 32 Hoss 3 blade

Liberator best: 107 mph w/ merc 34 Cleaver.

From a dig, Cougar is gone ...
Rolling start, a fun race...
Top end : All Cougar.

[Flightplan]

21’ Cougar MTR ...300X ...372 HP / 365 torque

21’ Liberator w/ 300R

Cougar best : 122 mph w/ 32 Hoss 3 blade

Liberator best: 107 mph w/ merc 34 Cleaver.

From a dig, Cougar is gone ...
Rolling start, a fun race...
Top end : All Cougar.

How are you getting 372 HP out of the X?

[AZMIDLYF]

How are you getting 372 HP out of the X?

The three letters before the 300X in the title.

[PRE-Z06]

How are you getting 372 HP out of the X?

https://www.screamandfly.com/showthr...08779-DBR-300x

[New Canoe]

The three letters before the 300X in the title.

Thank you ...!

I think Randy Corson got 112 mph with the 21’ Liberator 300R.

[Chaz]

Ramp rates vary so much off the seat that .050” is a better comparison than advertised numbers as heads aren’t even allowing much airflow at such low lift. Marine lobes are soft/slow for extended higher rpm use obviously so advertised (.006”) duration is higher than normal cams. A 2019 production engine has to succumb to emissions which makes my guess that intake duration is low and lsa is wide to make it as efficient as possible by exhausting as little unburnt fuel from no overlap. For reference the last NA 4.6L DOHC Ford from 15 years ago that had to comply with the EPA (so similar size, power and rpm as mentioned early)...
Intake: 184 deg @ .050/.394 lift
Exhaust: 196 deg @ .050/.397 lift
114 lobe center

My point was that the valves are off the seat. If it didn't matter, then I wasted a lot of my life on an old Superflow SF-110, Rottler, Sunnen and Serdi, valve face, seat and guide machines. And yes I'm old enough to where there was only Souex stones to use.
Today they punch the profile in a Newen seat profiler that will cut as many angles as you want and sweep the chamber all in one shot.
Anyway, you hear one rolling by you real docile , except for the "birds chirping" in the collector. You'll know he's "sweated" the numbers no one worries about ..

If we assume we can get 1hp for every degree of intake duration added, then there will be some nice gains to be had with hanging the valves open longer to ingest more air assuming the intake and exhaust can keep up. Hopefully this becomes the LS of outboards one day and maybe the Merc will make be more like this engine...

https://www.enginelabs.com/news/volv...percar-opener/
The Z06 came out in 1963 as I’m sure you know, I chose the screename because I had ‘99 FRC that everyone thought was a Z06 because the body looked the same. My late uncle had a 327 4-speed Camaro in the ‘70s and taught me a few things when I had the Vega, he for sure knew who the Grump was. Here’s a cam from a little 12:1 358ci engine when I worked at Team Texas that had over 300* advertised duration...

Attachment 440818

LH-(YF3E 6A273 BB)
Exhaust: 196 deg @ .050/.397 lift
114 lobe center

GM has used and reused badging so much, I just chose the latest .. hard to keep up but a C-5 with a "big hip kit" Is that what your saying .. ?

Bruce Crower actually ground a cam with some lift .. ? I always liked his rods, but his cam's were typical west coast long D and short L . Guys like Jessel brothers in New Jersey bushed the lifter bores and ran large diam lifters to have wheels that would get over monster lobes.

Well I put "mufflers on it .. LOL and your cam spec's" ... Tied it in a knot

Will it be the LS of outboards .. Yes and No !

Guys go to the junkyard, buy a $500 LS put it in a work truck .. it runs for another 100,000 miles.
Guys like the "Sloppy mechanics" buy the same $500 dollar motor, move the oil pick-up, put a set of valve springs on it, a 76 mm e-bay turbo, put it in a four door fairmont, run it on corn, and go 9.70's @ 135 .

I see the front page, merc is spending money on production of these motors.
But as it stands, as of now (for the most part) you pay your money and wait.
Mercury Racing can't sell warrantless motors in large volumes to the general public so I can't see the general public buying these motors brand new and doing anything to them that would void their warranty. So it will be a lonnngggggg time untill you see blowers, turbos and nitrous kits being sold in any volume for these motors.
And when you hurt one .. as it's been said ... MERCOSIL

If anything, the 3.0L is the LS , like em or not, every marina has a few broken ones here or there. I bought three of them ( powerheads) this year without really looking. One I traded some work for the other two I didn't pay over $ 250 dollars each for.
It's fairly cheap for me to put a new sleeve in a bad hole and a piston from another one, bore that back to standard and hone the other five and send it again . Or shoot them all .015 and put a set of soldiers in it .

A young man came up and bought a 4 shutter intake from me a couple weeks ago to put on his "EARLY MODEL 225 HP" He had a tuner, flowed the injectors, put reeds in it. Thats it !
Put it on a Mirage 4 seat taxi cab .. first time in the boat ever went 103 mph.
Brent put one of his Bravo wheels on , lifted the motor to XXXX above the pad .. and went 111 mph .
Not bad for 115 PSI notch sleeve 225 motor ... Now what to do with the other
$ 26,000.00 thousand ******* dollars he saved ...

[PRE-Z06]

My point was that the valves are off the seat. If it didn't matter, then I wasted a lot of my life on an old Superflow SF-110, Rottler, Sunnen and Serdi, valve face, seat and guide machines. And yes I'm old enough to where there was only Souex stones to use.
Today they punch the profile in a Newen seat profiler that will cut as many angles as you want and sweep the chamber all in one shot.
Anyway, you hear one rolling by you real docile , except for the "birds chirping" in the collector. You'll know he's "sweated" the numbers no one worries about ..



GM has used and reused badging so much, I just chose the latest .. hard to keep up but a C-5 with a "big hip kit" Is that what your saying .. ?

Bruce Crower actually ground a cam with some lift .. ? I always liked his rods, but his cam's were typical west coast long D and short L . Guys like Jessel brothers in New Jersey bushed the lifter bores and ran large diam lifters to have wheels that would get over monster lobes.

Well I put "mufflers on it .. LOL and your cam spec's" ... Tied it in a knot

Will it be the LS of outboards .. Yes and No !

Guys go to the junkyard, buy a $500 LS put it in a work truck .. it runs for another 100,000 miles.
Guys like the "Sloppy mechanics" buy the same $500 dollar motor, move the oil pick-up, put a set of valve springs on it, a 76 mm e-bay turbo, put it in a four door fairmont, run it on corn, and go 9.70's @ 135 .

I see the front page, merc is spending money on production of these motors.
But as it stands, as of now (for the most part) you pay your money and wait.
Mercury Racing can't sell warrantless motors in large volumes to the general public so I can't see the general public buying these motors brand new and doing anything to them that would void their warranty. So it will be a lonnngggggg time untill you see blowers, turbos and nitrous kits being sold in any volume for these motors.
And when you hurt one .. as it's been said ... MERCOSIL

If anything, the 3.0L is the LS , like em or not, every marina has a few broken ones here or there. I bought three of them ( powerheads) this year without really looking. One I traded some work for the other two I didn't pay over $ 250 dollars each for.
It's fairly cheap for me to put a new sleeve in a bad hole and a piston from another one, bore that back to standard and hone the other five and send it again . Or shoot them all .015 and put a set of soldiers in it .

A young man came up and bought a 4 shutter intake from me a couple weeks ago to put on his "EARLY MODEL 225 HP" He had a tuner, flowed the injectors, put reeds in it. Thats it !
Put it on a Mirage 4 seat taxi cab .. first time in the boat ever went 103 mph.
Brent put one of his Bravo wheels on , lifted the motor to XXXX above the pad .. and went 111 mph .
Not bad for 115 PSI notch sleeve 225 motor ... Now what to do with the other
$ 26,000.00 thousand ******* dollars he saved ...

I like to hear the birds chirp lol

Not to get off topic, but for your reading pleasure next time your dropping the kids off at the pool...
http://www.superchevy.com/features/1...orvette-models
I sold that car to a guy who crewed on a top alcohol funny car and ran this super street Camaro back in the day. Bought another look alike Z06 aka Grandsport as I kind of like being the underdog and keeping it stock as I don’t have deep pockets, but was within .3 last weekend of last year’s 3rd place national champion in his Z06 on a 37 second course. Tuner’s drag week fox body was a simple single turbo junkyard LS that runs 7s on pump+meth.

I hear ya the 4-strokes aren’t as cheap and it’ll probably be awhile before someone tears into one, but figure all it’d take for a more common 200hp Pro XS V8 to make more power than DBR 300X or similar to 400R (though it’s even heavier) which is much less than 300R to start with is the shorter runners, bigger throttle body and some aftermarket cams. Mill the heads, swap the stiffer mounts on and a sporty for it to fly. The only downside I see besides cost is the weight?

What flow numbers are you using for the heads?

[powerabout]

I like to hear the birds chirp lol

Not to get off topic, but for your reading pleasure next time your dropping the kids off at the pool...
http://www.superchevy.com/features/1...orvette-models
I sold that car to a guy who crewed on a top alcohol funny car and ran this super street Camaro back in the day. Bought another look alike Z06 aka Grandsport as I kind of like being the underdog and keeping it stock as I don’t have deep pockets, but was within .3 last weekend of last year’s 3rd place national champion on a 37 second course. Tuner’s drag week fox body was a simple single turbo junkyard LS that runs 7s on pump+meth. I hear ya the 4-strokes aren’t as cheap and it’ll probably be awhile before someone tears into one, but figure all it’d take for a more common 200hp Pro XS V8 to make similar power to DBR 300X which is much less than 300R to start with is the shorter runners, bigger throttle body and some aftermarket cams. Mill the heads, swap the stiffer mounts on and a sporty for it to fly. The only downside I see besides cost is the weight?

Here is what you are after but the cheaper version

[river rocket]

21’ Cougar MTR ...300X ...372 HP / 365 torque

21’ Liberator w/ 300R

Cougar best : 122 mph w/ 32 Hoss 3 blade

Liberator best: 107 mph w/ merc 34 Cleaver.

From a dig, Cougar is gone ...
Rolling start, a fun race...
Top end : All Cougar.

I have data logged the heck out of the 300R and 300XS on the same boat with the exact same setup running the exact same props. I have also tested the new 5 blades on a similar boat and found them to be on par with the ones I'm running in terms of acceleration. Top end they pull away a little, but that is 95 plus.

I agree, the 300R 1.75 struggles to keep up with a 300XS DBR 1.62 with light flywheel so I could see it struggling to keep up with an X. I also did testing with the same 300XS on my boat with 1.75's and it beat the 300R as well.

Out of the hole, the 300XS DBR takes the 300R. If you ignore the hole shot (I need to change my setup to account for the heavier motor) and look at it from 15 to top speed it gets closer, but the 300XS DBR still takes it. The 300XS DBR feels very much like my X in performance.

I love my R and would not go back, but the 300XS DBR was a hell of a motor. I could totally see an X giving the R an absolute run for its money. Especially if its got a little bit of work done on it.

The stock 300XS loses hands down to the 300R on my boat. 5-85, 5-90, 5-95 times and 1000', 1500', 2000', 3000', 4000', 5000' time testing shows it getting smoked. That's with and without prop pitch correction.

Fastbass Marine TV will have all the results up when I get a chance to put a video together and quit burning gas in the R. It puts a smile on my face every time I turn the key. They sound incredible. Check here for other tests https://www.youtube.com/channel/UC-g..._as=subscriber

[Chaz]

How long does it take to get to 120 ?

Axein .. for a friend ..

[Chaz]

Same air flow numbers that the program picked out back on post # 76 or 79 . ( mildly ported head )

So I wasn't that far off calling you .. ZR-1 Tell me true .. did ya cut the roof off when ya put a full SCCA cage in the car ...

I bought a 82 from a bodyshop as the rollback guy was loading it up to take to the crushers. My wife shook her head when I told her that $1500 beater from "crackistan" was our new date night car. My 14 year old kid and I built a hyd-roller, 10:1 406, 10" converter, 700R4 , 3.73:1 , drag radial , hooptie , that I threw him the keys to when he turned 16. He's been driving Jr. dragsters since 11 , and my motorhome and 28' box @ 15 so if anyone was going to jail it prob would have been me ..

BTW .. how come your 69 RS/SS didn't have Z-28 badges on it .. ???

OK Power .. actually, this post was for you ..

Monty built this guy one of his well proven many times over 380 HP V-8's ..

It's getting a 16" can. Single ram trim . 1.62 Sportmaster ..

Old belt sander stand drilled and bushings made for 2.5, 3.0, OMC 6 + 8



All his tiller, bushings, pin, yoke parts are all machined up + in the box. My 3.0 base plate misses one hole by .080" LOL copycats ...

[PRE-Z06]

Same air flow numbers that the program picked out back on post # 76 or 79 . ( mildly ported head )

So I wasn't that far off calling you .. ZR-1 Tell me true .. did ya cut the roof off when ya put a full SCCA cage in the car ...

I bought a 82 from a bodyshop as the rollback guy was loading it up to take to the crushers. My wife shook her head when I told her that $1500 beater from "crackistan" was our new date night car. My 14 year old kid and I built a hyd-roller, 10:1 406, 10" converter, 700R4 , 3.73:1 , drag radial , hooptie , that I threw him the keys to when he turned 16. He's been driving Jr. dragsters since 11 , and my motorhome and 28' box @ 15 so if anyone was going to jail it prob would have been me ..

BTW .. how come your 69 RS/SS didn't have Z-28 badges on it .. ???

OK Power .. actually, this post was for you ..

Monty built this guy one of his well proven many times over 380 HP V-8's ..

It's getting a 16" can. Single ram trim . 1.62 Sportmaster ..

Old belt sander stand drilled and bushings made for 2.5, 3.0, OMC 6 + 8



All his tiller, bushings, pin, yoke parts are all machined up + in the box. My 3.0 base plate misses one hole by .080" LOL copycats ...

No cage as just instructing, running time trials and solo events with SCCA as don’t have the budget for wheel to wheel. Took the GS to the drag strip just for fun when I first got it and ran the fastest pass that’s been done on the runflats in a stock one, then slapped on the drag radials and went faster than any stock manual C5Z06, C6 or C7 non Z06/ZR1 on different rear tires. I’ve always been under the impression straight line is for fast cars and curves are for fast drivers though.

Back to guessing the 300R engine specs, why did you choose data @50” of water? Thought the performance industry standard was 28”? Try using the below numbers @28” if you don’t mind which are roughly what a 4V mod motor head flows and see if that doesn’t bring the hp up as I think the numbers you chose are a little low and why down ~50hp best I can tell from your picture.
I/E: 1.45/1.18 valves, 220/150cfm@.400”, 210/145 @.350, 195/140@.300, 175/135@.250, 150/125@.200, 120/105@.150, 90/80@.100, 40/35@.050

[davemvegas]

I agree, the 300R 1.75 struggles to keep up with a 300XS DBR 1.62 with light flywheel so I could see it struggling to keep up with an X. I also did testing with the same 300XS on my boat with 1.75's and it beat the 300R as well.

When you say 300XS DBR...Are running a built DBR powerhead or a stock powerhead with the Level 1.3 kit? Reason i am asking is because i bought the DBR kit for my pair of motors on 22 FT Eliminator Daytona. I neither felt any noticeable power or seen any on my GPS. The kits did solve 2 issues i was having so i did get something positive for the cost. My boat would go into Guardian mode occasionally on long WOT looking for top speed. At 105 to 109 mph i would not hear the warning beep. But the pucker in my ass would work well when either motor would drop to 2000 RPM Guardian mode after bumping the 6400 Rev Limiter a few beeps. Yes it was a nice bow stuff and turn the few times it happened. The DBR 7000 RPM raised limiters fixed the issue. Other issue was a give and take trade off. Over 90 water would suck up the rear of motors and wet powerheads. The DBR kits have the air intake plate that you mount on front of cowl and allows you to seal the rear air intakes. The downside is from just off idle to about 2500 RPM the compressor noise and reeds slapping is a noisey combination. Never topped my best of 109 before kits, Never really felt better taking off. Did seem to have a little more midrange pull from 50 to 100 but i really had no data to compare.