Modifing the MCX

[Andyg]

On Saturday I installed my new Crane 1.6 ratio aluminum roller rockers in my 2003 MCX engine. I took some pictures throughout the process. It took us a total of about 4 hours from start to finish. I will be installing ETX exhaust manifolds later this week. They are off getting polished and I won't have them back until the end of the week. I lake tested the modifications today to see if I had any improvement. I was able to get another 1.5-2 MPH on the top end to 44 MPH. The 0-36 time is just over 7 seconds now. Unfortunately I didn't get a time before the modification. The othere thing I noted was that my wide open throttle RPMS went from 5000 to 5200 rpms. I should be able to go up in pitch on the prop now and get a few more MPHs.

The first picture is of the engine torn down with only one head left on.

[Andyg]

This picture shows the original pushrod holes in the heads. These needed to get modified to allow for the extra travel of the pushrods. I bought a special tool that allowed me to drill the hole larger.

[Andyg]

Here is a picture of the pushrod hole in the head after it was elongated.

[Andyg]

Here is a picture of a head with the original rockers removed.

[east tx skier]

Wow. That's a heck of a project. I can't remember what the 0--36 time is from the WSM test. I've got the '03 Review at my office. I'll check it tomorrow.

[Andyg]

Here is a picture of the original rocker arm. The original rocker arms were 1.5 ratio arms and were stamped steel. And pivot on the stud without bearings. The new rockers are machine out of aluminum and the pivot is a bearing. The tip also has a roller to allow the rocker arm to roll as it travels across the tip of the valve. The original arms just slide on an oil film on the end of the valve.

[Andyg]

Here is a picture of a head with the new roller rockers installed.

[SKI*MC]

you should run straight pipes all the way beck to get that real thoaty V-8 sound out of it!

[Andyg]

Here is a picture of the intake manifold with the red Plenum removed. You are looking down into the intake manifold from the top.

[Andyg]

Now I can't wait to get those ETX manifolds installed and change the prop out.

[ski_king]

Wow. That's a heck of a project. I can't remember what the 0--36 time is from the WSM test. I've got the '03 Review at my office. I'll check it tomorrow.
The 04 197 with the MCX is listed as 6.2 sec to 36 MPH in 04 WaterSki Buyers Guide.

[Andyg]

The 04 197 with the MCX is listed as 6.2 sec to 36 MPH in 04 WaterSki Buyers Guide.


I don't know how they did the timing on that. I was using a stop watch and would start it as soon as I hit the throttle.

[Hoosier Bob]

Great pics! Looks like a lot of fun! WaterSki Mag supposedly times the boat 0-36 while pulling some kind of a drone that simulates a 185 lbs skier. You should be under that. Anyway have fun and keep posting! :D I don't know how they did the timing on that. I was using a stop watch and would start it as soon as I hit the throttle.

[JimN]

Andy- do you know where Harley sends technicians for EFI training? You need to talk to the people in Indiana about the recal.

[Andyg]

At our Juneau Ave facility we have HD University where all the tech training is done. I assume, but don't know for sure that they have a class or a portion of a class specifically around the EFI system.

I saw the website for the place in Indiana on here a couple of months back.

[Andyg]

Jimn,
I just found on our internal website that we have an advanced EFI class at HD-U. You have to be a dealer tech though to take any of those classes.

It would be nice if Indmar had a program that you could modify the calibration. Harley has a software called the race tuner that allows you to adjust fuel and timing curves to calibrate the EFI system for any engine modifcations that are made. It requires a dyno to tune it properly, but it at least allows you to change it.

Do you know if Indmar ever plans on coming out with a closed loop EFI system? I would think you could put an 02 sensor in the exhaust manifold prior to where the water enters the exhaust.

[JimN]

When I was in Indiana for training in 2000, there was a motor on the dyno at Technical Services with an insert containing an 02 sensor. The problem as I have heard is that water can and does get back into the riser far enough to kill the 02 sensor. This sensor has been discussed in other threads, but I guess only Indmar can tell if it will go in soon.

[Jerseydave]

I guess I'm lucky......my 230VRS with the MCX runs 48-49 top end at 4,600 RPM's. Don't know 0-36 time but it's more than enough for me!

Is your MCX in a 197?

[Andyg]

I guess I'm lucky......my 230VRS with the MCX runs 48-49 top end at 4,600 RPM's. Don't know 0-36 time but it's more than enough for me!

Is your MCX in a 197?

I have a 2003 197 with 1:1 tranny and the MCX. Your hull is significantly different and is probably a big reason why you get such a higher top end. I do know that my combo is the slowest that I have heard of in a 197. One other thing to note is that you are probably running to much pitch on your prop. I have heard that it isn't good to be running at 4600 RPMs at WOT. It should be 4800-5200. I don't know how significant 200 RPMs is, but you may want to think about trying a new prop.

[Leroy]

Andy;


Really neat work and great to see these pictures! Your acceleration sounds great already

[bigmac]

One other thing to note is that you are probably running to much pitch on your prop. I have heard that it isn't good to be running at 4600 RPMs at WOT. It should be 4800-5200. I don't know how significant 200 RPMs is, but you may want to think about trying a new prop.

Very cool project, Andy.

I agree about NJ's prop, his engine has to be lugging. I'd rather be hitting the rev limiter...running WOT all day at 5200 RPM is probably easier on an engine than WOT at 4600. My own 230VRS/MCX does exactly 46 at 5100 RPM with the stock (on '04's) 14x18 / 0.1 propeller (OJ). It pulls hard out of the hole and I don't doubt the 4.4/5.4 seconds to 30/36. Overall though, I don't like my propeller. Even though it looks just fine/undamaged and performs OK, it cavitates on acceleration, is noisey, and vibrates. I'm taking it in to a prop shop today for a checkup/rebuild, and I'm ordering an Acme 847 13.5 x 17.5 in the spring.

In 2005, the MCX MariStars changed to a 13.7x17 OJ for the stock prop.

[bigmac]

It would be nice if Indmar had a program that you could modify the calibration. Harley has a software called the race tuner that allows you to adjust fuel and timing curves to calibrate the EFI system for any engine modifcations that are made. It requires a dyno to tune it properly, but it at least allows you to change it.


Heh...every other line in the MasterCraft owner's manual is a warning about this, that, or the other thing voiding the warranty. They even warn that re-propping the boat might void your warranty - I doubt Indmar OR MasterCraft is going to want all us MasterCraft owners tinkering with our AF curves. Not that it matters what they think...I don't think HyperTech ever asked GM if it was OK for them to sell a device to re-flash the GM ECM.

Even so, with all the marine engines out there using GM's MEFI (1-4), one would think it might be feasible to sell a solution used by the OTHER famous maker of ancient, open loop EFI systems, Harley Davidson. I could envision a PowerCommander (http://www.powercommander.com/) -type inline module programmable from your laptop. Downloadable maps customized for boarding or skiing, or barefooting...

[Andyg]

Heh...every other line in the MasterCraft owner's manual is a warning about this, that, or the other thing voiding the warranty. They even warn that re-propping the boat might void your warranty - I doubt Indmar OR MasterCraft is going to want all us MasterCraft owners tinkering with our AF curves. Not that it matters what they think...I don't think HyperTech ever asked GM if it was OK for them to sell a device to re-flash the GM ECM.

Even so, with all the marine engines out there using GM's MEFI (1-4), one would think it might be feasible to sell a solution used by the OTHER famous maker of ancient, open loop EFI systems, Harley Davidson. I could envision a PowerCommander (http://www.powercommander.com/) -type inline module programmable from your laptop. Downloadable maps customized for boarding or skiing, or barefooting...

It looks like there is a solution. However I am sure it isn't cheap. Technical Services (http://www.precisionautomotive.net/index.php) I believe did the calibration work for Indmar. They sell an aftermarket ECM that can be programmed with their software. The Indmar ECM is password protected so it cannot be modified, at least by the public. The problem buying a new ECM is you would probably have to have them tune your engine on their dyno.

[east tx skier]

The 04 197 with the MCX is listed as 6.2 sec to 36 MPH in 04 WaterSki Buyers Guide.

Okay, for 2003, the 197 Sammy Duval with an MCX and a Powerslot ran a 5.0 second 0--36. I don't find any boats tested with a 1:1.

Ski King, was the 04 test boat a 1:1?

[Andyg]

That is amazing that the powerslot drops over 2 seconds off the hole shot. Good luck to anyone that can hold on to a full throttle hole shot.

[MYMC]

That is amazing that the powerslot drops over 2 seconds off the hole shot
I keep telling you guys to buy the option... :rolleyes:

[east tx skier]

MyMC, what's the time with the 1.26:1 versus the 1.5:1? All the test boats in the 05 WSM review were 1:1s.

[MYMC]

Not sure...I have not seen test numbers, but seat of the pants tells me they are close to the 1.52 numbers. I'll see what I can find out on this.

[bigmac]

It looks like there is a solution. However I am sure it isn't cheap. Technical Services (http://www.precisionautomotive.net/index.php) I believe did the calibration work for Indmar. They sell an aftermarket ECM that can be programmed with their software. The Indmar ECM is password protected so it cannot be modified, at least by the public. The problem buying a new ECM is you would probably have to have them tune your engine on their dyno.

You'd think they would have a bunch of stock maps and would supply you with one when you buy their system.

Harleys are frequently modified. Even something as simple as a high flow air cleaner and lower-resistance exhaust require re-mapping an open loop system...whereas most of us don't really do that much to the power train of our later-model boats. And as to our EFI vehicles - those are usually NOT very highly tuned in favor of reliability. It appears that the stock MCX is already pretty highly tuned -- can't, or don't need to do the really simple stuff like air cleaner or pipes. And while I think your MCX project is VERY cool, that's more than what most of us want to take on, at least while our boats are still in warranty.

[JimN]

BigMac- the recal programs are generally loaded into the ECMs with a laptop, if it's in the boat. If it's out of the boat, a special harness is needed. It takes a few minutes and plugs into the diagnostic connector.

[bigmac]

BigMac- the recal programs are generally loaded into the ECMs with a laptop, if it's in the boat. If it's out of the boat, a special harness is needed. It takes a few minutes and plugs into the diagnostic connector.

Yeh. On my Harley, I had to choose between a PowerCommander and the Screamin' Eagle Race tuner. The latter is a program and cable that allows you to plug your laptop into the ECM and reflash it, whereas the PowerCommander is an added-on inline module that your laptop plugs into.

I went with the PowerCommander. DynoJet has a whole load of custom maps for a variety of engine accessories. You pick the map that matches your engine/pipe/aircleaner configuration, download the map from their website and upload it to the PowerCommander. You can tweak settings at various throttle positions if you want, but my solution was to put the bike on a dyno. The DynoJet dyno operator can generate an extremely accurate custom map.

You know it's the 21st century when you tune your Harley with a laptop attached. Actually, the software can be run on a PDA, so your Treo could do the same job.

[Andyg]

If anyone is serious about doing this modification on an 03 MCX feel free to PM and I will walk you through what is involved. I don't want to post a how to on this as I fear that someone may take this project on without realizing the complexity of such a change and cause permanent damage to a very expensive engine.


Thanks

Andyg

[Andyg]

I am done with the modifications to the MTX. I finished installing the polished ETX manifolds after work tonight. They look awesome. I attached a few pictures for your viewing pleasure.

I lake tested the boat tonight with the new 1.6 roller rockers, ETX manifolds and the new computer program. I am now up to 45 MPH and 5300 RPMs. I should be able to reprop it and get another 2 MPH out of it, which will bring up to right where I wanted to be. Now I can't wait till spring to use it. Too bad I have six months before spring is here.

[Andyg]

Here is one of the other side.

[Andyg]

And here is a picture of what the stock original manifolds look like.

[André]

Nice work Andy !
Is chrome standard for aftermarkets ETX ?

[Andyg]

Nice work Andy !
Is chrome standard for aftermarkets ETX ?

I had them polished locally, there is no chrome on them actually. They come black just like the stock ones when you order them.

[André]

Just polished? They did a great job!
Like you said,not a project for everyone...

[Leroy]

Look very nice! These are made for boats and have water flowing through them also?



Here is one of the other side.

[bigmac]

It's a beautiful project, Andy.

I have to wonder though, why didn't you go all the way and add a billet roller cam and hydraulic roller lifters while you were there? Seems like that would have added another 25 hp or so, even if you used a cam with the same lift.

Just curious...I was talking with my son about your project and those mods to a GM short block were part of project he did while he was at Wyotech (leaves for MMI in Phoenix in Feb - doing the HD course there).

[Andyg]

It's a beautiful project, Andy.

I have to wonder though, why didn't you go all the way and add a billet roller cam and hydraulic roller lifters while you were there? Seems like that would have added another 25 hp or so, even if you used a cam with the same lift.

Just curious...I was talking with my son about your project and those mods to a GM short block were part of project he did while he was at Wyotech (leaves for MMI in Phoenix in Feb - doing the HD course there).


I didn't really think about it actually. There were a couple of things that I thought about doing, but chickened out in the end. My friend that helped install the roller rockers wanted me to ditch the vortec heads and get a totally new cam. My biggest concern was being able to build an engine that I could use an existing indmar program for the calibration. So in the end I decided the roller rockers and ETX exhaust manifolds would give enough HP and still be able to function on an Indmar program.

[bigmac]

I didn't really think about it actually. There were a couple of things that I thought about doing, but chickened out in the end. My friend that help install the roller rockers wanted me to ditch the vortec heads and get a totally new cam. My biggest concern was being able to build an engine that I could use an existing indmar program for the calibration. So in the end I decided the roller rockers and ETX exhaust manifolds would give enough HP and still be able to function on an Indmar program. As I stated earlier that almost wasn't the case. The program that I was hoping to use wouldn't work so I was lucky enough to get one that I think will. I am now running an ECM with a program from a 2003 5.7L Hammerhead.

My kid tells me that it's hard to improve on the Vortec heads on that block. I would think that a roller cam/lifters with the same lift wouldn't really change your timing or fuel flow, but the reduction in friction is huge.

[Andyg]

My kid tells me that it's hard to improve on the Vortec heads on that block. I would think that a roller cam/lifters with the same lift wouldn't really change your timing or fuel flow, but the reduction in friction is huge.

Ya, I have heard the same thing about the vortec heads. There are some better heads still out there, but I didn't think it was worth the big bucks to add them. Besides if my wife new what I spent on the modifications she would probably shoot me.

[SKI*MC]

looks very cool, do the new maifolds do anything differnt than the other ones, they look like the new Cadilick Converters that Indmar was teasting on there engines.

[Ric]

Here is one of the other side.
That is even cooler than I thought it would look!

[erkoehler]

:D Lets summerize it and do some footin :headbang:

[Andyg]

:D Lets summerize it and do some footin :headbang:

It isn't winterized yet. I had it out last night and didn't winterize it after I was done. Unfortunately I don't have any time this weekend to go. I am off to Madison this morning to go to the Badger game. Sunday I am hauling the boat up to the cabin to put it away for the year. That is depending on how hungover I am tomorrow.

[erkoehler]

:noface: It isn't winterized yet. I had it out last night and didn't winterize it after I was done. Unfortunately I don't have any time this weekend to go. I am off to Madison this morning to go to the Badger game. Sunday I am hauling the boat up to the cabin to put it away for the year. That is depending on how hungover I am tomorrow.

:cry:

[Jim@BAWS]

Andy,
Not being a gear head...it looks awesome. My question is why?
Was there a problem with the motor? 03 would probably still be under warranty if there was an internal problem. The ETX manifolds would
have increased the TORQUE and top end. The addition of a stainless
13 x 14 OJ would have increased your top end. Just those 2 simple additions would have made a difference. Go with straight exhaust

The polished ex manifolds look awesome. reminds me of the 2003 LQ-9
Limited edition motor. I am sure the job you did was perfect and made a difference. Not argueing your efforts...hopefully it was not because of boredom

Thanks

Jim@BAWS

[Andyg]

oops!!!!!!!

[erkoehler]

Sounds like you got a dog of a motor if it is only doing 42. Double barefooting at 38 is NO FUN.

[tommcat]

It's a beautiful project, Andy.

I have to wonder though, why didn't you go all the way and add a billet roller cam and hydraulic roller lifters while you were there? Seems like that would have added another 25 hp or so, even if you used a cam with the same lift.

Just curious...I was talking with my son about your project and those mods to a GM short block were part of project he did while he was at Wyotech (leaves for MMI in Phoenix in Feb - doing the HD course there).
switching to a roller cam of the same lift and duration will not give you a 25 horse gain.

[bigmac]

switching to a roller cam of the same lift and duration will not give you a 25 horse gain.

I've heard other opinions on that, but here's what I know (thought I knew). Hopefully, you'll correct my misimpressions. It's not my area of expertise...I probably misspoke when I implied a HP gain based on reduction of friction alone.

I thought that you couldn't really have a roller cam and hydraulic roller lifters without getting extra duration. My understanding of the Voretc heads anyway is that they have really excellent mid-lift flow numbers, but don't really benefit from increased lift that much. The real benefit of a head like the Vortec is that the flows will increase substantially with increased duration alone, and the best way to accomplish that is hydraulic roller lifters and a roller cam.

:confused:

[tommcat]

I've heard other opinions on that, but here's what I know (thought I knew). Hopefully, you'll correct my misimpressions. It's not my area of expertise...I probably misspoke when I implied a HP gain based on reduction of friction alone.

I thought that you couldn't really have a roller cam and hydraulic roller lifters without getting extra duration. My understanding of the Voretc heads anyway is that they have really excellent mid-lift flow numbers, but don't really benefit from increased lift that much. The real benefit of a head like the Vortec is that the flows will increase substantially with increased duration alone, and the best way to accomplish that is hydraulic roller lifters and a roller cam.

:confused:you ARE correct in your assumption that HP will increase from switching to roller, it just will not be anywhere near that much power. and the main benefit to roller cams is being ABLE to run more lift than you could with a conventional cam.
as far as the vortec heads go, they are a great head but then again there are so many excellent heads out there these days that it would be damn near impossible to put on an aftermarket head and not get good gains. i've had great luck with all of them. GT40, vortec, edelbrock(one of my favorites) and many others.
and then you start getting into 23 degree heads and things get really interesting :D

[SKI*MC]

ok i think i have the answere to all of this under-rated hourse power. Add some NOS! or get the "suck my wake" boat from the great out doors.

[Ric]

supposedly those etx manifolds are giving you 5% more hp and saving something like 50% of the weight of the cast iron manifolds you removed.

[Andyg]

supposedly those etx manifolds are giving you 5% more hp and saving something like 50% of the weight of the cast iron manifolds you removed.

I haven't weighed one of the cast iron manifolds and risers yet, but I would guess they are at least 80 lbs each. The aluminum manifolds are 24 lbs each. So a total weight savings of over 100 lbs.

[H20skeefreek]

it'd be nice if those manifolds, or anthing lighter for that matter were available for the 351.

[MYMC]

Just to muddy the water for you...the advantage to a hyd. roller cam (or any roller cam for that matter) is not increased lift or duration but in the agressive ramp profile. The roller allows the lifter to follow a more radical cam profile providing better numbers. With a flat tappet camshaft (hyd or solid) the profile is dicated by the diameter of the lifter (among other things)...if the ramp is too radical it will cause the edge of the lifter to dig into the cam lobe...a roller doesn't have this issue.

Max lift was not the key in this install; however, increased valve action is/was. For each degree of camshaft rotation the valve was being moved farther and faster than the stock ratio rockers. The faster you can get the valve to move the better (within reason).

BTW: the marine 5.7ltr Vortec engine has a hyd. roller cam and lifters stock.
http://www.gm.com/automotive/gmpowertrain/engines/specialized/marine/2004_5700_marine.pdf

[east tx skier]

it'd be nice if those manifolds, or anthing lighter for that matter were available for the 351.

Throw an Edelbrock intake manifold on there. Much, much lighter than the cast iron stocker. Almost threw my "old man" back out taking the OEM manifold to the trash after nobody on here would buy it for shipping costs.

[H20skeefreek]

I will eventually do that, but I'd like to go to aluminum exhuast manifolds at the same time. there are several places that make them for the 350, but not the 351.