Engine Rebuilt Nightmare
 

I was going to get into the entire chain of events from the engine builder that had our engine the first week of Feb that did not get it to me until the week of July 5th! To the two so-called friends in the marine business who I was willing to pay to help me install everything all the way down to having to pull the engine three times!!!! For advice the coupler was bad to it was never aligned from the factory correctly!!! Oh and the most important thing, the radio stopped working and our soft band new cooler has a hole in it!

Well, finally the boat was put together and in the water for the Shootout last weekend. Good news for the most part.

The boat is a Baja by Fountain 26OL with the stringer hull, you remember the one Reggie got 69MPH out of for the Powerboat article. The engine is a 496 that was rebuilt from the crank out with Dart Heads. The best dyno was 560HP/544TQ @ 5400RPM. I was hoping for a little more, 575HP would have been cool but I guess I can strap on my Briggs & Stratton for the extra 15HP.

I also put on an IMCO neutral extension box with IMCO 2" shorty. Measured the distance from the keel to the prop shaft centerline and it is 4 7/8"

The first day on the water with her I was spinning a Bravo1 26P Merc labbed prop. It was only giving me 4900RPM and a top speed of 66MPH. (Before all the up grades and tons of $$$$ I was getting 61MPH) This past weekend I put the old 23P prop back on and was getting 5400RPM and still only 66MPH. So the fun of getting the right prop begins. Any suggestions would be great and I haven't had the chance to call any of the professional prop guys yet. Surely I can get more out of this boat than just 5MPH.

Another issue I am having is the idle. It idles like crAAp and I am thinking it has something to do with the fuel pressure. The original dyno had a fuel pressure of 44.5PSI @ 2800 and 41PSI @ 5400. with an average of 42.5 PSI @ 4100 I was told this will damage the engine. So I installed an adjustable pressure regulator and at the 11th hours I threw my hands up and told the shop that was aligning it to install it and set it at 49PSI. They set it at 52PSI so they told me. What are some of the thoughts about the PSI and where should it be base lined? I know this all depends on the engine and spark plugs. Can someone share or point me in the direction of a good reference for spark plug inspection? So I know what to look for while I fine tune it some more.

Sorry for the long winded post and I hope my ranting makes sense. And if you are reading this and love your boat but you are thinking about doing this one day I would suggest you don't if you do not want to start hating the very sight of it. :party-smiley-004:

Call Reggies new company...they can get it right....RF Powerboats. We have our 42ft Fountain Ex up there now...so far they have got 15MPH more out of it...and more is left. Very good people..they can dial it it. Trust me...over the last 5 years we have tried every avenue from self rigging..to "self professed" riggers. Take it to RF Powerboats over the winter...you wont be sorry.

Thanks for the reply, I will give them a call and see what they have to say.

They are just getting set up and are getting phone installed this week....website to be launched this week too. PM me if you want Lil R's cell number.

you're missing a good 7-8 mph somewhere....time to fire up the briggs...

Rick, I would have thought you would be in the low 70's. Sounds like you are down on power. To get your fuel mix correct you will have to duplicate the fuel pressure when they did the tuning. A wideband O2 is the best way to tune it. Your plugs should be light brown color, black is rich, peppered is real bad :eek:

Definitely should be faster than that, message me your number & I will call you in the morning.

Questions-was your 555 ecu re-programmed or did you switch everything over to mefi-4? If your motor was tuned at 45 psi at part throttle and 42 psi at wot, what were your afr's?? If you now have it set at 52 psi that is a good 10% richer than before, could be at 11.5-1 afr vs 12.5 on dyno at wot, not suggesting that you turn the press down and see what happens but it really sounds like your engine builder needs to ride in your boat with a 02 meter installed in your exhaust to see where you are at. Motors seem to richen up in the boat vs the dyno too, mine always has. I would expect to see you in the low 70's/high 60's depending on load. once you have afrs set right in the boat/fuel pressure right you then need to see where your at with the prop, a 26 might end up being too big, my 272 normally aspirated made 650 gross hp and it can only turn a 26 labbed 5400 at 75 mph or so, a 24 labbed might be in your future. Get your fuel correct and see where you are, Smitty

Artic is right - 52 is way too rich. I have a 496/600 package and it was set at 47 on the dyno. This doesnt mean to set yours at 47 it just means you need an AFR to get it right.

What else changed during the engine swap?

So, it's fuel injected and performance mods have been done. You did not mention it, thus I'm begging to ask........did you have someone program the computer for your motor ?

I have been following his project. A well know builder up north did the build and he had somone else do the programing. This is going to get interesting :party-smiley-004:

Is this a proven or tested setup with that hull?

Good question, Baja's generally go fastest with bow lift and trimmed out, might not be carrying the bow enough. I think with the right prop, probably a 5 blade you can achieve this without going back to your original set-up but it will take some testing, Smitty

Who's dyno was it on?... Are you sure that's an accurate HP number running all accessories with wet exhaust?

Reggie I will send you a PM, thanks!

Thank you for the reply. They reprogrammed the original ecu, we did not switch anything over. On the dyno sheet there are two columns A/F Left and A/F Right could that possible be the Air Fuel reading? There isn't an AFR column, sorry for my ignorance and I have a a lot to learn.

I agree 52 is way too rich and it is not what I asked the shop doing the finally installation to set it at.

When you ask what else changed during the engine swap what exactly are you asking about?

Yes, it is fuel injected and yes the ecu was sent out for reprogramming. I just simply plugged it in.

I just did a repower myself....had a 496 and researched it quite a bit before selling it and going with brand new horses. I've heard good and very bad stories about trying to beef up the 496. It has cast internals and needs to be completely replaced to make any kind of difference with maintaining reliability. I've got the 25 OL(not the 26) and it's 150 lbs less...and my 496 mag(375 HP) pushed it to 63-65mph at 5000 rpm depending on temp. If you are turning a 26p B1 at 4900 rpm, you should be seeing 70 at least. I'm not a fan of the B1 as it creates azz lift instead of bow lift like the baja hulls require. The B1 is made for a heavier boat. My opinion is if you find the HP and start getting 75-80 mph out of this setup...the B1 will create some issues in handling vs going to a 3 blade Mirage. I'm turning a 27 M+ on my 25' but am also putting out 700+ HP.

Artic, i'm curious about your comment on a 5 blade prop? You think the 5 blade will help in bow lift? Wouldn't it be hard to turn that thing to any rpm's with this setup? If you're getting 560 HP....IMO it should be turning a 25 Mirage. BBlades can offer a more professional than mine.

I certainly did not start the thread to looking to start a war. In fact my palms are sweaty right now as I replay to everyone's questions! :lolhit:

Dave, I do not have an answer for you. This was with the prop shaft centered with the keel on the driveway. Kind of ball park. I also have a X-dim of 15.5" that is off the Performance Sheet from Fountain. But then there was the discussion of whether or not the transom angle moved the X-dim when it went back a foot off the transom. So, I am not 100% clear on this either.

This was on the builders dyno and looking at the picture it was hooked up to a wet CMI exhaust system. The same exhaust that is on the boat right now. But with this being said I don't know if it was wet or dry. What I do have is 4 dyno sheets.

2 pulls @ 5200 RPM first 529HP then 532HP
2 pulls @ 5400 RPM first 537HP then 560HP

There is no notation of whether it is was dry or wet.

We built it from the crank out with all new internals and bearings. The crank and intake are still stock.

Stock intake? I would think that would be the first thing to scrap if your goal was 575HP.

It is on the scrap list.

Dave M, let me clarify the X-Dim. It is 15.5" and that is off the Performance Sheet from Fountain Powerboats.

Just order an Air/Fuel Ratio meter.

I will post my readings when I get it and hopefully I can get some good feedback.

Thanks again for all the replies!

Side note, I agree 100% on the props. I have had different styles of bajas and everyone says B1. Some worked ok, but the 3 blade mirage or quicksilver out performs on top end for me every time. Definatly has more bow lift, just not as good out of the hole.

Rick, did you have CMI weld bungs in the exhaust for the O2?

No, but they do have the bungs for the EGTs and I was thinking I could get the reading from there? At least I hope I can!

No, you will need to weld an O2 bung in the collector (if it's a header) or riser (if it's manifolds). The egt bungs is probably only 1/8" or 1/4" NPT where as the O2 sensor is 18mm.
Eddie

X2, I just welded O2 fittings into two of my tailpipes.

One thing to remember is that if you do have the o2 sensor installed, it has to be powered up, or it will dramatically shorten it's life.

The sensors don't react well to the marine environment, so put it in only when you intend to take A/F readings, and take it out and install the plug the rest of the time.

Eddie thank you, but not what I was hoping to find out. At least now I know non the less.

Thanks for the heads up and I wasn't planning on keeping it in place. Now I know for sure. Can you PM me some pictures of your set-up? I would like to get some ideas where to put it.

Thank you guys!!

Sound Right??
 

Some things to consider?

If you go by 425 prop shaft HP of 496 HO @ 61mph, think of the following.

If you had 560 dyno hp, and account for 10% hp loss of 56 HP at the prop due to parasitic drive loss, you would be looking at 504 prop shaft hp.

Now take the 504 and subtract 425 prop shaft HP and you get 79 hp gain over the stock motor.

Now if you rate 15 HP approx for each mph and multiply by the 5 mph gain you get 75hp. Sounds pretty close?

This extra HP you have and the 66mph may be realistic.

Just my thoughts. THX

Merc black motor HP numbers are at the flywheel, not the prop shaft.

Are you sure??
 

I will look more into it but for now.

http://www.sterndrives.com/496maghoengine.html

http://www.perfprotech.com/store/art...fications.aspx

Yes

Bob Llyod of Full Throttle Marine has dyno'd a 496 MAG HO at 387.8 HP at the prop at 5,000 RPM. You can find dyno sheets at his site: www.fullthrottlemarine.com

Wrong, the 496 HO is propshaft HP. At least thats what merc publishes......

Thanks for the input and I understand what you are saying. But wouldn't the extension box and 2" shorty also add to the equation of the top speed as well?

http://www.go-fast.com/boat_speed_predictions.htm

IMO and experience with running a -2" on a straight bottem V, your -2" isn't really going to help until you get into speeds around 70 an above, like mentioned above it could actually be hurting you if your loosing the ability to carry the bow, the added wetted surface could be a henderence, my .02

Interesting data
 

That is an interesting article.

However, 425 - 388 = 37 HP difference.

504 PSHP - 388PSHP = 116HP DIFFERENCE

Based on the revised 116 HP increase from stock.
8 MPH INCREASE ASSUMING 15 HP PER MPH

7 MPH INCREASE ASSUMING 17 HP PER MPH

6 MPH INCREASE ASSUMING 20 HP PER MPH

Knowing that hull design, beam width, and weight has great effect on top speed and in determining HP PER MPH?

IMO whether 79 or 116 extra PSHP , 66 to 68 would be a realistic top speed number for the 26 Outlaw with that addtional HP

Also, were the speeds recorded by GPS, Radar or DreamOmeter?

I think a Outlaw 26 would have trouble breaking 70 with 504 HP?

I see that BobL runs a Land and Sea Dynometer prop dyno. What type of dyno does Mercury run to verify there prop shaft hp ratings?

Thanks

The speeds I am posting are GPS.

I understand that the Nordic is a stepped hull and ours is not. It is also a 28 foot boat but we probably have the same amount of hull in the water. Their average was 63 (just on the concept of the step this number should blow ours away but it doesn't) just about 1.5- 2 MPH faster than ours with a 496HO. But with the Raylar kit (525) it picked up 9MPH and was comparable to the blue 525. And with my 575 kit/upgrade (560HP) I picked up 5MPH so far and I should be content with that because it is an Outlaw. I understand I have to adjust the A/F ratio and fuel pressure I get that. 525 (473) getting 72MPH is realistic and ours getting above 70MPH is not. This is where I am a little confused.

Then I was under the impression the E-box and shorty would also improve speeds and now some are saying they will not.

Something is wrong.

Who and what do I believe at this point?

Rick, I am not trying to stir you up here. But remember when we talked several month ago and I recomended doing one thing at a time, that way you know were your speed came from. Everything I have done I have seen results, raising my x dim up 3" gave me about 3-4MPH, and thats with no xbox. I do think you could go up higher, I would have used the 3" raised box since you needed new exhaust anyway. I did my engine work first then later raised the x, some guys have done the xbox first then the engine later. With what you have done you have no idea what helped you. I do think you are on the right track with getting the O2 checked, just need to get the O2 bungs welded in, not sure why they chose to put EGT bungs in, O2 is way better for tuning. You have to have a perfect tune to get the best speed. Knowing what to shoot for is the hard part. I lost a litte speed this year, I started leaning it out in very small amounts and now I am almost back to normal. I was using 12.5 for my WOT target, I have it at 12.8 now and seems to be doing well for speed. I am thinking about leaning out to 12.9 and seing what that does. I just don't want to go BOOM !!! :lolhit:

What they make stock Period!
 

Just to give everyone here some more credible info:

Raylar has dyno tested on ours and other dynos probably more 496Mag and 496HO engines both stock and with our various upgrades, kits and engine packages than almost anybody on the planet.
A stock full y equipped 496Mag makes about 365-380HP at 4800 rpms at the crankshaft.
A stock fully equipped 496MAG HO makes 421-430 HP at 5000 rpms at the crankshaft.
This is on calibrated, SAE standard testing, with correction factors and specific fuel gravity calculation adjustments and these numbers are pretty much spot on - PERIOD!

Best Regards,
Ray @ Raylar