Flaming 525 EFI's

[Racerguymiami]

Just ordered a 525 engine/drive....then I see this on another site. Pretty darn humorous. I should of hired the 'Mentalist' and taken him up to Mercury to handpick the best on the production line. How do you pick the best out of a row of identical looking engines. I couldn't find any with the serial # ending in Fountain.



"<I have had 3 different engine packages in the same boat with the same drives.

Boat: 2000 38 Fountain Fever running XR's on Imco extension boxes with -2 Imco shorties.

1st set of engines: Merc 525's (a set picked off the production line personally by an accomplished racer and later when I was selling them they were dynoed by Joey Griffen as part of the sale and he said it was one of the best sets of 525's he'd ever seen on his dyno at 570+ hp).

Results: 85MPH is the best I saw running a set of stock 4 bladed Bravos at 5250' ish. on a cool Oct day.

2nd engine package: A set of first Gen Ilmor 625's.

Results: 89 MPH on a moderate July day running a set of labbed 27 P5X's at 5850.

3rd set of Engines. Ilmor Gen 3 710's.

Results have only ran the boat a few times. 94 MPH running stock 27 P5X's around 6200 on a moderate June day. Not sure but I may have been getting in the rev limiter. I have a set of 28 labbed P5X's that should push the boat to around 96 mph.

Merc 525: 85


Ilmor 625: 89


Ilmor 710: 94 (with more in it likely)

I have heard countless people here on OSO recommend the Merc 525's over the 600's because they say the 600's are only a couple to 3-4 MPH faster than the 525's.

I had one of the best sets of 525's that a racer handpicked off the production line and it was at least 9mph slower than the Ilmor 710's that I have only briefly tested with one set of props that are likely too small.>"

 

[imco offshore]

Chris your right ,,you might want to call Cheif engines ,,they recently dynoed a pair of 525,s at 600 hp each,, the normal is 560 --600 ,,to me that is a big difference for engines that are suposto be idenical,,if you read the rules for an org,the rule is 525 merc sealed engines ,,BUT not over 550 hp... so what do you do ,if you buy a new MERC 525 and it is one of those 575-600 ,??

 

[TYPHOON]

Sell it for more than you paid for. :cheers2:

 

[XtremeRacing]

George,

They are way over that now the latest I heard was almost 620 hp. Also all the new 525 are hand built no more production line 525's

 

[Racerguymiami]

I was at Cheif recently wanting Tommy to dyno the engine I bought last year. Dynoed it at Carolina and pulled 590HP. This is as it came sealed from Mercury. I've been told the new motors make that on a bad day. I really can't figure out why Mercury would do this as it pretty much negates the 600 if the word gets out. Although tempted, I won't be putting this one on the dyno.

 

[XtremeRacing]

Most all the part are the same with some minor changes. I was told it has the same Cam, but the cam postion sensor have been moved. Also the boxes have been programed a little different still 5450 RPM just different fuel mixture, timing , and some head flow.

 

[imco offshore]

Randy , do you think the whole world is making this up,,,it is what it is ,,,and 580 - 600 is the new normal ,,,

 

[Dunbar 104]

Can't retune a good running motor and pick up 50+ hp at the same rpm. Sounds more like the heads are a revised castings, or cnc ported plus the other stuff. I know of a couple new 525s that have dynoed over 600hp. I wonder what the updates are going to cost?

 

[MOBILEMERCMAN]

Doesn't Mercury's rebuild include heads. They are up dating and superseding all the time.

Mark, maybe it only costs their rebuild.

 

[TYPHOON]

George, OK they are making more power now than last year and the year before. The only solution I can see is a org buying a land and sea dyno and bringing it to every race. Dyno before you race to adjust your weight HP/weight and dyno out after the race. Sounds simple to me. Is it spot on no but its the same for everyone. News flash guys if we have comitted racers in our class P1 will buy the dyno. So who is in?

1) Typhoon
2) Pirates
3) Octane
4) Time Bandet

We need to know who else. Think in terms of 8 teams. P1 will not buy a 30K pcs of equipment for 4 teams.

 

[Steve Miklos]

I own a land and sea dyno and tried to make it work for APBA. I can assure you there are too may variables and it is not that portable. Brian Hollis can fill you in also.
Steve

 

[Ratickle]

There is one slight issue I believe all of us forget sometimes. I think in around 1985 IO and Outbord engine HP ratings were changed from crankshaft HP ratings to Propshaft HP ratings. Taking the average HP loss of 6% every time any drive changes directions, that would make a 525 propshaft rating 588 at the crank (12%).

So, to me, 600 would not be any big deal for an engine rated at 525 at the prop.....

 

[imco offshore]

does merc rate their engines at the prop shaft ?? i thought all the dyno sheets were ,engine crankshaft ,,from merc for the 525 ,,?no matter how it,s measured 50 -6o hp is 2- 3 mph ,,,so it,s cheeper to buy a new motor for the speed gain,,we all know 2-3 mph cost a bankroll,,
Either way ,,everyone (svl,s) needs to get on the same page to salvage the class,,we were real close last year ,,,IT CAN HAPPEN AGAIN ,, put the knifes down, come back to the table,,and regroup,,,BEFORE it,s too late and too expensive to back-up

 

[Wil Ros]

does merc rate their engines at the prop shaft ?? i thought all the dyno sheets were ,engine crankshaft ,,from merc for the 525 ,,?no matter how it,s measured 50 -6o hp is 2- 3 mph ,,,so it,s cheeper to buy a new motor for the speed gain,,we all know 2-3 mph cost a bankroll,,
Either way ,,everyone (svl,s) needs to get on the same page to salvage the class,,we were real close last year ,,,IT CAN HAPPEN AGAIN ,, put the knifes down, come back to the table,,and regroup,,,BEFORE it,s too late and too expensive to back-up

Very well said !!!!!

Let's get it pointing in the right direction .

Wil

 

[XtremeRacing]

Tom at Cheif has dyno a bunch of 525's and seen some pretty big number you might want to talk to him he might have some opinion on why the HP gain and where its coming from. I think Mark is right heads that merc are using must have some change to them.