Merc 525SC Question

[bigq]

Looking at a boat with a Merc 525SC that has the upgraded Whipple package. How many hours can you get out of these until a refresh and anyone have a cost estimate on a refresh? This is a carb motor btw.
Thanks

[VegasHallett]

I got over 640 hours on my 502 with a whipple. As long as the engine has upgraded head gaskets and the owner has taken care of the motor (oil change, etc), I don't see why you can't get more than I received. My motor finally blew a head gasket since the original owner never upgraded from stock (common problem). We tore apart the motor and all parts, bearings, rods, crank, rings looked great. I decided to go to a 540 and upgrade everything for more HP but I had the options of just replacing the head gaskets if I wanted too.
You can run a leak down test on the motor if needed. Don't bother running a compression test that just tells you that a piston is in the cylinder. A leak down test will give you more info....

[bigq]

I got over 640 hours on my 502 with a whipple. As long as the engine has upgraded head gaskets and the owner has taken care of the motor (oil change, etc), I don't see why you can't get more than I received. My motor finally blew a head gasket since the original owner never upgraded from stock (common problem). We tore apart the motor and all parts, bearings, rods, crank, rings looked great. I decided to go to a 540 and upgrade everything for more HP but I had the options of just replacing the head gaskets if I wanted too.
You can run a leak down test on the motor if needed. Don't bother running a compression test that just tells you that a piston is in the cylinder. A leak down test will give you more info....
Yea the shop said they did a leak down test on it ( was a trade in) and drove it, I dont know the numbers, but he said all was good. Looks like a well takedn care of boat. He said it is about 360 hrs, but gave me the guy left the key on story so it shows more.
I can't find the kit on the Whipple site anymore and I don't remember what it entailed. I think it was the cooler, pulley and ECM recal.

[Glamasu]

Is this a 525efi converted?
Or the 454 witha little blower called the 525sc? Like this one

[DMOORE]

Like Glamasu said, is it a 525 with a whipple, or a 525SC that has had it's B&M blower replaced with a whipple. Two very different packages.
Darrell.

[bigq]

It is the factory merc 525sc blue motor with the Whipple conversion from the b&m.

[Glamasu]

It is the factory merc 525sc blue motor with the Whipple conversion from the b&m.
The one in the pic is a factory 525sc....Don't be mislead its only a 454 with a Baby blower (Weiand 144 ??) Pulls 5lbs of boost at 5k....
I guess to answer you question it all depends on what you want to do...5K Rpm all day.....Something is gonna let go...if you drive it rationaly you will problably get several seasons out of it....Besides running that motor W.O.T all day is gonna be real expensive....If I lean on mine alot I can burn 80 gallons no problem real quick....Like from topock to the channel and back running between 4500 and 5k will take 50+ gallons...
Mike

[DMOORE]

The good news is the 525SC was an all forged motor. Quite capable of running a very long time and making some good power.
Darrell.

[cfm]

Have not seen the whipple package but here are my notes on these engine's. Special note is on total timing. Rev engine until timing stops advancing and then set total.
I have found that total is at approx 4200rpm.
454cid
4 bolt block
forged crank, 7/16" rods, forged pistons
7.5:1 compression
rectangle heads
Holley Dominator 1050 carb - jetted 98 square + 6.5 high flow (not standard one's)power valves front and rear.
177 supercharger
AC Delco MR41T spark plugs - gap .035"
35° Total timing - typically reached at 4200rpm
Premium fuel required. Merc suggests min 92 octane
And following hyd flat tappet cam:
Merc 400 / 420 / 425 / 525SC
Crane Part#132561 Grind # H-228/312-2S-14 T1.2
Duration at .004" : 298°, 296°
Duration at .050" : 228°, 236°
Lift with 1.7 rocker: .530", .551"
LSA 114°LSA
ICL 109° ATDC , ECL 119° BTDC

[bigq]

Have not seen the whipple package but here are my notes on these engine's. Special note is on total timing. Rev engine until timing stops advancing and then set total.
I have found that total is at approx 4200rpm.
454cid
4 bolt block
forged crank, 7/16" rods, forged pistons
7.5:1 compression
rectangle heads
Holley Dominator 1050 carb - jetted 98 square + 6.5 high flow (not standard one's)power valves front and rear.
177 supercharger
AC Delco MR41T spark plugs - gap .035"
35° Total timing - typically reached at 4200rpm
Premium fuel required. Merc suggests min 92 octane
And following hyd flat tappet cam:
Merc 400 / 420 / 425 / 525SC
Crane Part#132561 Grind # H-228/312-2S-14 T1.2
Duration at .004" : 298°, 296°
Duration at .050" : 228°, 236°
Lift with 1.7 rocker: .530", .551"
LSA 114°LSA
ICL 109° ATDC , ECL 119° BTDC
Good stuff.
Here is the pic of the motor.
http://www.***boat.com/image_center/...89556497_3.jpg