525 SC vs 502 Mag pros and cons
#1
Got a couple questions for all my more experienced OSO brothers. What are the pros vs cons between these two motors. I know the 525 has more hp but would be less reliable or need maintained more due to the blower. How big of a maintenance difference is there and at what cost?? Thanks guys.
#2
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Joined: Jul 2007
Posts: 180
Likes: 1
From: Shorewood, Ill
Kind of depends if you do some things yourself or not. I have 525sc's and they have been great. Over 502's, Oil changes are more frequent and the blower oil gets changed. But otherwise run it hard just like the 502's. And the torque from a blower motor is awesome, plus the whine at high end.
The 525 sc's are carbed so they are a bit moody when first starting cold, but mine are perfect quick start the rest of the weekend. Compared to 502's probably mpi. And you's spend a bit more in fuel with the 525sc. But it's all reletive, the more HP you got the more fuel you burn period.
You might have to do heads sooner or equal, depends how hard either motor was run.
The 525 sc's are carbed so they are a bit moody when first starting cold, but mine are perfect quick start the rest of the weekend. Compared to 502's probably mpi. And you's spend a bit more in fuel with the 525sc. But it's all reletive, the more HP you got the more fuel you burn period.
You might have to do heads sooner or equal, depends how hard either motor was run.
#3
I know I've heard people say that blower motors or even the Merc Blue motors need partial and full rebuilds faster than the Black motors. Didnt know how big of a difference there really was. I try to do alot of the simple stuff myself but have a local certified mechanic take care of the more complicated issues.
#4
My 525SC was a great engine. I did a top end refresh at 350hrs. About the only extra maintenance I did was to change the oil, blower lube and fuel pump lube every 30hrs or so.
You would have to modify your back seat a little in your 240 to have clearance for the blower.
It was definately a lot thirstier in my 28 Pantera than my hopped up 454mag was in my 24 Outlaw.
You would have to modify your back seat a little in your 240 to have clearance for the blower.
It was definately a lot thirstier in my 28 Pantera than my hopped up 454mag was in my 24 Outlaw.
#5
I had a 525sc that was chilled in my 97 24 outlaw and had twin (non chilled) 525sc's in my 95 Top Gun. Rebuilt two motors over a 10 year period. One when I sucked a valve and the other I can't remember.
Those 502's are pretty freakin bullet proof though. They'll be slower, easier on fuel, and in the long run cheaper to maintain. The 525SC is just a baby wiend blower on a 454. It'll be faster but the problem is they produce a lot of heat and can't (or shouldn't that is) be run for long periods at WOT, whereas the 502 you can pin it to the wall and virtually walk away! Same with the merc 454's (non blown) they're just hearty motors. In others words the speed is relative because while the 525SC will be faster it won't e faster for longer periods. Kinda the tortoise and the haire theory.
And griff is 100% right, if you're putting it in your 240 you'll have to notch the firewall and seat out a bit to get the upper pulley in there. Did this on my outlaw.
Those 502's are pretty freakin bullet proof though. They'll be slower, easier on fuel, and in the long run cheaper to maintain. The 525SC is just a baby wiend blower on a 454. It'll be faster but the problem is they produce a lot of heat and can't (or shouldn't that is) be run for long periods at WOT, whereas the 502 you can pin it to the wall and virtually walk away! Same with the merc 454's (non blown) they're just hearty motors. In others words the speed is relative because while the 525SC will be faster it won't e faster for longer periods. Kinda the tortoise and the haire theory.
And griff is 100% right, if you're putting it in your 240 you'll have to notch the firewall and seat out a bit to get the upper pulley in there. Did this on my outlaw.
#6
Not looking to swap in my 240. Been very happy with the stock 454mag in it. Im going to look at the two 36 outlaws at Grand Sport Center. Driving there on Sunday and hope to look at both boats in detail on Monday before returning to Pittsburgh.





