682gold

iTrader: (3)

I am not sure if this has been covered but the question is to repower or upgrade items on my motors to give me more HP and torque. Where to go / what to do??

Griff

You can get to about 600hp using the 177 blower, but its maxed out there. A set of 250/256 blowers would help a lot and you could still use your current 1050 carbs.

Increasing static comp to about 8.5:1 and upgrading to a roller cam should get you to 575hp or so.

Young Performance

How much power/speed increase are you looking for. That will determine if you should start with what you have or sell them as is and start over. Those engines still bring pretty good money if they are in good shape. How much time is on them? Has anything been done to them so far?
Eddie

hullofjustis

iTrader: (1)

you can use an inner cooler and increase boost. however if you are looking for more speed? like i have said in many threads raising the x dimension works wonders for speed increase depending on your hull /boat. measure your propshaft at neutral trim and see how far below the bottom of the hull it is. if your x dimension is burried towards the bottom of your boat and say your propshaft is 7 inches below the bottom of the hull on a single engine application you could put a -2 or -3 imco lower drive and raise the x dimension 2-3 inches on your boat and pick up as much as 5mph just. by raising the x dimension. you can have all the horsepower in the world but if you are dragging an anchor you will only go so fast.

MILD THUNDER

iTrader: (3)

Problem with the 525c is the tiny blower, coupled with low compression. Even if you add an intercooler, the gains are not that great. Simply because you are trying to get more boost, which the blower then becomes inefficient, throwing the intercooler in there also adds a restricition, in which again, the blower must be turned up. So lets say for example you seek 7lbs of boost with the intercooler. You're gonna need to really go down on the top pulley size to get there.

If the engine is healthy and low time, and its simply a "add more power" type of thing, I'd consider a larger blower, run a little more boost. You'll see a nice gain in power even with the larger blower at stock boost level, the air charge will be substantially cooler. What I'm getting at, is dont waste much time on sticking with that blower. You can go thru the entire engine, raise compression, roller cam upgrade, better heads, etc, but that blower is still gonna hold ya back to around 600hp like Griff said.

I started with 177's at 5lbs of boost on my 454s when I installed them in my old 38 Fountain. Boat ran 77-78. Switched to 250 blowers, no other changes, 7lbs of boost, ran 83. Rebuilt engines, no major changes as far as compression or cylinder heads, installed 420 Blowers, 6lbs of boost, boat runs 88 so far and still not propped 100%. Besides the speed increase, another thing I noticed about running the larger blower at 7% under. Is that the boat is less affected by the ambient conditions. With the smaller blowers, on a hot humid day, the engines layed down a bunch. The difference now, is alot less drastic.


Theres a lot of ways to add more power to the 525sc. It all comes down to budget and how much power you wanna make. Or like Eddie said, maybe just sell complete and start fresh with a larger cubic inch engine.

dsmawd350

What's a fair price for a recently freshened 525sc

Griff

Refresh or full rebuilds???? 6-8k each depending on what was done.

682gold

iTrader: (3)

My 525sc's are in good shape. One will need to be freshened up soon and the other has been completely rebuilt. new block, heads etc. I have been looking at 540's, 555's and am going to do something after the season. Would consider trade or partial trade towards my upgrade if anyone is interested. Can here mine run. They are in boat and will push my 38 75-81 depending on the weight and props.

Donzi38ZX525SC

Hello,
Just reading your post here from quite a while back. Sounds like you're in the know with the 525s. I have a pair of 1999 525SC that are in very good condition, but looking to increase my output. The obvious goal is as much power/torque as possible, without having to go into the bottom ends. In other words, I'd like to shoot for the biggest bang for the buck. Thinking definitely a larger blower to start, but if it make more sense to to blower, heads, and cams, then that's the route I'd take. Having said that, inter-cooling is interesting as well; just really wanting to find the combination that will achieve the most gain. Your thoughts are appreciated.
Thank you

Padraig

Contact Eddie Young, Young Performance.

Padraig