MINK

Long story short I lost one of my engines two seasons ago and am finally ready to put everything back together - both engines are "stock" 525sc engines which are 454 ci with wiend 177 blowers. I know larger blowers or intercoolers would be the way to go but not looking to spend that amount of cash at this time and am overall happy with the performance with the power it was at.

Was looking for info on putting I different cam in the engines while they were out and was hopeful someone may have some experience here - not looking for crazy amounts of more power just a few extra ponies while the engines were tore down.

thanks,

MILD THUNDER

iTrader: (3)

Stock cam
http://www.summitracing.com/parts/CRN-132561/

More aggressive cam that works well in that combo, although I wouldn't go with it, unless you were either turning the boost up a little with a smaller pulley, or raising the static compression from stock. (assuming staying flat tappet)

http://www.summitracing.com/parts/crn-134561

mike tkach

iTrader: (3)

like mild said,raise the compression ratio to 8.5 to 9 to one and go to a hyd roller cam.the 7.5 to 1 comp ratio it came with is just to low to make any power with the small supercharger.

MILD THUNDER

iTrader: (3)

Wayne272 here installed the second flat tappet cam I posted, in his 525SC clones, with 8.7ish static compression. With only 4-4.5lbs of boost, it made around 575HP at 5400, and 600ftlbs of torque. Thats with the stock GM iron heads, stock mag pistons, etc. A smaller pulley, to get the boost to around 5-5.5lbs, it probably would have made right at 600hp/620ish ft lbs.

I know a guy who will be putting up some nice B&M 250 blowers for sale soon, complete setups.

MINK

Awesome, exactly the info I'm looking for - it was running 5-5.5 pounds of boost before the motors were pulled, I was told it already had the smaller pulley done but from the documentation I was provided the bottom ends are stock compression which it sounds like I will have to raise. I would be very pleased to be 550-600 a side.

abones

FWIW some info on a similar engine i did back in the late 80s in a 25 Checkmate, started with a merc 440 cyclone based platform,I believe was 9.2 or near that for static compression, ran ordinary premium fuel, installed Lighting headers, B&M 174 blower if memory serves me correctly, a reed hyd flat tappet cam 250/250 @ .50 570/570, Holley boost referanced 850 carb 78 pri 98 secondarys, water/meth injected at 2lbs boost, and that engine ran flawless for years!!

So would agree and asy up the CR if you can!

ezstriper

I rebuilt a pair of these a couple of years ago for a friend of mine, he wanted to keep as close to stock as possible, Bob M. @ marine kinectics did some in a roller, way to many issues now days with flat tappets and worked great...he can help you out with this for sure..

Griff

A Crane 731 is a good off the shelf roller cam upgrade. Its what I used in my 525SC.
The cam, lifters, springs timing chain set and misc will run about $1500.
Its was good for about a 150-200rpm increase on the top end with better midrange torque.

mike tkach

iTrader: (3)

^^^^^^ the 731 and a bump in compression to 8.5 will wake it up!

abones

Agree as well, more CR and roller cam.