Smoked 502 tonite
 

Wife and I were going to dinner and I smoked my starboard 502, in the inter coastal 2700 rpm, 50psi oil pressure, 21 psi water pressure, 250 degrees. Don't quite know what happened yet, felt the drag then engine quit, the dreaded Jamoca milkshake all over the bilge.

Wife not to happy, so Rosy will be my friend for a while.........LOL

In all seriousness I would like to rebuild to blower motors, rebuild the short blocks to basically stock configuration, use 8/71 roots style blowers, no inter coolers and under drive about 20%. I don't want to get to crazy and go much over 650 HP.

Really looking for advice on cam and carb configurations, trying to get some dependability out of this and don't want to upgrade drives, it's a 32 Fever.

If anybody has built a nice combination please share.

250 is awfully high. Prolly popped a head gasket. Should be in the 160-180 range.

You can build good 650s without the cost of blowers.
But they sure sound sweet..

Go NA if only shooting for 650hp.

Any suggestions on a nice NA build sheet,

You are 1 phone call away from having 650 hp na motors. Call Bob Madera @ (858) 654-8583

I did both mine this past winter with Bob. Was shooting for 650, they went 675is with 715 tq. Really nice motors. They weren't cheap but less expensive than blower motors. Bob is definitely the guy to talk to as well as buy the parts from. You'll also get a helluva education about making power along the way if you so desire. He'll take all the time you want to explain why your'e spending your money on this part or that part rather than else where. He's a gentleman and a real pleasure to work with. Do yourself a favor and call him. You won't regret it. BTW, my stuff is on file with Bob under John Cook, not that he'll need it but you might want to mention it being 650 is what your'e looking for. If you like to talk on the phone you can reach me at 901-491-4500.

I couldn't of said it any better then that.

You aren't far from Ron Potter in Sarasota. He's the man for engines. His shop is cleaner than my kitchen, literally! Tell him Josh sent you.

Without a doubt Bob is the man, just started myself rebuilding my 502 and looking to make 700, first call I made was to.... Yes Bob M

Pay up, fill us in some details on your build. I'm doing 2 509's for my own boat this winter (on top of 6 other builds) with bob.

I'd want to know why it was overheating.

UPDATE.................... Spoke to Bob Madera at Marine Kinetics, truly a gentleman and a wealth of information. First step is pull my engines, I am only breaking down the engine that the head gasket blew on, after the magmaflux and the sonic gram of the block and crank. If the block and crank are good, then I will disassemble the other motor take that to the machine shop have the same processes done and start to proceed rebuilding to 509s basically stock short blocks, but then; Aluminum Heads, roller valve train, Marine Kinetics custom grind cam, single plane manifold, Nickerson 950, stainless marine exhaust, etc. should be a 625 hp combination per Bob M.

If the block and crank are bad it will be 2 Dart big M block, with scat rotating assembly for a 598, then whatever Bob M recommends for the heads, valve train etc.

I will then sell the other running 502 complete, to generate revenue for the build.

As far as the overheating is concerned all new oversized oil coolers, oversized lines with sweeping turns, retain water pumps with thermostats

540 with Callies Compstar cranks, Callies Ultra H beam rods, Carrillo pistons, AFR oval port heads, 300cc, full CNC porting, runners and combustion chamber, Victor Jr 4150 flange intake with a Reher-Morrison anti reversion plate and spacer and Pro Systems Dominators. Scorpion Roller Rockers, and Bob's roller cams, and stud girdles. SM exhaust with dry tails. I got them finished and Installed last week in June and have around 250 hours on them. My only regret is not having a faster hull. Looking for that now.