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NEW zz502/502

no actually i bought exactly the same thing from the same guy, he saved me some money and said he had anouther shortblock to sell, so i thought id try to help out others on the board.
i have found the flywheel i was looking for, a good deal at 100 bucks too, he has more to ship if anyone buys this shortblock.

my motor is in the shop getting balanced and clearanced, deck the block and get the heads prepared. cant wait, itll be next year to run it, unless..........

maybe ill get it in, who knows!!
 
Kevin,those linkys no worky.
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Looks like we are running the same power Kevin.Strange how fast things change.When I jioned the forum you were an outboard guy,and look at ya know,BigBlock Chevrolet man!Got bit by the bigger,faster,better bug,didnt ya?
 
Hey guy's... Hate to sour a good deal on those ZZ502 automotive crate motors... They have all the right bases for a sweet marine application, BUT... they MUST be "MARINIZED"... and I'm not talking about the external "bolt-ons"...

#1. The exhaust valves MUST BE CHANGED to severe duty MARINE rated ones...A #1 MUST!!!
#2. The exhaust valve seat width needs to be wider than auto-use...(for better exhaust valve cooling under continuous load).
#3. The piston to wall clearence MUST BE CHECKED... too tight and it'll scuff or seize...re-hone if needed to open it up.
#4. The upper piston ring gap needs to be checked and set to marine specs...lots more heat and load to deal with... can scuff & sieze if not done or checked!
#5. The ZZ502 Camshaft is NOT the correct grind for peak torque and horsepower for a marine application...change it or you'll have a 350hp@5000rpm dud! It'll make 500+hp @ 5000rpm with the CORRECT MARINE CAM
#6. Make sure you have the CORRECT flywheel for that motor!!! Gen 4, gen 5, gen 6 are all extenally balanced...wrong one and you vibrate the crank right out of it!
#7. Get some marine HEADERS...stock manifolds will CHOKE any performance gains this motor can give you BIG TIME!!!
#8. Good marine ignition system (MSD)...well worth the money over stock Merc stuff!

Aren't Big-Blocks Fun??? They sound great, lots of potential, but more work than the old "point and go" outboard... Jim.
 
Jim,
have to agree with you on most things here!!
BUT...........

#1. shortblocks dont come with heads!! so the valve issue applies to the heads you choose not the shortblock!!
#2. id like to see your data on the zz502 cam being a dud, i spoke with dennis moore, the cam is actually pretty decent,very similar to that of the crane 168721, only the LS is at 110* which could cause some reversion if not carefull! many guys are running this cam currently. tell me what you know about it, im all ears.
#3. shortblock comes with a harmonic balancer, it needs the flywheel. anyone who needs it i can get several for about $125, takeoffs.
#4. ive been investigating the ignition,the thunderbolt 4 merc system seems to be extremely reliable (according to other users) below 6000 rpm, the msd,dui, and crane come recommended above that.
#5. better exhaust is a must if your moving more air, will help the flow for sure, I AGREE!!

the shortblock is nothing more than a 502 mag, the clearances should be checked and ring end gap adjusted, maybe even a higher tension oil ring. i had mine done at a local shop, to "marine" specs.

still all said, find me a NEW 502 short block for 3400 bucks! Im just trying to pass a good deal on to others! Im sure that you can find a rebuilt fresh one for similar money, but not brand spankin new.

correct me if im wrong here

kevin
 
yeah, you too fnshr, whats that new ride got in it, hows it run. hit me with some details when you get it out!!!
 
Still counting the days till I pick it up.Tommorow is the big day!!!!!
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I hope I get one day to run it,at least one day.Heck,Ill throw on a snowmobile suit if I have to and winterize it at the launch when were done playin in the 42 degree water!
 
Some other things to think about when installing an automotive engine in performance boat without it MARINIZED

Automotive engine clearances set to run at 180-220 degrees, that overheating in a boat

Automotive engines are set up to run at a cruise range of 2000 -2500 RPM or less, actualy needing less than 50HP to run 55-60 MPH (in some apps it might be as low as HP in the teens )
Marine engines run 3500+RPM cruising and need 500+HP in the 4700-5200 rpm range at 60MPH

Automotive engines likely have steel freeze plugs, marine engines should have brass

If you want it to stay pretty all the external bolts will need to be replaced with stainless

ect. and so on and so on....
 
Hey kev how's the motor coming?What did it cost for the machine work?Just trying to get a ballpark on cost for my retrofit.
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Call me when you get ready to pull it out I'll come give you a hand.
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Talk to me Kevin!What are you having done to that BB Chevy?I would like to mod my motor a bit this winter,maybe headers,cam swap,ignition and such,J Rumon from the forum has aloof past experience with the 502 and gave me some tips on how to sqweeze about 500 hp out of it for a little bit of cash,or should I say a couple grand or so,which to a guy with 4 boys is a lot of cash!Let me know how your motor turns out,you are a speed freak like me and cant leave anything alone can ya?I bet the only stock vehicle you own is the company truck.I just totalled out my MINT CONDITION Caprice w/the LT1,had done MANY mods to it,I may even buy it back from the insurance company so I can strip the car of all the aftermarket parts since they dont give you sh!t for them!Next time I will insure for actual cash value ,even if it costs more,I had twice the money in that ride than the piddly 6000.00 they gave me for it!It only had 63000 mile on it,never left the garage unless it was a trip up north.Time to find a good used Suburban,Exursion or Dodge Cummins truck,gotta stay with the full size iron after taking a hit at 60 broadside,Im a firm believer in BIG cars,had I been in a Saturn or something like that I probably wouldnt be sittin here right now.Thank you GM for a full frame car!Too bad they discontinued the BIG v8 CAR,i SURE LOVED BLOWING THOSE RICER KIDS OFF THE ROAD WITH MY 4500 LB TANKER!
 
Ive talked to Jrumon too, he knows his s**t, the 502 has tons of potential, ive heard alot of guys just bolting on prochargers to stock setups and gaining as much as 8-10 mph, some say many hours no probs, others arent so fond of it. its usually the cheapest form of hp!!
follow jrumons advise, i think hes close to you too!! intake,carb, head porting(hes got some for sale), cam and exhaust should pick you up a few!!
your new on looks good!!
kevin
 
jrumon,

sorry to sound so short in my reply way back!!, i did some checking and with "my" setup the zz502 cam WILL be a dud!! im using the rect port heads and the zz cam will not work!!

i stand corrected, however, i guess it does work well with other setups!!

my apologies........

kevin
 
Not a problem... It's a live and learn type thing... boat's don't like street cams! If I can offer suggestions or help... I try!!! I've built over 50 marine motors (for my boats and others) from mild to wild... I guess I know a few things or so...Jim.
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