Hi

Friend of mine has a boat with 2 x 502 carb engine. Both are very used and he think for some new stuff

Now we start thinking for something new.

In Mind are:

540, alu-heads rect. carb, Rollercam

or

454 maybe stroked to 496 and blow it with a 177 Weiand or a vortech with a carb and a roller cam

Boat will run on saltwater, 5.200rpm is what the engine shout run, i have no informations about drive and prop

Anybody has some "Yes" or "No"for the different mills?

a 540 N/A would be nice and reliable, make good power and torque, and can be had for fairly inexpensive.

a blown 496 could also make great power and be reliable, and may cost a little more up front.

The 540 will probably have to be spun more than 5200rpm to really get into the power, depending on the cam you go with.

If you have 502's, why would you want to change to a 454 or 496??? Are these HP motors or Mag's?

Either way, a 502 block is a good start for Horsepower.. you can even make them into a short deck 540 very easily

The 502 can be sold here in germany for a good amount and will make a good start-up-moneyfor the both other engines. I have a good engine builder in Baltimore. First calculation said a 540 with a new dart block would be near the same as a used rebuild 454 will cost with a 177 blower, i can get both unter 10.000 each complete running

I would be VERY suprised if you could get a turnkey 540 with a Big M for under $10k. Built with cheap internals I guess it is possible, but not with good stuff.

Figure $2500 for the Block
$2k for rods
$1500 for crank
$2500 for aluminum heads/ $1500 for iron
$1k for cam and lifters

Add everything else in and $10k will be a stretch just for parts if you are using good stuff.

If you can get it, by all means go for it.

Agreed.. a 4.25 Stroker kit plus some pocket porting of the heads there is on the 502 plus a blower.. there we go with budget Torque Monsters... that would be my route with the 10K budget per engine. Or even better.. go Turbo...and look at Big Rig size whistlers..

if fuel consumption is a issue,which im sure it is in germany,,,,,,unless your filthy rich,i would go with n/a 502/540.the blown motors tend to be alittle thristy,harder to keep in tune,unless efi.if h/p is your thing,go blown.i like both.

No need for 2500.00 connecting rods in a N/A 540CI marine motor. A decent set of manley, callies compstars, heck even some GM dimple rods would work fine. Same goes for the crank. Sure if you want 1000HP blown power, than go with the billet stuff

Like us all, he'll want a blower eventually, it's an addiction