454 mag/454 stock

[HoleShot]

I am trying to help out a friend that had a little problem over the winter, he has twin 454 330 stock but now has 1 because he did not winterize it right, he has access to a 454 mag engine and wants to try to match it to the 454 330hp. he plans to change the heads, intakes and exhaust on the 330 with mag parts will this work? I know the cranks are different but I don't know what else is different and don't want to tell him something that will make his problem any worse, :confused: If anyone can help I can send his phone # or just reply and I will forward it he is not on line.

[Air 22]

If you need stock 454MAG manifolds and Risers i have a set from 1995 454MAG. Just removed them and area ready ship. Let me know if your interested. wink

Dwight

[MOP]

Is the motor alright except for a cracked block?

If so why not fix it, if you run salt water through it it will rust the crack shut. It takes about a week and a half of filling and leaking a little rusty water in the bilge, but it will shut off. I have done this on many boat and car engines that the welders have turned down, most the time the welder will crack it worse from improper heating. I've had them crack between the casting plugs (falsely know as freeze plugs)and still had tehm heal up just fine. The car guys after the weeping fully stopped went right back to there normal pressure cap and coolants with no further leaking. Cast iron expands as it rusts it is self healing! Try it you'll like it another Old Fart Trick and it does work very well.

[Fish boy]

M.O.P., I am constantly amazed by your pearls of wisdom.

[MOP]

Got mail from one of the more knowledgable members on this one. He is right I don't think about the real cold areas that can and many times do cause more damage. Down here it does not stay cold enough long enough for us to see internal passages break. My thoughts after being enlightened would be if it runs, fire it up a few times, if it only leaks out the sides try my trick it does work. But it may be worthless in your area. If it is Ok except for the outer wall don't use Goo on it, rust it back the Goo's don't last. And many times brazing cracks them worse.

[PaulO]

Check the 454 "Mag" engine because depending on the year and drive that it was mated to, it may be a cast crank 330 hp anyway. Lot's of the "mags" were the low performance 330s.
Paul

[CaptWK]

I have Merc 454 mags in my 1987 Z29. They are rated at 330hp each. The stock 454s did come at 300hp and the 454s mags were 330hp. There is a 360hp model out there also. Look at the numbers on the valve covers if possible or Merc engines have a plate on the motors. What year is the boat?

[MR MAGOO]

In 1987 the 454 Magnum was just a Gen 4,330 hp 454 mated to an Alpha One drive. This was the ONLY year that the Magnum was actually a cast crank,cast pistons,oval port head 454. Starting in 1988 the 454 Magnum was the motor previously known as the 370, offered only with a TRS drive. The motor was now rated as 365 hp and was a marinized version of the LS6 crate motor.

Kurt.