Tedd Thompson

Just wondering, what are the advantages or disadvantages of a marine 455 . One showed up on Craig's list yesterday with a spun rod but otherwise compleat. Would it make a good car core or are there problems to over come?Their looking for $400 or best offer.

2blu442

I've purchased a few boat engines over the years. The potential positives are they use a manual transmission flywheel which never see a clutch just the starter. So except for the ring gear you can get a like new manual transmission flywheel. Also if it has the original heads they would be the Ka which have the larger 2.07 intake valves. Often they have aftermarket intakes too. I would go look at it, but $400 may be on the high side unless it has low miles on it. If you can use the block and pistons it in and just replace the crank, new bearings and gaskets for a budget rebuild, maybe new lifters and cam too. That might give you a nice motor at a discounted price.

I've been told some of the later blocks don't have the hole drilled for manual transmission linkage, so depending on your application you may want to check for that.

Another possible negative, if it's been run in salt water there could be damage from corrosion. I have a set of heads that were badly rusted due to the log style exhaust manifolds running salt water through them. I can't picture just how that happened, but the walls of the heads are very thin.

1969w3155

Also keep in mind if this engine was used in a dual set up in a boat (twin engines, twin drives) that it might have a counter rotating reciprocating assembly, as in that type of application, one engine turned clockwise and the other would rotate counter clockwise.

toro68

Does the heads say, "Ka" or "K"?

2blu442

toro68, I've heard of just K heads but every marine engine I've seen were Ka.

Either way Ted, if you have any questions about casting number or parts on it post your questions and we'll try to help you out. John

ozoneblue

Dont know about the 455s But most marine engines have SS valves & different bore & stroke for running 4000 RPM hrs @ A time I used a 302 Fd & 2.5 Chv Great for HWY builders

dan2286

Wouldn't that only use a different cam and starter?

Tedd Thompson

Thanks for the replies guys , good info. I haven't seen the motor as yet, only pictures. I'll see if it's still available tonight. I'm not pressed for a motor as I haven't found a car I like as yet. I'm looking for somthing luxury 1935 to 1939, 4 doors and side wheels,big and ganster looking. Maybe a Lasal, Cad, Olds or Buick. I plan on powering it with an olds power plant of some kind.. Like it to look mostly stock with new goodies on the inside. .... Tedd

svnt442

I've never seen a reverse rotation Olds. I've also seen a dual blown 540 BBC speed boat and neither of those were reverse rotation engines either.
That would require a lot of special parts for the jet drives as well.

joe_padavano

You're suggesting that 302 Ford marine engines use a different bore and stroke than 302 street engines? Sorry but I'll remain very skeptical of this until I see hard proof. The production numbers of marine engines is so small that building a custom reciprocating assembly defeats the purpose of using a car-based engine in the first place.

The Olds 455 marine engines used a stock bore, stock stroke, and stock valves from the factory. Any stainless valves were installed by an aftermarket builder.

70 cutlass s

I have seen a 302 marine engine apart it had the same bore and stroke as any other 302.