Engine Question
 

First time on any forum, ever. Anyway I picked up a 96 24' outlaw with a 502 magnum Mpi at a insurance auction, it was a flood recovery so I knew I'd have to rebuild the engine, what I didn't know was it had a cracked block. I bought two mercruser 420 cyclone engines ( got a good deal). Anyway the question is to any knowledgeable boat people is, can I use the fuel injection system off the 502, on the 420 and could I use the roller cam and lifters also?

THe ecm will need to be reprogrammed. You can do a roller cam/lifters, you just need to get the correct lifters for the block, correct valve springs etc....

Thanks phragle . The 420 is going to get freshened up, rings bearings etc. they have good heads which will be sent to the machine shop, factory gold crane roller rockers, but with flat tapets, is using the roller cam out of the 502 worth messing with?

Thanks phragle . The 420 is going to get freshened up, rings bearings etc. they have good heads which will be sent to the machine shop, factory gold crane roller rockers, but with flat tapets, is using the roller cam out of the 502 worth messing with?

Have you priced a decent set of retro roller lifters? (assuming the 420 is a mkIV block) If you are going to do a roller conversion, go with a cam that meets your needs. An off the shelf cam fitting your needs could easily be less expensive than the lifters.

Is the 420 a mkIV and the 502 a gen VI ?

How much power are you trying to make?

By saying "good heads" do you mean they arent wasted or are they good aftermarket heads ?

The 420 still has essentially the same rectangle iron factory GM heads as the 502. What year 420's? Iron GM heads that spent 20+ years in salt water are scrap metal. They rot through at the end exhaust guide. Your 502 heads, being much younger are gonna be waaay better condition. Same chambers, ports... Just need to have the valve studs threaded to 7/16ths. BUT, when a set of heads land in a shop, they generally cost 500 on up to get back. So consider upgrading the heads instead of reconditioning what you have. The 2 cams are very little different in profile and power output. The biggest diff between a 420 and a 365 hp 454 mag is the 420 is rated at the flywheel. The 365 rated at the prop. Whatcha got for exhausts? The 502 still used factory merc wet-joint center dumps. And they cracked too. Speaking of cracked 502 blocks, where are you? I am playing with fixing cracked 502 blocks. Philly area.

Non engine related however make sure and inspect all and any areas where water could have made its way in to the boat and remained saturated for any llength of time. Especially transom and stringers. Sometimes individuals have a tendency to drill, cut etc for something and don't seal off properly or at all. Hopefully all is sealed and no issues but just never know who did what before flood damage. Just a heads up anyway and good luck with your project and welcome to the oso.

Flood boat - if the electronics, ignition systems, wiring harness and ecm have been under water, I really never seen any of that fair very well especially down the road. I am dealing with flood boats as we speak thru various Insurance companies.

could just buy my 525 sc and swap your accessories on to it and be done...just had to mention that lol

Stewart

Word around the campfire is several of them are being purchased from insurance companies etc and hahauled up north to sell. I can't imagine being an adjuster down in parts of Florida and Texas right now.

Engine Question
 

On the rear engine riders, sometimes it helps to put a little weight in the front like a cinder block.

The 420 is mk IV and the 502 is gen 6, I'm just looking to get a working engine right now, I read that a roller cam would get me more hp, and is more reliable, so I just figured that well I got one lying here. Maybe I should just swap both the merc 420s for a 502 short block. Btw they are out of a 80s formula, fresh water boat 400 hours. Also the outlaw I picked up is not from the Florida hurricane, I got it out of New Hampshire, more than likely someone didn't winterize it, cracked the block and decide to sink it at the boat launch to collect the insurance, who knows. But their is no sigh that it seen salt water. To dereknkathy, I live 1/2 a mile from the boat launch at Raystown lake, central Pa, if you come boating there will be a cracked block here for you, lol. So any good advice is welcome, thanks.

Flood boats? You wanna see flood boats? You shoulda been there for hurricane sandy. Oh. You are there now. Oh. And a funny thing about tidal surges. They can tell an alpha from a bravo. With Sandy, the tidal surge went down and every bravo drive was mysteriously no longer attached to the boat.


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Flood boats
​​​​​. Yachtsalvage.com. during sandy they set up a lot on the back side of a municipal airport. I hadda go to main office in mass for my crownline. It was on a trailer. Bad 350 mpi was in shop. Bravo 3 stored. Somehow hurricane sandy fired up a forklift and lifTed my crownline by the windshield.
​​​​ then made the bravo e and the bad 350 mpi disappear. And the ecu, water pumo, everything. Made a windshield fit of a 200 buck 90 regal. Still have a nice gen 1 alpha with transom dirt cheap. Always trailered. 1.62 ratio. Runs bigger boat fine with 21
​​​or 23 prop.
​​​​​​ but I dIgress. I am sure yacht salvage will set up a location Houston and s. Fla. Some decent shape. Some slid upside down 500 feet with a 20000 lb sportfish on top of them.
​​​​

What???

Somebody else brought up flood boats. I digressed a bit as I been around that block. YOUR flood boat. Do you know or can you figure out how much of your was under water?

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you can bet there will be a bunch after this season !!!

I'm not sure what was flooded, it had docking stamp for 2016, a couple of freeze plugs were popped out, so I figured it went threw a New Hampshire winter, the only thing that may cause me trouble is the wiring harness and Ecm, but I seen one on ebay for $200.

Just an engine freeze, no biggy... Surpised insurance would cover anything to do with owner stupidity. I Thought it was retrieved under water or something similar. Your first post indicates flooding. Cracked block is more like a couple gallons of water in the bilge. Doubt your ecm or wiring harness is damaged. Good luck.

Post # 1 says its a flood recovery boat. Bought at a Insurance Auction. I have never seen a Insurance company get involved with a miss maintained boat and or not a winterized boat period for a claim or buy back thru them.

I miss spoke, I bought it from an auction, bidding was opon approval, so I just figured it was threw the insurance company. thanks for the help guys.

If it was from Winnipesaukee, it may have been stuck at a dock or boathouse. Our lake reached record low levels last year, especially fall, and a bunch of boats couldn't be pulled from their docks/boathouses. A few boats near me where stuck at their docks for the winter. Was very interesting...never saw it that low (in memory) in 45yrs I've been there.