Magnum marine

"Here's a guy who's st

"Here's a guy who's starting to sell marineized Magnums....I don't think I would hesitate to replace an LA with one of these. Only issue I could see is the water pump is probably reverse rotation due to the original serpentine belt design....Any thoughts....???

Jack

http://cgi.ebay.com/ebaymotors/Reman-Chrysler-Magnum-Marine-318-Long-Block-Engin e_W0QQcmdZViewItemQQhashZitem1e0368ba9QQitemZ8056638377QQptZMotorsQ5fCarQ5fTruck Q5fPartsQ5fAccessories"

"What’s up Jack?

I’m not s

"What’s up Jack?

I’m not sure about the water pump rotation…..might not be an issue at all. Otherwise, the only non-swapable parts that come to mind are the intake and valve covers…….things that relate specifically to the Magnum heads. Having said that, it would be worth confirming the exhaust manifold fit.

Although the heads and valvetrain of the Magnum are modernized and, in theory, should be more conducive to performance, I think the power differences are marginal (on paper least). Even if all other things are equal, moving from a flat tappet to a roller lifter is a nice upgrade.

It’s a little ambitious but a Magnum could also give you the option of fuel injection."

"I went from the LA to Magnum,

"I went from the LA to Magnum, I am very happy, I used LA water pump,timing cover, fuel pump, Distributor, mounts, Carb, exhaust manifolds, alternator, and raw water pump. Had to make a bushing for the fuel pump drive"

"I thought someone on here sai

"I thought someone on here said they converted. Were did you get yours Scott...? I ask the seller about the cam specs and didn't get an answer so I'm assuming there reg. long blocks with brass freeze plugs which probably would give sufficient
perf. but how much of a 'marine' motor it is, is anybody's guess. I did find a late model Magnum engine awhile ago that was a industrial/marine engine that even had a tag on it saying not for street use so Chrysler still has their toe in the the water somewhat....pardon the pun....
.
Now if we can get one of those Illmor V-10's in a vintage boat......

Jack"

"I used a truck block, and a c

"I used a truck block, and a custom ground cam to la340 spec. now have a Edelbrock 1409 carb "

OK, I'll throw out some other issues. First you have to grind the head lip near the outer boat holes so the manifold will seat if not done already.

Next, The raw water pump will hit the front of the head. You have to cut the front ear back to clear the pump.

Next come the issue of the magnum balance if you use a 360 It is different than the LM engines. This is how I solved it & it worked for me , But you might want to rebalance the flywheel.

Now on to the cam, No provision for the fuel eccentric. Here is what I did. The cam key from the LM engine is longer & will tie both pieces together when the bolt goes through.Hughes engines sell the adaptor to use the Magnum cam & LA/ LM cover.

I also used the truck pan, But Luzzo racing makes a adaptor to use the 318/340 pan on the magnum engines.

I bought a marine Chrysler 360 and I want to install it in a 1987 19' Malibu Sunsetter ski boat. It needs to be rebuilt and I'm wondering whether I should just rob the marine parts from my older 360 and hit up a junkyard for a fuel-injected Magnum 360. I have a friend with some in his junkyard, so acquiring one isn't such a difficulty. I might actually get a running one.

I assume, though I haven't verified, that the Malibu requires a reverse-rotation engine. So I'm wondering what I'd need to do to make the cam work. Scotty, did your marine Magnum 360 wind up reverse rotation? Can I just rob the marine cam out of the older carbed 360 and re-grind it and install it in the Magnum? Or do you have to stay in normal rotation with the marine Magnum conversion? Is the cam the only significant barrier to reverse rotation, or am I missing something else essential? Or what's the downside (if any) of using the Magnum in standard rotation in the SunSetter hull?

Well maybe this concern is easily addressed. I did some preliminary research on my Sunsetter and it might actually be standard rotation. The original engine is gone, so I can't look at it, but the prop & shaft remain. It looks to me like the prop turns opposite my Correct Craft reverse rotation boat, so maybe I can just use a Magnum 360 with a normal rotation configuration. I'm still looking for confirmation on the direction of the Sunsetter, though, so I'm happy to hear from anybody who has a definitive answer. My Sunsetter is 25 miles away at the moment, so I'm just looking at a very dim photo of the prop and it appears to be opposite orientation of the Correct Craft.

I have a almost new reverse rotation 340 spec marine cam & matching pushrods for the magnum cam swap if you have to go that direction...

Dave, I've all but absolutely confirmed that my Sunsetter takes a standard rotation engine, so I think that simplifies things a lot. But you've provoked questions. Is the marine 340 cam much different than the marine 360? It's my amateur understanding that Chrysler Marine only had two cams for the LA small block: 318 & 360. I guess that would be four if you count reverse rotation separately. Is the 340 cam one of those, or different?

I have a friend with a selection of Magnum 5.9's, all in trucks. I'm sorely tempted to pull a running engine, adapt my marine 360 parts, and see what it'll do on the water with as little changed as possible. I'd like to use the factory fuel injection too, if possible. I wonder if you can comment on how appropriate a truck cam is for a boat? Both are low-end, high-torque applications, so it wouldn't be like trying to use a coupe/sedan street/drag cam. Also, apparently you didn't go with the Magnum fuel injection. I'm wondering if there's anybody out there who has and figured out a way to mount exhaust O2 sensors so they don't drown. Is that why you went with a carb?

The cam is copy of the 340 hi po cam from the 275 HP engine. The Magnum works great in my wakeboard boat with a extra 2000 lbs ballast. With a 13x12 Acme prop it turns about 4200. I could lower the pitch & spin the engine higher.

But your Magnum is now carbed, correct? I'm investigating whether I can retain the fuel injection. Location of an O2 sensor seems to be a significant hurdle, although maybe not an absolute killer.

Is that 340 hipo cam a street cam? Is it good for low-end torque? And where did your cam come from? Crane or elsewhere?

That's a lot of great info on the Magnum conv. Dave. I only wish you came along a couple months
ago when I was already to pull the trigger and go the Magnum route until I stumbled on a 340.

As for your cam I just went through deciding what spec would give me max HP and a good low idle
and could've gotten the P4452782 off the guy who sold me the motor but found an old marine cam
with the same lift .429/.444 but the duration is lower 210/220 vs 228/235. I was told the 340 cams
preferred a slightly higher stall in the cars so the idle could be set higher around 8-900 and I needed mine
to be down around 500.

What do you like better about the 1409 over the Holley...???

Jack