Merc 420 Cyclone engines

Here's the link to all the pictures I took today. Tomorrow I'm going to attempt to turn over the starboard engine. I checked the dip stick and it looked normal. Oil reached the full mark, had no discolorization. The intake manifold shows no signs of moisture and the rockers are anodized so i couldnt see any rust in there.

www.photobucket.com/projectdad

you guys should enjoy these pictures. Let me know what you think...
 
You should pull your props. See what condition your prop shafts are in. They are hardened so the will rust. When the rust at the seal surface it ruins the shaft. Clean them and grease them. When you use it in salt water you should clean them every time you use it.

Overall it looks to be in very good condition. As mentioned earlier it would be nice to pick up a pair of 502 marine replacement engines to drop in. Everything there will bolt right up.

If you were local I would be all about helping you restore it. You got something to treasure there.
 
What Jim said. The propshafts tend to rust where the seal behind the prop sits.Sometimes they can be saved if they are messed up. The older ssm were known for leaking prop shaft seals, due to what Jim said. Some guys have used speedi sleeves, spray welded, and some other things to save the shafts.

The boat looks great though man! I think with a fresh pair of marine big blocks, your in business!! Just as a fyi,I have a buddy who installed a pair of GM 454/420hp crate engines in his old Formula. After rebuilding and messing with his old 454's, he went brand new GM long blocks. Been in the boat since late 90's I believe, no troubles whatsover.
 
Here is the way I look at it . Spend money on new crate engines. nearly every penny spent is on new parts. Rebuild, buy used and rebuild half or more our your well earned money buys labor.

A few years later you have either almost new engines or a bunch of old stuff.
 
I would rebuild what u have with new parts if they turn out to be shot !
These are/where very good engines and drives, no need to rerig something that worked for decades!

To rebuild these engines from top to bottom with reusing the old crank ( after magnafluxing and same with rods ! can't be that much. As soon as u have new honed and decked blocks, rings ..springs and lifters ..maybe pistons and cam...its NEW !

The TRS II sportmasters are awsome and will outlast the power of these HP 420s ..after a nice rebuild they should easaly make 450 HP..or bore them out same crank and some other stuff..550-600 HP no problem on pump gas N/A and the drives can take it !
Best bet on drive rebuild is either Jerry Haney, or Mel Riggs !
Best stop for engine would be my engine builder i think ..others are Tyler Crocket and ofcoarse Innovation..since they dealed with these engines all the time back when.
but 2 out of these 3 engine builders are not cheap.

Best advice..do it once and do it right, i learned the hard way ..LOL;)
 
Here is the way I look at it . Spend money on new crate engines. nearly every penny spent is on new parts. Rebuild, buy used and rebuild half or more our your well earned money buys labor.

A few years later you have either almost new engines or a bunch of old stuff.

I have to agree. Going with new gm, you get new blocks, cranks, rods, heads, valves, pistons, etc. Nothing has seen salt, stress, etc. Proven engine combo.

The scary part of rebuilding old engines, is the total parts list cost, machine work, and you need to hope the builder does it right. Id imagine by the time you do a full rebuild on a old 454/420, you'll easily be at the cost of a brand new gm 454ho shipped to your door. Hell, its easy to have 1k dollars in just rebuilding one pair of heads. Most I might do to the crate motor would be a cam swap for something a little hotter than what they come with.

Granted if big power is the goal, then you would wanna go custom. Engine masters did a 454ho marine engine. They left the shortblock stock, low compression. Ended up around 8.2:1 I believe. Slapped a set of dart 310 aluminium out of the box heads on, a comp cam, and made 520hp and 500+ ft lbs. Not bad for a 87 octane 454 marine engine.
 
Another way to go is to call all the reputable engine builders out there and see who had a set completely redone and left because the person lost their job or got a divorce.

They are out there, sometimes at a great price.
 
Scott he has #3's.

Plus do you know where California is?

One motor is missing the last thing he should do is start collecting used parts to rebuild it. If the good one runs and looks like it is OK sell it to someone how likes rebuilding old stuff. Let him deal with it. Let it hundred dollar him to death.
 
Scott he has #3's.

Plus do you know where California is?

One motor is missing the last thing he should do is start collecting used parts to rebuild it. If the good one runs and looks like it is OK sell it to someone how likes rebuilding old stuff. Let him deal with it. Let it hundred dollar him to death.

OH...3s are even better , i thought these are TRS with the speedy lower..and i did not know 1 engine is missing !

I have 2 complete rebuild HP 420s here btw.

but waht can be missing?? its a gen 4 block with good parts, so just build an other one !
These parts are still available..all of them !
 
Other thing is, this young man, isnt very knowledgeable yet, with marine engines, rigging, etc.

For guys like us Scott, we know where to look, what to look for, and how to put it together. He'd probably get nickel and dimed to death. He might get with some engine builder out there who will see he is a little green, and run with that.

Im really diggin the boat though man. Super cool old wave crusher with great drives. Keep us in the loop on its progress!!
 
Other thing is, this young man, isnt very knowledgeable yet, with marine engines, rigging, etc.

For guys like us Scott, we know where to look, what to look for, and how to put it together. He'd probably get nickel and dimed to death. He might get with some engine builder out there who will see he is a little green, and run with that.

Im really diggin the boat though man. Super cool old wave crusher with great drives. Keep us in the loop on its progress!!

Didnt think about that....

btw, like your new cig line...CIG KILLER..LMAO
:driving::smash:
 
To bad he is so far out west and not closer to the midwest where we could help with hands on stuff. As said above, go with new longblocks. Ive tried the other way and almost cried after it was said and done. YOu will be light years ahead. Also, before you make any large purchases for this boat, hit one of us in a thread, PM, email, smoke signal, anyway possible so we as a collective team can help you out. I know that thru my years on these forums, I have been helped by several people and saved me countless headaches. I m sure we all have the same stories about this but you will see as time goes on, we are all a big family with one shared love which is power boating.

Chris


PS... if you give your cell number out eventually your new SOS friends will drunk dial you and send you funny A$$ txt msgs. :smash: :sifone:
 
all great info here... I found a local guy that does mobile repair on boats in the area. I had him come out and check everything out. He suggested i take out that old motor and sell it, and go with new engines. He said i was a little short on parts to buy a couple long blocks to make them work as far as the one engine goes. I did turn over the engine that is in the boat now so it is a good sign that the engine is still worth a few bucks towards new engines.

I am very interested in the purchase of a couple 454's that a member on here PM'd me about. His user name is C35 and he's got a couple of 454's for $7500 plus shipping.

We pulled the plugs on the drives and the oil came out bright green, he said it looked like fresh oil and that the drive had a fresh service done to it. Probably done 15 years ago right before the engine blew. He seemed like a very nice knowlegdable guy. He didn't charge me anything to come out and take a look, he also didn't try and sell me on anything.
 
Last edited:
I am new to the boating world, but i did have an engine rebuilt at a local shop for my chevelle, and in the end i wished i had gone crate. time+cost+oil leak= headache

here is the info on the engines im interested in.

"I have a pair of brand new GM Performance 454's. They were $5800 apiece at Summit Racing. They've been marinized by Falcione in Ohio. Stainless valves, Clay Smith cams (similar to Crane 741 but with a little more lift), Crane roller tip rockers, brass freeze plugs, felpro marine gaskets. They were run in on Falcione's dyno for 90 minutes."
 
Get ahold of Falcione and see if they have the specs on them. If they dynoed them, they should have.


Does anyone on here know them?
 
just read this,

We pulled the plugs on the drives and the oil came out bright green, he said it looked like fresh oil and that the drive had a fresh service done to it. Probably done 15 years ago right before the engine blew.

.............

a little advice...I WOULD GET THEM CHECKED ANYWAYS !!!

if something is wrong seal wise..and they just filled new oild in ..it looks ok but if u run it then the oil will go FAST..and u will end up burning the upper gear !
THIS GEAR SET IS ~ $ 1500-3000 + labor !!

Why i tell u this? because it happend to me when i bought my boat ...did 93 for about 1 minute..and the gear was melted on to the down shaft !!!
Only because the propshaft seal was worn ! OH..and the oil loked like brand new and the guy i bought the boat from said the drive is freah rebuild !:ack2:
 
Back
Top