377 Scorpion Motor??
 

I am looking for info on this motor.

What is in it for parts

What are the problems

What kind of injection

How many cubic inches

I do not know anything about them just looking for info.

Jon

Re: 377 Scorpion Motor??
 

Here are some specs...

http://www.bullockmarine.com/mercury...rpion_377.html

Re: 377 Scorpion Motor??
 

The only problem I ever heard was its price, also no smartcraft onboard either I believe. I liked it, but there was little demand for a pumped up small block. Personally I would rather have those vs the "little" 496

Re: 377 Scorpion Motor??
 

Hey Bud,,
I looked into those myself for my Boat but the extra cost and weight turned me towards the 6.2's.
Is the House finished yet where you can get your Boat on the water this year?

Mitch

Re: 377 Scorpion Motor??
 

Big boat no but the Donzi will be running just like last year. I am going to work on the boat this weekend some as I have to get ready to head down to Florida to do some work. Works out well as my buddy is going to keep his boat on my dock.

This motor would be for a buddy of mine, not me. Would be going into a pachanga that currently has a stock 350.

Jon

Re: 377 Scorpion Motor??
 

Pachanga with a stock 350. It must be an old one?
Well I guess whats old considering they stopped making them in 1991 :D

Re: 377 Scorpion Motor??
 

I think they have stopped making the 377 .A buddy of mine had them in a 28 donzi ,It ran ok. I think I would have opted for the stock 6.2 & installed aluminum heads & vortec superchargers for less money and a fair amount more hp.

Re: 377 Scorpion Motor??
 

Ummm... 377? :D

They were not overly popular, and cost more than an HP500EFI. They were all hand built, and basically as tweaked as you could possibly make a SBC (5.7L taken out to 6.2L). I looked into them briefly years ago when I was considering a purchase of a Stingray.

The attraction at that time was you could get as much HP as a 454 Mag (310HP) with a SBC motor 377 Scorpion (320HP) but the price was ballistic. I was also told that if they do let go, there often was not much left to put back together.

Re: 377 Scorpion Motor??
 

The Scorpion was 350hp at the prop and is discontinued. The regular 377 is 320hp at the prop. A stroked 350.

Re: 377 Scorpion Motor??
 

The GM crate HT383 is a really good one to think about and has great potential, with a few mods it will crank out as much if not more then the 377. Summit has a good price on them.

http://store.summitracing.com/partde...t=nal-12499101

Re: 377 Scorpion Motor??
 

the 377 isnt a 5.7, its a destroked 400, which is basically a small block 400 with a 350 crank, you get the addidional cubes from the bore and stroke, they are higher revving and very good for a lighter weight boat. people liked them because they wound up fast.

Re: 377 Scorpion Motor??
 

Spec sheet...

Re: 377 Scorpion Motor??
 

Jon, I hear you're going to be in Ocala. Are you going to be down on a weekend?

Re: 377 Scorpion Motor??
 

Jon, a while back I remember reading on the TBM website about a guy up your way who was juicing up small blocks and even had an exchange program, maybe someone from the Baja clan will read this and know who it was.

Cuda, Jon told me he'll be here from the 23rd to the 28th or 29th. I want to run up the river on the 28th, (to the Glen where else?) :) I know the water's low, but I got in there easily a couple of weeks back. Let me know!!!

Re: 377 Scorpion Motor??
 

Guys I am going to be in Ocala the days that Unsane posted. Land in Orlando at about 2 on Sunday and will be working tell we are done. If you guys can make it up that we we can grab a couple a brews.

Jon

Re: 377 Scorpion Motor??
 

No....other way around. Mercs 377 is a 350 block with a 400 crank. The 377 is a stroked 350. 4.00" bore (same as a 350/5.7) and a 3.75" stroke. The 350 has a 3.48" stroke. When bored once to 4.03" it becomes a 383.

The old chevy 400 small block was a 4.125" bore x 3.75" stroke. The 400 block was a siamese block and had lots of head gasket trouble.

You can make a 377 by putting a 350 crank in a 400 bored 30 over block yielding 4.155" bore x 3.48" stroke but Merc did it the other way because the 350 block is far superior to the old 400 block. The 400 small block was discontinued in about 1980.

Re: 377 Scorpion Motor??
 

Hi.

I´m just installing a Scorpion 377 in my Smuggler28.

I got this letter from Jonas at http://www.northoffshore.com/ when locking for info about the 377.

Thanks Jonas.



The 377 Blue Scorpion comes from Mercury Racing and is totally hand built,


different crank, rods, pistons, lifters and rockers. It is all balanced and blueprinted as well. Many were used in the APBA circuit in the bat boats...


Almost none of them had to be touched other than oil changes for the entire season.

There is a big differance in the acceleration and torque. The 377 is rated 350 Propshaft HP.



www.NorthOffshore.com

Re: 377 Scorpion Motor??
 

I am currently installing Scorpion engines in my Formula 292 Fastech. I got some information in a PM last year from fellow OSO member Bikini Bottom, and I hope Ken doesn't mind me quoting him:
Quote start:
"Formula sold the 292 with Scorpions with the 1.65's. The "stock" props are a labbed 32's. On a good cool day, I can spin them but I am thinking about either going with 30's, taking the 32's down an inch or getting some hydomotive five blades for a better hole-shot. Most days with the 32's 3/4 tank and five people, I spin the engines to 4900-5000rpms at 76mph gps. The best I've seen is 81 @ 5100 light on a cool day. I'd like to be pulling 5200 next year.
The engines have been great but I have had to replace a thermostat and have blown out a cooling hose. I replaced the manifolds with Stainless Marine performance manifolds. This winter I'm going to have the ECUs reprogrammed and get new flame arrestors. The only other performance change I've done is to install full size tabs for better rough performance and planing time."
Quote end.
Based on this info from Bikini Bottom I decided to buy a Formula 292 without engines installed, and with 2 new in crate Scorpion engines. Looking at the performance numbers I think there is more than a 30 HP difference (350-320) between the Scorpion and the standard 6.2 litre. But that is just my opinion based on the performance numbers on a Formula 292 Fastech. I have no dyno numbers to back up that claim.
Brian

Re: 377 Scorpion Motor??
 

Well he purchased the motor I am sure that he will let ya all know how it goes :drink: :drink:

Re: 377 Scorpion Motor??
 

Thanks for all the info guys!!! :D Yeah, I'm the guy who bought it. (I've been on the road most of this week, away from the board)

I'm pretty excited about the Scorpion, It's going into my 22 Pachanga. Should make for a fun economical ride! :D

One more question, currently the boat still has an Alpha Gen I drive and I'd like to drop the new mill in this weekend. Can I hook up the shift interupter switch to the 377 Scorpon ignition system?

Thanks,
Kurt

Re: 377 Scorpion Motor??
 

On second thought you should put that in my Donzi. It is a much better platform then that Cruiser that you have :p :p

Re: 377 Scorpion Motor??
 

Do you know if the Stainless Marin manifolds go straight on whitout re-mapping the injectionsystem?
Or are the re-mapping of the ECU a direct action due to this?

What flame arrestor did he go for?

Keen on knowing.

Regards fm Sweden.

Ricky.
www.smuggler.se

Re: 377 Scorpion Motor??
 

Nice to see some people from Scandinavia on OSO.
I do believe that the Stainless Marine manifolds can be installed without remapping the ECU, but may be better performance can be gained by remapping the ECU. I don't know what flame arrestor he decided to go for.
I guess we have to ask Bikini Bottom (Ken) to step in here and answer your questions :-)
I replied this morning to an email I received from Ken telling him that I quoted him on this thread. So he will probably check it soon and reply to your questions.
Brian

Re: 377 Scorpion Motor??
 

Thanks for the welcome Brian.
And thanks for the answer to.

I still got at couples of weeks before the boat goes in to the water with the new Scorpion 377 and it should be very interesting to see the result with the the new engine since the old engine was a ordernary 5,7/260hp.

Du you know the reason for the waterhose and thermostat problems on Bikin Bottom:s 377?

Ricky.
www.smuggler.se

Re: 377 Scorpion Motor??
 

No actually I don't. It does sound a bit strange, but I guess anything can happen. Ken will hopefully answer this question too.

Re: 377 Scorpion Motor??
 

Sorry guys been a bit busy lately.

The Stainless Manifolds went on without any ECU remapping and it runs fine w/o it. It does smoke a bit more and leaves more soot on the stern that's why I'm remapping the ECUs. I hope to get full combustion and a few more RPMs on top. I haven't ordered the flame arrestors yet but they are standard carb style round arrestors.

The thermostat issues were a pain but in the end, I had a bad thermostat that caused overpressure in the cooling system. After chasing a surging temp problem for half the season, I ended up replacing both stats at the end of last season. Temp stabilized and no leaking issues. I thought originally that I had sucked up some mud/debris and that was causing cooling problems but after back-flushing both motors (port twice to no avail) and replacing the port stat with a spare from the local shop, I still had a temp fluctuation issue so I ordered two new Thermostats from BAM...problem solved.

I have loved the motors, they run great cruise well and spin really nicely WOT. Let me know what you guys think after they're in.

Re: 377 Scorpion Motor??
 

Hi Bikini Bottom an thanks for your reply.

My 377 is now installed in the boat and started, im hopeing to put the boat in the water in a couple of weeks and start propp-testing.

Really look forward to see what the little bigblock wannabee can do.

Re: 377 Scorpion Motor??
 

I see on the merc spec sheet they are showing 969 lbs?,that must be including the outdrive and transom assembly,can't imagine a sbc even fully accessorized weighing anywhere close to that,Smitty

Re: 377 Scorpion Motor??
 

The Smuggler 28 is now in the water and the Scorpion 377 has run for about 20 hours.

Im still in progress of testing propps etc but i must say that the little 377 is a real piece of art.

The Smuggler 28 weighing about 2300kg now runs 48 knots and the torque of the little 377 is really impressing.

The engine tops out at 5100rpm with full petrol tank and fully loaded boat.

Im running a Volvo duopropp-drive witch is propably not the most effishient drive and the propp-range for these drives is a bit limited.
Last run was with the biggest props avalible for this drives and those ones are right now at the prop-shop for modifying, plan is to try to take rpm down 200-300rpm to give som extra thrust.
If this does not work satisfying i think i go for a new Bravo1 drive for the next summer instead.

Really impressing litte engine the 377.

Ricky
www.smuggler.se
[email protected]

Re: 377 Scorpion Motor??
 

Did you noticed any gain in horsepower/rpm after installing the Stainless marin headders and remapping ECM??

How mouch are the upgrade supposed to give?

Ricky.
www.smuggler.se
[email protected]

What kind of hours before recomended refresh.

This thread is three years old!

Yea i know someone sent me the link to it , im just looking for a few answers for a buddy before he buys scorpions and this was a good thread.

I got 750 hrs on mine still running strong 2000 Donzi Scorpion ZX 28