Mercruiser 3.7 liter pictures

The famous Mercruiser 3.7 liter inline 4 marine engine. I know there aren't many pictures out there so here's a few. More coming next weekend when I take it apart to see what it needs to run.

This is just a large top picture. The big hole with gunk in it is the intake manifold where a carb. should be fitted on. I'll be using Chevrolet throttle body fuel injection with a megasquirt ECU, though.


The large, bottom pulley here is the alternator. It's basically complete trash although I don't know what kind of alternator should be used as a replacement or where it could be found. Some other HAMB members definitely should know, though.


This is the top of the cast heads. Aluminum Ford 429 or 460 heads should bolt right on though. On this particular middle, the wide open throttle is at 4400-4800 RPM and produces 165 horsepower. 160, 175, and 180 horsepower variants exist as well. Mine is a "3rd generation." The first ones were the 1_ _ series. Their numbers denoted horsepower. Early ones came with forged cranks but later ones came with cast cranks because of vibration issues. Then came the 470 and 485. The 4 was the number of cylinders and the 70/85 stood for how much horsepower +100 they made. This is the newest type that are simply Mercruiser 3.7 liters. Each has various slight differences.


This frontal pully is the power steering pump (I believe) and alternator.


This is the back end of the block. It has a common Chevy bolt pattern but a Ford flywheel that sticks out a bit further than a Chevy. I've heard 3 different things, some on this forum, some from others. If anyone could specifically confirm or deny any of these rumors, I'd appreciate it tremendously. The first is to grind the block down 5/8ths of an inch. The second is to use a Ford transmission with a Chevy bell housing. I don't know who makes such adapters. The final one is to use a Ford input shaft in the Chevy transmission. Again, any confirmation or even refuting any of these rumors would be much appreciated. These are just things I've heard/read.


Enjoy.

 

where did you find that?
wow what a great hot rod motor

 

A friend of mine's dad gave it to me. He was going to put it into a '55 Bel Air sedan but when he found out I'm building a custom-framed car, he said I could have it if I let him drive the thing at races.

The friend's dad found it at a boatyard. The boatyard was closing down and there were outboard motors laying around. He just snapped this beauty up.

Information is hard to come by, though. Any information that exists is limited to this and the ford460 forums.

 

I think Chevy/Ford trans bellhousings should be available.

Here is one:
http://store.summitracing.com/partdetail.asp?part=ADD-712549&autoview=sku

 

http://store.summitracing.com/partdetail.asp?autofilter=1∂=LAK-15060&N=700+4294908216+115&autoview=sku

 

Appreciate the pics and look forward to more. What kind of project is this going into?

There are a couple companies that make bolt on automotive style 60 amp alternator conversions.

 

A locost. It's a replica of the 1956+ Lotus 7. Probably not a car that tingles HAMB's collective taste buds but there's something beautiful about 250 foot pounds of torque in a car that weighs 1500 pounds!

Regarding the amp, do you have any links specifically?

Also, thanks for the bell housing links.

 

Light and quick, what is not to like.
Should be a cool ride; as long as you are not afraid of big trucks.

I assume you are also on Lowcostusa.com ?

 

Lotus is cool. I know a guy here with a Mercruiser in a 29 fendered 27 roadster.

 

A friend of mine has a C-4 behind his, in a track roadster.He built his own exhaust & intake system.

 

Imagine a Mercruiser 3.7 with a Kaase Boss 9 cylinder head.
http://www.jonkaaseracingengines.co...9-kaase-nine-semi-hemisperical-bbf-heads.html
Designed to fit on a 460 block.

Wouldn't be cheap, but it would be a sharp piece.

 

I hope you are going to build it stronger than a 7 ,that Mercury is one heavy lump.
Does it run?
water cooled exhaust?.
http://au.youtube.com/watch?v=dQvqKLo6o9I

 

I'm fearless! It'll have a basic roll cage. Forums are http://locostusa.com/forums.

Do you know the price on just a single head itself? If it's less than 2 grand, it may be in my price range.

Well, this coming Saturday, you get to be the first people on the internet to see the internals of it. That's when I find out if it runs. The frame is going to be reinforced with gusset plates at every joint for better structural stability but the stock frame is surprisingly strong though. Someone put a 5 liter V8 from a 3rd generation mustang into his Locost without issues. He autocrosses it and everything. http://www.locostusa.com/forums/viewtopic.php?t=3054. If he can autocross it and put it through those stresses, a 3.7 aluminum block shouldn't be a huge issue.

 

Dowel pin pattern is Chevy as are half the bolts. Crank rear is 289. Starter is on wrong side so you may have to grind housing for clearance. I cut and moved pocket and modified flange, but I was having fun. I did Chevy/Ford as I wanted to use a Zoom trans (non OD mid '80's F150 Tremec with top mount shifter). But my work truck blew trans so got the Zoom and it was replaced by a 3550 behind Mercruiser. I had a thick flywheel made and the center bored same as SBC crank so I could put adapter pilot bearing in flywheel. No reason to use just Ford, though, as this method will work with other trans.

 

I got a 250 chevy mercruiser for free from a guy whose boat was rotten. It had a slightly split water jacket under the intake. I JB welded it, poured some POR 15 in it, rolled it around and put a new head gasket on it. Stuck it in my 48 fleetline coupe, put duals and a 4bbl on it, have been driving the pants off it. Good luck with t 4 banger. I think the mercruisers are all ballanced.

 

Most of the V8 guys run 1 1/4" tubes for the chassis.
---
These heads should be priced more reasonable:
http://www.jonkaaseracingengines.co...e-products/188-kaase-p-51-cylinder-heads.html
You would have to contact Kaase for the price on the Boss 9 head.

 

Google "mercruiser 3.7 alternator" you'll get many results. They aren't cheap, but you could also use the images to backyard engineer your own version.

 

One Boss head plus the rocker arms will put you over your $2K range.

There is some information about these to be found on 460Ford.com. The bottom ends are not the strongest without some mods, apparently...but there's at least one used for drag racing with an A head on it, so the guy must have figured out some way to hold it together.

 

Heres a thought, Boat engines have cam shafts ground to give power in a very small rev range. Unlike a car where you are up and down the rev range all day,a boat sits at one speed for hours at a time . Where do these engines develop power? . A prop only needs to turn at 1800 RPM (as an example) . You wouldn't want an engine to perform like that in a car. You may need to re think the cam timing and ignition curve to get it to perform properly.
Guys that have installed ex aircraft engines ( Rolls merlin Vs Roll Meteor etc ) have discovered this in race cars.

 

A 3.7 L Banger is way Cool. Saw one at a tractor pull on a mini Rod Sounded great. Looking forward to more Pics. Good Luck with your project.

 

Mazda truck used a really small light alt. home built aircraft builders use them. all you need for simple cars.

 

Hi,

This is "the friends dad". I'm not sure whether I'm doing mgrinshpon any favors or not but after watching him with his head stuck inside a computer for the last 5 years I thought it might be good to get his hands dirty.

My neighbor had an earlier version of this motor in his boat and it was fast and just sipped the fuel, I was hooked. People talk about problems with them but it seems that swapping on an aluminum head and ditching the stock charging system takes care of about 90% of them. You have to love an all aluminun 225 cubic inch four cylinder.

I found HAMB by googling for mercruiser 3.7 info. I guess I've been "lurking" around but I've been very impressed with the knowledge level on HAMB. Very refreshing after the kids on the Honda boards.

 

This weekend, it got taken out and put on a stand instead of being disassembled because a Civic needed to run more than a Mercruiser needed to be taken apart. However, some things were learned.

Here, the 3.7 comes out from its hiding spot in the garage. This is the intake side. You can see the intake manifold has some kooky oil-cooler underneath it. It looks to be unscrewable.


This is the back end that would connect to the transmission. This cover is on top of the flywheelesque assembly underneath. 5 bolts. There's a cover on the other side that needs to be taken off.


This is the exhaust side. Towards the rear of the engine is the starter. You can see it attached to the housing. There's also a random plate smack dab in the middle of the engine block. Finally, at the front is a scythe-type aluminum pieces. It can come right off. It was probably an engine mount for when the engine was sitting in an outboard motor in some fellow's motorboat.


And here is the housing off. Those 6 screws attached to the flywheel are just a cover for the real flywheel underneath. It was taken off with the utmost precision and care. You know, with a hammer.


Here's the coupling and flywheelish thing taken off. 6 screws for the coupling and 6 more for the flywheel. Those flywheel screws are strong and almost certainly reusable.


Here's some random piece of aluminum being removed at the front. It was probably an engine mount but no more.


And here's the engine at rest after a hard day of being dismantled and hoisted up onto an engine stand.

 

Cool thread. I worked on one of these many moons ago in Florida.. Kinda looks like something AMC would design

 

How so?

And next weekend or the weekend after, there will be a step-by-step disassembly guide (until we get stuck because we don't have the proper tool).

 

Lets see...A Ford cylinder head, GM power steering pump..ford type solenoid..kinda mixture of differant manfactures parts to make one run

 

Add to that a 153 Chevy distributor (w/ Ford oil pump drive), a 392 IH starter, a 350 Chevy bellhousing pattern (mostly), and a 289 Ford crank snout and flange.

 

I can just picture you at the parts counter at NAPA.
Airconditioning on that sir...

 

ahhh,phil knows about them!

 

heres the deal,mill 5/8ths off the back of the block,run a chevy bell housing,you have to notch it for the starter,then run a ford flywheel with a chevy clutch disc and a ford pressure plate,you have to drill the crank for a pilot bushing.
use a chevy tranny.
they built those motors right and left hand rotation,make sure you have the one you need,the cam and the starter is different.
use the stock cam,its plenty good enough,built a header or use a 429 mainfold,run rubber motor mounts too.
its a good engine,i ran 186 at b-ville with one.