The elusive 224/3.7 MerCruiser banger

I remember your block, see how it cleans up and then decide, what is there to loose?
New custom pistons are expensive, what about sleeving it to a smaller standard size?
Or if that was no good would it be cheaper to cut down a soft larger piston ( anything but hypereutectic) ?
Randy got a lot of power from a smaller engine ( which I think was destroked).
Cheap used(.030 over & worn like yours) blocks are around if saving yours looks too expensive. But finding a solution would be a service.

 

Notches are in a different postion for Hemi, and the conrod small end is a different diameter on the rods I'm using. So, not interested in anything but a proper custom piston.

I don't know how a sleeve within a sleeve (even if cast in) would work.



... Probably should buy the standard bore block I have access to about 1050 miles away, but I hate having junk around, so easy to drown in it... *wry smile*

 

I understand. I've been doing it "on the cheap". I had a different make engine with odd size pistons and rods. Special pistons would have cost me about $500 each. It would have been better to use common 4" pistons on special rods [ $400 per rod]. As it also had other problems [antifreeze leak and not very good head] I decided on a merc engine as it already had strong rods, was much lighter and had some easy to get parts and would cost about the same.


Having stuff around is inevitable. Sometimes it gets excessive, I stored an engine in a bathtub for a week angering an ex-wife who wanted a bath. 40 years later I've acres of room, a much better wife and still have the little engine that once temporarily slept in my bathtub.

 

aidr

There is a guy named Sarge Nichols who runs 470s in dragsters.

I think he has run them up to 250 inches or more.

He is the 470 Mercruiser Guru for The Inliners Magazine.

If you are interested in contacting him private message me and I will give you his email address.

He was featured in the Inliners Magazine several years ago.

He showed 3 engines and their specs.

I think that either he or Randi Dupree from this thread said that they sleeved these engines all of the way to the aluminum.

Dick

 

Yes, I've got a phone number but no email for Sarge. I must have left 6 or 7 phone messages, trying to get a hold of him. Honestly I just gave up trying to track him down.

The block is at the machine shop now, and they think they can get a good bore with a 4.40" . Honestly I'm doubtful, and I have to order big dollars based on what he says. *anxiety*

I'm dealing with Ron @ Diamond pistons, based on Jon Kaase's staff member's recommendation.
Here's something one of you might really be able to help me on. One of the "star'ed" (mandatory) fields to fill in on the piston order form, is the bore length, top to bottom. Since I am going to be asking him for a good "safe" (ie quiet) skirt shape I want to give him everything he wants to know. I know some Ford 460 blocks have an issue where the piston pulls down out of the bore, and I don't honestly know if the Mercruiser is better or worse in this regard. Looks like I'll have 1.59" compression distance, which is plenty with the small pin and thin rings (.866" and .043/.043/3mm). Also with my small cam relative to the ones the V8 Boss guys run, the piston notches can be far less deep.

 

Another ten thousandths on the bore does not sound bad.
What are the pistons going to cost?

As long as you are having pistons made up, I'd specify a floating wristpin rather than letting a machine shop assemble them. I watched in astonishment as he heated my rod ends cherry red to expand them to slip the wristpins in. I said"Can you get away doing that?" He blithely replied "Oh yes, I do them all that way".

For the integrity of your rods I'd not heat them over 500 F.
Use spiral lock wristpin retainers.


Diamond does have a good selection of oversize big block Ford pistons.

 

A source of cheap 12 volt generators:
Garden tractors.

Wards and Sears 10 horsepower horizontal shaft single cylinder garden tractors made in the 60's and 70's used a Delco generator which worked as both a starter and as a generator.

It looks like it is a automotive generator. The internal circuit should be the same as that in the car generator. External wiring is different so that it can be run part time as a starter motor. Just wire it as a car generator would be wired. A 12 volt generator voltage regulator will be required.

I just removed one from a Wards mower that I have here. You should be able to find one very cheaply [ free to $50.]

It looks right and it is for 12 volt systems. I doubt that they put out much amperage compared to an alternator, none of the car generators did.

 

I have one of those starter/generators on my 10hp Kohler Cub Cadet.

They make these in CW and CCW rotation, depends upon which end of the crank they drive off, so be careful what you buy. You have to install new fields to change them and it costs.

Don't know where you find'em for $50, 'cause the cores are worth more than that for exchange on a rebuilt one.

My DELCO was toast deluxe, so I went on eBay and bought a new Chinese knockoff for about $120. Works great.

They make a long one and a short one.

 

$50 for an old unwanted garden tractor/lawnmower being disposed of seems within reason to me.

I've a friend in Florida who has bought several for about that.
[and on my asking why he ever bought them, he said he wanted to mow his grass. :0) ]

Once they are being parted out or sold commercially , the prices would increase.


What you paid for new on ebay is 1/4 of a new generator price posted here by Dick
so it is still a bargain. Ebay prices are set higher than what one can find locally for unwanted things in private sales.

ps: I appreciate the info you included and will check the direction of rotation.

 

I went to a starter, alternator and generator rebuilding shop today and found out the following:

You can buy a rebuilt 12 volt car generator here for about $140 the regulator costs $40 more.

Garden tractor starter-generators are low output generators, they have a closed case and no cooling fan.
They are good for 10 amps output but at 15 amps they burn out. So they can run an ignition coil but not a lot more.

A car generator is fan cooled and puts out a more useful 30 amperes.

Generators do not seem like a good option other than looking right.

 

Dennis,

The Powergen is not a generator at all.

It is a very will made custom alternator that looks like a stock generator encept that it is 1/4" larger in diameter than a stock generator.

It puts out 60 amps at idle and 75 amps at speed.

The bearings and other detail is ilistrated in the second picture below.

It is not bought because it is cheap but rather because it looks original.

I like it because it is stealth that is in keeping with the simplicity of the no nonsense 470 appearance.

Unlike most modern or High Output 4 cylinder engines that have wires, hoses and sensors hanging all over them to say nothing of overhead cam shafts and fuel injectors.

The 470 has the ability to be set up to look like a tractor engine.

Painted early Ford engine green it will even fool many people who aren't familiar with the Model A Ford flathead.

Dick
.

 

This is what a 1927- 1928 ford generator looks like. Surprisingly like the proportions of an alternator, it must not have worked out.

 

I just bought a 12 volt generator in a wrecking yard here for $15. Replaced its bearing for $3.80. The regulator was $5. Bought another spare regulator for $5 (looks new inside)
If old appearance is important and generators are this cheap, why even worry about other options?
Alternators are superior in being lighter, smaller, rpm resistant and able to put out much more current. They are reliable and have few moving parts.
Generators are cheap, easy(unless it is burned up) to repair and look really old. They are easy to understand.
They also weigh more, are bigger and come apart at high rpm.

 

If 30 to 40 amps is adiquit generators are fine.

Reliability is not the only reason that they went to the alternator during the 1950s.

The 1930 Independant technoligies extended cab Pickup I will put one of these engines in has electric rear and door windows, electric radiator fan, airconditioning and high output stainless headlights.

The 60 to 75 amps the PowerGen provides will give me a little more assurance that it will start reliably those with any other electrical drains that I am likely to put on it.

And again I like the looks of them.

I will save much more by painting the truck myself than the extra cost of the Powergen.

One thing about this forium is that every one has their own way of doing things.

I often spend more on some parts of the build and save on others.

Dick
.

 

I saw a ford generator in the pile...It was spooky in that it looked exactly like the powergen. It also had some rubber flap-like vents over the vent holes in the housing . They have an appearance which is immediately identifiable as Ford.

 

Hey guys,
I have a new 3.7 in my boat and want to remedy the alternator and water pump weaknesses before they kill my motor. Jonesracing has a belt drive system for pumps and alts. Any shops out there familiar with these mods?

 

What do you guys think of cutting a single plane 460 V8 intake manifold in half to get a decent 4bbl intake for the 3.7?

 

My Clymer's Mercruiser owner's manual has tons of information on these motors. Just look for a MM 470 shop manual.

 

I've worked on dozens of these Mercruisers over the years. They are very cool. They put out a LOT of power for their small displacement. There were a couple of drawbacks with them however. Since new they do NOT idle smooth no matter what you do to them. Drop a cylinder and the things would almost jump out of the boat! The chevy 2.5s and 3.0s idled a lot better. When there was a pump failure in the outdrive, the raw water cooled voltage regulator would overheat, set the engine harness on fire, and then proceed to burn the engine box, and then the rest of the boat...good times. The inner seal and shaft surface on the circulator pump would fail and then pump antifreeze into the engine oil making for nice milk shakes in the crankcase. Both of these problems were very common on those engines. You could redi sleeve the pump shafts and replace the seals and gaskets and that problem went away. The charging system could just be replaced with a remote mounted self exciting alternator like every other marine engine using Sierra's kit # 18-5953 conversion kit, if you had the room in front of the engine to mount the new pulley on the harmonic balancer. Most recently I have had trouble finding silly parts like head bolts and push rods (which come in different lengths to adjust the lash), they have both been discontinued by Mercuiser. The aluminum 4 barrel intake that came on the 190hp version was really cool and was a direct bolt on. I "might" have one if you're interested. Good luck with this beast. They were impressive.

 

xtian999,

The problem with cutting a 460 intake manifold in half and installing it on a 470 Mercruiser is that the heads on a V8 sit on an angle.

The head on a 470 sits flat. The 460 intake would be sitting at quite an angle.

I am using the stock 470 Mercruiser 190 hp intake.

It is very well designed and uses a 750 QuardaJet 4 barrel carb that is jetted for this engine.

The second picture is upside down.

That and the performance aluminum head will give brisk and reliable performance..

If you read back in this thread you will see a solution for the water pump problem.

And as sugested a marine alternator will solve the alternator problem in a boat. Coast Guard requirment.

Any alternator will work in a car.

They are a great engine when the 2 above weaknesses are addressed.

Dick

 

Form follows function. I can live with an angled intake if it is cool. Maybe with an angled spacer under the nitrous plate. Thanks.

 

You may be able to go with the angled intake but can the carburator?

Your talking about quite an angle.

Dick
.

 

So, a high rise single plane manifold is about 45 degrees off level and about straight even with the head. Not much angle if the head is level. Just a small wedge spacer would put the carb dead level. That would be totally cool on my boat. It is a 17 foot vee hull, and could stand to look a little more anti-social.

I love to start it up while the exhaust is still out of the water as I lower the boat lift. The exhaust sound is raucous!

I doubt that a spread bore carb and big valves will make it much faster than it is, but it will be fun to drive with a huge carb hanging in breeze. A Rat Boat!

 

The stock Mercruiser 4 barrel manifold uses the stock QuadraJet 750cfm carb with jets right for the engine.

That carb has 2 small 1.365" primaries and 2 hermongus 2.245" secondaries.

The advantages of this carb are that while running at slow speeds it gets good mileage on the primaries only.

As the engine can take the extra carburation the vacuum secondaries slowly open up.

A regular large 4 barrel carb will over carburate the engine off of the line.

That is if you wide open the throttle off the line it will bog down from too much flow.

Figure that the 750 cfm carbs were run on V8s.

Figure that if you put 2 750s on a V8 and opened the throttle all of the way from idle it would cough and die.

The QuadraJet is the perfect solution.

I am betting that the Mercury Marine engineers knew what they were doing when they set up the 190 hp 470s.

I am changing the head and eliminating the waterpump and alternator problems and leaving the rest alone.

If it ain't broke don't fix it.

Dick

 

I agree, the original carb tuning has been very well figured out.
The only thing that could stuff it up, is a radical change in exhaust back pressure away from the usual simple marine installation it was designed for.

 

I'm hoping that the aluminum performance head and the 2 1/2" side dump exhaust manifold will be at least as free flowing or even better flowing than the convoluted water cooled exhaust that is used in the boat.

I am looking at the Service Manual N0. 8 at the exhaust manifold.

It looks to be much more restrictive than the ford side dump manifolds that I have.

The exhaust exits the top of the Manifold and enters the exhaust elbow/resevour then it mixes with the water from the heat exchange and enters the upper exhaust pipe that has a flapper valve. It then enters the lower end unit and exits thru the center of the Prop.

I am sure that the engineers at Mercury Marine use the best possible methods of cooling the exhaust manifold and relieving the exaust but I don't think they can beat the side dump manifold or a tube header for flow.

I am using the ford truck manifold because it flows nicely and is cheeper than a header.

It also helps the engine look stock.

Dick
.

 

Each cylinder should have its own carb on this motor. I wish I knew where to find that setup.

 

If I ever get around to doing this, I would really like to have EFI, with individual throttle butterflies on each port.
Not difficult to do, it just takes money I don't have right now.

 

I recommend using the original 190hp Mercruiser Qjet on it. They have different jets, metering rods, accelerator pump adjustment , and secondary opening point ( the mechanical throttle plate link part) than the V8 or V6 qjets. I ran into this when I was doing all the remans for the local marine supply warehouse here. Do a few hundred of them and you pick up on these things without even trying.

 

Good advice. I will keep an eye out for them. Any special markings to look for?