The elusive 224/3.7 MerCruiser banger

Haha, it is not that bad Dennis.
Usually only three ignition questions, how many cylinders, how many coils, and what is the incoming static timing from the cam sensor.
This last one is usually a default value set to maybe between 60 to 70 BTDC, wherever you have locked your cam sensor. If your ignition map says the timing should 28 degrees, but your timing light says it is actually 26 degrees, you can either shift the cam sensor back two degrees, or tweak the value in software to make the ignition map read exactly right.

You just fill in the ignition timing values you want to have over the entire speed and load range. You will be given an example map for a similar type of engine that comes with the computer, or you can set the timing up on a dyno for the very best results.

. Once you have done this once, you will never ever go back to messing around with distributor springs and weights, and vacuum advance cans.

 

Is the 60 degree figure just a datum line far away from the actual timing setting? I have wondered why it is so far from the actual timing.

Yes it is nicer to do it electronically rather than fiddling with springs etc. no parts to look for on Craig'slist or down somewhere on the floor. There is, however a satisfaction in being able to pick up little [ and big] bits of metal and cut them to a needed dimension. And there is a simplicity in seeing a burned-up thing and saying "Ah ha I have found the problem."

Your suggestions are excellent and the electronic solution could be about the same price as a carbureted one. It is worth the experimenting. Thanks.
Dennis

 

Sixty degrees BTDC is now fairly typical of what most electronic systems require as the fixed base timing input.
You might be quite surprised when you start tuning your new EFI, how lean you can run it at very small throttle openings without misfiring, and how much ignition advance it likes when running like that. Even on small bore four cylinder engines I have seen ignition timings of 50 BTDC, and any retard from that figure, drops off power on the dyno. That is where the economy comes from.

I have spent vastly more money on carbs and the endless small parts required to tinker around with those carbs over the years. It is just endless.......
A tunable EFI is a big one time hit financially, but after that you can play around with it forever, and it costs nothing further to do so.

 

I love this thread.. I am finally getting close to finding a engine to begin my Build with.

 

I just found this thread and am fascinated by the motor. It sounds like cooling is one of the major issues/problems but we are looking to run the motor in a dragster.

I don't see any reference to HardBlock in the waterjacket. Is anyone (other than Sarge Nichols) running one of these in a dragster?

Any other links or threads that I should be reading to get more familiar with the motor

Thanks

Paul

 

Hi Paul,

Actually the cooling on one of these engines with an aluminum aftermarket head is very good and no problem in a street machine.

But if you are going to run one in a dragster then it might be a necessary to use HardBlok.

I have yet to actually communicate with any one who has had unreasonable block failure with the Mercruiser casting.

Mercury Marine engineers have lots of experience with high output aluminum blocks on their outboard motors.

The materials and casting techniques used by the Mercruiser engineers are probably as good as or better than any in the industry.

There are other engines that use the open jacket design used in the 470.

I have not heard that this is a problem for the 470.

I think that with the stock web between the bores being about .45" so a not too greedy .010 overbore to clean up a stock block and a 4" stroked crank would give you a 240 cu/in engine while retaining as much linner strength as possible at .43".

I would go to a turbo for more power rather than compromise the web strength.

Or another solution using Hard block might be to fill the jacket with paraffin to within about 1/2" of the top then HardBlok the rest.

After it sets then drill holes where the head gasket water jacket holes are and every 1/2" around the rest of the circumference.

Then heat the block to remove the paraffin.

I would think that this would give you the rigidity you are seeking while retaining the cooling.

If more rigidity is necessary several layers of HardBlok could me installed an inch or 2 apart.

How does HardBlok compaire to JB Weld ?

Randy Dupree has run these engines at the Maxton mile and Bonneville but I don't remember if he used HardBlock in the bottom of the waterjacket or not.

If he did I assume that he didn't fill the jacket all the way.

You can contact Randy here on the HAMB and Sarge on the Inliners.

Dick

 

Im glad to see that this thread is still going. Im still looking for an engine...

 

I have been looking at the pictures of this engine . I remember the Motormount part of this thread... I think the motormaunts are just like the mounts for a Small Block Chevy... I havent taken any measurements but it is an eyeball look... anyone oout there that can compare?

 

Looks like the same bolt patern.

 

Nope. On the first page of this thread you will see I used the mounts off a 6 which put the mounts at a 45* angle as they were meant to work and the two bolts across were wider so I welded a strap, then bolted up V8 mounts and P&J frame mounts. Also mounts the mounts right side up.

 

OK I didnt measure with anything but my eye....

 

I posted pictures of several motor mounts that I considered last year. Note that there is a lot of variation in mounts depending on the factory(and country) making them.
It is critical that the mount not be able to pull apart and drop the engine. You could saftey them with a chain. Although big block chevrolet mounts had a hook affair to prevent coming apart, on some of them it looked too weak to be much more than a decoration. They are big ugly mounts.

I ended up using new style mounts from a chevrolet v6 which had the rubber fully captured. Note that the left and right mounts are different but they can be cut to be the same. Given the choice, just buy the ones shaped as you need them.
These mounts were softer than the other mounts that I had bought. After you get it set up in the car you will know how stiff you want them to be. I feel a softer mount does a better job of isolating vibration, but it will not be as rigid in locating the engine.
As to the softness and vibration, softer mounts isolate lower frequencies but harder ones are as good at isolating high frequencies. Soft mounts also allow the engine to compress them when it should be moving the car. I'd avoid a large hard mount as it will transmit vibration as a block of wood does.
The traditional ford mounts that Dick posted photos of should work well and they are easy to use.

You can work the details out as you will be fabbing up the parts to make it all fit.

I'm glad you are underway.

I'm currently fitting an I beam axle in my car and putting rack & pinion steering on the axle. So I've been researching that.
Dennis

 

Note that there ae things which affect the location of the mounts {The oil filter}
so they are not be straight across from eachother. So you will have to measure both sides when figuring it out. (Guess who didn't ) I got more practise making the mounts. A hydraulic press was very helpful in bending them to shape.
dennis

 

look in craigslist for a boat with a good motor but some other problem.

 

As I recall Q-jets like a little less pressure than your typical Holley; 4 or 5psi at the carb also the power valve is designed to be closed at idle & cruise and open up at WOT and has the equivalnt flow of stepping up the 4 or 5 jet sizes. So you might want to check it. Look at the plugs if they have a black powdery coating that's another indication that the mixtures way FAT. Hope that's helpful.

P.S. Thanks to all you guys who are sharing your builds hard won info....

 

Black on the sparkplugs? I've black all over the car behind the exhaust outlet. black everywhere. I think my regulator is set at 4psi but it seems half a dozen jets rich.
For now it has a stock carter carb with #69 mainjet. The powervalves are available but hard to find as they are not supposed to fail [hah!] I cleaned this one but a quicker "fix" will be to temporairily swap over to an autolite carb that i know works.
Not much carb work right now as I'm changing its front axle and steering and am learning about the taper of ford and tyota balljoint studs in converting to rack and pinion steering. Also a little rubber molding as I was going to make mounts for one rack. I think this prevents the pinion gear teeth breaking.
dennis

 

Hey guys... Found a link to download a free TM on the Mercruiser 3.7L...
Here it is
http://www.4shared.com/get/gh-PNxn3/Mercruiser_Service_Manual_8_19.html

 

If you ever have to replace that thing take it out of the car and set it down next to the new one for a few minutes before you install the new one. In fact, go ahead and leave the two of them alone together. Take a walk into the house for a short break. That'll give the old one time to tell the new one what will happen if it misbehaves.

 

I'd not thought of that, ( leaving the new one right next to the old well-behaved one for 5 minutes). It will make a good story if nothing else. It will be like when I once put a big turnip into a blood pressure checking machine at Safeway, and confirmed that a turnip is without blood pressure.

 

Beetroots definitely bleed when stabbed.

 

Hi everybody.

My fabrications for the engine still going on, the intake manifold soon ready (some brackets for the fuelrail are missing). The exhaust manifold are missing the pipes for the wastegate. My powerglide soon comming back from the rebuild. I going to leave the crankshaft to get it balanced. I ordered the sealings for the engine. There still some things to order to the engine. I have some pipes to fabricate for the turbo, I have to rebuild the fuelsystem, fit in my drysump system and fabricate a new oiltray, and also do some bodywork on the front

I wonder about the front crankshaft seal. I see that you are using ford smallblock balancer so I suppose that the seal also are ford smallblock. The reson I am asking is that I cant order that seal from our marine shop and also I havent ordered my SFI balacer yet.

Dick, if you read this I tried to mail you and I also left you a PM

 

turboclubnorth,

Sierra part number 18-0578 is the part that replaces the Mercruiser part nimber 26-67388 front oil seal.

Sierre is a devision of Teleflex Marine. www.teleflexmarine.com

Teleflex lists them for $25.99 US.

I am thinking about installing a 700R4 GM overdrive automatic noncomputer model behind one of the 470s.

How are you handeling the Ford crank to Chevrolet Flywheel conversion for your PowerGlide ?

Dick

 

Hi Dick.
I think I buy one of this that someone recomended in the thread http://www.prwonlinestore.com/small...verterboltpattern-157teethneutralbalance.aspx

I cant find the post in the thread right now. I hope it will fit my engine and transmission, it´s also god to have a dual pattern for the converter. Regarding the front crankshaft seal I found it (silly me it was in the box for the frontcoverseal) but thank you for the information Dick I wrote down the numbers. Does it matter witch ford smallblock modell of balancer I buy? I suppose I narrow my options with a zero balanced, SFI approved one.

Dick I can write down the information in mail here if your mail not working
/Johan​

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Hi,
I have just discovered this forum after a lot of internet reasearch on this engine. This is by far the most informative place I've found yet. So thank you all for sharing your info and knowledge! I am currantly building one of these motors, however, mine will be repowering an old boat. I have finished the bottom end, and have made a few changes to fix existing problems, and to avoid future problems. the block has been bored .060 which was the minimum to clean it, it has been decked, line honed, and studed with arp studs to the mains and head. All internals have been balanced from balancer to flywheel. The pistons are sealed power speed pro forged, the rods are original, but have been magnifluxed, reconditioned, and resized, with arp bolts.The head is original cast iron, and has also been magnifluxed,it is currantly being ported and cc-ed. After porting work it will receive, new guides and seats. The camshaft is a Crane regrind to mercruiser 190 hp specs, I can supply specs later if anyone is interested.I will be running the 4 barrel setup. I currantly have .022 piston to deck clearence. I would appreiciate any ideas andhelp anyone can offer on this setup, after reading some of the comments on here. I am assumeing I need at least a 100cc combustion chamber, as I woulld like to come in at 8.5 or less. Thanks for all your help!

Robin

 

Welcome Robin,
Yours sounds right, my engine is zero decked for more turbulence and less detonation. My cranking compression is 185psi. head volume 102cc. cant really tell much as although I have 20 minutes on my engine it was way rich and without load so I can't say much yet except that it is way louder than anything else that I have. Do post your cam info. there can never be too much information. we were doing that here last year. I'm using a regrind on 115 degree lobe centers.
I have a photo of my new carb on my motor that I will soon post. My Mercruiser Rochester was running smoking rich at everything but full throttle. So it seemed expedient to fit a motocraft carb. I've several of them here as they are a simple carb which works well, being common and inexpensive helps too. Used carbs are a longshot nowadays. Most of them are parts donor carbs. rather than the good carbs the sellers claimed they were.

Robin, running them in a boat is far harder than in a car. the company retarded the ignition timing as a patchwork fix as the stock Merc compression ratio was too high for the available fuel when poorer fuel came on the market. .

 

Dick
I had to make a gearbox to reverse my unexpected reverse steering. I say this as if one turns a rack & pinion upside down, the car steers backwards. [DUH] This took some time but it is in and working my steering is 3.3 turns lock to lock so the ratio seems right.
So that's why I've not posted, I was working on something not related to the merc engine.

 

this shows a $10 motocraft carb. [2100] bolted on. Wide but not tall they fit fairly well.
Adapting parts are : carb adapter plate and two thick fiber stand off "gaskets"
the Ford valve cover gave a little more room, The stock merc. throttle linkage fits almost as is. The white dome is a plastic camping dinner plate.

 

I got rid of the mercruiser waterpump today. I cut 1/2" to 3/4" off the nose of the camshaft. A Dorman "cup plug # 570-026 presses into the camshaft opening in the waterpump housing perfectly. (It is a size slightly less than 1 .5") . The rear half of the Mercruiser waterpump housing is un-modified and fills with coolant. The front half of the housing is replaced with a 1/4" aluminum plate that a Toyota Corolla water pump bolts onto.

 

As plugging the cam passageway into the water pump was so easy, I immediately made a plate adapting a Toyota corolla water pump to my Mercruiser 470.

The plate takes its shape mainly from the Merc. water pump which it covers.
Flow considerations determine the location of the outlet of the Toyota pump. Coolant flows through a hole in the plate located near the Merc. pump outlet opening. The shape and size of outlet hole in the plate is determined by the passageway walls of the two pumps. It is as large as I could make it.

In the pictures the adapting plate is still blue from its layout fluid. A set of 5/16" studs hold the Toyota pump on the plate. I will use allen head capscrews in some locations on the plate as they are smaller than an ordinary bolt head.
You can see two black bolts countersunk to clear the water pump impeller.

 

By nothing more than luck, my waterpump pulley lined up nicely with the vibration dampener pulley. That saved me a day [working at my speed].
I made a mount for a generator taking pains to align it with the other two pullies, but even so It was not as close as the accidental alignment of the first two pullies.

Electric waterpumps have their advantages:
1. Easy (quick) to install as alignment doesn't matter.
2. Can be run of just the battry taking little engine power (for a brief run).
3. No drivebelt to fall off.
4. Pump location is not restricted.