The elusive 224/3.7 MerCruiser banger

The inner diameter of the sleeves scales to 4.25". The sleeves look as thick as old cannon barrels leaving lots of room for boring. Does the bore for the sleeves coming near the outer diameter of the threads for the head fasteners reduce fastener retaining strength there?

 

Yes you are correct on both items. Myself and my machinist friend set down drew out something close we simply CNC’ed the plate as a proof of concept, made sure we were weren’t going to get too deep in the bolt hold the went with the same program except for it was internal. The press is very light because I filled my block.

 

Chris,
Thank you for explaining the process of making and installing the plate. Are you and/or your machinist friend interested in making and selling some of these plates? I believe several folks on here would be interested. If not, would you consider providing the CAD files so we could have them made locally? I would be interested in purchasing them.

Bruce

 

Yesterday I tried the acetone transfer from paper to aluminum and although it did transfer, the image was too faint to be of use. I used fast reducer and did not scrub the aluminum. Here is a comparison of several options for transfering an image to wood but it should work on metal too.
I have attached below information on aluminum solder available in the local welding store. press control + to enlarge it so it is readable.
The solder I have flows easily so a 0.006 gap is suggested.

 

I wish I could, we did my block in the late 1990’ (1998-1999) my machinist passed away 4 years ago . I explain the process we did though, the 10 bolt holes are the same spacing as the bore , 4.900 between them up and down side to side, bore is on a 4.900 bore space once those holes are placed . We decided to use a 1/2 mill so all radius have to be a minimum of 1/4 inch once the cylinders are bored out the rest of the measurements are just deciding how much ledge you can get away with before your either into the bolt holes or into the outside of the block.

 

Jose if I’m not mistaken is going to run a 4.650 bore. As he’s planning on going to a better head and a billet crank. He runs his in sand drags .

 

Some of you have questioned Clint's method of cutting an inch off the deck as it relates to faster grip. Here’s the deal I think with head studs. This should be all that’s needed 1.125 thread engagement.

https://www.disher.com/2016/06/01/bolt-boot-camp-6-things-know-threaded-fasteners/

 

Chris,

Thanx for the info about the deck plates and fasteners. You have really helped here with your willingness to share from your experience.
Sorry to hear about your machinist friend. Unfortunately, when these guys pass, so much information is lost. This thread should help in that regard.

 

This video should help disperse some of the myths about port CC’s hope you enjoy!!

https://fb.watch/2HEo3aRoW7/

 

I’m the first to admit I’m far from a know everything about this engine, but like me posting 3 different decks. They all work, just different ways to get there. So much of the information on engines ( any engine) is based on the way it was done 20-50 years ago. CC of ports to define how big is too big , how much cam is streetable , how much rpm can I turn , how much carb is too big. Big advance’s have been made. My engineer friend told me “ you can’t get too big of a valve in a two valve head, you can have too much port for the valve size, but not too much valve. Here is a perfect example, today’s LS engine 6.0 liter those heads stock flow over 310 cfm. That’s from the factory !!! Mild port job your looking at 340+. These engines go 150k + miles. Start and drive great. 30 years ago if you were to say I can run a street engine with a head that flows 320 cfm with good street manners you would have been laughed outa town. Airflow regardless of rpm or CI. Is the key to making hp. Again the ports need to be of proper size for the valve . Just look at motorcycle heads, 4-5 valve heads. Don’t be stuck in the passed .

 

dennis g,
You are looking for a way to transfer your pattern to the aluminum. My preferred method is to skip that step. I sacrifice the pattern. Small patterns are simple to reproduce, just make a copy on the printer. The deck insert would require a new one to be made. I simply spray contact cement on the parts. Follow the cans directions on spraying one surface or both. My choices are 3M 77 or 3M 90. This method does require cleanup of the part to remove the paper and glue.

How good does the pattern have to be and how do you draw it? Some of my methods are pretty crude, but they work. For the deck plate pattern you need a piece of paper at least 22" long. There is an old school print shop near me. They have off fall rolls of paper in a variety of widths. This stuff is junk for them. A roll lasts me years for my uses. (this stuff also works when masking for paint jobs). Place the paper on the deck. Put a couple heavy pieces on top (I used short pieces of 4x4 wood), one centered and the other on the end. With your DIRTY finger rub the exposed deck. The edges will "print" with the dirt. Move the center weight to the end you just "printed". Repeat the rubbing step. Move the weight once more and complete the pattern. You will have to make your finger tips "dirty" a couple times. I made 2 deck insert patterns in less than 10 min.

Another weird thing I use in my garage is Press & Seal. It is a kitchen wrap used to seal containers (if your wife hasn't heard of it get her a roll too). One side is tacky. I have a short block here. I have a piece of Press and Seal placed on top to keep the cylinders clean. This stuff is not strong so another cover has to go over it. It will cut on the blocks edges or cylinders if you rub your finger on it too hard. The residue from the Press and Seal helped my pattern paper stay in place. You've seen high dollar show cars brought into shows with their tires covered to keep them clean, right? Press and Seal works for that.

 

Beck, that is an excellent way to make a pattern. I have used it for some time and it was the starting point for the files I sent out a few pages back. your point of doing it directly is a good one. The more steps there are, the more places there are for things to go wrong, and errors creep in. I have noticed that the outside of mercrusier cylinders vary from ones having odd lumps here and there (on 170) to ones having even bulges on the thrust sides and the side across from them.(on 488)
I glue sandpaper onto marble slabs (the ones which test as being flat) for surfacing with 3m 77. It glues well but I found that my glue spray can plugged up after being used.
I did not kknow of stick and seal and will try some. We used to use "parafilm" in labs, it seemed to be like parafin but it was stretchy, acid proof and sealed well.

 

We know that our headgaskets need sealant beads, and that the gaskets now comon lack them. We also know that aluminum heads are superior to iron heads but that the aluminum heads are designed for V8 engines so there is no front outlet for coolant.
Now my question, aren't the best head gaskets somewhat incompatable with the best heads, as water passages in the gaskets are to control water flow pattern in the heads and Mercruiser heads have an outlet at the front while unmodified Ford pattern heads have water outlets at the side?

Compare a Mercruiser gasket with a Ford gasket to decide this issue.

For those of us running side coolant outlets, have you had cooling difficulties as I did?

Because I changed to a different waterpump design , I can't tell if the difficulty I had was due to the Mercruiser gasket, my Toyota water pump or the ignition being retarded to work with a "stock" cam grind.

I can say that with the special cam grind that I requested, at 11:1 compression ratio the engine did not knock and had little difficulty with overheating.

So I'd like to hear from you on your experience with this.

 

Dennis G, As far as experience, I have none to offer. I can only offer my thoughts.

These motors are unique and those of us playing with them need to be above the SBC assembly level. Most of us are trying to reengineer these things. Mercruiser spent millions doing that. We have to be smarter than them, right?

We gotta’ get that hot coolant out. That means we have to either cut up the front of our new expensive aluminum head or we have to cut some holes in both ends of the intake manifold. 2 barrel manifolds are cheap, but I don’t want to trash a 4 bbl one. Then we figure out a way to attach and seal the outlets.

As far as head gaskets go, they are totally compatible with the heads. It's the blocks that they are not compatible with. Lets take a look at those head gaskets. Other than the sealant stripes vs rings, aren’t they pretty much the same. Compare the Fel Pro gasket in post #2345 and the Mercruiser gasket in post #2355. Perhaps I’m missing something but aren’t the holes very similar. Both gaskets are designed to put a lot more and equal coolant through the exhaust side of the head. The intake side has holes decreasing in size toward the front. The copper gasket in post #2345 has smaller coolant holes on the exhaust side, but how big are the mating holes in the head? I don’t know.

I can’t see your water pump causing your heating problem. As long as the Toyota pump was turning the right direction and the pump discharge was not obstructed, you’re good. I see your water pump conversion as a coolant improvement. As I said above, I think the head gaskets are useable as long as it seals. I’m not smart enough to analyze the timing vs heat. Are you running the same carb? Could it have been that lean?

 

I've always used autolite 2100 carbs. With a $10 adapter they bolt onto the merc manifold and it is not hard to make a 2 bl. autolite carb dance to your tune. they are simple to tune, cheap at swapmeets and work well I've jets from 40 to 65 for mine.
The best ones are from a 289 Mustang or Fairlane in the mid to late 1960's because they are the right size for our engines. 2100s were also used on larger engines than the 289 and 305 with different ventruris and jets but those will never adjust to the Merc engine. Holly jets fit the 2100. A worn carb is not bad as you know it worked a long time and you can rebush the throttle shaft with brass tubing from a model airplane store. If the idle mixture is too lean and refuses to adjust, drill out the idle restrictor found behind a lead plug. With a wide band oxygen sensor jetting is easy.

 

I was breaking in a merc 120. It was timed wrong with its advance retarded to 20 degrees and with short stacks exhaust acted as a weed burner on the blackberries within 8 feet of the engine. 32 degrees advance at 2100 rpm works well on the merc 170/190/470/488 s but one camshaft required the ignition advance retarded to 28 degrees advance or it knocked and then its exhaust temp was 1700 F even at light throttle. Ignition advance timing is critical to engine heat output.

 

I just started working on my project. Don't really want to change the subject here, but how do you guy's get the black paint off these things? I see some of you guy's have really nice clean looking like new blocks. How did you get there, or are they just painted aluminum color?

 

True engine builders will cringe at my method. When I started working on mine I had access to a large glass bead blaster with dust collector. Larger blast media would work faster than glass beads. I taped up everyplace I didn't want to hit with the abrasive. It took a few hours, but came out clean. Blasting the water passage is the hardest. This isn't a good idea if you aren't boring and having the block cleaned. This requires removing all the coolant and oil plugs and really cleaned it many times. The glass beads hang in there, which later destroys everything. I epoxy primed and painted mine silver. It looks like fresh aluminum. Painting like I did isn't the best thing to do if your worried about cooling. I come from a street rod background, so I just had to make it shine. A thin coat of black paint is the best heat transfer. There used to be "radiator black" paint available. My thought was, their water cooled not air.

 

Thanks Beck, my block will barely fit in my blast cabinet and I may try it. I have tried paint stripper, didn't work, barely touched the paint. Tried a wire brush, terrible finish with that. Should of left it, as the black paint was good, I just didn't like it black.

 

Remember, this is a Ford cousin, so why not just paint it "Model A/ V8 green" over the black? LOL!!

 

That factory paint is amazingly tough. Remember to clean, clean, clean after it's blasted.
One of the early posters here, dawford, was using his in a Model A. I believe it was painted green to hide it as best as possible. His posts start back on page 3.

 

I painted one mercruiser engine orange and another "old ford green" and left another black. I sprayed color over the black original paint and kept touch up paint handy. Thin paint helps heat loss thick paint prevents heat loss. What matters is that the metal should be covered with a thin layer of some organic material, oil for example would be ok as long as it was a thin layer. That is why rattle can paint is good, it makes a very thin coat. Color makes no difference as heat is radiated in the infra red below the frequencies associated with colors.

 

Has anyone had success with the headgasket that has no sealant bead?

 

I have been very hesitant to post the following, being afraid readers will see this as a successful modification. This is nothing more than a TEST. I am unsure if the epoxy will hold up to the heat and stresses of usage. I doubt this block will ever see service, so further information on its success or failure is doubtful. The following information is an explanation of how I did it, NOT a “how to” on it.

I had been stating that I thought epoxy would work to “glue” a deck plate in. Further research on most of the epoxies showed that it would probably fail due to the heat. Most manufacturers rate the upper heat of their epoxy on when it totally fails. There is another temperature that they don’t rate. That is when the epoxy starts to get soft.

For example, the epoxy used on Ford truck bed sides is loosened with a heat gun. Somewhere around 185 deg F the epoxy softens and is separated by prying the pieces apart. If the epoxy softens when used holding a deck plate in the clamping pressure on it would push it deeper into the block destroying its seal.

There were a few candidates that have better listed properties. Cotronics Corp has 2 possibilities. Duralco 4540 and Durabond 454B. They appear to be nearly the same, 454B is thicker. They are both rated to 500 deg F. Unfortunately Cotronics has a $100 minimum order, so I did not order any to test. I know nothing about that manufacturer.

My other option was silly simple, Original JB Weld. JB Weld is rated to 550 deg F. Most of us are familiar with the product. A 10 oz. package is available online for about $14. One of these is enough. Some of the epoxies set fast enough that I wouldn’t have had enough time to “butter” all the surfaces before assembly. JB Weld has a fairly long working time.

The outside nightly temperature here has been in the mid 30s. I left the heat off in my garage overnight to cool it down to further slow the cure time. It was about 60 deg. After I had everything “glued” I turned the heat back on to 70 deg. I put a couple little electric heaters at the ends of the block to bring it up to about 80 deg.

I have a small mill. I mounted the block on the table and trued it. Using a 3/8” end mill I cut .360” steps at all the bolt bosses. That would give me a stop when putting the 3/8” thick deck plate in. I used the end mill to slightly cut all the perimeter of the block. That took it down to clean metal. I cleaned the cylinder ODs using a ¼” sanding drum in my Dremel. There were a few places to tight for it which I used a small stone on. The metal has to be clean for the epoxy to stick.

I cut the plate from 3/8” 6061 plate. It wasn’t easy. I cut the outside dimensions using a table saw. Wear safety glasses! I then cut the bolt notches using a band saw. The blade won’t turn tight enough so little wedges need to be cut out. I thought I would be able to cut the cylinder bores out on the band saw, but my blade wouldn’t turn tight enough. I struggled through the 1st hole cutting wedges. The other 3 I marked the center and used a 4 ¾” hole saw. That still isn’t big enough. I used a big end mill like a spindle sander and removed the rest. There were a lot of hours fitting the plate to the block with a file and carbide burr.

I intentionally put a gap between my spacer plate and the block. I thought a tight fit would cut the epoxy off of the parts as I put them together. I didn’t have a problem getting the pieces glued and assembled by myself. It is really messy. Initially I used gloves, but the epoxy basically pulls them off. I wound up with bare hands. Once I had the parts together I used a 1” piece of body putty spreader to work the JB Weld into the joints. When happy, I put some wax paper under 9/16” washers and bolted it in each head bolt hole. It was quite a mess when finished. After a few days I took it to have it decked. I intentionally had .015” of the plate sticking out of the block. Because of the amount of metal to be removed I was charged a bit extra. After decking there were some small spots where there were air bubbles opened up. Using a tiny burr on my Dremel I opened these up and roughed them up to allow patching with more JB Weld applied with a tooth pick.

I did that just a few minutes ago. After curing I will gently sand the high spots off completing the installation.

I still need to drill coolant passage holes into the filler plate.

REMEMBER; this is NOT a proven instillation. It is possible it will fail.

Click on a photo and scroll left or right to see all 4 photos full size.

 

Beck, what a great post. Magnificent detail: clearly written, especially well explained and very well illustrated I'd not hesitate to use that block, or your method which is well thought out and is a method that we can do ourselves. It is particularly good as a well planned experiment.
Your many hours of labor have paid off,
dennis

 

Deck plate setup….. I would do some things differently the next time.

If using a 1/4" or a 3/8” thick plate again I would cut the block differently next time. I would cut the entire bolt boss off to a depth slightly less than that. I would “square up” the deck opening. That eliminates cutting all of the notches in the outside of the deck plate around the bolt bosses. It does however create another problem if you are planning to use epoxy. The epoxy is going to want to run into the bolt holes when the plate is installed. A Q-Tip with acetone would help clean it up. I would grease the bolts and bolt holes so they don’t get glued tight. If it was being welded in there wouldn’t be an issue. Definitely bolt the deck plate in while welding or gluing.

The OD of the cylinder walls is not round. Things get easier with round cylinders. I would devise a holder for a router, and make them round. The drop out from my 4 ¾” hole saw is larger than the cylinder bore. I would take one of those drop outs and chuck it into my lathe. I would cut the diameter to be a snug fit into the cylinder bore. The center would have been drilled and tapped to fit a heim joint. That heim joint would be the center pivot for a router bracket. The router will sit flat on all the surrounding block deck, it just need something to guide it in a circle. Use a cutter small enough to clear the block walls. Router bracketry depends on your router.

Obviously I wouldn’t try to cut the cylinder bores into the deck plate with the band saw. That was a failure. Using a mill and having round cylinder ODs makes it much easier. Using my 4 ¾” hole saw I would cut the 4 bores on 4.9” centers. I would then swap the hole saw for a boring bar and gently take the holes to the correct diameter. The cutter will want to snag on the opening. Take into consideration how much clearance to add. Whether you’re using epoxy or welding, you will want some clearance. If it is a tight fit and you’re welding there won’t be enough penetration and when the block is decked you will probably be back down to the joint. If not it will be very weak.

If you’re going to add big aftermarket sleeves you don’t need to worry about putting the cylinder holes into the plate. Cut the cylinders off deep enough to get them out of the way and run the plate over them. You will want to put a hole there to allow an indicator into the cylinders to find centers of the original bores.

Now you need to measure the distance from the cylinder OD to the block. It may be different from side to side and end to end. Measure carefully, calculate your clearance on both sides of the plate into this measurement. Cut the outside of the plate with an end mill.

Attach by your preferred method. Above I showed how I test fit a deck plate with epoxy. In my opinion I would not do that if the block machining was not completed yet. Welding is a much more secure option. The only reason I did it on that block was because it was already finished machined and I was afraid of warpage.

1 other thing I would change. I wasn't careful enough when I was masking my cylinders with tape. Since I used epoxy and wasn't going to bore or hone again I was trying to protect the cylinder walls. I accomplished that, but I didn't get the tape high enough to protect the chamfer at the top of the bore. I need to clean that up.

 

Nice job, Beck!
I know we discussed filling the block temporarily with sugar or soda to keep the glue from dripping into the water jacket. Did you decide against it? I would use soda and then recycle it in my blast cabinet.

Another thought: When drilling the water passages in the deck plate, it might be worthwhile to copy the Mercruiser gasket for hole size. They obviously felt the need to force more water to the back of the block and head. It can't hurt.

Stay tuned for my solution to make the outside of the cylinders round and concentric with the bores.

 

That's like the "Honda method" I was describing about 10 pages back. It works fine for those guys running 40+ pounds of boost, so it should be fine for everyone's needs.

 

I did not put anything in the block before gluing. I am sure there are JB Weld goobers hanging in there. The steps I machined into the bolt bosses located the depth of the filler plate.

I have made a major coolant routing change on that block. If you look at the "finished" photo you can see a tube coming out of each cylinder. Those are the coolant inlets which will be tied to a coolant manifold. The manifold is designed to deliver equal flow to each cylinder. That should eliminate the extra heat at the rear of the motor. This is something I copied from others. The tubes are from Sweet mfg on ebay. I used 5/8 dia so I could use regular heater hose. The tubes were glued into the block holes with JB Weld. I am building the manifold out of copper water line fittings and tube. A 1/2" copper tube is 5/8" OD.


I have also modified the crankcase venting system. 2 fellow tractor pullers running these engines have issues of spraying oil out the valve cover breather when they really rev their engines. At high RPM the motor over oils the top end putting a lot of oil in the valve cover. They also have some blow-by when turning that RPM. That creates a battle in the oil drain back holes. The blow-by wants up and out. The oil wants back down to the pan. The blow-by wins taking oil out the valve cover breather.

Since I moved the coolant inlets to the side of the block the old inlet was plated off close to #1 cylinder. I was using JB Weld everywhere else so I just glued an aluminum plug into the hole. I drilled a hole in the timing chain cover and a few in the block to connect the crankcase area to the old water inlet area. I added a vent tube going down the front of the cover. This is now my crankcase vent. This eliminates the fight between the blow-by and oil draining from the valve cover. I am also adding another drain tube from the side of the valve cover to the fuel pump block off plate.

As I stated above; This is a test, not a "how to".

I wonder if I could get sponsorship from JB Weld. This sounds like a commercial, but I have no connection to that company.