The elusive 224/3.7 MerCruiser banger

The Salem laser guy said that my most recent drawings are better but that they are not useable as the lines appear as two lines. When the laser encounters that it cuts a circle. He connected to two other cad/cam men and they could not do anything with the files either. I asked about line width and he said that was not a problem. So I am going to cut a thin one by hand (from an acetone transfered pattern)to make a template to test fit.

$60 each for 2 is ok. As expected , laser cutting is less $18 to 24 for cutting + $15 for material + $26 for loading and deburing (most of the $26 was for deburring which we can skip and do ourselves). But there are "hoops to jump through " for the laser process.

 

I will have to look at the block I have, wondering if a small shelf could be milled into the edge of the block for the plate to sit on. The lifter / push rod opening side is the problem area if the plate had a ledge to sit on epoxy would probably work fine. I recall someone talking about the head bolts a while back, most all late model stuff use aluminum heads and blocks and almost every thing uses stretch to yield head bolts. I think the 9/16 bolts on these engines might be to stiff and lose their torque after repeated heat cycling. I wonder if tread inserts and using 1/2" stretch to yield bolts would help.

 

I torque my headbolts to 125 lbs and follow the Mercruiser suggestion of using their "Perfect seal" on headbolt threads. Removal torque is higher and I think snapping a wasted bolt in the block is a concern. Studs would not have this removal problem. They do incease their clamping force as the aluminum warms expanding more than steel but this is limited by coolant temperature

Your suggestion of a shelf is reasonable but there is so little material there, I would worry about removing any of it. Randy suggested bolting and gluing metal in there. It could be a shelf or material extending to the gasket surface. Doing this requires drilling holes across the lifter gallery which would have to be plugged after the socket head bolts or rivits are in place.

The problem is coolant leaking over the edge of the block into the oil. We could seal the water passages between block and head with o rings. That would put much less force on the aluminum or Devcon filler plug that we would put in IF only the o ring was in contact there. that could be done by making a large hole in the gasket to locate the o ring and replacing the head gasket's water restriction with a drilled plug in the head at that point. The drilled a hole should equal the diameter of the former water restriction hole in the gasket.

A cold solution that could be used on a more or less intact engine is appealing.

 

I found that the double lines my DXF drawings are there as part of the conversion process.
It is not hard to overcome them but that takes more knowledge than
i have at the moment to do this.

 

this is the better set of files from the scanner at the blueprint company. they are good files but have to be converted to DXF format before being usable.
Drawing 3 is the best one of them. its jpeg image is available but too much memory to be posted here. It is just a conversion of the pdf file.

 

@Three Widow's Garage,
Up until a couple of years ago, this thread had a contributor with the screen name IADR. He was an advocate of reduced shank studs. He purchased some from C&C Motorsports. These were turned down in the center. Not clear on if C&C did this or he had them done elsewhere. IADR was a stickler for detail and he particularly purchased these studs because they had more thread engagement in the block.
I think @beck also purchased C&C studs. I do not know if he reduced the shank diameter on his.

My thoughts on the closing the deck:
Until Mercruiser changed the head gasket, eliminating the sealing bead, there was no good reason to close the deck up for a stock rebuild and probably not even for a mild hop up.
Since it appears that the good gaskets are not available and probably won't be again:
I think that a half inch or so of Devcon at the top of the block is worth doing just for peace of mind.
If the performance is to be greatly increased, especially with a big bore or long stroke crank, reinforcing the deck with an aluminum plate, is the prudent thing to do. Welding it in place would likely be the most bulletproof assembly. But, with the modern day adhesives, welding might just bring on more problems than it solves. I think that the adhesive or Devcon might act as a dampening medium to stabilize the top of the cylinder bores.
For an all out race build, the block can be extended with a thick plate between it and the head. this allows longer cylinder sleeves. Theoretically, the engine can be made to have a 4.600" bore with a 4.150" stroke using the stock crankshaft without welding. (276 cu.in.) The largest combination I have seen is 4.500" with a 4.150" stroke (a mere 264 cu.in.) The plate for this type of build is only limited by the builders imagination. I'm imagining such a combination, but it's not even to the drawing board yet.
I would like to see a plate routered out. If that process can be used effectively, I can see how it could be used to make the ultimate Mercruiser. 3WG, are you up for the challenge?

If anyone has information on IADR I would really like to get in touch with him. He was from Edmonton with little other info. He mentioned in one of his posts that his health might be a limiting factor in his build.

Thanx,

Bruce

 

I did purchase C&C studs but for a different reason. Mine are not reduced diameter. Mine were purchased longer than stock due to the thickness of my aftermarket head.

 

I spoke to my local shop that does laser cutting. They have never cut aluminum, just stainless steel. They are concerned their machine is not high enough wattage (2000 W) to work with aluminum. They have been wanting to try it though. I told them I'd play if they would.

I ask about how to get a top quality file for the cutting operation. My contact at that business doesn't run that machine or program for it so he couldn't provide that info. He did however think water jet cutting would work better for this job.

 

I got word from my local laser cutter. They can't cut that thick of aluminum.
I have been seeing a lot of facebook adds for the decorative steel signs. Most of these guys work economically. I wonder if they would be interested in our insert. I am concerned that their machines are not large enough also.

 

I had my blueprint shop copy the original prints today so that I can use the acetone transfer process to mark the pattern onto aluminum. If it works, I can mail them to you. It seems easy enough to rough cut them with a saw and file to final size.

Aluminum has the advantage of matching the block in thermal expansion. The local metal fab shop said they laser cut lots of aluminum and 1/4 to 3/8 is not a problem for them.

I'm hung up on transferring file data into dxf because the sign shop wants $85 to do that, it seems like price gouging. There are outfits online [artlogo and radish drawing] who do this for $5 or $6. Their service is necessary [ unless I use my wife's computer that she uses all day and download a program] as each of the 5 free online conversion programs that I tried produces a line at both edges of a templates line and the laser will not cut a double line.

 

Bruce has mentioned adhesives so here are tables from the Locktite Sourcebook:

View attachment 4888267

 

The preceeding charts from the Locktite sourcebook are for the adhesives and sealants.
I marked those of interest to us.
The acrylics have better heat resistance so I included them.
The above epoxy adhesive chart does not show heat resistance, critical information for us.
Anarobic Sealants are worth using but not for block filling. 518 is a favorite of mine.
Another sealant that I like is Hi Tack it is good to 500F

 

This temperature resistance information is later in the sourcebook. Note that many epoxies do not resist the temperatures of our engines, mine was at 265F one day. I used the 300F resistant marine epoxy to glue aluminum blocks aginst the cylinders in its water jacket. My engine got really hot ( lacking water) but the epoxy is still is ok in there. It is a harder epoxy.

 

Devcon with its 350 F temperature resistance is clearly a good choice.

 

Lots of interesting stuff since i looked last ! Its bin a few years ! I built my motor 9 years ago because of this thread !
My motor is in a small jet boat. currently its bored 30 over and stroked .100, custom colt cam , eagle 440 chrysler rods and edlbrock head . works good ! roughly 240 hp at 4500 rpm, thats a guess but running a jet pump is close to a dyno and the guys at Scott in NZ suggest that's where I am at.
I had intended to weld in a block plate last time mine was apart but got in a rush and passed, I am interested in your plans of gluing it in.

 

https://beta.sharecad.org/ this viewer works on my dxf files

 

it is easier for you to just convert the best pdf (#3) to a dwg file. The only dwg files I have are the early ones. You must view it before trying it as it may have double lines as so many automatic converters produce. I decided to pay to have the conversion and a Chinese firm (that works 24 hrs per day) called "radishdrawing" looked at file #3 and will do it for $6 they said it would be a single line as we need The problem is that they want to be paid by pay pal and pay pal requires a cell phone for identity so that leaves me out of it. I will post a link to them : radishdrawing@gmail.com

since posting the above I contacted another company: artlogo.net
they have similar prices and have a nevada phone number So they looked at my drawing and said $8 i said visa card and they have not responded.

 

Had some free time yesterday, used Sketch Up to draw a file from measurements. Cut this with plasma to check fit, only 1/8 sheet, need a few minor tweaks then I will cut from 1/4" material. My intent is to tig weld in I may just weld the lifter wall solid and interment weld the rest. I think any way these are cut they will require some hand fitting as the blocks have some inconsistency in the casting process. When I get the .dxf file sorted I will see if I can post it or message me and I can send it to you. Black Friday special.

 

I'm delighted to see it. It looks so good as I've been nailing jelly to a tree. I had expected that file work would be needed. Yes the castings will vary slightly and when I drew the little circles next to the lifter gallery wall I could see that I drew mine poorly there but no matter what I did it looked wrong so to fix that, I expected to fill and file as needed.

yes, That one joint should be tig welded or brazed or soldered as it is the one near the sealing problem. It looks like the aluminum around the second headbolt is too tight against the fill plate to the rear of the headbolt. Filing the plate there would tighten the loose spot around the first cylinder. I'd planned on soldering or brazing it so the gaps would be filled by that process. I noticed odd random lumps of aluminum on the cylinders of my engines.

A CD is almost the same diameter as the outside of the cylinders and is helpful for that.

A friend said that rubbing chalk on your file will keep it from filing up with aluminum. It works when I remember to do it. Body files are good on aluminum also. I'm pleased that you had the courage to do the first cutting.

 

Three Widow's Garage,
That looks like a great first attempt. If plasma is that good, I don't see why we would need to get any fancier. I expected that some hand fitting would be necessary. What is the thickness limit for the plasma?

Even though I have access to a plasma cutter, I would be willing to purchase a plate or two from you to help offset the cost and compensate you for your time. Or, maybe guys wanting the file could contribute to your hot rod fund.

Thanx,

Bruce

 

I'll try to cut on from 1/4" this weekend, I think I still have a piece large enough. My plasma cutter is the small Miller and wont give a clean cut on much over 1/4 "in steel, I never tried it on any thicker aluminum. If I can get a satisfactory part I don't mind making a few. I need to do some practice runs trying to tig some of the plasma cut plate to same cast and see how it goes, been welding over forty years, relatively new to tig welding. Thinking the plasma cut edges will need to be cleaned off well. When I finish correcting my drawing I will post it if anyone wants to give it a shot.

 

Does your photo show the inside of the transom? or does the engine face the other way with the pump inside the boat? Did the pump you used come with the boat or did you adda diferent one? It looks good and I am pleased that it is serving you well. your throttle linkage is nicer than the ones I use.

 

There is an advantage that we have not mentioned for having a metal plate across the water jacket. It will help transfer heat out of the hottest part of the engine. That is its one big advantage over a Devcon fill as
Devcon works the other way, insulating the outside of the tops of the cylinders. Aluminum heads carry heat away well also when compared to cast iron.
I put an aluminum plate on the bottom fin of a 2 stroke aircooled ultralight engine which then ran lower head temperatures [350f instead of 375f]. This approximates what our deck fill plate would do.

 

Nice work Three Widow's Garage! You guys are really progressing. I was wondering how much variance there was from block to block. For welding I am sure the plasma cut edge and the cast block will need to be cleaned. I'm picturing a Dremel tool with the round sanding drum.
Three Widow's Garage, your plasma is computer operated? This wasn't done by hand with a pattern, right?
I would be very interested in the file when someone gets a nice fit! I can see each of us wanting something a little different. I'm still leaning toward more thickness.
I'm guessing the same file would work for water jet?

 

Yes it should work for a water jet. how thick do you want your aluminum Beck? Laser cutting is charged by the minute and thick material cuts slower. I'm not into selling anything. My files are free and if the cutter here does plates you will have them at what he charges me plus the actual shipping cost. But I can't convert them properly and two of the converting services seem to want paypal. You could send cylinder head template002 to them and with paypal have a file in a few hours. it has a gap in one spot but otherwise is a better fitting file than 003.

 

I think I would go with 5/16" thick.
I thought you said in your 2255 and 2268 Posts that #3 was the best one? Here you said #2 is best?
How is the gap in file #2 filled to make a good file?
How do you take this "file" to the cutter, on a flash drive or email it to them?

You guys have me all fired up and ready to do this, unfortunately I have 1 nearly completed motor, 1 assembled short block, and one stocker never disassembled. Naturally the ones I want this on are the assembled ones. That means complete disassembly, install the plate, mill the block, then full reassembly. I need to take a step back and do some weighing. If everything is too heavy for me to make my weight class the 1st thing I'm doing is switching to methanol fuel, removing all cooling, and running a dry block which would make this modification unnecessary for me. However, if someone gets this all lined out I am in for a couple parts.

 

Beck, file 3 is one of the old files that I re-inked. Files 1 and 2 are new, done from a single new tracing. the lines on 3 are complete there is a gap in one line on files 1 and 2 but the shapes of the aluminum where the head bolts go are better on 1 and 2 which are the same tracing. File 2 has more contrast in its scanning. 1 and 2 look the same to me. I assume there would be small errors that I would have to manually repair with a hand file once it was laser cut. I email the digital file to bill@martinmetalfab.net
If the file is good (it must be single lines), he cuts it and I go to pay and pick it up from him. the files must be vector files for him to use dwg and dxf are the right types for laser cutting. They have continuous lines. Scanning drawing makes raster files jpeg pdf are two examples of raster files. Raster files are of pixles and useless for cad cam cutting. The fab shops can only work with vector files and they do not know how to convert a raster file to a vector file. The scanning company can work only with raster files and sends them out for conversion to get a vector file.

I have a completed motor with 45 minutes time with its head off for glaze break and ring change out, a junk split block and a supposedly running motor with its head off for inspection, it is as yet unconverted ( no 5/8" milling removal from its back end ).

 

the thing that is shaped like a roof is the hardest part of the drawing to get right. the two bumps near its proximal (close to the block) end never seem quite right but this is one of the better ones.you can see that the raster image is composed of little blobs of pigment.

 

A small dremel sanding drum or burr is the best tool to clean some of the aluminum but there are places where a small file must be used. load the teeth with chalk before using so they don't fill up.patience is required.