The elusive 224/3.7 MerCruiser banger

Sounds that way to me also but if he did not have much metal to work with perhaps he used smaller studs. I tried it on a tractor engine and hit the water jacket after 3/16",swore, gave up and plugged the hole
Only after I built manifolds on old heads did they come out un-warped

For a cast iron head, I was going to make cast iron studs. It would be an excellent material match and machines nicely. Old cam shafts are nice cast iron.

 

I used sheet cork composition for my intake gasket material. It was thick and soft both were things I needed as the head and block mating surfaces for the intake manifold were at slightly different heights and I did not want to pull the block out and re-surface it as this head will be replaced with an aluminum one later. Cork has to be re-tightened but it seals much better than a fancy gasket material I bought for use there (I went back to using cork).

Your gor-tex tape idea reminded me of this:
I had to fit a 1.5" long coolant hose in after everything was assembled so I wound self-vulcanizing rubber electrical tape over the joint and covered it with a wide hose clamp. It stood 18 psi and 260 degrees for 3 years until I replaced it with fresh rubber electrical tape. Rubber tape deteriorates if exposed to air.
(Not that you would be using rubber tape).

Gasoline and alcohol resistance are of paramount importance for that gasket unless you are injecting fuel inboard of it. Some materials "resist" fuel others are actually fuel proof. check the next two post's attachment for relative fuel resistance of different gasket materials.

 

I checked materials 2 months ago, I wrote out what I found so this may help you:

 

And this is specific to cork composition gaskets:

 

I am trying to do my calculations for stroke/compression height/rod length so I used your numbers to make sure I had the formula right.
10.272" (our deck height, .050" less than the 460) – 2.080" (half of stroke for crank centerline) – 6.657" (rod length) = 1.535” (compression height for a 0 deck block)
What am I missing? It appears to me your piston will be .055" out the top of the hole???

 

I did find something new when searching for rods. Molnar is now making rods sepcifically for stroker BBF motors. Attached is their description. They are available in 6.700 and 6.750" lengths. Our bore spacing is BBF so it apples to our motors. The cheapest I have found them is $560 for a set of 8. The owner of Molnar worked for Oliver for many years. He then started K1 which he sold to Wiseco. Molnar is his new company. The BBC rods have been used for years without issue, but I do like this idea.

NOTE: These Stroker rods are specifically designed to be used with a Stroker Crank that has a 2.2 BB Chevy Pin.
In the past most of us have used the BBC Connecting Rod for this application, the difference is that the BBF bore spacing is greater than the big block Chevy. In addition to that the BBF Rods are closer together than the BB Chevy, so when using BB Chevy Rods for these Stroker Applications the pin is actually .100 off the center line and can cause additional wear and breakage. These specific BB Ford rods are made to adjust for that bore spacing and should be used in place of std BB Chevy rods.

 

No offset with 4 cylinder as the custom crank will center rods under bores.. Rods will need a chamfer on both sides as V8 rods have a chamfer on one side and a flat face where the two rods face each other. A 4 cylinder will have a crank fillet on both sides of the rod.

 

You won't need to chamfer the rods, but you WILL need to chamfer the bearing shells to match the crank.

 

Wouldn't bearings purchased for these motors already be chamfered? I could understand if I bought mains for a V8, but these are supposed to be for a 4 cyl.
Phil, 1934, I don't intend to start an argument, but do you agree with this or do you think the rods need chamfering also?

 

The 429/460 bearings fit the stock rods, but the V-8 rod bearings only have the edge next to the crank chamfered, so for use in the 4cyl the other edge ALSO needs to be chamfered for crank clearance, & with a little careful fitting they do fit properly. You can chamfer the rods if you want to, but the bearing edges are where the clearance for the crank radius is needed. For any bearing sizes it's a good idea to check to see that there is enough chamfer(if any) on the bearing shells at assembly, as not all mfgrs chamfer both edges. Refer to Phil1934's comment above.

 

I just checked my stock rods out. They do have a chamfer on both sides. This motor has been rebuilt before and has rods from at least 2 motors. It is obvious the rods were machined at different times. One side is chamfered less on some of the rods.
The rods have replacement bearings and the shell is narrow enough that there is no chamfer on either side. There is plenty of clearance to allow no binding. That is not what I want the next set to look like!
Does anyone have suggestions on what brand of main bearings to buy? A part # would be fantastic.

 

Last week, my engine ruptured cylinder #4 while starting.
It could have been from coolant leakage although I was not aware of any.

 

Wow, bad luck. There had to be something in there, coolant or a big load of fuel. I have never heard of a cylinder wall breaking. Normally it causes a bent rod. Hydraulic lock doesn't take much fluid. 100 cc head volume and a little more for gasket space and it is full. Unlike air, it will not compress.

 

Pictures or it didn't happen! You wish.

 

The photo is from inside its 4th cylinder. water has caused insignificant surface blemishes since I opened it up last week. My local boatyard supplied a new head gasket today which has no beads of sealant. I suggest you NOT buy that plain gasket and it is unlikely it will seal ( I was using the good gasket $60 with the raised sealant beads).

Now, a possible way to solve the water leaking problem in spite of bad gaskets:
1. make it a closed deck engine.
2. close the coolant passages in the head.
3. mill the block and the head mating surfaces
4. run coolant hoses from block to head on the outside of both sides of the engine. The holes in the head gasket are not very large. So small hoses, say 5/16" might be enough. I don't know what is involved in placing spigots in the block. the castings are pretty thin, it looks like Mercruiser glued the waterneck into the heads they used, so that method is possible..

 

So, can you just resleeve that cylinder? I like the idea of closing the deck. Seems to me the whole assembly would become more stable.

 

I always thought the closed deck looked cool but was also funtional. Just use thick welding rod cause you are gonna get some big gaps to fill.

 

I don't think so. The steel sleeve is contained in the aluminum casting. If the sleeve cracked the casting did too.
There is a repair method, but finding a new block would be less expensive. To repair you would have to machine out all of the steel sleeves and aluminum walls. The top of the deck would need to be closed. New bores and lower registers would be machined into the block. Then new sleeves installed. This would allow big bores. With a bigger hole at the base of the bore for the new sleeve the block would be a bit weaker on the bottom.

Boss9 Brian, Didn't you say you were drilling water holes in the top of your closed block?

 

I just got a quote to make a new solid roller camshaft. The mfg has a minimum of 4 core production runs. 1 finished cam and 3 blank cores was priced at $4300. Wow! The 3 extra cores is the killer for me. Anyone else need a $1400 roller cam?

These cams do have the distributor drive gear on them. They would require a different gear on the distributor. Does anyone know what drive gear is used on our distributor? They have to interchange with something else.

 

I would think Chevy II gear. Mine is at old house now or I would compare to my SBC distributors to see if same

 

Below are a couple of photos from the net. One is the 3.7, the other is a Chevy V8 HEI. You can see there is a shoulder on the top of the 470 gear but not on the V8. The bottom shoulder appears longer on the 3.7 gear also.

If I have a roller cam ground the distributor gear will need to be changed to match the hardness of the cam. The new cam and old gear will not like each other and both will be destroyed.

I am trying to get my build figured out. Each solution creates another problem. I am very concerned about the original distributor. I can convert it to an electronic unit, but I don't think it will have enough power to light a big load of alcohol. I can hook it to an MSD box to provide more power, but then the problem becomes cross-firing in the small cap. The end result for ignition may have to be a distributorless ignition. That creates an external oil pump issue, but allows me to run a cam without a cam gear which is easier and less expensive to have built.

 

I am in the planning stages of using one of these engines in a track roadster/street rod. My first inclination is to have a roller cam (probably hydraulic). I would likely use a 4 cylinder HEI driven from the front of the cam. A dry sump takes care of the oiling. Surely the most expensive route, but in the end maybe not.
Not having a distributor gear really opens the cam options. Just about any machinist can rough out a billet. Then pay the cam guy for the lobe work.
BTW Beck, I think you might find a closer match to a Ford distributor. They used that hex drive a long time and I bet that Mercury adapted theirs form a Ford. It might even be a Ford!

 

I think one of these motors would be great in a track roadster. I had a narrowed 27 track roadster with a 2300 Ford and a 4 speed. It was great fun. This would be better, but a shaker in that light of a car.

You can convert the original distributor using a Chrysler reluctor and pickup wired to a GM module. Put a Ford E-coil with it and your set. Or you could just pay these guys to do it. Good photos for DIY guys here also. For a 4 cyl you need to use a 8 cyl reluctor and neatly remove every other web.
http://www.lindertech.com/bhrs/

If you are set on putting the distributor on the front of the motor look at the MSD early flathead unit. These are the crab style cap. You will have to remove every other plug tower. It is short and driven from a spade. There are many drives available to bolt on the front of the SBC timing chain gear (which is what ours are). Just cut off the cam shaft. The drives are used for mechanical fuel injection pumps and such.

The cams need to be rough cut (within .020" on the lobes) then heat treated. Then the cam grinder can finish them.

I believe our distributor is the same as the Chevy II 4 cylinder with an adapter to adjust the length. The pump hex drive is Ford. I hoped the distributor gear was something from one of the two. If the gear is a special Mercruiser part it would require more machining making it non-cost effective for roller cam usage. Your front drive setup would be a cheaper option at that point. Driving from the front of the cam removes the need for matching the camshaft gear materials.

 

Pretty sure Chevy as Sarge Nichols had an HEI distributor in his (old Inliners book) Page 26 Randy said he used Chevy V8 distributor

 

Has anyone gone to a crank fire system? Thats what I'm probably going to do.

 

Yes I am considering it. Without going to a complete fuel/ignition computer it is a little difficult, but possible. For example, MSD uses a distributor in all of it's systems. It may be crank triggered, but the distributor decides which plug to fire. There are about 5 components needed for a distributorless stand alone system. That means you need 5 of these $$$$$, but still less than an efi/ignition system. If you are going the EFI route, you were headed that direction anyway.

 

That is mind boggling.

There is cheaper way to re-sleeve these engines: Melling makes a sleeve which should press directly into a 30 thousandths over size Mercruiser 470 bore and have the proper three thousandths inch interference. its part number is: CSL 518A.015

For those sleeves the piston diameter would have to be a 5 thousandths oversize 4 1/8" piston.

It is not as bad an option as it sounds because cylinder strength in a 470 is not much. (I went through the calculation and was unimpressed with the strength as there is no margin for things going wrong)

So it is imperative that the cylinder be supported around its top where the forces on it are greatest.
One option is welding aluminum plate into the deck closing
other option would be to fill the top of the block with high temperature epoxy .

 

The 470 has a reputation for knocking,
this is the best explanation of it I have ever seen:
http://www.contactmagazine.com/Issue54/EngineBasics.html

 

[QUOTE="GearheadsQCE, post: 11163096, member: 145496" I like the idea of closing the deck. Seems to me the whole assembly would become more stable.[/QUOTE]

You are right, the cylinder strength is marginal so closing the deck would give critically needed support right where it is needed.