The elusive 224/3.7 MerCruiser banger

Anyone know if a standard Ford 1"-12 x 3/4"-16 oil filter adapter fits in our blocks?



I'd measure but I'm not near any of my engines and I'm trying to figure out whether I should pass up on an attractively priced sandwich adapter for a 3/4"-16 application (the stock right angle adapter puts the oil filter in conflict with my engine mount).

 

I have had mine out but don't remember. I want to say they are not the same. Pretty sure the 3.7 uses a Chevy filter. Will have to look later today.

 

I just went and popped one out to measure. Mercruiser is filter side 13/16" x 16, block side 1" x 12. I measured a Ford one while I was at it 3/4" x 16 filter side, block 1 1/16" x 12. So not the same.

 

The 488 has stock parts you may be able to use for moving the oil filter as its oil cooler was on the bottom of the intake manifold with high pressure hoses running to the block and oil filter.
There was a conical adapter that screwed onto the side of the block where the oil filter is on many 3.7s. With the conical right angle adapter and hoses for the oil cooler, The adapter gets to hoses somehow so you can adapt anything you want. You may have to make the parts but that is no challenge to you.

 

I have the OE right angle adapters that is used with the oil cooler in the intake. None of the orientations it puts the oil filter in are sensible for my packaging situation. Sticking right out the side of the block is pretty perfect so sandwich adapter it is. I scored a decent one (i.e. not the $15-20 Chinese ones you need to port in order to have reasonable flow) for under $20 open box on eBay. It's 3/4 thread but after looking up and comparing the threads I'm just going to tap the female side to 13/16.

 

Parker makes push lok hoses #836 is rated 400 psi. withstands oil better than water or air and the pressure rating is good to 302 F I prefer that hose as it is much easier to use than the much stiffer single wire hydraulic hose type unless the hose is exposed to abrasion.

 

Refrigeration copper and AN flare nuts will be fine since it's such a short direct run.

Frankly I'm surprised Mercury didn't do a hard line from the factory. They did for the fuel.

Oh, and the "nice" oil filter adapter also needed porting to have reasonable port size but way less than one of the cheapest ones. That's a 1/2 MT2 collet poking through for scale



The bore to the main oil galley is 9/16, maybe a little under. A 1/2 dowel was loose. So I drilled the threaded adapter to 9/16. The OEM nipple is 1/2 hex.


The block side uses a standard GM 3-7/16 flange so I still have to whip something up for that since my sandwhich adapter is wrong. Not surprising. This is how it goes when you have money.

 

" I'm surprised Mercury didn't do a hard line from the factory. They did for the fuel. "

When possible, fuel lines under pressure should be metal as fuel line fires are hard to ignore.

30 years ago I stupidly ran a hose from my fuel pump to my van's carburetor.
Later, when smelling gasoline, I made another stupid mistake, one of ignoring it and was driving along with excited people pointing at the flames coming out under my car. I did save the car as after the fuel pump stopped, the fire only had wiring insulation to burn.

 

The Mercruiser oil pump looks like a Ford oil pump. Does anyone know what it really is?
A Melling 83 and Melling 89 resemble it. I have had both cast iron and aluminum versions of the Mercruiser pump. The paper gaskets are commonly left out of pumps by previous owners. The oil pump pickup tube is sealed to the pump body with an O ring that I've never been able to buy. It is square in cross section after service but perhaps it began life round in cross section.

 

From time to time we need to replace timing chains. I took a chain to a bearing supply store and was told that it was a #35 chain. The price for a 10 foot #38 double roller chain is $54 including a master link.

It seemed expensive, but Napa asks $96 for a double row 3/8 pitch
timing chain for a ford 460. (roughly twice the price for about 1/5 as much chain) my Mercruiser chain is about 25 inches long.

The lesson is that buying from industrial supply stores will cost you less.

Chains come in different strength ratings and even electroplated finishes are available. I'd avoid stainless chains as the material is not as strong.

 

As the original waterpump impeller looks advanced compared with a Toyota corolla waterpump I thought I'd try the Mercruiser pump on one engine. Here is what I found:
The Mercruiser pump has special seals with a brass body rather than steel and they are enclosed on the spring side which faces away from the oil. A ordinary seal can be pressed in with a socket reversed. Protecting the seal from water is difficult as its spring must be covered yet remain flexible. The body of the seal can be protected with a layer of your choice (i'm trying RTV).
conclusions:
1. It is better to simply replace the Mercruiser water pump. with an electric pump or a Toyota Corolla water pump than to rebuild the Merc waterpump without Mercruiser parts.
2. The proper seals in the Mercruiser water pump are not commonly available seals for reasons of rust. Seals for this application are sold by marine parts stores. I do not know if they are brass or steel.
3. adequate corrosion inhibiting in the coolant is critically important to this engine.

Some of the pumps are aluminum others are nylon nylon has a very high melt point around 500F but depending on the type of nylon, it softens at much lower temperatures. water keeps it softer and more ductile (ie . plastic). I do not know if it will warp, but that needs to be known. Ignition timing must be paid attention to as it has a strong influence on engine temperature.

The above pump prices do not include a pump output regulator. The pump should pump at all times but it should vary its output in accordance with engine temperature.

 

On the subject of water pumps, I am thinking the industrial seals will work fine with water-less coolant as, as far as I have been lead to believe corrosion is eliminated (or close to). It is something I have been kicking around for months as it is the cam that is the biggest issue. It is the rust on the cam that takes out the seals. On acquiring another engine that had proper AF in the system since new corrosion is pretty minimal and the seals and cam are in good condition. So, I think neglect of the engines we are getting is a factor too. Yes, anything from Mercury is top extortion price so I too want options, but for me the stock water pump is must have item bust because of space.

 

4.5 is the limit - I have been able to model it pretty well and that is where it lands. you have to go to a 2.2 journal and not all rods would do it, it would have to be a steel rod but the one I have tested misses by oh, .040 the tight part is actually at 4 o-clock where it gets really close to the block. It seems to clear the cylinders fine but you also have to watch the counter weights as the piston draws down so far the crank weights have to be trimmed back from the stock diameter to clear the bottom of the piston. 272 cubic inches awaits

 

These engines mostly just sit in marine environments. It's not like pleasure craft rack up tons of hours running. Having worked on boats in my youth I feel very, very, comfortable saying that the cam is corroding from the atmosphere side before it's corroding from the coolant side.

 

I remember seeing steel ladders on a saltwater pier completely rusted away in the tidal zone but "intact" if always below water and "intact" where they were always above water. Rusting requires both water and air. The drainage chamber between the cam seals is air filled. Instructions were to grease fill it but doing that blocks water drainage unless the grease melts enough to run completely out of the small water drain hole.

I saw Mercruiser camshaft nose seals for sale online yesterday. Not horribly expensive but I can not tell if they are actually proper. Some of this is because industrial seals often have a greenish coating that gives them a brass-like appearance.

 

Sean, see if a BMW electric coolant pump would work for you. There would be a lot of freedom in locating it. They had longevity problems so a new one may be best.

The next post is a good way to go. It is often easier to begin with a universal pump.

 

I've been running my 3.7L for a few years now, with the Davies Craig electric water pump #8970, and its been no less than perfect. Cam is sealed off with a plug. Water pump controller holds the coolant temp exactly where I set it (175) and controls the electric fan as well, although you can run them separately.

 

cost of two water pump seals $40 (mercruiser double sided seals)
cost of two speedy sleeves $64 (prices vary from $46 to $90)
$ 0 ( you may just be able to polish the camshaft end)
$104 per rebuild

Davies Craig electric pump $175 to $400
$1 welch plug
for another $72 the problem is over forever. It looks like an obvious choice.
now what my rebuild actually cost:
speedi seal $32 each (1 destroyed) $64
cam seals 5.32 each (2 destroyed) 21.28
sleeve sealant $14.
rotor seal 15
postage (rotor seal) 17
total $131.28
the cost approximates the cheapest electric pump.
But I wanted to try it for the experience.

 

Not having to cut a firewall or run an asinine cooling/fan package because you made an already fairly long 460 even longer....

priceless

 

compare the costs:
waterpump gasket and seals set $100
two speedi sleeves $ 64 ( price varies)
ttl $164

versus Davies Craig pump $179 to $400 problem over forever

So I saw that ebay had a new one for $115. pushed the "buy it now". Did I buy it? Almost and I'm glad I didn't.
It was in Australia where they are made so the cost of shipping I'd pay would exceed the $65 saved buying it in Australia and there would still be customs duty to pay. A big retailer can import a shipping container of pumps reducing the high cost of shipping.

the controller sounds excellent, you can make a crude one from common parts two thermostat switches (180 degrees and 200 degrees) and a 1/4 ohm 25 watt resistor in series with the lower temperature switch which above 180 degrees would run the pump motor at 83 watts. The higher temperature switch would run the pump at 120 watts beginning at 200 degrees.

 

Dennis, you're sort of misunderstanding or exaggerating what you understand of the Davies Craig water pump controller. While it probably could be copied with a lot of hard work and a raspberry Pi or whatever the small computer of your choice is, the concept is that it slows and controls the coolant speed to quickly warm up then control temp to the degree continuously. When you get into an expensive build like I did, temp control becomes very important - and it saves you from a lot of the potential head gasket issues. For me to pull my engine/trans combo, I basically have to disassemble the front half of my truck. Sometimes $200 isn't the problem you think it is.

 

Indeed the marine environment may be a major factor, where I am boats die from neglect and poor maintenance. (Near Red Deer Alberta) I have gotten to be well acquainted with the local boat guy and am now #1 on the 470 dispersal list when they get scrapped. He concurs the issues as people just don't winterize properly and the dog houses on the boats act like a sauna with water in the bilge, hot cold etc. which create a horrible environment. But the local climate here is very dry so once this is in something with 4 wheels and a garage those exacerbating issues should go away. I do see the pros to the remote pump but my issue is where to put it. The neat package of the built in pump for me a big plus and offsets the PIA factor- in this project anyway.

 

Lifter Gallery Cover
I have a question. I have been thinking to do the mod that machines off the lifter gallery cover bosses to install roller lifers. It occurred to me that I could find no actual reason that Mercury put a cover there instead of just relieving the casting from the top down all the way to the lifter floor. Am I missing something as to why there is a removable cover there at all? My thought is to just permanently seal it off and drop the lifters in from the top like you would anyway.

 

So you can R&R lifters without removing the head.

 

It is amazing how many things can go wrong with a stock water pump rebuild:

1. The shaft seals should be brass ones (about $20) and also double sided so they can be pressed in easily.
regular shaft seals $5 can be put in but they are steel and rust without corrosion protection around water.

The seal spring pops off easily if the seal is treated roughly.
The seals springs may rust (I don't know about this aspect of the spring). I tried sealing the seal using a layer of RTV that seems ok but the seals are stiffer depending on the amount of rtv. I always use antifreeze in my engines. Maby the RTV is overkill.

2. the cam wears where the seals run on it, very small wear can be polished away .

3. A Speedi sleeve is put on where wear is serious:
You must cut the installing flange before install to avoid tearing the sleeve
They are tight and may stretch to fit during installation ( I'm guessing on this)
The sleeve will be sealed to the shaft and retained by sleeve retaining compound. It is tempting to add retaining compound to retain the seal but its use around the seal will make removal of an intact seal very difficult.

4. you must position the seal so it runs on the sleeve.

5. If you only need one Speedi sleeve it probably will be the one near the coolant. So with just the front sleeve in place the rear seal will catch on the sleeve making removal difficult after a test fit. I paid $32 for one sleeve

6. Common seals are frail and easily bent so push them in with a socket that will only push on the very edge of the seal.

7. the rotor/dampener seal is available $15 or so and I paid $17 for its shipping then I found I have a new one from a gasket set.

8. the 1/8" hollow brass plug is for the pump impeller cavity A previous owner glued it in and even a propane torch plus a wrench and vice grip pliers were not enough to loosen it. It collects sediment. and that has to be cleaned out before the plug will screw in properly and not leak.

the other hole which drains the seal chamber has no plug and must be open so it can drain to keep coolant out of the engine oil. Old hard grease can plug the drain so I have mixed feelings about filling the chamber with grease.

I learned most of the above by making mistakes, lots of them. I used Toyota water pumps on my other 3.7 engines. It was much easier to use an electric pump or a Toyota pump than to deal with the Mercruiser waterpump.

 

Anyway,

Here's a CAD file for the pump housing. The bolt holes are intentionally undersized. I had one made out of .040ish aluminum to cure the problem where the pump impeller hits the housing if you use sealant instead of gaskets. Obviously one could use this template to make a gasket too.

Ignore the 6.2 Detroit water neck I shoved in the middle of it as a convenience for when having parts made.

 

Very nice indeed. I do my gaskets myself and trace a good "store bought one" onto sheet aluminum as a template for making the next gasket. never considered a non gasket setup. It would be ok. The holes on mine are undersized as I trace with a sharpie. Out of curiosity, why are the ready made gasket bolt holes so large?

 

Anyone wanna go 50-50 with me on a set of tall aluminum valve covers? Or anyone have a single they want to sell? There's a lot of options in the $90-110 range.

No idea. I suspect they're worried about people tearing them when ham fistedly sending bolts through.

 

my rocker arms hit the stock valve covers so I made an aluminum template for the gasket and glued a rubber rocker arm cover gasket to each side. It gave me about 1/2" extra clearance and the gasket did not squirm out of place. Its pictures are back in this thread.

 

I need ~4.125". The stock valve covers are great and I wish I could run one but it's not even close. I could buy some cheap steel ones and weld but that's no cost savings over aluminum if I split the cost with someone.