The elusive 224/3.7 MerCruiser banger

That was my exhaust manifold. Go back to page 6 to read yearly differences.

 

I didn't realize the differences, would use the same manifold as you and add an O2 bung to pipe.

 

Gm 10.4 clutch. Pic of the throwout fork is with the bearing touching the plate. I need the fork way back.

 

Notches are stress risers and the bellhousing is stressed.
Cracks begin at sharp edges. Aluminum is sensitive to this problem.

Chevy aluminum bellhousings are still only $20 at swapmeets.
There are two rear hole sizes the small hole for car transmissions and a larger one for pickup transmissions with their useless gear ratio in low.

As one mounting hole and a dowelpin are missing from your bellhousing , buy the next inexpensive one you find. Make the holes at the end of the opening then used a hacksaw to cut in to the hole. Finish the edges with a body-file (aluminum does not plug them up) and sandpaper to get a smooth cut that will not propagate cracks.

If you use a miniature starter you do not have to cut the bellhousing and it is half the weight of the big starter. Check the direction of rotation before buying a starter

You will have a very nice looking car with your Vega body.

 

Weaknesses of this engine:
they can be remedied
- some headgaskets seem to not seal well so they need frequent replacement.

- the waterpump is driven off of the camshaft so with a little wear antifreeze leaks into engine oil.
A belt driven Toyota Corolla waterpump can be fitted. I posted the drawing for its adapting plate.

- its voltage regulator is water cooled, burns out easily and is very expensive. Use something else.

- the alternator is on the end of the crankshaft so it does not put out much current which is ok on a boat. For a car use a faster spinning belt driven alternator I used a generator and it worked very well.

- the open deck design lets the cylinders move. Give them some support.
Most epoxy fillers soften with heat. Cement fillers don't soften.

- the cylinder walls are thin and do not have much material for reboring

- the cast iron head does not breathe well and is heavy.
Aluminum is much lighter and is compatible with the block. It can handle more compression without detonating.

Strengths
-the engine is very light so take advantage of this.
Put it in a very light car
keep the engine light
use light heads,
light starters
light alternators and
light manifolds
a small fuel tank
light wheels and tires.
- It has exceptional torque
- it has good power
- you can say it is based on a big block Ford
- it can be found for $100 in boatyards as they usually don't rebuild them

 

The stress riser fact is on the mind. My dowel pins line up. If this bell breaks I'll just have to find a 4 cyl monza housing because it uses that one hole by the starter. With the tranny on it it does pull a small gap between the bell and engine. Might not last but that's not the immediate goal. It's just to make it work for a bit just to laugh at haters. And then make it better. Too bad these weigh 450 lbs without the exhaust. It can get down to 350 with the crankshaft lightened, a lighter flywheel 137 tooth sbf, and a head. If I pick up a cheap one I'll disassemble it and cut the block for my cj8. I'll 3.7 swap the white house next to make it run better.

 

Just found the solution to my starter issue. I found this after I bought the hard to find cast bracket for my old style starter. Google 3.7 high torque starter to find it. This means next bellhousing I use when mine breaks I don't have to cut into it.

 

Got the throwout bearing spaced with a bunch of washers welded to it. Definetly imbalanced. But next is to drill the crankshaft and then it's ready to go in the car.

 

It is the starter I use.
It is not expensive.
it is physically small ahead of the bell housing and
it fits without chopping up the bell housing.
it weighs about half as much as the direct drive starter.

 

I used the big old starter in my first engine (It came to me as a basket case so I did not know of the bracket which was missing). I just bolted the starter to the engine as is done in cars and it was never a problem for my engines.
Mercruiser used starter end brackets on more than one engine but was it just company policy to use them? Mine seem ok without them.

 

Don't lighten the crankshaft or the rotating weight on it. It must have the weight. Big 4 cylinder engines usually have vibration problems. Read Randy Dupree's comment on it early in this thread...it did not work out at all for him. He is an expert on these engines.

 

Or just take out weight and make sure it's balanced. Not hard. Where ever you can cut weight do it.

 

I will try to sneak in a picture of the Anglia I am wiring. It has one of the engines that is the topic of this thread but it is way off topic. The owner added 1 inch to the height of the block. If you look closely you can see the spacer just below the head. The crankshaft is a one off billet, and so is the camshaft, along with lots of other one of kind pieces. It is turbocharged and fuel injected. It uses a racing powerglide transmission. It should make about 600 HP in the current setup and other combinations can make even more HP. It is to be street driven.

John

 

WZ,
If he is on here let us know. If not, see if you can get him to join in on the fun.
We don't have to talk about the off topic stuff but I for one would like to know more about the engine. Like, who made the cam, crank, pistons etc.

 

One of my cars weighs 1100 lbs complete with a full tank of fuel so you can see I feel that weight reduction is critically important. A lot of weight can be removed from a car for better performance but there are better places to remove weight than a Mercruiser 470 series crankshaft.

 

I see a turbo and I most definitely would like to know more about this engine..

 

Lots of directions to go for power. Seal the deck stud the mains find a forged crank. Kaase boss 9 heads move 405 cfm. Now making a cam wouldn't be all that bad. I could build one with a lathe and have someone grind it for a roller. Or stick with a wedge head and shove 30 psi into it and make 1000hp, but then you would have to splay the mains and really thicken the deck. Just dreaming, but my next post I will post about a real concern with cars.

 

So sitting in a boat these have a front and rear sump, the front sump is where the pump hangs. My 470 holds 5.5 quarts. From bottom of pan to valve cover it's huge, way taller than a sbc. I had to notch my oil pan about 1.5 inches and angle my motor wayyy up to get it to fit in my h body. Now, if I where to pour in 5.5 quarts, half the back of the crank would be dipping in oil. So now, I have to adjust the oil level where it's enough to dissipate heat into and the crank is not dipping into it. It will take a bit but I'll have the crank an inch away from the oil and remark the dipstick, and hopefully when I go down my steep driveway I don't blow up my motor when I step on my brakes. If I only have to run a quart less I think I will be fine.

 

The owner of the car is not on here. The owner/builder is a master craftsman. It is an awesome build. He has been slowly building this for several years in his spare time.
The cam is a custom built piece. The owner used to teach machine shop. One of his students is now a talented machinist. That student cut a couple roller cam cores. The owner had 2 of these ground (he was unhappy with the 1st grind). He made the cams with a SBC snout. He and another of his old students, who now is a performance engine builder, figured out a way to combine SBC and BBF adjustable timing sets to complete the timing chain. Precision machining and shimming are required. I tried but I couldn't figure it out.
The crank was made by a guy that typically builds smaller size cranks (motorcycle size). I spoke with the guy and he was NOT interested in building another. I tried to coax, but it didn't help.
If you search this thread for WZ JUNK postings you will find more info on the motor. A few of my posts also have some of it's info. Page 40, post #1192, has a front photo from a few years ago.

Update: I just spoke with WZ JUNK. There used to be more photos of that motor here, but they have been deleted as not being appropriate for the site. He is hoping to post more, but they too may not stay up long. There is a big turbo and EFI on it. That is a shame because so much of what has been done on this motor doesn't relate to those 2 items and traditional style builders could use some of those ideas. There is also some nice metal work on that car that is appropriate to this site.

 

Beck,
Thanx for clarifying. I didn't make the connection between the latest WZ post and the earlier ones. Hopefully we can see some more pictures and details.
Looks like Comp has ground these cams before. But since this is a dry sump motor the need for the distributor/oil pump drive goes away. The basic cam isn't a trick but as you have said the timing chain could be a challenge and/or expensive.
Do you think if we drafted a series of questions we could twist WZ's arm to ask Doug ?

 

I believe beyond a reasonable doubt that some motor out there uses our timing chain set up. Can someone tell me why his photos aren't allowed?

 

Spirit of the site. Doesn't fit it due to turbo and efi. Some things are allowed to slide, like this thread. Thankfully.

If he has pictures someplace else please let us know where.

 

I don't think its the turbo, after all what about the old Corvairs and olds 215 turbo.

 

I just re-read the first 20 pages of this thread. It is amazing. I was in my initial build then and lots of invaluable information was given. For anyone who skipped it to begin at this end of the thread ...go back and read the early part, it is really valuable.

 

Dennis,
I've done this several times, too. It repeaks my interest each time.

 

Even just the first ten reveal a ton of info.

 

Alright, well damm. Lesson learned, when drilling for accuracy with handheld equipment, step up drill bits little by little. Picture explains itself. Might not be able to see it, but I drilled it offset. And over the clutch.

 

Yeah, I believe that pilot bore needs to be machined in a lathe to be done properly. I just had it done to my 324 olds crank.


Sent from my iPhone using H.A.M.B.

 

I think I'll get it with an 8th of step up from 5/8 tomorrow. Hell, my jeep with a sbc and 465 ran no pilot for 75000. Grabbed funny but did break the diaphragm.

 

Got it drilled. I won't share what I accidentally did to the pilot bushing I had, it's embarrassing how I messed up. But drilled it 1/4 inch deep and going to make a super tight press fit.