View Full Version : My Minx engine

03-28-2005, 10:50 PM
When I was forced into repowering the Minx I bought 15 months ago, i had some specific ideas of things I wanted to accomplish.
1) A transom water pickup with a sea strainer, and crank driven seawater pump.
2) Closed cooling system with an electric coolant circulating pump.
3) A double remote oil filter assembly and a BBC oil cooler. I think the total oil capacity is about ten quarts.

I started out with a completely rebuilt (including align bored and new crank) '96 Vortec 5.7 liter SBC, carbed w/ a Holley 4160 marine carb on an Edelbrock Performer intake manifold, fed by a Holley marine electric pump w/ a Holley regulator, a Federal Mogul Speed Pro cam, and Stainless Marine exhaust manifolds.
Also I installed a Faria Fuel Manager, however it's not currently working because, I think, it's too close to the electric circ pump (it's mounted directly behind it), so i'll have to move it.
The electric circ pump is a Mezziere 55 GPM remote pump. It draws 7.5 amps (no load), and has a service life of 1,400 hours. It works extremely well. It eliminates a drive belt, and probably saves 2-5 HP.
The crank driven Johnson seawater pump also saves a drive belt (more HP), but its REAL saving grace is it's VERY easy to rebuild. Remove four screws and replace the impellor from the FRONT!
To mount the circ pump, I designed and had a bracket fabricated to mount not only the pump, but the circuit breaker assembly, fuel water seperator and a terminal strip.
Take a look at the pics, I'll answer any questions anyone has.
So far, it seems to be running pretty well. I've done almost no tuning. Only set initial timing, idle mixture, and float level, so there's some room for improvement.
Right now I'm running a borrowed 25" cleaver, and almost right out of the box it did 64 MPH (GPS) with two aboard and probably 30 gallons of gas.
I'm still learning a lot about it, Buizzilla has given me some tips but I haven't had a chance to incorporate any of them.

Fish boy
04-03-2005, 08:46 AM
Looks good george! A lot of work, but well worth it.:)

04-03-2005, 11:58 AM
I like the bilge, very clean. Exactly what kind of paint was used on it?

04-03-2005, 12:16 PM
Georges motor hole and quite a few others are so sweet, I will have to put a lock on my Plain Jane's motor hole.

04-03-2005, 12:20 PM
I like the bilge, very clean. Exactly what kind of paint was used on it?

Tommy check Georges post below #22 George is out of town and hitting the board when he can.


07-16-2005, 11:50 AM
GCarter, your post has me confused. I always thought that a closed system was where you had a radiator and didn't run raw water through the engine, so why would you need a water pickup? I've always been an outboard guy, so I/Os are new to me.

07-16-2005, 11:51 AM
GCarter, your post has me confused. I always thought that a closed system was where you had a radiator and didn't run raw water through the engine, so why would you need a water pickup? I've always been an outboard guy, so I/Os are new to me.
You still need raw water to cool the fresh water, no radiator, just a heat exchanger. Radiator would require good air flow and a fan.


07-16-2005, 01:25 PM
Thanks, now I get it. the big can on the front of the engine is the heat exchanger. I guess one of the things that was confusing me was that I've seen pictures of boats with radiators in front of the engine on the online boat trader and I always wondered how that could possibly work.

07-16-2005, 10:58 PM
Most all outdrives have water pickups in the drive itself. These may be in various places; on the sides, or down on the bottom front. Alphas even have the seawater pump in the drive. San Juan engineering told me the Alpha pump's vanes are too long and in warm water (over 80* like where I live) they stop pumping because the vanes don't follow the pump housing. So I blocked off the water passage in the gimbal housing, and installed a Stainless Marine water pickup in the starboard side of the transom. That in turn, feeds the Johnson crank driven pump you can see on the front of the engine. That pump supplies raw water to the heat exchanger to cool the engine coolant.

07-17-2005, 11:29 AM
Awesome George. Your workmanship and innovation is very inspirational.
I am amazed at the overall complexity when you get all of these systems plumbed etc. as compared to my little H&M ford pkg -- which of course has none of the things you described but still was a very nice pkg for simplicity.
My '97 Bravo 1 pkg in the 22 is also very complicated looking even without
a closed cooling system --- someday I will cover my entire body with vaseline and try to slip into the engine compartment enough to locate everything (such as the water pump, or maybe it is in the drive?? it was on the engine in my TRS 22) --- this winter I will chg all hoses and do some engine painting etc. so that will be educational. When Donzi installed the platforms on the outside of the engine stringers they made access even more difficult. In summary, Very nice work!!

Dr. Dan
07-20-2005, 06:19 AM
:spongebob Nice Pics George....Thanks for sharing...looks great...

Doc :smash:

07-20-2005, 11:40 PM
Thanks Dan!
I hope you make it to Sarasota.
This boat just hasn't run at WOT like I think it should. I've been picking some brains and collecting some bits and pieces to help tune the carb. The engine now has about 25 hours. Today I started the tuning process by installing a new set of plugs. If you haven't seen the Florida weather map lately, we're definately in the middle of the monsoon season. The temp was about 98* in the warehouse and the humidity matched perfectly. After an hour in both sides of the engine compartment, there was a pint of sweat in the bilge, not to mention I was soaked from head to toe. Fortunately, most of the rest of this process is done on the top of the engine.

07-21-2005, 09:25 AM
Lookin good George!!

Jamie / Lakeside Restorations

half shell
07-23-2005, 09:45 PM
George looks great ! However I have one question why carb over fuel injection ?

I have looked at several 80,s boats and am undecided if I would be happy with carbs.

Regards Bob

07-23-2005, 10:38 PM
Well, cost is a large factor. New intake, carb and fuel pump are less than $1,000.00. The whole engine cost me less than $3,500.00, except the SST manifolds, which came with the boat.
I think Big Griz's Procharged Criterion is carbed. There just isn't any large performance deficit to pay w/ carbs.
FI, while wonderful, is much more expensive. You're kind of stuck w/Mercruiser engines or an after market FI. Have you ever tried to set up an after market FI? Nightmare doesn't even come close.
The main advantages of FI are consistency, efficiency, but not economy of purchase.
Now, of course, all of this is just my opinion. If I were in the market for a new turn key crate engine, then FI would be high on my list.

07-25-2005, 08:55 PM
George, have you considered putting the impeller back in the Alpha and just dumping the water back over just for more cooling of the drive?

07-25-2005, 09:41 PM
Joe, It does that anyway. Everything is in the drive except the impellor. So it should be moving water through from the forward motion. You probably remember there's also a drive shower.


07-25-2005, 10:12 PM
Yes, I know it has the drive shower. Do you dump the water out the shower? I wanted to know your thoughts on that. I had an alpha that didn't have the impeller in it when I got it. Obviously, the guy that had it before me was running seawater pumps. My marine mechanic at the time told me that it needed the water to run up the foot for cooling. My argument was that the quarter inch tube running up the foot didn't matter a hill of beans compared to the fact that the entire foot is generally imersed in water. When I first read yours though, I thought you said the water was blocked off. I should have read farther. :)

07-26-2005, 12:38 PM
Joe, what I blocked off was the passage through the gimbal. It's similar to the blocking plate for the exhaust. The passage through the drive is open. It even has the hose nipple screwed into the front of the driveshaft housing. There just isn't any hose. So the water is forced into the foot by the forward motion, it goes upward through the pump housing (minus the impellor), up the tube into the driveshaft housing cavity and out the hose nipple to splash back into the water. It would be interesting to see how much water actually moves through it, but that might be difficult.
And I did think about trying to utilize the water to operate a shower, but showers are so darn inexpensive these days it wasn't worth trying.

07-30-2005, 06:12 PM
Well I've been planning to make some corrections/repairs and this week seemed to be the time.
The last two times we had it out, there was a pretty strong smell of burning rubber. The only thing I could think of was V-belts.
So what I found was the belt groove in the alternator pulley was too narrow! Details, details!!! I removed the alternator and had the local rebuilder change the pulley with a wider groove. Back on went the alternator with a new belt.
Also I wanted to change the thermostat from 190* to 180*. Additionally the electric circulating pump dischaqrge hose has been occasionally dripping since I've been using it.
I was able to drain the coolant without loosing more than about 6 oz. I removed the circ pump and changed the discharge hose. While I had the pump off I removed the Faria fuel manager because I think it's been restricting fuel flow at WOT. Also It wasn't working because it was too close to the circ pump motor and it was picking up noise.
So I finally got it all baqck together.
Here are a few pics showing the circ pump with and without the inlet hose, the seawater pump, and the oil cooler on the bottom.
You have no idea how hard it is to take pics like these taken from under the back seat.