The Geoduck's A4

[ThomasJ.]

Heres some of the parts being replaced and condition of things...
You guys have the knowledge!
Theres a few things im rather uncertain on, like the condition of the Water-Exhaust... those cracks kinda creep me out. Though I think ive decided to go with a Dry stack.

The Waterjacket area was REALLY bad.... Ive used Spring-wire and cleaned off welding rods and used pieces of 3/8 and 1/4 cable, with one end welded together for a drill chuck, and the other end frayed entirely and whipped an inch back with wire, Thus making a very long drill operated wire-brush of sorts.

Iv'e managed to get most of the rust and gunk out, Ive seen some cool posts about miriatic acid... ?

The cam is alittle pitted in some spots... pretty minor though.

Had a broken valve to deal with and a broken spring...
So new springs, and a new set of Exhaust valves, as the old ones are horribly rusty along the shanks, which leads to new Valve guides aswell...

The valve seats on the block were HORRID. I had to make a tool outof the old exhaust valves to fix them....
The lifters are a tad sticky too.

Wrist pins are pitted and rusty, and are getting replaced...
Not too much else to mention...

Pictures!








Anything i should know at this point with how the valve seats look or any tricks to freeing up lifters and such? Someone suggested to me that i get the block VERY. lightly shaved, as its abit beat up....

I spose i should hone the cylinders a tad more too...
Tell me if i'm posting too much!
It just gives me peace of mind to have this stuff in-front of experienced eyes!
I have some more to come!
Thomas~

[Will Jacocks]

That actually looks pretty clean! As long as the surface is straight and not warped, it should work just fine!

[ndutton]

I don't think anyone has a problem with frequent posts but you might consider fewer threads, like maybe consolidate into a Geoduck project thread. As it's been going we have to follow several threads to keep up.

For instance, while you're getting into this overhaul aggressively don't forget what's been found on the thread regarding the prop. Admin Bill raised the question and Thatch correctly determined it's the wrong rotation for your A-4. If your variable pitch prop has the ability to be reconfigured into a right hand rotation, you're good. That will be determined by the mechanical design inside. Otherwise, you're in the market for a replacement prop and shaft.

I'm enjoying the energy of the project but remember the goal is to have a working propulsion system for Geoduck and that could mean another grand (aka one boat unit) in a replacement prop, shaft, cutlass bearing and stuffing box if your very cool existing prop cannot be reconfigured.

And if there was concern over the overall weight of the installation and Geoduck's ability to handle it, that heat exchanger isn't helping any (another thread).

[Mark Millbauer]

Thomas,
Very interesting project. keep up the good work.
Can you please describe further the tool you made form an old valve to clean up the valve seats? A picture perhaps?

Thanks

Mark

[thatch]

Thomas,
Because of the cracks in your manifold, it would certainly be a good idea to check the block out carefully for any additional cracking. The first area to look should be around the bottom of the cylinders in the crankshaft area.
Tom

[CalebD]

Bill's point.

"Admin Bill raised the question and Thatch correctly determined it's the wrong rotation for your A-4. If your variable pitch prop has the ability to be reconfigured into a right hand rotation, you're good." quoting Neil. Bill did comment on this in another Geoduck thread. Maybe it would be easier if you kept most of your info on one thread; we don't seem to mind really long threads around here. Keep on posting though, however you choose.

For the group:

The cool variable pitch prop he has is left handed spin (LH) and the A4 delivers a right handed spin (RH). Getting a right handed prop would solve the problem but eliminate the variable pitch prop most likely.

Isn't there some kind of gear box/transmission he could use that would change the RH nature of the A4 to drive a LH prop?

Would a 'V drive' setup make sense (where the engine's shaft faces forward and is geared back to a shaft to the stern)?

Fun project.

[edwardc]

Would a 'V drive' setup make sense (where the engine's shaft faces forward and is geared back to a shaft to the stern)?

I'm afraid the V-Drive wouldn't help with the rotation problem. While it does reverse the the direction of the rotation, remember that the engine is sitting backwards, so it's rotation is already reversed! The V-drive reverses it back to normal.

And it that doesn't confuse you, you need another beer!

[ThomasJ.]

okay!

Alright ill post all "Geoduck related" things here from now on, If that works. =]
Afterall, it is one BIG overhaul of a rather small boat...

So, to tie everything into one...

Whew those cracks! thankyou, that was most informative!
Checked the engine very closely for cracks with a light, and saw nothing... But just for fun I will be borrowing a magniflux set from a friend to REALLY make sure.

I asked around, And theres some talk of an old heat exchanger at my Uncle's farm down the road.... (My family is kindof spread all over this Island) So ill take a peek tomorrow, see if its the appropriate size.
Theres LOTS of fun stuff around here! Just a matter of digging for it~

The prop saddens me... I now fully see.. for some reason i had it in my mind, that the A4 turned the same direction as most engines i know of...
Lister Diesels to Wisconsin engines and small flatheads and such.

I would like to clean off the Geo's prop, and take some better close ups of it's Prop blade shape.... just incase.

It appears that it is much the same both ways in SOME respects. The leading edge is different, yes... But its got a thicker base, allowing for abit of a curve in the blade both ways... If that makes sense.

Controllable Pitch blades are slightly different from a conventional fixed aren't they?
I guess im grasping at straws... Would really like to keep that prop.
But yes, It is definitely backwards.

No matter what though, The A4 shall be restored to running condition. The thought of a gearbox to reverse the rotation hit me when reading the above suggestion.

In the vast heaps of scrap and junk collected over the years, i know of several little "crash-box"es, Little marine ones. Ill take a peek... They all however have one end of them moving back and fourth...but my little spline set-up could accommodate that as a slipshaft of sorts!

I would say the one i have in mind right now is about a foot and a half long, So i WOULD havto cut the shaft, but it would be fit into place with a small sled bolted into the keel for support much like the engine one~

Hate to loose that CPP though... Its partly what made this boat special.


Got some Red Ceder 4 by 4s together to make a narrower mount for the Atomic... Any other wood i should consider? Or is Yellow / Red ceder about it?

Saddened but hopeful!

Part of me almost wants to try the prop in reverse just in the name of science!
Can always change it out after!

Thomas~


<<EDIT>>

The tool i made for the valve seats!

I took one of the more rusted worn exhaust valves and using the lathe for perfect center,drilled a hole in the top at 1/4.
Then i took the broken exhaust valve, And put it in the lathe, And took one side of it down so it was a few thou over 1/4.
With a press, i pressed the two together, And then made cuts in the intact valve's sealing surface with a dremil, cutting them at a slight angle.




Then filling the cuts with compound, I was able to chuck the thing in the drill (yes the seats were THAT bad) And on the "gear 1" setting, and with some up and down movement of coarse, carefully touch up the seats.
I dunno if its crazy or not but...
The seats were pretty much non recognizable due to extremely hardened rust and malformation to start with, and they actually look like they would seal now!

Hope that helped!
Thomas~

[CalebD]

I'm no expert.

I'm afraid the V-Drive wouldn't help with the rotation problem. While it does reverse the the direction of the rotation, remember that the engine is sitting backwards, so it's rotation is already reversed! The V-drive reverses it back to normal.

And it that doesn't confuse you, you need another beer!

I'm having another beer but I did think that through somewhat.

With the engine shaft facing the stern of the boat all it needs to convert from RH to LH rotation is one set of gears. With the engine's shaft facing forward there would need to be on gear in between the primaries to make the rotation go in reverse.

I imagine there must be some kind of gear box you could fabricate or that already exists to do this.

Just a thought.

[ndutton]

I'd first look at what the options are as to how the blades mount into the hub and if there's a possibility of reversing them and still have pitch control in a right hand direction. I would think the design would have that option (one size fits all).

Only after determining it cannot be done would I head down the path of prop and shaft replacement or reversing gear.

Part of me almost wants to try the prop in reverse just in the name of science!

Part of your new engine disagrees and will absolutely howl in protest.

[ThomasJ.]

oops!

Haha Yikes! I didn't mean the engine's gear itself in reverse, I understood it wouldn't like that...
Seems to me the reverse gear is a planetary system inside that cage? And your holding a certain member of it in order to get reverse?
And another to get forward?
If so, the reverse setting will have twice the parts moving twice as fast inside.... scarey over long periods indeed....

I meant keep the prop how it is and just give it a wee try!
Its being a tad ignorant of the fact the prop is turning the wrong way but...
Im rather curious as to it's performance! 0.o

Sorry for the thoughtless typing... sometimes i get goin'!
Thomas~

[tony201]

Tomas

Good idea for that valve tool

[lat 64]

So,... Do I have a different rotation on my reduction-gear A-4?
I think so, but I never skulled it out.. I googled around but fund not much in the way of small reversing gears. I'll bet there's one out there though. Probably in your uncle's attic on the other side of the island.

Perhaps a hydraulic pump and motor. Just thinkin' out loud now.

Russ

[BryanLee]

I just took a reduction gear off an old spare A4, it was left full of water though, so the reduction gear is quite frozen up. Not sure if it is salvageable or not yet, but if it would change the prop rotation, I might be able to clean it up enough to be usable. Anyone know for sure if it does change the rotation?

[BryanLee]

I meant keep the prop how it is and just give it a wee try!

I was thinking the same thing, but had not mentioned it yet. If there is no easy way to change the direction right now, I would totally install it and see what happens. The prop might not be as efficient when shifted into (reverse) mode, but with a larger engine then necessary, that might not matter too much. Of course it might, but would not hurt to try if your only other option is to swap the prop, you can always do that latter.