1963? Hydrodyne custome deluxe 1700 restoration thread

I removed a lifter and found the bottom of it pretty pitted, probably sat there and rusted to the cam. The rest came out fine and look usable, just the one was really bad. Then I went ahead and pulled piston #1 and wow was I surprised. It actually looks pretty good. A bit of wear on the side, but for a low compression 110HP motor it would work. Bore needs to be honed some, but the bore gauge says it is still pretty tight, so I could open it a couple thou and it would work. Biggest shock was the bearings look really good. Like almost new good! Crank was flawless on the rod #1 journal, so I popped the bearing out and sure enough, been turned .010 How about that, I bought a motor that was recently rebuilt and then let sit. Even if the block is cracked, I figure the crank, bearings and pistons/rods were worth it alone.

 

So then I dig into the other 3 pistons and that is where the happy feeling ends and I scratch my head. The crank is fine so far, all the bearings look good on the rods, bores look salvageable if the block is not cracked, but the other three pistons are scrap. In the below pic, you can see down into what I think is bore #3, not too bad. Bit of a ridge at the top, but it is pretty fine and will hone out. Not perfect, but not looking for a like new engine right now. I put the bore gauge through it and it does have a bit of a taper at the top end and it is the original bore. Pistons say standard on them also.

 

This is where it gets weird. The three pistons are terrible. At the same spot, there is severe scoring on the side just above the top compression ring. Like huge grooves. Guessing detonation and scoring against the block is what it looks like. The scoring is bad, but it is covered in varnish from combustion, which is odd. Maybe the fixed timing issue and continued to run it, not sure. But there are not the same marks in the cylinder walls. I know the piston is aluminum, but the block should have wore also from how bad the grooves are. to top it off, two of the pistons are cracked around the ring grooves, pretty serious failure for no marks in the bores. I mean the bores have wear, but not what i would expect of have seen in the past for the piston damage! And why would someone take it apart, turn the crank and put that crap back in? Other than a new set of pistons is about $650 from what I have seen. Still, I wonder if parts were put into a different block or something. Definately odd.
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So next I need to finish stripping it down and see what else is bad. Still haven't removed a main cap, but with how the rods look, seems like they will be fine. My original motor I noticed the tops of all the pistons are pitted, thinking detonation there also. Might be more mild than the other engine, not sure but will stop the guessing when I strip that one down.

Oh yeah, I am thinking the crank in the original is bad due to the detonation indication on the top of the pistons. That detonation will destroy a bearing and mare the crank, have seen it before. So I was happy to see that this crank looks perfect. Another reason I think the piston damage happened before the crank was turned. that much damage to pistons would have shown in the rod bearing on the rod side. Too much hammering not too. Really weird.

Starting to regret the no outboard, but that hood scoop is just too cool! Dang! A hundred horse would be so easy to drop on this thing. There is a 2007 115 HP EFI merc locally for $5700 with only 170 hours on it! Of course, wife would kill me for spending $5700 right now..... But that would run awesome! Maybe I could modify the hood scoop to mount on the OB cowl.......

 

You must enough parts on hand by now to build a new engine with minimal expenditure. This is the Volvo engine? Years ago I rebuilt a 153ci Mercruiser 4 banger that had been submerged in salt water. I had to replace the pistons as I had to hammer/break the old ones out of the block due to the pistons rusting to the bores. I had the crank shaft reground for larger journals and simply honed the cylinders. Where it really got interesting is all the moving parts that were still good I mixed up not knowing you should keep them separate in cylinder groups for balancing. So I took the basket full of parts to a postal scale and weighed them all and re-arranged until I had 4 piles of parts that equaled in weight. Backyard balancing an engine at it's best. I put it all together and it ran fine.

Any hull work? I and probably many others are following your project.

 

Engine update: So this engine from Grand Rapids is rather confusing. Take a look at the attached picture, this crank is freshly turned .010 on mains and rods. It looks brand new! bearings are nice also, probably took some wear from me turning the motor over by hand while inspecting it. But the crank and bearings are beautiful. That right there made the purchase worthwhile, as long as I build an engine anyways. What confuses me is I broke it down the rest of the way and while cleaning the block off, I found globs of grease like stuff on the inside of the block. Upon investigation, I realized the block was upside down on the stand and it was globs of assembly lube from the camshaft where it had oozed out the sides of the bearings and run down the block walls, then solidified there like a grease. This engine was never run or never run long enough to heat up, weird considering the condition of the pistons and lack of damage to the block walls. Still planning on putting the head back on it, replace the freeze plug and pressurize the block to see if it leaks. I can not see anything and I washed the heck out of it to include a bunch of sediment and rust from the cooling passages.
Timing gears look great, water pump housing looks good, just needs the impellor for it. So I still need to look at both blocks, both heads and inspect the other piston set. That is the killer, new pistons and rings will run $700 delivered from what I can find. I can buy a nice rotating assebly to build a 400HP chevy for that much! I am hoping the blocks will be good, heads good and at the worst, I wait to find a better set of pistons while I put the rest of the boat together.

 

So I have been working on the hull stuff some also. The bench seat is painted and some of the plywood panels are cut for the new seat pads. They are waiting to be resined. Attached is a picture of the engine cowl sitting in place with the new paint, not too bad. Boat will look sharp for sure. I also have the rear engine wall painted and primed the seat base tonight.

 

The seat base was very springy when it was in the boat, and for good reason. The part you stand on was 1/2" plywood just "kinda" attached to the fiberglass with two little 1/2" bulk heads below it that kinda fit to the hull. It was not sealed and was falling apart. The shock mount was also failing due to how it was attached. So I redid it all. We got a bunch of plywood in at work with some old equipment we got. This stuff is solid, the 3/4" is like 12 plys, the half inch is 7 or 8 plys. very solid and strong stuff, so I am using it! I put the seat base upside down on a little jig to hold it flat while I redid it. With the failing of the old plywood and time in the hull, it was not the best of shape so I knew I had to stress it back into shape while it was being glassed. Once I knew it was flat, I sanded the bottom raw glass side and added a layer of 18oz roving with a nice wet layup. Onto this I placed the new 1/2" plywood that had been coated in resin also. I then added another pice of 1/2" plywood to the rear section of the seat base, where the arms and shock mount are. I cut it so I could still get access to the bolt heads if I ever need to. This whole assembly was then weighted down to crush the warped glass seat base into the flat forming jig while it cured. Once that cured, I added another strip of 3/4" plywood that is 12" wide from the front to the back. This whole thing is brushed with a couple coats of resin and layers of 6 oz glass or 1.5oz matt. It is now SOLID! On the old one, it was only the front piece of 1/2" plywood glued to the bottom of the seat mount. It wasn't even tabbed in around the edges. Got wet, rotted and fell right off.

On the original, they actually cut out the shock mount, put a piece of wood in the bottom of the hull, some core mat over that and then set the shock mount piece back in there. It did not last, it had busted loose since then. I did not like this, so I went my own route and I am happy with it. The original piece is glassed back in and bondo over it to blend it back in. It was at this point that I decided this late 50's, early 60's fiberglass how to is for the birds. I am redoing this boat and I will just do it my way. Right or wrong, I am not trying to replicate there practices back then, we have learned a bit about this stuff over the past 50 years.

 

So then I flipped it over, did my sanding and cleaning and shot it with some primer. tomorrow i am planning on painting it and it will then be stored until the hull is ready for it. On the top side is the old piece that they put in under the shock mount to take the force of the seat moving. We learn, we go on but not the best solution. But 50 years ago, this was cutting edge stuff. Heck, glass practices back in the 80's on my formula are terrible by today's standards!

 

So that brings me to my next bit of Hydrodyne heresy. hey, that could be the boat name right there! "Hydrodyne Heresy" LOL

I am going a different route on the floor coring. As was brought up, the biggest concern is getting the bottom of the boat flat since the core is out and there is not a mold. Granted I did build a nice jig it is sitting in right now, but I really am wondering about how flat it would be. So here is my thought after studying the curves and flat sections of the hull. Replace the rear wood with 1/2" plywood, the center oak with 1/2" plywood and do the front with end grain balsa. My thought is this, I am going to be adding roving to the fresh sanded hull to add strength. Into this wet layer, I will put the pre glassed 1/2" plywood and weight it down into the hull. The 1/2" plywood is already straight and I am thinking it will sandwich the flimsy hull nicely between it and the 2x's that are under the hull for the jig. Once set up, more glass and roving over the top of it. Bu the time the three pieces of plywood are in the boat, the form will be set and then the end grain balsa can be done up front. Glass it all, blend it in and then remount the seat base. At that point, I am ready for the two layers of 3/4" plywood on the transom.

So far I have the three pieces of plywood cut and the edges sanded ready to be glassed first. The bottom of the boat has been mosty sanded to remove all the resin irregularities that were left from the previous core. With how poorly the old balsa core was attached, i figure it will be way stronger and only a little heavier than when new. Plus I am going to build in side benches, so the middle floor section will be only between the benches which will be lighter than the original floor that went from side to side.

Guess we will find out how it will work, huh? I know, not how it was originally done, but I am concerned about getting that flimsy floor to actually be flat. And not concerned about performance that much, this is a cruiser!