Boat 170 rebuild/repower... info needed!?

First off thanks for the previous help...
Im the owner of a 1964 Correct Craft straight inboard boat. A few years ago, I had asked a few questions on the site, trying to ID what I actually had, and found it very helpful.

Well, Im needing some more info. The boat is powered by what is rated at a 100 HP, 170. This year Ive been having some issues with engine oil pressure inconsistancies. The boat still runs pretty good, and its not the best timing(slow at work), but am wondering if this winter is time for a rebuild/ repower, and need to start checking into options and costs?? The boat is used weekly, and reliability is very important. I also have what I believe to be a late 60's "donor" 200 from a Maverick that I would like to use if possible, but have some questions. How much HP and torque can be obtained from a mildly built 200? / What are the normal operating RPMS? / WOT RPMs? /And mainly, will all my "marine-stuff" directly bolt from the 170 to the 200?


Being in a boat the engine must have enough low end torque to get the hull on plane( or pull a recreational skier). Once on plane, the engine pretty much has a constant pull (they dont coast). The engine configuration is a little different than your normal auto. It is a flywheel forward setup, where you can actually see the flywheel.

There is an aluminum engine mount supporting the front and is bolted into what would nomally be the back of the block. The trans is mounted to what would normally be the front of the block, via another motor mount/ adapter, and shares engine oil. The marine oil pan is cast aluminum and must be re-used. The exhaust is an aluminum log-style manifold, cooled by spent engine water, and also must be re-used. Carburation is thru a Carter YH, sidedraft, also used on turbo Corvairs of the day. This was done for engine box clearance.
I,ve posted pics before, but thought it might be best to tag them here also ...











Sorry for the long post...
but any input, ideas, suggestions, etc.,,, are appreciated!

I have not seen marine setups that were that different before. The 170 guys should be able to tell you if they noticed any differences in the blocks as far as mounting holes and such. I would be curious if there are any differences in the crank or other changes for things like oil drain back. The cam choice is going have more to do with the performance than the displacement.

I kind of doubt that swapping for a stock 200 will show much of a performance gain on the water.
You might be able to get a built 200 to rev a bit higher at WOT but at 3/4 throttle (say 3200rpm) the boat speed will be the same. I would consider freshening up the original motor if it needs it.
Or you could build a smokin' hot 200...

JackFish,
I understand the RPM's probably arent going to change much, however I'm hoping the extra HP and torque of a 200, at a given RPM, will allow me to go with an higher pitched prop. (like changing gear ratios in a rearend) Higher pitched prop = more speed at that given RPM.

As they say, theres no replacement for displacement.

First off, thanks for the pics! I've heard of Ford inline boat engines, but never seen one - that's nice!

I'd think that a 200 would be a good swap. You'd gain enough low-end torque to really jump up on plane or pull a skier with the same prop or you could maybe step up in pitch like you said. I'll bet that all bolt holes are same-same, back then they didn't make many changes to marinize engines like they do now.

I've got a '62 Chris-Craft with a Chevy 283 that's also flywheel-forward like yours, and there's one thing you'll run into if you swap engines - that transmission looks like the old standby "Paragon" gearbox, and they get their oil via a drilled passageway in the snout of the engine crankshaft that goes back to the #1 main bearing to route pressurized oil to the tranny - otherwise centrifugal force would keep the oil away from the spinning gears. The bolt that attaches the transmission to the crank is also unique, with a calibrated hole in it to restrict the oil flow. You'll need to have the 200 crank drilled and maybe tapped to match the old 170 one, and reuse that bolt. Shouldn't be any problem for a decent machine shop.

That carb might be on the small side for a 200, but I have no idea. Changing/upgrading it would probably be a headache because of engine-box clearance, unless you wanted to mod the engine box. (some Chris-Craft models had a pretty cool-looking bulge/scoop in their engine covers because of tall carbs.)

Probably a good idea to switch from points ignition to at least a pertronix or DuraSpark electronic ignition.

I'm curious about the cooling system...

Looks like the water pump picks up raw water and sends it to the automotive block water pump area, but is also hooked to the thermostat and exhaust manifold. So water enters the block where a car's water pump would be, goes forward/up along the length of the block, and then back down/rearward through the head to a thermostat, excess going to the exhaust manifold for cooling/silencing.

So what keeps air from getting trapped in the highest part of the engine / head? I'm asking because my 283 had no thermostat(s), and adding one means a lot of extra goofy plumbing to avoid air traps, or spending a TON of money on used CC thermostats.

James,
Thanks for the info on the Paragon oil supply. I never knew how it got there. Im sure my machinist would be able to prep the 200 crank.

Talking about cooling, I cant get this to run any temp. Its supposed to have a 140 tstat, I installed a 160. My gauge will occasionally run up at idle, but drops to the 100 range while running. We are wondering if the raw water pump has too much pressure and is actually forcing the tstat's spring open so it cant build up heat? I may try to install a ball valve in the "out" line of the pump, so I can throttle the supply down a little? As for the air lock, I drill a 1/8" hole in the t.stat.

Im checking on the Carter YH , to see what cfm they are, and if any thing can be done to it. One thing in my favor is the engine will probably never see any R's over 3500 or so, and more than likely, be cruising in the 28 to3 grand area. I would REALLY need to see some HP increase before I'd chop this engine cover!

The dizzy is a Mallory unit. They do make an electronic conversion for it, but to date have kept it the points type. BTW, it uses the same points as an old dual point, fairly easy to find. The Mallory 6 beater marine cap however, was a different story.

Howdy Steve:

What is the casting code on the 170 head? Is this a solid lifter block? Are the rocker arms adjustible? Is the Mallory distributor centrifugal advance only? What is the initial advance set at? How much vacuum does this engine pull?

I'm thinking that a 200 would offer enough more torque that it would be helpful in pulling a skiier out of the water, and maintaining speed against a Slalom skiiers pull. I'd settle for either a stock cam or an RV type profile with about 256 duration and more lift then stock. An aftermarket 256 will be alot fatter profile then the stockers 256 degree profile. The stock lift is .348" on a 170. .372" on a later model 200, but I'd be shooting for about .400". Throttle response would be real important to me too. I'd also be curious to know what the stock CR is.

Keep the info coming.

Adios, David

Vacuum advance is pretty much just a car thing. Most other applications that have constant loads just have mechanical advance. Boats, tractors, generators, pumps, stuff like that.

The way the fresh water cooling systems work is the fresh water is pumped to the T stat housing. The engine system is still a complete loop there is just no radiator. The t stat regulates how much fresh water is introduced into the engine's loop. What ever the engine does not take just gets dumped into the exhaust manifold. The water goes there to keep the surface temp of the manifold below whatever the magic temp the marine certification people came up with. They dont want high temps in enclosed spaces where fuel vapors could be. The water usually dumps into the exhaust stream after the last cylinder. All enclosed marine exhausts are this way. Having your engine out in the open is the only way to have zoomies or headers.

64 inboard":xonz96b7 said:

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The dizzy is a Mallory unit. They do make an electronic conversion for it, but to date have kept it the points type....

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Just keep using the points. When it really, truly MUST run, there is nothing as reliable as well maintained breaker points (think airplanes). It would take a pretty savvy dyno operator to find any useful power gains while operating in boat motor parameters.

Definitely upgrade to the 200; even with the stock carb some careful port work and a mild cam will definitely improve volumetric efficiency for a nice power gain.

The 100 hp rating for a stock 170 and the 120 hp rating for a stock 200 are pretty optimistic (they are gross hp rating numbers) the net rating for a Ford 300 is 125 hp.
Joe

Just plain cool. I want a ride. :mrgreen:

Hey guys,
I cant believe I found the casting numbers I had written down right after getting the boat. The head is D 3 DE. The block is C 3 DE. Im guessing its a solid lift just because of the age? The rockers are adjustable. I believe I set the valves at .016 hot (thats from memory) The Mallory has only mechanical advance. I have not checked the initial timing nor engine vacuum (good idea tho).

I did pull a quick compression test. Cold, with all plugs out and throttle open, everything ran 130 + - a couple pounds. Pretty even . The manual calls for 160 lbs. Does that sound a bit high? The manual also calls for 8.7:1 CR.

I called an old Correct Caft parts guy I know in FLA this morning (not many left that know the 60's boats). I asked him about the 170/marine conversion. He said the long blocks pretty much got sent to Interceptor (the marinizer) in stock, of the shelf configuration. Altho he couldn't give me the specs, he was pretty certain the cams were the stock specs a car would have used. Especially since all they did was physically turn the motor backwards in the boat. (FYI, all my other boats are V8s and actually run the engine/crankshaft backwards, or CCW, but thats a whole 'nother story ..LOL)

Joe, Im kinda with you on the points...especially for now. Id rather use the money toward the engine rebuild than an EI. (I can always do that later) The boat just doesnt turn enough R's and usually have fairly low hours, to have the timing accuracy completely shot.

jamyers":1hymwxf7 said:

Just plain cool. I want a ride. :mrgreen:

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Bring that "Chrisy" of yours ....we'd have a great time!


Thought Id post a few more pics of the boat...


Heres what the 170 looked like when I bought her....


new floor,side panels, and "rattle can overhaul"...



first time in water after resto...



one of my favorite pass-times....

64 inboard":1erzi8zs said:

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I did pull a quick compression test. Cold, with all plugs out and throttle open, everything ran 130 + - a couple pounds. Pretty even . The manual calls for 160 lbs.....

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I seriously doubt that thing EVER developed 160 lbs on its best day.....

HowdyBack Steve:

Please verify that the head casting is a "D3DE"???? If it is, It is likely not the original head. The D3xx code indicates a 1973 casting. If it is a D3, then combustion chamber volumes and head gasket thicknesses become a question. Either (or both?) of these will cause lower cylinder pressure, vacuum and torque. Do you have any engine history? Does the engine burn any oil? This engine may not need a complete, bottom up, rebuild. If the head is a D3xx you may be able to solve many of your concerns with a valve job type rebuild, to re-establish stock CR. Milling the head, a three angle valve job, back-cut the intakes, new valve stem seals and some port and chamber clean up could possibly be your smile generater. A valve job type rebuild might be the best, cheapest, and easiest first step. It it takes care of your immediate concerns you will have saved yourself the hassle of pulling the engine and messing with adapting a 200.

Verify the head casting by looking for the casting code on the tip of the intake log, in your case, in front of the carb flange.

Keep it coming.

Adios, David

David,
You know, I was just looking at the pic I just posted of the pre-painted engine. Does it look like the head is raw cast, while the block appears to have original paint? Ive owned the boat for 4 or 5 years has always run so-so (heck,its a six banger you think it could have the wrong CC heads/ CR? Im going to try to call the PO and see if he knows anything of its history.

As for oil consumption, the boat has never used any oil. This wont cure the inconsistant oil pressure tho, will it?

Just checked head casting sure looks like D3DE 6080 AA Thats the number on top of the intake portion of the head... Can you tell what motor it was originally on by this?

Talked with PO, He new nothing of a head swap. Boat sat for some years before he got it.

Soooo, ? Think its a 73?

64 inboard":3cpinrqt said:

jamyers":3cpinrqt said:

Just plain cool. I want a ride. :mrgreen:

Click to expand...

Bring that "Chrisy" of yours ....we'd have a great time!

Click to expand...

I'd love to. Unfortunately, it need some new frames, a new bottom and topsides.

OK,
So along with the "what head is on the boat now question"? comes the "What exactly is my potential donor motor" question?

I pulled the numbers as best I could in the barn its stored in. The exhaust manifold has what looks like C8DE. The block looks to have the same numbers as exhaust,along with a "12" above , and a "6015B" below that set of casting numbers.

The intake(head?) is kind of hard to read,but looks like C8(9?)D(J?)E. So it could be the same but the 8 might be a 9? and the D could be a J? It also has "E17" cast above and "6090M" below those casting #s.

Soooo, any idea what it is? Im guessing a 1968 vintage? Any way to tell if its a 200 for sure?


BTW .....James, You could just come up, theres another old Correct Craft with a Chrysler 360, setting in the barn just waiting for someone to pull around.

Your donor is a '68 200 engine, both block and head. A 170 would have a different casting code. And yes, looks like the head on the boat right now has been replaced. A code starting with "D3" indicates a 1973 part.

Gotta say, very cool boat. I need one.