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

[80broncoman]

James,
..... 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.
.....

Get your self one of these thermostats water pressure won't effect it.
http://www.jegs.com/i/Mr.+Gasket/720/4363/10002/-1
I just showed you jegs so you could see it. Regular parts stores sometimes have them.
I have no idea how they have on of these sixs plumbed for cooling, but
I have also heard of people rerouting the water from the pump across the exh first to warm it up a bit??, although I am wondering what thermal shock is going to there. That way the water isn't 60-80F going into the block and head. Or a even better idea might be to route it to the sides of the oil pan first?? (wraping the pan with pipe or hose to do the same thing to a lesser extent.)

 

[CZLN6]

Howdy Steve:

You will need to do some more work on the casting # on the donor head. If it has an "M" suffix it is most likely an C9xx head, which could have been in a '69 vehicle, with the block and exhaust manifold having a C8XX code. If you measure the carb bore into the manifold a C9xx - M will measure 1.75". A C8xx will measure 1.5". A 200 will have five freeze plugs under the exhaust manifold and 3 bolts holding the water pump on. The starter will be situated above the oil pan gasket line. A 250 will have 4 bolts holding the water pump to the block and the starter will be below the oil pan gasket line.

You have two good choices as far as engine upgrades are concerned. One is more expensive and labor intensive.

As for the eratic oil pressure, have you tried over filling the crankcase? How many quarts of oil do you add on an oil change? It could be that more oil is needed because of the unique pan and trans in this case. Describe again your concern for the oil pressure, please.

PS- I'm off to judge a horse show in Wyoming tommorrow and then to North Dakota for 2 weeks, so if I don't post for awhile, don't worry. I'll be back.

Adios, David

 

[jamyers]

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.

OOO, that'd be nice. Where ya located, how far from Abilene Texas?

 

[64 inboard]

James,
Im in NW IL ... just a little "jont" down the road, but there's usually a few cool brews around when we hit the water.


David,
I know the donor engine has 5 freeze plugs, the rest I'll need to check out. As for oil pressure, here's a link to a previous post kinda describing whats going on.

viewtopic.php?f=1&t=58289

I think Ive got 5 qts of oil in it right now. It is to the top of the dipstick mark....probably could add a little more, but the eratric pressure hasnt really been a problem before. I did check and the Paragon gearbox and engine do in fact share the same oil supply, the front of the block's pan is open, and mates directly to the trans.

Can you tell by my pics what is in the place of the area a water pump would normally be mounted?

Have a great time, hopefully time is on my side. I wont tear into it until its too cold to go out ...In the meantime, I'll be studying my new "textbook" when I get it in the mail! 8)

 

[jamyers]

Can you tell by my pics what is in the place of the area a water pump would normally be mounted?

An automobile engine will have its water pump bolt to the front of the block, just under the thermostat housing. Looks like where your raw-water pump feeds into the block.

 

[64 inboard]

A few updates: a couple more questions......

As for the eratic oil pressure , I changed oil and added some Marvel Mystery to it. Took the boat out for an hour or so, and the oil pressure is improved....runs in the 30 to 40 lb area. So that makes me happy! On the downside, I can only get the engine to spin up to about 2700 R's, at about 2/3 throttle. (any throttle above 2/3 = no response) On a 170, what would the normal R's turn during WOT? Also, is there any way to tell how many cc's the current head on the 170 has?, (1973 date/ D3DE)


I did receive the Falcon Six handbook a week ago, Very informative reading. As for the potential 170-to-200 swap, Do both of these engines have the 3 bolt water pumps?

Also, Im pretty sure the donor is a 200, not a 250, the block ht is around 8", not 10" that the handbook says a 250 has.

 

[early ford fan]

check the distributer cap to see if its burnt .also check the points.lack of rpm is usually electrical.

 

[Lazy JW]

....... I can only get the engine to spin up to about 2700 R's, at about 2/3 throttle. (any throttle above 2/3 = no response)

If the ignition is bad due to burned points, cap, etc. it will miss-fire at heavy load. If it is running smoothly but simply refuses to go faster, try adjusting the timing (both earlier and later). I am assuming that it previously DID pull to a faster rpm.

On a 170, what would the normal R's turn during WOT?.....

This depends upon the load applied. Too much load will = less rpm. As mentioned above, if the engine used to pull faster rpm then you do have an engine issue. If it never did, then you may still have an engine issue, or perhaps the wrong prop.

If I were wanting top performance from a stock 170 in a boat I would have the prop pitched to allow it to turn at least 3500 rpm or thereabouts (wherever it is rated at max horsepower).
Joe

 

[fordconvert]

Too much prop for the available power can limit engine rpm on a boat. If the engine is truly getting weak it just may not have the power to spin that prop anymore. If you have one step less pitch it may be worth a try to see if the r's come back.

 

[64 inboard]

The boat had a 12 pitch when I got it. We hardly ever pull skiers with it, so for cruising, Ive been running a 13 pitch, which could definately be part of the rpm problem. The boat used to run in the low 3,000 R area.


One thing that happened tho. I tagged my 13 pitch prop a few weeks ago and installed a used prop I had on the shelf. The "backup" prop was marked 13 pitch, but I have no way to verify its accuracy. Even new, the same pitched prop from two different manufacturers can have two totally different characteristics. It still does seam odd to loose that many Rs. tho. I may try one of my 12's again to see what happens.


As for the dizzy, its a Mallory with a 2 year old cap and rotor. I did have a problem earlier this year when the boat just pretty much quit running. I had tried a lot of different things and as a last ditch effort, re-installed the original points and condensor in it. It fired on them, so something happened to the 2 year old replacements? I just got new ones, but havent gotten them in yet.

 

[JackFish]

What about converting it to a DS2?

 

[Lazy JW]

Once the ignition is up to proper shape, try some different advance levels. Is it practical to adjust this while the boat is operating under full load? I would play with the timing with this prop, then switch props and play with it a bit more; that engine will pull 3500 rpm safely for long periods of time.
Joe

 

[69.5Mav]

"As for the erratic oil pressure, I changed oil and added some Marvel Mystery to it."

One of the things I have personally seen is oil pressure become erratic because of foaming. The old oil gets pumped full of tiny little bubbles and the pump can't deliver proper oil pressure all the time. It’s easy to fix just change the oil. The bearing surface can get scuffed when this happens over an extended period. This causes extra power robbing friction but will eventually disappear as the scuffing gets polished out.

What type of oil did you use? Ordinary motor oil no longer has any Zink in it and can lead to cam/lifter failure. I use Rottella 15-30W diesel oil for the Zink in it, They haven't removed it yet. Or I add comp cams break in lube to the oil.

Where did you get the exhaust manifold and are they still available? I would get better heat in my Mav with that in the heater loop. I've got more cooling then I need.

Good Luck
69.5mav

 

[fordconvert]

The quality of the points I have been around the last several years is crap. I used to use standard ignition blue streak's. I have not been able to find those lately but next time I was going to seek those out and see if they are still good. The blue streaks just look a lot better built than most. I have had a problem with the typical ones sticking open occasionally. The blue streaks also have a little lube wick on them. Same goes with condensers. I have had them short which pretty much is like having the points closed all the time.

Have you used a timing light to confirm that the advance weights are working in the distributor?

Have you looked to make sure the exhaust path is clear? I have seen collapsed pipes and lots of sand/ mud. Its just like running a car with a plugged cat, they run nice and smooth but just cant seem to make any power.

Props are measured in diameter and pitch. The diameter is easy to figure out. The pitch is a little harder. Theory is assuming no losses or slippage the pitch number is the distance it would travel in 1 full turn. If you imagine the prop is a screw and the water is a nut its how far in it goes in 1 turn.

When you take a prop in for repair and it has a generally rough edges they will usually cut the whole worst blade down till its got a clean edge and then trim the others to match. If you have chunks missing they replace those first then do the clean up and cut to match thing. This reduces the area and diameter. With some of the more high tech blade designs this starts to really change things. I have 2 19's. One has been fixed several times and is at least an inch smaller than the newer one. It acts more like a 17 but seems to cavitate easily I assume because that little extra slight roll at the edge of the blades is gone. When I first bought the new one I took it back to the shop because it just looked too big. Over the years there has also been several blade designs. Im not sure what is out there for yours but mine is a Mercruiser so with the proper adapters I can install a current design prop on mine. The same diameter and pitch and series Quicksilver and the same Michigan will have slight differences in the blade shape if you look close.

 

[64 inboard]

Ive been running straight 30 Valvoline. I know when I rebuild the engine, I'll probably start using the zink addative.

The exhaust manifold is aluminum and is water cooled., To my knowledge it's not being made anymore. I plan to polish it someday. BTW.. no obstructions in it.

I havent checked the dizzy advance with a light, but the weights were sticking when I got the boat. I have cleaned and lubed them and are now working freely, but dont have the actual timing specs.

The boat originally had a 12-12 nibral wheel. Ive run a 12-13 for a long time and got 3200 r's out of the old one. This 12-13 prop could be holding me back from being able to spin my old 3200, yet alone the 3500. Who knows the efficiency factor on any of these old ones!? LOL

As far as drives, being a straight inboard, this just runs a 1" tapered/keyed shaft, so most 12" inboard type prop will work.

 

[69.5Mav]

Any updates?

 

[64 inboard]

Any updates?

Installed the new Mallory points and condensor a few weeks ago. (man are these cheapo- constructed)

We've been running the boat a little. After adding some MM oil, the pressure has been consistant in the 30 to 40 range, so thats good. Motor still wont run over 2600 r's, but could be the 13 pitch prop. Im hoping to change to a 12 before going out again. (thats what it had originally).

Been doing some thinking on the rebuild/ transplant of a 200. Maybe an aluminum head? (Im very impressed with the HP numbers I see in car applications) But, Im very concerned about the potential HP gains(or lack thereof) changing to the CI head. Since the exhaust is water cooled, I have to use my stock manifold and am wondering if it might be too resticted? I measured a spare exhaust manifold I have, and it only has a 2" square opening at the back where the elbow drop bolts on. This is also where the spent cooling water is also introduced into the system.

The other thing, and not as big a problem, is the aluminum intake manifold/carb clearance to the engine cover, both width and height.


Any ideas what "real-world" HP could be expected, with or without the CI head?

I keep thinking about the V8 option, but when we go out and I hear that ol six banger singing, with the water in the exhaust, its like nothing Ive heard before.

Any thoughts or ideas?

 

[jamyers]

...I keep thinking about the V8 option, but when we go out and I hear that ol six banger singing, with the water in the exhaust, its like nothing Ive heard before.

Any thoughts or ideas?

I don't have a boat to put it in, but if you go V8, I call dibs on that 6!

 

[64 inboard]

James,
I'll keep that in mind.

I would really like to keep the 6 banger. Part of the uniqueness of the boat is the six. I've been doing some searching, but am having trouble finding the true potential of this application.(using both the alum. head and /or a "re-worked" cast iron one). Maybe no one really knows?
anyway...what to do, what to do?

 

[Thad]

One problem with V's, 6 or 8, would be side clearance. The "V" is wider than an "I" and addition of marine exhaust manifolds you would not be able to get past the engine box.