1977 Chrysler Replacement Prop

Sabbath

Petty Officer 2nd Class
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Feb 27, 2011
Messages
122
So it would appear that I am in need of a new prop for my 1977 115hp Chrysler OB

WHICH is the wrong prop for the boat anyhow. Well, not wrong, but incorrect.

Currently it has a prop on it which has venting for the exhaust through the prop, which the Chrysler doesnt need to have. So looking on Ebay, i've found another prop which i THINK is the right one but need some confirmation from you guru's before i spend my money

Current Prop is:

SOLAS 0D 3x13 25x17R 15 tooth

New Prop is:

Manufacturer - Michigan Wheel Corp
Size - 13 1/4 x 17
Part Number - 072107 (old # SPC.180)
Shaft Size - 15 Tooth Spline Rubber Hub
Rotation - Right Hand
Material - Aluminum
Number Of Blades - 3
Cupped - No
Condition - New out of box
Application - Force, Chrysler US marine Single Exhaust 70-140HP

$(KGrHqV,!k0E68MhP!F7BO3Sl,feVQ~~60_12.JPG


Boat is a 14ft approx fibreglass

Any help appreciated :)
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 1977 Chrysler Replacement Prop

102_0250.jpg

Save your Money!

There is NO loss of performance using a thru-hub exhaust prop on a single exhaust lower unit.

Don't buy that 17 pitch prop. It will not have enough pitch for a 14 foot boat. You will need 19 or 21 pitch.

Look in the next reply at this 14 foot flat bottom boat running a 21 pitch with a stock Force 125. Also look at the variety of props I have at times used on my various engines. The one on the Glastron (black dual exhaust lower unit) is a 19 pitch on a 105 on a 15 foot hull.

102_6412.jpg102_6371.jpg102_6374.jpgView attachment 127411103_6259.jpg See next for more photos.
 

Frank Acampora

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Joined
Jan 19, 2007
Messages
12,004
Re: 1977 Chrysler Replacement Prop

100_5944.jpg102_0193.jpg100_6141.jpgworking copy.jpg103_6268.jpg

The 15 footer in the avatar gets 45 top speed with a 105 (90 at the prop) and a 19 pitch prop. The 14 footer gets 60 with a 21 pitch and a 125. So: your 115 should be somewhere in between.

The top stainless is a Michigan open hub suitable for thru exhaust or single exhaust. The bottom is a stock Chrysler (Michigan) suitable for single exhaust only.

The bronze is a solid hub Mercury racing prop. Black prop is a Vortex aluminum 13 X 19.

By all means, buy a stainless. They run at least two MPH faster. AND if you have not done so, jack the engine on the transom so the anti-ventilation plate is at least one inch above the bottom or the vee. Look back at the black dual exhaust lower and you will see the plate is one inch above the bottom of the vee.

If your 115 has the small WB carbs (1 5/16 venturi) then again, by all means get two manifolds from a Force 120 or a Chrysler 125-140 and subsitiute the larger TC carbs (1 5/8 venturi).

Show a couple of better photos of your hull--I believe you did post a couple in another thread.
 

Sabbath

Petty Officer 2nd Class
Joined
Feb 27, 2011
Messages
122
Re: 1977 Chrysler Replacement Prop

Thanks Frank, I'll try put some photos up later, I'm at work on the phone ATM. The reason behind looking for another prop is that the current one is spun, plus the blades have had some decent strikes. Thanks for your replies, will have a detailed look when I get home
 

spool

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Oct 11, 2011
Messages
126
Re: 1977 Chrysler Replacement Prop

View attachment 127418View attachment 127419View attachment 127420View attachment 127421View attachment 127422

The 15 footer in the avatar gets 45 top speed with a 105 (90 at the prop) and a 19 pitch prop. The 14 footer gets 60 with a 21 pitch and a 125. So: your 115 should be somewhere in between.

The top stainless is a Michigan open hub suitable for thru exhaust or single exhaust. The bottom is a stock Chrysler (Michigan) suitable for single exhaust only.

The bronze is a solid hub Mercury racing prop. Black prop is a Vortex aluminum 13 X 19.

By all means, buy a stainless. They run at least two MPH faster. AND if you have not done so, jack the engine on the transom so the anti-ventilation plate is at least one inch above the bottom or the vee. Look back at the black dual exhaust lower and you will see the plate is one inch above the bottom of the vee.

If your 115 has the small WB carbs (1 5/16 venturi) then again, by all means get two manifolds from a Force 120 or a Chrysler 125-140 and subsitiute the larger TC carbs (1 5/8 venturi).

Show a couple of better photos of your hull--I believe you did post a couple in another thread.

Frank, I'm pretty sure he has the TC carbs, i have the WB and his look larger & different than mine, Sabby i thought your chrysler was a '71

When we went out on it it seemed to free rev under high load and rpm, at lower throttle it was ok
 

Sabbath

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Feb 27, 2011
Messages
122
Re: 1977 Chrysler Replacement Prop

Frank, I'm pretty sure he has the TC carbs, i have the WB and his look larger & different than mine, Sabby i thought your chrysler was a '71

When we went out on it it seemed to free rev under high load and rpm, at lower throttle it was ok

Nah, i was guessing early 70's but finally got around to looking the number up and it's either a 77 or 78
 

Sabbath

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Feb 27, 2011
Messages
122
Re: 1977 Chrysler Replacement Prop

Hull pictures:

IMG_0616.jpg


So, it would appear that i dont have any of the rear with the leg down, and it means moving two cars, hitching the boat up and dragging it a metre forward, taking straps off etc. I'll do it on the weekend though if it's still pertinent.

The motor is raised up off the transom about 4 inches higher than if it was on the transom

This is the prop i currently have, and why i want/need to replace it:
IMG_0715.jpg

IMG_0716.jpg


Found this prop here, if im understanding it right, it's a 19 pitch?

http://www.ebay.com.au/itm/Force-Ma...AU_Boat_Parts_Accessories&hash=item5647b83b89

Sorry, this is going to be mainly me finding prop's and asking if they're OK.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 1977 Chrysler Replacement Prop

102_6651.jpg100_6082.jpg100_6171.jpg

Probably will not fit but it is way too expensive for an aluminum prop anyway. I am not familiar with the late 90s gearcase size so the hub might be too large a diameter. And, Isn't the Au dollar stronger than US meaning that that prop is more expensive in US dollars? Before buying any prop listed for late 1990s Force engines ask the seller for the actual hub diameter and compare to your lower unit. Your lower unit gearcase has just over 4 inch outside diameter and the prop hub where it fits into the gearcase casting needs to be just shy of 3 3/4 inch.

Anyway: For that money you can get a very good condition used stainless. AND---At 250 plus shipping that is too much money to experiment. Yes, I told you that you probably need a 19 pitch, BUT---that was an approximation. You really need to see what the top RPM are with the current prop and adjust from there.

No tach? Break down and buy one, even if it is a tiny tach. Without a tach, you are flying blind. Can't get where you are going unless you kmow where you are now.

At the current time, your beater prop can be repaired. Take each bent blade, one at a time and put it against an end grain of a 2 X 4 or 4 X 4. Gently tap out the bend working slowly to avoid cracking off the bent portion. Cast metal is always brittle. These cast aluminum props can be worked but if you try to do too much at once they will break. Once blades are approximately correct, file the edges smooth.

It can be re-hubbed for about 45 bucks and the same price for blade repair. So, for around 90 bucks your current aluminum prop can be made good again. However, with your engine jacked as high as you say, are you sure the hub is spun? Is it possible that at high speed/rpm you are ventilating?

In the photos, all I could see on the hub was"Michigan" I could not make out what appeared to be numbers in the first photo. Look between the blades and in the back or in the front. In one of these three places there will be a number with a suffix--maybe. The suffix, if it has it will be 17, 19, 21 etc. This is the pitch of your prop. If you are happy with performance now, that is the pitch you will want to buy.

As far as the year of your engine: These are not critical for me to remember but a one piece lower unit was designed around 1978. IF your engine has a distributor, it will most likely be 1977-78. If it has Prestolite ignition without a distributor, then it will be 79 to 84.

If your carbs have the black plastic covers or if they are missing, if the carbs have three threaded screw holes in the front, they are big TC carbs. Yeah, yeah! I said black plastic but I always paint mine. The WB carbs only have two bolt holes in front.
 

Sabbath

Petty Officer 2nd Class
Joined
Feb 27, 2011
Messages
122
Re: 1977 Chrysler Replacement Prop

View attachment 127469View attachment 127470View attachment 127471

Probably will not fit but it is way too expensive for an aluminum prop anyway. I am not familiar with the late 90s gearcase size so the hub might be too large a diameter. And, Isn't the Au dollar stronger than US meaning that that prop is more expensive in US dollars? Before buying any prop listed for late 1990s Force engines ask the seller for the actual hub diameter and compare to your lower unit. Your lower unit gearcase has just over 4 inch outside diameter and the prop hub where it fits into the gearcase casting needs to be just shy of 3 3/4 inch.
The AUD and USD are pretty much on parity now i think, it's a dollar or two different. But, it's all i can find bar going brand new from Solas, which is still $300+ so im expecting to pay around that much. But not sure entirely how much is "too much" as there seems to be a lack of availability of props to suit my needs.

Anyway: For that money you can get a very good condition used stainless. AND---At 250 plus shipping that is too much money to experiment. Yes, I told you that you probably need a 19 pitch, BUT---that was an approximation. You really need to see what the top RPM are with the current prop and adjust from there.
With the 17 (i think it's a 17 pitch 3x13 25x17R on the current prop) it goes ok. The boat hasnt run right since i bought it, so tach, speedo etc havent been installed or bothered with as yet but it seemed to get up and go ok. It sits in the hole for a bit and then when it tries to climb up on plane it gets there, and over-revs.

No tach? Break down and buy one, even if it is a tiny tach. Without a tach, you are flying blind. Can't get where you are going unless you kmow where you are now.
I'll be getting one soon, money's a bit tight at the moment and i know it's the wrong way to do it, but to get back on the water and test my top RPM, i think im going to need a new prop because of the over-revving issue

At the current time, your beater prop can be repaired. Take each bent blade, one at a time and put it against an end grain of a 2 X 4 or 4 X 4. Gently tap out the bend working slowly to avoid cracking off the bent portion. Cast metal is always brittle. These cast aluminum props can be worked but if you try to do too much at once they will break. Once blades are approximately correct, file the edges smooth.

It can be re-hubbed for about 45 bucks and the same price for blade repair. So, for around 90 bucks your current aluminum prop can be made good again. However, with your engine jacked as high as you say, are you sure the hub is spun? Is it possible that at high speed/rpm you are ventilating?
I've found another hub, but the bush alone is $90 from the place i found it, and then ontop of that, add the cost of repair and im probably close to $200 to get this repaired. Although then i will know that the prop fits the shaft etc. The prop shops around here are annoyingly closed until monday, so i will have to wait until then to get a final answer and to even see if they can get a prop in for me. Maybe i should wait until then? *shrugs*

Im pretty sure that it isnt ventilating, Spool was out with me when we were testing it and he had his head stuck out over the transom and was watching the leg and reported that it was in the water while it was free-revving. So from that im assuming that it's far enough in the water, bar any issues with ventilating from behind the prop, or under the cavitation plate which couldnt be seen from above while the boat is underway

In the photos, all I could see on the hub was"Michigan" I could not make out what appeared to be numbers in the first photo. Look between the blades and in the back or in the front. In one of these three places there will be a number with a suffix--maybe. The suffix, if it has it will be 17, 19, 21 etc. This is the pitch of your prop. If you are happy with performance now, that is the pitch you will want to buy.
Written on the prop is "Solas" 0D 3x13 25x17R

As far as the year of your engine: These are not critical for me to remember but a one piece lower unit was designed around 1978. IF your engine has a distributor, it will most likely be 1977-78. If it has Prestolite ignition without a distributor, then it will be 79 to 84.

If your carbs have the black plastic covers or if they are missing, if the carbs have three threaded screw holes in the front, they are big TC carbs. Yeah, yeah! I said black plastic but I always paint mine. The WB carbs only have two bolt holes in front.

Yeah, carbs do have the black plastic covers, with the 3 screw holes in the front.

Thanks heaps for the time you're spending Frank, appreciate it greatly.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 1977 Chrysler Replacement Prop

102_6505.jpg102_6504.jpgTry HMS hubs. They are here in the US and I don't know whether they will export ship, but their hubs run about 30 bucks if you are an individual. If you have a press, (and actually, 2 ton is sufficient but I use 6 ton capacity.) the old hub can be pressed out and the new one pressed in with a little soapy water for lubricant. If you have an old tapered roller bearing laying around, one with the correct small sized outer race works well as a pressing funnel. I---ahem--use an old outer race from the forward gear of the one piece lower unit.

Lacking that, It is possible to "pin" the hub. Not quite as easily as with this 10 inch one, but still do-able. Notice the three stainless 1/4 diameter 3/4 inch long setscrews.

If you weren't all the way down there, I would sell you a decent prop but I suspect that shipping will kill you.

Your prop, from description, seems to be ventilating when the boat gets on plane. Because your engine is set so high, it becomes easier for the prop to suck in air. One thing you want to do is cup the blades. This does help some with ventilation and does give a better "bite" on the water. If you have not experimented with engine height, you may also want to try lowering it a bit. Of course, this depends upon whether or not you have a jackplate with setback. Setback does allow you to run the engine higher.
 

Sabbath

Petty Officer 2nd Class
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Feb 27, 2011
Messages
122
Re: 1977 Chrysler Replacement Prop

Just sent an email to HMS asking them for a price, so they should get back to me Monday my time hopefully. Our prop shop re-opens on Monday aswell so im going to take the current prop down there to see what, if anything they can do for it, and to get a quote on its replacement.

I've included a couple of photo's of how the motor has been set up on the transom. Havent been able to lower the leg down to show it in relation with the hull depth yet sorry:

IMG_0718.jpg

IMG_0717.jpg
 

Frank Acampora

Supreme Mariner
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Jan 19, 2007
Messages
12,004
Re: 1977 Chrysler Replacement Prop

Well, Judging by the size of the jackplates and the transom clamps, it looks like the transom was originally a 15 inch transom and that's why the engine is jacked so high. You REALLY need to get that baby running right and post a couple of photos on plane, at speed. Or rather, I need you to do it. It is an exciting looking boat. You said it was approximately 14 feet long-- 4 1/2 meters?
 

Sabbath

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Feb 27, 2011
Messages
122
Re: 1977 Chrysler Replacement Prop

Well, Judging by the size of the jackplates and the transom clamps, it looks like the transom was originally a 15 inch transom and that's why the engine is jacked so high. You REALLY need to get that baby running right and post a couple of photos on plane, at speed. Or rather, I need you to do it. It is an exciting looking boat. You said it was approximately 14 feet long-- 4 1/2 meters?

Ended up biting the bullet and went and bought another prop today. Ran me about $280, but quoted repairs were close to $170

I decided to go to a 19pp, got it fitted up and should be going out this weekend to test how it goes so will get some pictures of the boat in its entirety then Frank. Will also report back on how the boat performed:

IMG_0719.jpg


(i realise there is no nut on the shaft yet) :p

Please ignore the pile of **** in the background...it's a work in progress sorta
 

Sabbath

Petty Officer 2nd Class
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Feb 27, 2011
Messages
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Re: 1977 Chrysler Replacement Prop

Hmmm.

Went back out to the boat today to play around with the prop, and tried spinning it before tightening the nut and found that the prop fouls up on the exhaust snout. I tried loosening the snout and turning it both ways, but it still hits no matter where i position it. I took a photo showing the difference between the old and new prop on the snout. Anybody got any ideas what i can do to fix this?


Old Prop
IMG_0725.jpg


New Prop
IMG_0726.jpg
 

Sabbath

Petty Officer 2nd Class
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Messages
122
Re: 1977 Chrysler Replacement Prop

Returned the prop. Going to take the boat to a different prop shop tomorrow and try and match it to the motor because it appears to be an issue with the 77/78 year model and the rake on the prop?

Barring that, might have to buy this

http://boatpropellers.iboats.com/Ch...19.00-Pitch_Propellers/173/?*******=626592882

and suck up the shipping. Aslong as it's going to fit ofcourse.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 1977 Chrysler Replacement Prop

102_6373.jpg102_6371.jpg102_6372.jpg102_6374.jpg102_6376.jpg

That's a high rake prop and if it does not enter the gearcase all the way, you need to make a few easy modifications to make it clear the exhaust snout. If it does enter the gearcase all the way, then it can not be made to fit and you would need to grind clearance in the exhaust snout.

Remove the anode from behind the prop and attach a stainless split collar--I think it is 1 1/8. Use the kind with two halves and two screws. They are expensive though. I paid 35 bucks for one. Slide it back until it almost touches the spool. There is a small land on the shaft there which will locate it. Tighten it really well. Now, use a couple of thin spacers to keep the prop from entering the gearcase too far.

Use the original thrust washer on the front of the prop along with a regular washer and prop nut. at this point, the blades should clear the snout by about 1/8 inch.

I do have a post on this either here in props or over in the Chrysler forum.

I believe I have the Michigan Match in stainless and there is no clearance problem. That prop should fit.
 

Frank Acampora

Supreme Mariner
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Messages
12,004
Re: 1977 Chrysler Replacement Prop

100_6143.jpg100_6141.jpg

The prop with the red tailcone and the top prop in the next photo are the Michigan stainless equivalent of Michigan match. I think I posted these photos before but just in case, here they are again.

Oh, by the way: If you are not using a tailcone, No performance difference will be noted. However as a safety, put a cotter pin or bolt through the hole in the shaft to retain the nut if it works loose.
 

Sabbath

Petty Officer 2nd Class
Joined
Feb 27, 2011
Messages
122
Re: 1977 Chrysler Replacement Prop

View attachment 128156View attachment 128157

The prop with the red tailcone and the top prop in the next photo are the Michigan stainless equivalent of Michigan match. I think I posted these photos before but just in case, here they are again.

Oh, by the way: If you are not using a tailcone, No performance difference will be noted. However as a safety, put a cotter pin or bolt through the hole in the shaft to retain the nut if it works loose.

Thanks for that, if i cant get a prop that doesnt foul the exhaust i'll use your process, wont be using a tailcone, but have splitpins, dont trust it without a split pin, too much time and effort for the prop to go floating off unexpectedly
 
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