69 Chrysler 55 HP

[tater76]

Re: 69 Chrysler 55 HP

Awesome!!! love it when something works out. Oh, and thanks for the heads up on the cross reference of part #'s. Yup the shift linkage can be very touchy on my 55, one turn seems to make all the difference sometimes, but sounds like you have found the same thing
And if mama is happy the world is happy right?!

 

[jmulz824]

Re: 69 Chrysler 55 HP

Hopefully the Borg Warner ones work better / longer than the napa parts, or just work in general, and since mama is happy hopefully the world becomes a better place.....

On a 15'6 tri hull, how much mph should I expect? I have a speedo, dunno if it works right, but it seems about 20 mph is all I can get out of it, it feels faster than that but, 20 mph on the water seems like 35 in a car. Any ideas on how fast it should go? I know it's not going to be a race boat going 80 mph. Just curious.

 

[tater76]

Re: 69 Chrysler 55 HP

Well..... it really depends on your setup. If the motor is mounted correctly, ie. cavitation plate inline with bottom of hull, motor is running tip top, water is glass, boat is not full of water soaked foam and wood, 2-3 passengers, cooler, at least one fuel tank, gear, correct prop, etc.. Yup 20-25 is about right I tried for two years to get my little 55 to push the boat in my avatar past 20. When I ran my tests I ran one 6 gal tank, two adults, one child, one cooler, fishing gear, trolling motor, two batteries, two anchors, and a partridge in a pear tree. 18-20mph was the norm with a 10X10 prop. I did buy a 10X12 that seemed to help a little, but took ALOT longer to plane out. Don't trust your speedo, if you have a smart phone download a free mph app, they work great! What size is your prop?

 

[jmulz824]

Re: 69 Chrysler 55 HP

I'll take some pics and post them when I get home, and try to get an idea of what the prop is.

 

[jmulz824]

Re: 69 Chrysler 55 HP

Ok, looking at the prop, the only numbers I see on it are 278 10, no dashes, decimals or other hieroglyphics. Here is a pic of the motor on the back of the boat, the plate sits approx 1 inch below the bottom of the boat.



It doesn't look out of position to me, so I'm guessing that is about top speed. I'm going to check the timing which I haven't done and see if that makes a difference in getting a few more rpms.

 

[tater76]

Re: 69 Chrysler 55 HP

Yup, your a little low on the transom. The clamp should not sit flush on cap of it, and the cav plate should be level with the bottom of the hull. Get rid of the whale tail to gain a few more mph too. I picked up at least 2 when I removed mine. Mine was set exactly the same way, raised it with a little improvement in speed. Timing will definitely affect your WOT and top speed.

 

[jmulz824]

Re: 69 Chrysler 55 HP

I'll remove the whale tail, but I don't know if I'll move the motor, not sure how bad I want to drill more holes in this thing....Thanks for the insight though.

 

[fucawi]

Re: 69 Chrysler 55 HP

yes its too low you are dragging that whale tail under the water ....shuould be just above the water on the plane.....
I carnt see this 10 x10 prop being right.....I got a 35 hp and it had a 10 x10 on it ...bought a 30 hp and it had a 10x13 on it ...now considering this 55hp is equivalent to a modern 50 hp shaft output motor ......if you double the pitch 2 x 10 = 20 and take 80% of that its a good indication of speed at 6000rpm and 2 :1 g box ratio....study of other 50 hp shows up to 16pitch for a samll boat and I think it should run 14 p on about a 14 ft boat.

IN the end accurate rpm measurement and a prop to load it into the right range remembering a 2 inch change in pitch changes rpm 400 rpm.

heavy boat ..standard size americans full of burgers..beer bait and kids= slow

 

[tater76]

Re: 69 Chrysler 55 HP

jmulz, 10x10 is standard on 55hp and 50hp of many years. I have 2 55hp about the same year as yours that have the 10x10, and an 85 50hp with it also. I have tried a 10x12 on my 55 with a little more success, but the motor was just not big enough for my boat.

fucawi, bad form sir, Maybe this is just your personality, who knows, but there is never any reason to insult another mans country the way you just did with that nasty generalization. Online etiquette is a very serious issue, what may seem to be a joke or ribbing, can be construed as serious insult by others. Remember, true emotion is difficult to convey online so think before you write.

 

[fucawi]

Re: 69 Chrysler 55 HP

Wow tater we are touchy ....dont get me started on the french ..but you arnt french so you would not care ....

so 10 x 10 is standard on 30 hp through 55 ...thats crazy...more power should drive a bigger pitch prop or you go just as fast with a 30 hp as you do with a 55 on the same boat.
I once has a 70 hp driving a 17p ..upgraded to a 115 hp ..they gave me a 17p !!! I went mad same speed and same noise level ..ended up with a 20 p and a quiet fast ride ...yamaha dont you love them .....

 

[jmulz824]

Re: 69 Chrysler 55 HP

I think it's fairly funny since I'm all of 5'9 165..... I'm not going to slow the boat down much.

the boat bow to stern is only 15ft, I have 2 other props the look the same size and pitch, with a tape they measure about 10 in across. Pitch I'm unsure of how to measure, these props are pretty old and not many markings on them.

On one of the props, next to where teeth are by the pin there is a 14, do I have a 10 x 14 maybe?

 

[tater76]

Re: 69 Chrysler 55 HP

The 14 stands for the number of splines on the prop shaft if I remember correctly. I am not sure how one would measure the pitch though? maybe someone will chime in?

 

[fucawi]

Re: 69 Chrysler 55 HP

almost inpossibe to measure for the home guy unless you can find some marking ....
I have never seen a prop ( I once sold them by the hundred) with the spline count marked .it is most probably the pitch...on all the genuine chryslers I have seen the markings are between the blades on the boss ..under the paint...

 

[jmulz824]

Re: 69 Chrysler 55 HP

Well, A BIG thanks to everyone on here, Tater, fucawi, I thinks I got the boat good to go, had it out several times with no issues, motor runs great, shifts great!

I was pleasantly surprised how the boat went without the whale tail on it. Removing it, picked up 2 to 3 mph, I could hear an increase in the RPM at WOT, I had it going 22 on lake which was no where near glass at the time.

Thanks again!