Where to buy a Chrysler prop??

[Kenny1970]

I realy need a high pitch prop for a 1971 Chrysler 120hp

I had a 13 X 17 and it must just be for sking or something.

I found a new 13 1/4 x 19 and installed it but the rpms still are way to high at WOT.""6300 RPM""

I think I need a 13 x 21 or 13 X 23 but can't find one any where.

Could some one please tell me where I might find one or does some one out there have one that they might want to sale?

I am pushing a 1971 Thunderbird Pacemaker 16 foot ski boat with the 120HP Chrysler

It only does 27 mph at 5200 rpm but will go 35 at 6300.
Thanks in advance
Kenny

 

[JCF350]

Re: Where to buy a Chrysler prop??

Take your prop to a prop shop and have it re-pitched, or most likely cup it or add some more cupping to it.

 

[steelespike]

Re: Where to buy a Chrysler prop??

You may want to check that your tach is accurate It would seem to me that unless you are running a very light boat your rpm would be closer to the max rpm.

 

[MikDee]

Re: Where to buy a Chrysler prop??

Chrysler, & Force motors are getting hard to find a prop for, I just picked up a 4blade 13X17" composite prop reasonably from comprop.com I think the peformance is great. Check it out.

 

[ron7000]

Re: Where to buy a Chrysler prop??

try here

 

[Texasmark]

Re: Where to buy a Chrysler prop??

Yeah right ron. Two totally different companies and one is kaput as you well know.

I had an 85hp ('71 as I recall) with the standard white alum prop with the pointed hub. The prop was built kinda funny in that the leading edge came out from the hub pirpendicular then made a hump (S curve sort of thing) and thenstarted the rake to the rear (like other props).

You hear about cavitation and ventilation. Well this prop suffered from real cavitation right there at that initial blade origin. There was a circle about the size of a dime where all the paint wore off and the blade started developing pits. Never saw that before or since.

Mark

 

[Kenny1970]

Re: Where to buy a Chrysler prop??

The boat is very new to me.I just picked it up from some old man that had it covered in his barn for the last 15 years.

It still looks new.

All that I have done to it is wash all the dust off of it and wax it.
I took the carbs apart and cleaned them.
I put a new water pump in the lower unit.

It first had a 13 x17 prop that spun the hub when I first tested it.but lucky me there was 2 more of the same pitch props that the old man put in the boat.
I changed it out and tried again and this time it realy came alive and would put you in your seat.I was kind of worried about the screws breaking that held the seat that I was sitting on.

I am guessing that the boat is about 700 pounds and with the engine 900pounds.

I lift the front of it up all the time to place it better on the trailer after I pull it out of the water.

A few people have told me before that the factory tack on that old of a boat should not evin work any more. "37 years old "

It runs great and and I just don't want blow it up.

I have always been told bad things about Chryslers but I have naver had a boat that ran and handled as well as this one.

The only down fall so far about it is that at idle in gear at 850 rpm in the no wake zone it is moveing 2 mph faster than the other boats.

Can the tacks just get old and start reading higher rpms because when it is reading 5200 rpms it is only 3/4 the way down.

I only saw 35 mph at 6300 rpm because I let off of the gas before the rpms went higher.It was still climbing and it was still going faster and faster.

Last Question? How do you test the tack or do I just have to buy a new one and put it in its place?

Thanks again for all the replys

Kenny

 

[MikDee]

Re: Where to buy a Chrysler prop??

A 16' boat sounds kinda small for a 120hp motor, unless it heavily built it (but it don't sound like it) it should fly! This is good, as long as it can hold that horsepower, I don't really doubt your tach, I'd say a 13X19, or 13X21prop, should be about right (for speed), with the 13X17 prop for skiing, or tubing (a load).

 

[Frank Acampora]

Re: Where to buy a Chrysler prop??

Kenny--Kenny--Kenny-- Go over to the Chrysler Crew and talk to Franz at Franzmarine. He undoubtably has a prop for you.

850 is a little too high an idle; it should be 700-750 in gear BUT if you put on a higher pitch prop it will drop some. Nonetheless, you need to loosen the stop screw locknut and screw out the screw about 1/8 turn at a time until the idle comes down to where you want it. ---Careful--lower than 700 and it will stall--very embarassing while docking. Note that this screw is near the bottom of the linkage tower, behind the lower carb. and bears against the block at idle.

Now, 17 pitch on a 16 foot boat with your 120 is definitely underpropped. That prop would be for about a 20 footer. You will want at least a 19 pitch and maybe the 21. Just as a rough comparison, MY Chrysler 90 on a 15 foot Glastron (in the avatar) swings both a 19 pitch and a 21 pitch. RPMs are lower (around 5000) with the 21 but top speed is the same. Cupping the 19 won't get you more speed but RPMs will drop and the prop won't ventilate as much in the turns.

Again, see Franz. He hooked me up with a pair of beautiful bronze props for my 90. You can see them in the photo album Frank's boats in the Chrysler Crew.

 

[45Auto]

Re: Where to buy a Chrysler prop??

My Force 120 (black painted Chrysler) hit the redline at 5200 RPM with a 13 x 19 on an 18' Bayliner. With a 13 x 21 it could only turn about 4900 RPM. Top speed was in the mid-high forties with either prop.

Your 16' should be lighter than the Bayliner, I would guess you would want at least the 21 pitch, maybe a 23.

 

[Frank Acampora]

Re: Where to buy a Chrysler prop??

Auto: even though its the same block, your Force is rated at the prop; his Chrysler is rated at the powerhead. Makes a difference of about 15-20 horsepower. A 23 pitch will most likely overprop his engine --even on a light boat. And his hole shot will be crappy. Additionally, remember that he has the two piece lower unit. I think 19 splines on the prop shaft and a "shear" pin prop locator--no thrust washer.
I don't think 23 pitch props were readily available then, now, they are probably rarer than hen's teeth. But if anyone would have one, Franz would.

 

[Texasmark]

Re: Where to buy a Chrysler prop??

Hey Frank, being an ex Chrysler owner and having some convictions about it (1971 3 cyl 85 to be exact), what's this about where the engines are rated?

Doesn't make sense to rate at powerhead back when nobody else was doing it and then when everyone else is powerhead (brake hp) rating you go to prop rating when Brunswick buys you out and everyone else is not prop rated.

Got me really confused man and 20% is 20%.....makes a difference.

Thanks,

Mark

 

[Kenny1970]

Re: Where to buy a Chrysler prop??

Ok Frank Thanks for the info .
I emailed him asking if he had one.
I also saw the prop that you got from him.
It looks nice,How does a 2 blade work compaired to a 3 blade?

 

[Frank Acampora]

Re: Where to buy a Chrysler prop??

That bronze prop is cupped and solid hubbed for a racing application. Its diameter is either 12 or 12 1/2 inches and each blade has more area than the blade of a three blade prop. But, total blade area is less. Since the hub is not as long as the hub of the stock three blade, I was able to install a split stainless shaft collar behind it to act as a thrust washer. That 5/16 shear pin taking all the forward thrust loads always bothered me. Now, the shear pin just keeps the prop from falling off in reverse.

However, I do not have that engine set up for racing so in this application, the cupped two blade bronze 19 runs at just about the same rpm and speed as an uncupped 3 blade 19 pitch. It just feels better to me and looks waaay classier backing up on the ramp. Initially, I used a cloth wheel with jewelers emery, then red rouge (redundant--I know), Then jewelers white polishing compound. Now, I polish it with Brasso every week before I use it. --It's the little things that count.

Texasmark: West Bend and Chrysler were always rated at the powerhead While Merc always under rated or understated their horspower and I'm not sure about OMC. The only time Chryslers were anywhere close was when set up for racing with pipes, special ignition, and racing lower unit.

However, in the early '80s the Outboard Marine Manufacturers Association --or something, whatever the hell they called themselves-- decreed that all outboard engines should be rated at the prop. I recently found out that at this time, the company was still Chrysler and to comply, the venerable 105 was re-rated as 90. So, at one point, Chrysler made a 4 cylinder 90 hp engine. Something I never knew until now; I always thought that all Chrysler and Force 90s were 3 cylinders.

To the best of my knowledge, all outboards are now rated at the prop.

 

[JCF350]

Re: Where to buy a Chrysler prop??

That bronze prop is cupped and solid hubbed for a racing application. Its diameter is either 12 or 12 1/2 inches and each blade has more area than the blade of a three blade prop. But, total blade area is less. Since the hub is not as long as the hub of the stock three blade, I was able to install a split stainless shaft collar behind it to act as a thrust washer. That 5/16 shear pin taking all the forward thrust loads always bothered me. Now, the shear pin just keeps the prop from falling off in reverse.

However, I do not have that engine set up for racing so in this application, the cupped two blade bronze 19 runs at just about the same rpm and speed as an uncupped 3 blade 19 pitch. It just feels better to me and looks waaay classier backing up on the ramp. Initially, I used a cloth wheel with jewelers emery, then red rouge (redundant--I know), Then jewelers white polishing compound. Now, I polish it with Brasso every week before I use it. --It's the little things that count.

Texasmark: West Bend and Chrysler were always rated at the powerhead While Merc always under rated or understated their horspower and I'm not sure about OMC. The only time Chryslers were anywhere close was when set up for racing with pipes, special ignition, and racing lower unit.

However, in the early '80s the Outboard Marine Manufacturers Association --or something, whatever the hell they called themselves-- decreed that all outboard engines should be rated at the prop. I recently found out that at this time, the company was still Chrysler and to comply, the venerable 105 was re-rated as 90. So, at one point, Chrysler made a 4 cylinder 90 hp engine. Something I never knew until now; I always thought that all Chrysler and Force 90s were 3 cylinders.

To the best of my knowledge, all outboards are now rated at the prop.

OMC rated theirs at the power head also, that's why the Merc's (rated at the prop) were always faster than everybody else.

BTW: polished brass props look "way cool" !!!

 

[Texasmark]

Re: Where to buy a Chrysler prop??

JCF

Agree on OMC "BIA Certified BRAKE HP", brake being net powerhead power....big deal, before the changeover in the 80's.

Was not aware Merc was always prop rated. Agree on their conservative ratings and when I was an OMC nut, I never remember smoking a Merc.

Would really like to know the right answer as it affects my replies when applicable.

Frank, thanks.

Mark

 

[JCF350]

Re: Where to buy a Chrysler prop??

My information was provided to me by the Marine engines instructor where I learned Marine engines (1976). Later on (1978) I went to the Mercury and Mercruiser Factory school in Orlando and I saw nothing but propshaft mounted dynamometers used when checking motors for rated horsepower (also for when they were doing performance work).

 

[Texasmark]

Re: Where to buy a Chrysler prop??

Thanks JCF. No wonder they were HOT.

Mark

 

[Kenny1970]

Re: Where to buy a Chrysler prop??

Ok Frank Thanks for the info .
I emailed him asking if he had one.
I also saw the prop that you got from him.
It looks nice,How does a 2 blade work compaired to a 3 blade?

I know this is way old but here is the update on the 120 Chrysler rpm problem.
I put a 21 pitch cuped stanless prop and it now does 5200 rpm at WOT with 150 pound me and a 200 pound friend with 6 gal. of fuel.
Now the hole shot sucks but I think I will put a Hydrofoil on the engine to take care of that problem.

What is a good one that would work for that heavy old 120hp Chrysler?

Thanks Kenny

 

[Gary H NC]

Re: Where to buy a Chrysler prop??

Hydro foil is a bad idea in my opinion...Smart Tabs are the way to go..