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Transmission question

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craigjudge
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Transmission question

Post by craigjudge » Sun Aug 14, 2011 5:59 pm

As my Lancer project nears completion I just picked up the next project. It's a 76 25 Express Cruiser. I know it's not a big dollar boat but I want something big enough to overnight every now and then. The boat came without a motor which I already have. I've got a 76 307 that according to my research came with the boat. The question is what transmission should I go with. Can't seem to find any info . Any help is appreciated.
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Ollon
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Transmission question

Post by Ollon » Mon Aug 15, 2011 2:30 pm

Any Paragon from a Chris Craft 283 should work since a 307 is just a bored out 283. I would probably go with a 2:1 reduction gear.

rgmxk22
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Post by rgmxk22 » Thu Aug 18, 2011 12:44 pm

I might be able to look at a sister ship of your's, a 1972 model and see what transmission is in that one. I know it has a 307 in it and I believe it was a G series CC engine.

I don't know about using a reduction gear in a 25 footer like your's. Most smaller boats like your's have usually been direct drive from what I've seen. I usually see reduction gears in larger boats, like my dad's 31' CC uses paragons with 1.5 to 1 reduction gears. We bought engines out of a 34' CC Connie once and they were 2.5 to 1 gears.

So if i can I'll look at the 1972 like your's and see what's in it for a trans. But the boat might be sold soon, so I'll do what I can.

Ron Michael
CC XK22
Ohio

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craigjudge
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Post by craigjudge » Thu Aug 18, 2011 1:16 pm

that would be great. hate to buy the wrong one.

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Post by rgmxk22 » Tue Aug 23, 2011 7:09 pm

Hi,

I had a chance over the weekend to take a look at that sister ship to the one you own and need the transmission information. Keep in mind that this is a 1972 model of the 25' CC like your's, and it has a 307 G series CC engine like I mentioned earlier.

The ID plate on the trans was stamped as a Paragon P-21R and it was direct drive. I've included a few pics of the boat and trans. Hope this helps.

Ron Michael
72 CC XK22
Ohio

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Paul P
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Post by Paul P » Wed Aug 24, 2011 3:18 pm

At first I thought your direct drive comment was faulty but upon looking I see you are very correct. Good info.


Paragon hyroglyphics goes like this.

The P series has a P 200, P 300 and P 400 model. The 200, 300, 400 part of the equation designates the gear size, which is not directly tied to the reduction, but more so the load capacity of the transmission.

The 1, 2, 3, 4, designation on a transmission correlates like so:

1 = direct drive
2 = 1.5:1
3 = 2.0:1
4 = 2.5:1

Therefore a P 21 would be the Paragon 200 series in a direct drive configuration.


Regards, Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

rgmxk22
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Post by rgmxk22 » Wed Aug 24, 2011 8:40 pm

Thanks for the assit Paul with the de-coding of the Paragon numbers. I'm more familar with the old Paragon HF-7s, so to see your info on the P-series was new to me.

I didn't figure that a 25' would need a reduction gear because from what I know and have seen, you need a reduction gear to let you swing a larger prop with a smallish engine like a small block Chevy. With the reduction gear, you should be sort of multiplying the torque out of a little engine to move a big boat.

For example, a friend of ours had a 67 27' CC Commander sport fisheman with a flybridge. It has twin 283F series engines in it and was a direct drive set up. Now my dad has a 31' 1963 CC Sea Skiff express powered by a pair of flywheel forward 283s with 1.5 to 1 reduction gears. Basically the same horsepower in both boats, but the 31' is a lot heavier. But with the reduction gears and larger props, it works.

In fact, I don't recall seeing any inboard powered boats 28' and smaller with reduction gears on them over the years.

Ron Michael
CC XK22
Ohio

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craigjudge
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Post by craigjudge » Wed Aug 24, 2011 9:51 pm

This has been very informative. Thanks for all the effort doing the research. I will be slowly putting the pieces together over the next year while I enjoy the Lancer.
I'll post some pictures of the Lancer in a week or so when I've finished the final assembly. Cheers!

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Paul P
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Post by Paul P » Thu Aug 25, 2011 11:48 am

props, gearing, hull profile, power, and weight all come into play.

the 23' Lancer inboard has a 1.5:1 reduction. I discussed the issues with many people when I decided to install a 427 motor in mine, and one thought was go with direct drive and a 13" prop, the other thought was a concern to get enough prop under that particular deep v hull and the 1.5:1 came with a stock 15x16 I believe, so with a 427 I'll be way up into the 20" pitch. Maybe I should have gone with a direct drive with all that additional power, but I decided to stay with what Chris Craft used specifically becaue of the deep v hull drag factor and the tunnel pocket for the prop. Many of the boats that have a flatter bottom like a runabout can get away with a direct drive becuase a flat bottom is the fastest (until you get to the chop) :-)

Regards,

Paul
1956 17' CC Sportsman, 300-hp
1957 17' CC Sportsman, 95-hp
1966 20' CC fiberglass Sea Skiff, 210-hp+
1973 23' CC Lancer inboard project, 427/375-hp.
1966 38' CC Commander Express, 427/300-hp(2)

So many boats.........so little time.....but what a way to go!!

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craigjudge
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Post by craigjudge » Fri Aug 26, 2011 6:58 am

Based on some quick internet searches it shouldn't be too difficult to find a P21 trans. I'm also looking for a local engine builder in Connecticut or Rhode Island who can rebuild my 307. It would be better if they were a full service yard and could install it when completed.

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