Paragon to Velvet drive swap

[pete s]

Wondering if anyone has done a swap from paragon to velvet drives? I have a 1976 Chris Craft 35’ aft cabin that I am thinking of doing the swap. The boat currently has flywheel forward mounted 350’s with paragon drives, about 1800 hours. I have a set of 1996 crusader 5.7 with velvet drives with 100 hours in another boat that I am going to scrap. I would need to make one counter rotating but thinking other than that it shouldn’t be too bad.

 

[Scott Danforth]

Wondering if anyone has done a swap from paragon to velvet drives? I have a 1976 Chris Craft 35’ aft cabin that I am thinking of doing the swap. The boat currently has flywheel forward mounted 350’s with paragon drives, about 1800 hours. I have a set of 1996 crusader 5.7 with velvet drives with 100 hours in another boat that I am going to scrap. I would need to make one counter rotating but thinking other than that it shouldn’t be too bad.

shouldnt need to make one counter rotating. the velvet drive should be easily set up to run CW or CCW as RH motors do not exist anymore.

 

[pete s]

The boat I will be taking the velvet drives out of has two right hand props on it. I realize I can change the input rotation on the velvet drives but I don’t think the output is able to be changed. On the Chris Craft I definitely want counter rotating props so unfortunately I’d have to make one counter rotating.

 

[Scott Danforth]

The boat I will be taking the velvet drives out of has two right hand props on it. I realize I can change the input rotation on the velvet drives but I don’t think the output is able to be changed. On the Chris Craft I definitely want counter rotating props so unfortunately I’d have to make one counter rotating.

you realize that the crank required to change to a RH motor does not exist for a 1-piece RMS motor

the cost to custom machine a crank may exceed the price of changing the rotation direction on the velvet drive.

do you have series 71 units or 5000 series units?

 

[pete s]

Extremely long story short (as possible) one of the motors (both purchased new in 1994) was a counter rotating engine. The p.o. had the engines rebuilt by local marina in 2020. At that time the shop assembled both engines as standard rotation on accident. This was not caught until priming oil system with the starter before starting and they were not able to build oil pressure (due to counter rotating starter) In the mean time the boat’s owner passed away and his son wanted nothing to do with the boat. I purchased the boat a year later from the son. The shop had put all of the counter rotating parts in a tote on the boat so I do have them. The pictures are from the owners/parts manual that he gotten with the new engines/trans that’s show it definitely does exist.
The trans are 71’s with 1:1 ratio.

 

[pete s]

Extremely long story short (as possible) one of the motors (both purchased new in 1994) was a counter rotating engine. The p.o. had the engines rebuilt by local marina in 2020. At that time the shop assembled both engines as standard rotation on accident. This was not caught until priming oil system with the starter before starting and they were not able to build oil pressure (due to counter rotating starter) In the mean time the boat’s owner passed away and his son wanted nothing to do with the boat. I purchased the boat a year later from the son. The shop had put all of the counter rotating parts in a tote on the boat so I do have them. The pictures are from the owners/parts manual that he gotten with the new engines/trans that’s show it definitely does exist.
The trans are 71’s with 1:1 ratio.View attachment 371855View attachment 371856

I’m sorry I do see above I put 1996 but either way still a one pice rear

 

[Scott Danforth]

71's cant be swapped

you will have to pull the motor apart to verify the knurling on the seals is correct for a RH motor or it will pump oil out as it rotates

you will have to source the timing components for a RH motor

PCMC was the last engine builder to custom make RH motors because they had a stock-pile of 71 drives. they basically took stock GM motors apart and had their machine shop make modifications. which is also one of the reasons why the engine RPM's are only 4400 RPM where the standard GM motors were 4800 RPM

 

[pete s]

I am aware of the challenges with the rh motor, I am actually an automotive tech so very familiar with engines.
My biggest question is the Paragon trans. Is it worth the work involved to get rid of them and switch to velvet drives. I have not heard or read many good things about the paragons.

 

[Scott Danforth]

me personally, I would drop in a set of diesels and new transmissions

 

[alldodge]

I am aware of the challenges with the rh motor, I am actually an automotive tech so very familiar with engines.
My biggest question is the Paragon trans. Is it worth the work involved to get rid of them and switch to velvet drives. I have not heard or read many good things about the paragons.

My opinion
If you "really" like the boat and plan to keep it do what ever to make it yours. No one "I know of" has ever broke even on a boat

If I was going to keep it, then update with LH motors and get a RH 72 drive to work with the LH motor

 

[pete s]

Thank you for the info! That definitely makes more sense. I really do not like a rh engine, huge pain. As far as diesel goes, I’d love to but just can’t justify that large of a cost.

I like the boat however more importantly my wife loves it lol. I have restored a number of boats so definitely know all too well it has to be something you love not an investment.

 

[Scott Danforth]

As far as diesel goes, I’d love to but just can’t justify that large of a cost.

I like the boat however more importantly my wife loves it lol.

if the later is true, then the prior is worth it.

 

[QBhoy]

Pretty sure you can have your wish of counter rotating set up. Those gearboxes can go anyway you like. Two normal LH engines can be made to go anyway you like at the prop end. All you need is a prop to suit.

 

[muc]

Pretty sure you can have your wish of counter rotating set up. Those gearboxes can go anyway you like. Two normal LH engines can be made to go anyway you like at the prop end. All you need is a prop to suit.

This is not correct for Velvet Drives. they will burn up if you try to run one in reverse at high speeds.

I think the biggest problem you will face is engine height. The flywheel forward engines were used to get the engine low in the bilge and keep shaft angle down. If you have to raise the salon floor 6-8" you might not be to happy with the boat anymore.

I had less problems with Paragon trans then I did with Velvet Drives.

 

[alldodge]

I had less problems with Paragon trans then I did with Velvet Drives.

72 series can run in reverse as direct by moving pump 180 degrees

 

[muc]

72 series can run in reverse as direct by moving pump 180 degrees

If you mean the input shaft running in reverse --- yes. But it is using the forward clutch pack.
You can't just put a RH prop on the end of the shaft and shift the trans into reverse like you can with a Hurth.

 

[kenny nunez]

Marine Power in Pontchoula,La. Still advertises LH & RH 5.7s. So it appears that they are still available.

 

[Scott Danforth]

Marine Power in Pontchoula,La. Still advertises LH & RH 5.7s. So it appears that they are still available.

Marine power builds their own motor. I used to sell them heat exchangers