Velvet drive info

[~DarkNemesis~]

Is there a way to tell the difference between a 70c and a 71c? I have a manual that contains both from BorgWarner but even after reading, I cant seem to find a way to tell them apart. I must be missing something and we need to know so this guy can order the correct kit. The velvet drive I bought last spring has no tag or visible markings. The manual I have covers the 70c and 71c plus service info for the early asi-70b, asi-71b, asi-70 and asi-71. My question is, are there ways to visually tell them apart. Lack of parts? different parts? Are they exactly the same? I know they are very close, Im not going to chance it for 160$ Maybe someone knows a company local in hampton roads that can look at it for us?

[prowlersfish]

Should be the same kit . the Kits I use cover 70-71-72 , gears


I can tell by looking . BTW the should be drawings in the book , I believe they stoped using the 70 series in the 1960s

[~DarkNemesis~]

I had a feeling the manual was missing a few pages, its hand made, photo copied in a binder. No pictures of full assembly. Would you be interested in the job?

[prowlersfish]

Post a photo , I thought you where get rid of the boat and moveing up ? Can't do the job ( scewed up arm ) .

[~DarkNemesis~]

I am. Trying to work a deal with a guy. Told him i would help best i could. . Its alot of boat on the dry to get rid of. Thanks for your honesty, im welding on the truck tonight. Ill ppst a picture in the morning. Its all sand blasted and just the tranny no mounts. Im may get stuck with this boat. Hes asking really dumb stuff like i did. I dont have the heart to cut this boat apart. I know what i said

[rossjo]

I had a feeling the manual was missing a few pages, its hand made, photo copied in a binder. No pictures of full assembly.

The ID tag is located on the top of the left-hand transmission mount (per the owner's manual).

Here are the specs, classifications and owners manuals for the 71c & 72c:

Velvet Drive 71c-72c Series (Straight Drive):
http://RNR-MARINE.com/TROJAN/Borg-Warne ... _Specs.pdf
http://RNR-MARINE.com/TROJAN/Borg-Warne ... atings.pdf
http://RNR-MARINE.com/TROJAN/Borg-Warne ... Manual.pdf

The 72c ( 10-18-xxx-xx ) was built heavier (and weighed 8 or 14 lbs more) than the 71c ( 10-17-xxx-xx & 10-04-xxx-xx ) and could handle more HP. For example, the maximum ratings were on the In-Line 1:1 models:

Model 71C In-Line 1:1 :

• . gas HP 310@4200RPM
  . Diesel HP 182@3200RPM

Model 72C In-Line 1:1 :

• . Gas HP 475@4200RPM
  . Diesel HP 274@3200RPM

The in-line trannies had 2 different reduction housings: 6-bolt (old) or 4-bolt (new). Older style reduction housing on the Borg Warner/Velvet Drive 71C and 72C had 6 bolts holding on a bearing housing retainer. The output coupler seal was smaller, resulting in a smaller diameter seal surface on the output coupler. The bearing used in the older style is more expensive as well.

The two reasons for still using an older style reduction housing are: 1) You can bolt a bracket to the back end, which can be used with a shift control cable, and 2) To be able to use a 4-inch diameter output coupler instead of a 5-inch (both transmissions shown to the right have 5-inch couplers, but only the older style has the option of using a 4-inch coupler).



Good luck ...

[prowlersfish]

Is there a way to tell the difference between a 70c and a 71c?


The velvet drive I bought last spring has no tag or visible markings

There is no tag on it . And its a 1 to 1 gear , I should be able to ID it the are differences in the case

[~DarkNemesis~]

thans paul and Ross, let me clean up my mess from last night and ill put a picture up. Correct, no tag. no numbers that i see. I post it up in a couple hours, thanks again. Thats some good info Ross. We do know its a 1;1 I remember paul saying so when he found it for me.

[rossjo]

No need to wait for Paul to drive over. If there is no tag, and its a direct drive (1:1 ratio) unit you can measure the housing to tell the difference between a 71C and a 72C unit (and look at the shape, which is harder to quantify here).

The length ("C" in the picture below) is the easiest check:

• > The 71C "C" length is 10-1/2 inches from the point it mounts on the bellhousing to the end of the output flange.
  > The 72C "C" length is 11-7/16 inches from the point it mounts on the bellhousing to the output flange.

[prowlersfish]

Ross waiting on a PHOTO not driving over . And he is tryin to tell if its a 70C or 71C . ( not 72 )


And its a 1 to 1 not a reduction gear unit

If my scaner worked I would post the drawings of the 70C 1:1

[prowlersfish]

This could solve the proplem

http://norfolk.craigslist.org/boa/3323165986.html

[prowlersfish]

This could solve the proplem ( I know you don't like diesels but that could be a deal or a po-

http://norfolk.craigslist.org/boa/3323165986.html

[trojanmanXS]

yep hijacking the post, why arent you finishing it Jeff? other then the fact it SUCKS and takes forever I'm witness to this. but I was really looking forward to seeing that boat all black like the transom. well in any case let me know what your up to these days

[rossjo]

Ross waiting on a PHOTO not driving over . And he is tryin to tell if its a 70C or 71C . ( not 72 )

And its a 1 to 1 gear , I should be able to ID it the are differences in the case

70C & 71C are the same size (same 10-1/2" C dim. mentioned above) ...
so you won't be able to tell that from a photo.



FYI - the 70C is only rated to 180HP. Not sure you can externally ID it versus a 71C without the tag.

Here is the 70/71 service manual ... differences are noted ...

http://rnr-marine.com/trojan/Borg-Warne ... -&-71C.pdf

[prowlersfish]

The drawings I have show some slight differences but it could be the differences in the year .I will look at them again when I get a chance .But its really is no big deal as they take the same kit anyway .


http://www.ebay.com/itm/VELVET-DRIVE-70 ... 3cbaae5ffc


Recc you get a kit with the bronze clutches