User Tag List
Results 1 to 15 of 23
Thread: Test Wheels For Merc V8 ProXs
-
07-20-2020, 03:38 PM #16000 RPM
- Join Date
- Nov 2006
- Posts
- 1,491
- Thanks (Given)
- 13
- Thanks (Received)
- 129
- Likes (Given)
- 70
- Likes (Received)
- 626
- Mentioned
- 35 Post(s)
- Tagged
- 0 Thread(s)
Test Wheels For Merc V8 ProXs
Anybody out there making a test wheel for these motors (1 1/4 dia outdrive spline)?
-
07-21-2020, 08:26 AM #2
You'll have to make your own. Quicksilver , aluminum , 17 - 19 pitch props are less than $100 .
Start out with 2 - 2.5" blades . I'll be a bit tight , but a good place to begin ..
-
capteliminator liked this post
-
07-21-2020, 11:21 AM #36000 RPM
- Join Date
- Nov 2006
- Posts
- 1,491
- Thanks (Given)
- 13
- Thanks (Received)
- 129
- Likes (Given)
- 70
- Likes (Received)
- 626
- Mentioned
- 35 Post(s)
- Tagged
- 0 Thread(s)
Test Wheel DIY
Great idea. After you cut the blades down, did you have a prop shop spin balance it? I was thinking of having a hub machined to accept the Merc 1 &1/4 hub kit and having a 3/8 inch disc attached to it. I'm not really fond of having anything spin to it at with any pitch to it at all.
-
07-21-2020, 09:59 PM #4
I balance my own props , flywheels and crankshafts ..
I own a matching left to this prop and no I didn't balance it .
The blades are very short , were layed out , scribed , band saw cut around an arbor , and any place the line was still showing , was brought down on a 16 x 96 inch belt sander .. Balanced .. good enough
BTW .. when you get some time , go to a good crank balance guy , have him balance your prop .. knock the hub out , shove it back in 90 or 180 degrees from where it was , spin it again .. get back to me with what ya find ..
It's a test wheel (and a poor mans dyno).. so it's meant to put a slight load on the motor while the rings bed in. It's also good for running the motor up thru the rev range to hear if it noses over , misses , pop's etc. And you can watch the timing come in , what happens when ( and exactly where) it goes on the limiter . Data log . As well as do a wide open plug chop , with all the convenience of your truck hooked to the trailer and the boat tied to the trailer . Bury the wheel in the water , you really cant feel it once it loads the park pawl in the truck's transmission . And the water looks like a cross between a mullet run and the bubbles in a fish aquarium …
I'm not really fond of having anything spin to it at with any pitch to it at all.Not sure how to say this ...
It's a boat , it uses a "full size" propeller . This is a partial propeller , less of everything . And rotates close to the shaft centerline .
A test prop with a known value , will grab the motor and say .. not one more RPM if it's not up to the task.
A disc on the other hand will continue to spin .. in a time to RPM mode . Without the electronic's to record that .. it's pretty much useless.
But to each their own ..
The reason I said , mine would be tight , here is an old Merc service bulletin :
300 hp = 11.625" x 17" x 3 blade
Yup , this here motor makes 379 hp ..😁Then how come it will only go 5200 RPM .. on this 400 horse test wheel ..😢
-
capteliminator, rgsauger liked this post
-
07-22-2020, 09:53 AM #56000 RPM
- Join Date
- Nov 2006
- Posts
- 1,491
- Thanks (Given)
- 13
- Thanks (Received)
- 129
- Likes (Given)
- 70
- Likes (Received)
- 626
- Mentioned
- 35 Post(s)
- Tagged
- 0 Thread(s)
DIY Stubby Prop Test Wheel
Thankyou for the great tech page response! I'm guessing that your BTW note means that the balance "shifts" if the hub insert position changes. Is the trailing edge of your test prop cupped? Did you follow the radial contour of the original prop blade profile dia for the shorter blade cuts (layout)? Did the prop exhaust hub originally have a diffuser ring? I guess there are 2 schools of thought on using a "stubby" prop or a disc and pros and cons for both. Stubby definitely better for ring set though.
-
07-23-2020, 08:22 AM #6
Yes it will change , not a lot , a few grams maybe .... but it will change .
A friend found those props in a clearence or disccontinued model sale . He bought a bunch of them , drop shipped them to me , I cut them and sent them out to the other guys on the buy in .
Thats just the way they came , no vent holes , no blowout ring , the cup is factory .
The OMC test wheels were a flat disc but had an outer band that looked like a disc brake rotors cooling fins or a Ferris wheel … still had blades of sorts which discharged water radially instead of back …
-
07-23-2020, 09:25 AM #7The Historic Photo Master
- Join Date
- Jan 2004
- Location
- Florida
- Posts
- 37,827
- Thanks (Given)
- 64
- Thanks (Received)
- 1667
- Likes (Given)
- 337
- Likes (Received)
- 19200
- Mentioned
- 3 Post(s)
- Tagged
- 0 Thread(s)
...did the 4 blade aluminum in your above photo have the torque ll replaceable hub as you recieved them, or?
-
07-23-2020, 02:02 PM #8
There is an old Mercury service bulletin on how to cut down a 3-blade aluminum prop to a test prop. Looks just like Chaz’ except one blade less.
Markus' Performance Boating Links:
www.toastedmarshmallow.com/performance
-
07-23-2020, 06:10 PM #9
Hubs purchased separately. In my case I put a used set in that I reglued the rubber baby buggy bumpers back in place … They only get used for maybe an hour or so on new builds , or diagnosing a motor that would rather shoot ducks than run smooth .. then back in the basket of deplorables they go ..
Marcus … feel free to read post #4 ..
-
rgsauger liked this post
-
07-23-2020, 06:25 PM #10
OMC test wheels look more like the stator in my my bolt together torque converters than a propeller ...
Chaz = wunderin, where do the exhaust exit at ....
Ohh wait , I see now …
-
07-23-2020, 07:06 PM #11The Historic Photo Master
- Join Date
- Jan 2004
- Location
- Florida
- Posts
- 37,827
- Thanks (Given)
- 64
- Thanks (Received)
- 1667
- Likes (Given)
- 337
- Likes (Received)
- 19200
- Mentioned
- 3 Post(s)
- Tagged
- 0 Thread(s)
short spline. yup, omc...
-
07-23-2020, 07:14 PM #12The Historic Photo Master
- Join Date
- Jan 2004
- Location
- Florida
- Posts
- 37,827
- Thanks (Given)
- 64
- Thanks (Received)
- 1667
- Likes (Given)
- 337
- Likes (Received)
- 19200
- Mentioned
- 3 Post(s)
- Tagged
- 0 Thread(s)
...ok, so they are the torque ll hubs. gotcha. if they were the old press-in hub style, i was going to mention that the old volvo sterndrive replacement rubber press-in hubs were 1 1/4'' splines, and they are still orderable by your local favorite prop shop or marine wholesale house.
-
H2OPERF thanked for this post
-
07-23-2020, 08:14 PM #13
-
07-23-2020, 08:40 PM #14
Seein that shear pin hub reminded me of when I was a kid . Hit some coral rocks over by Sands Cut on the N. side of Elliot Key.
An old man had baby food jars full of screws and nails in his tool box .. fixed me up pretty good .. channel locks and hammer straighten job on the wheel , nail in the slot , and sent me on my way ..
Had to be 1971 or 2 . Well before I had a restricted license . Even if I had any money I doubt he would have taken it .. I'm glad to say I have tried to "pay it forward" ever since .
I had one guy say to me .. when I asked for a tow to Sand Sprit Park , from about 400 yards away .. he said , you got a cell phone ? yes sir , good you'll be OK as he sped away .. Typical spoiled rich POS types ..
Actually did me a favor .. next boat to come along 20 seconds later .. was two very nice young ladies that were more than willing to help ..
-
07-24-2020, 06:28 AM #15Screaming And Flying!
- Join Date
- Dec 2001
- Posts
- 9,502
- Thanks (Given)
- 23
- Thanks (Received)
- 269
- Likes (Given)
- 191
- Likes (Received)
- 1975
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
Sexist...…..
Similar Threads
-
ProXS 250 problems, need Merc tech in Jax!
By tow_life in forum Technical DiscussionReplies: 5Last Post: 11-26-2018, 04:22 AM -
2011 Merc 150 ProXS more HP
By mtstringer in forum Technical DiscussionReplies: 1Last Post: 05-27-2018, 08:34 AM -
Merc 3.0L ProXS heads
By malexie in forum Misc. Parts and AccessoriesReplies: 0Last Post: 06-28-2016, 10:49 AM -
Merc 225 proxs
By HMF RACING in forum General Boating DiscussionReplies: 7Last Post: 08-01-2009, 10:00 AM