PDA

View Full Version : FLYWHEEL OR FLEXPLATE



76 sanger hydro
02-07-2002, 08:57 PM
IN MY 76 SKI HYDRO DO I RUN A FLYWHEEL OR A FLEXFLATE WHAT ARE ADVANTAGES AND DIS ADVANTAGES OF EACH THANKS ALL

Fired Up
02-07-2002, 09:09 PM
I would like to add to your question. If you run a flex plate you need to add what is called a "Button". This I guess makes up the distance between the flex plate and drive shaft that a thicker flywheel would be. My question is: How is a button attached? Is it bolted on the flexplate with the existing bolts?

boat030
02-08-2002, 08:28 AM
go with the flexplate, the button is attached to the same holes as the flexplate you just bolt the whole package on at once make sure you use some lock tight on the bolts. I might be wrong on this but i think the main advantage is just the weight difference. somebody that knows more about motors could answer that part.

LeE ss13
02-08-2002, 10:25 AM
Under NO circumstances should you use an automotive flexplate. Because they have no Torque Converter to hold them ridged, they flex and break around the center. Tom Label of Auto Marine Engineering in Glendora CA was in his race boat on the holding rope at Phoenix when the guy next to him started his engine and the flex plate he was running came apart and sent a six inch piece of the ring gear into Tom's shoulder. It had to be surgically removed. He still has the X-ray. Now they do make an after market flex plate that is welded all the way around and much thicker. I have seen the drag guys use them. Most of us circle guys use lightened aluminum high performace flywheels. Just my $ .13 ...
--------
LeE ss13

boat030
02-08-2002, 11:03 AM
i believe the one we use is from B&M.

restofreak
02-08-2002, 11:48 AM
We have been using flexplates on all our jets and flats for over 30 years, and on all our customers perf boats. From low HP to high HP and never seen one come apart or had any trouble of any kind. Only disadvantage I know of is when you come off the throttle there is no enertia so RPM drops off "right now". My .02.

superdave013
02-08-2002, 12:08 PM
I use flex plates but only SFI approved ones. They are way thicker. One thing though is if you are externally balanced the weight on the flex plate might hit the engine plate.

schiada96
02-08-2002, 12:09 PM
I use a flywheel it will help if the boat leaves the water not to over rev too fast, and also on the load back into the water not so much shock on the crank. my 02

superdave013
02-08-2002, 04:19 PM
Originally posted by schiada96:
I use a flywheel it will help if the boat leaves the water not to over rev too fast, and also on the load back into the water not so much shock on the crank. my 02
Ok, you got me on that one. I ran flex plates on my flats.
Flywheel on the cruiser as quick reving is not the main concern.

schiada96
02-08-2002, 06:23 PM
Ok you got me on that one too its just what Lee told me. We need to get together and get those transitions done.

LeE ss13
02-08-2002, 10:54 PM
Originally posted by restofreak:
We have been using flexplates on all our jets and flats for over 30 years, and on all our customers perf boats. From low HP to high HP and never seen one come apart or had any trouble of any kind. Only disadvantage I know of is when you come off the throttle there is no enertia so RPM drops off "right now". My .02.
In 30 years I have seen 3 fail. One almost killed Tom Label. That's good enough for me.
--------
LeE ss13

V-Drive Tom
02-09-2002, 09:48 AM
Originally posted by 76 sanger hydro:
IN MY 76 SKI HYDRO DO I RUN A FLYWHEEL OR A FLEXFLATE WHAT ARE ADVANTAGES AND DIS ADVANTAGES OF EACH THANKS ALL
76 Sanger Hydro and Fired Up--
It's not a button, it's a driveline takeoff. (Button term is used when you're talking about a solid splined driveline setup) Same takeoff works on either flex or flywheel with different length bolts.
As to flywheel or flexplate, aluminum flywheel would be the BEST method, but the most expensive. You will be much happier (trying) to idle in the five-mile zone with some weight on the crankshaft.
If your engine is going to turn under 6500-6700 rpm or so, and you care about just standard driving and playing around, a steel flywheel is good. (Good after-market high performance flywheel).
If there's not much money and you're horny to go to the water, put a NEW flexplate on and GO!!!!!!

Flat Screwd
02-10-2002, 07:46 PM
I have seen them both ways , I chucked up the flywheel of my BBO and spun off at least 8 pounds and then had it nutral balanced. And my hondo came with a flex plate but I felt that becuase I was building a blower motor that I needed some type of harmonics dampener so I got a alum flywheel.

Jetboatguru
02-10-2002, 08:45 PM
In case you guys are not aware, Vdrive TOM is Tom Bentley of Menkens V-drives. The dude has been around the block and has most everything you need right in his shop.

Fired Up
02-10-2002, 10:01 PM
Will grade 8 hardened allen bolts do? Or should they be specific bolts made for the Flexplate such as those made by ARP?

boat030
02-11-2002, 08:13 AM
Tom will know the answer to this but i'm pretty sure ours were grade 8. i know they weren't anything we had to order from ARP.

Jetboatguru
02-11-2002, 09:30 AM
Fired up. I have a complete set of bolts that came out of the motor from your boat. Come by and grab them anytime.
Boat030 is a wannabe.

boat030
02-11-2002, 10:53 AM
a wannabe what? i know i don't wannabe anything to do with jet boats http://free.***boat.net/ubb/tongue.gif

boat030
02-11-2002, 11:22 AM
jetboatguru i am a wannabe ski flat racer can you give me any pointers???

Fired Up
02-12-2002, 04:53 PM
Thanks JBG,
I'll do that. Been a hectic week with the fires down south. I'll call first.

LeE ss13
02-12-2002, 06:56 PM
Originally posted by boat030:
jetboatguru i am a wannabe ski flat racer can you give me any pointers???
SKI FLAT, as in NJBA ??? Well ... have I got some stories and otherwise unwanted advice for you !!!
------
LeE ss13
[This message has been edited by LeE ss13 (edited February 12, 2002).]

boat030
02-12-2002, 08:42 PM
i was hoping for some advice from jetboatguru, but what do you got???

Jetboatguru
02-12-2002, 10:06 PM
My advice is cheat like a Mutha F er and don't paint your boat to like a nasty flame job. Wassup Mike

boat030
02-13-2002, 08:00 AM
i was planning on running a 500" chevy in that class. is that o.k. you're are just jealous of the flame job http://free.***boat.net/ubb/eek.gif

Jetboatguru
02-13-2002, 09:34 AM
ATTA baby Mike,
If you ain't cheatin, you ain't trying. What is Cooper gonna do?
Say it ain't so,
Are you driving a black sponsoned machine that begins with M and ends with S?
Come clean

boat030
02-13-2002, 10:16 AM
i think cooper is gonna run this season in comp flat again at least that's what he told me when i talked to him in vegas. i'm not coming clean about what i'm driving this year quite yet http://free.***boat.net/ubb/confused.gif what are you up too?

Jetboatguru
02-13-2002, 10:36 AM
YOU ARE DRIVING IT!!!!!!!!!!!!!!!!!!!!!!!!
AH HAH!!!!!!!!!!!!
Any answer other than "NO, I am not driving it" is a dead giveaway.
Go Mikey!!!!!!!!!!!

LeE ss13
02-13-2002, 12:45 PM
Originally posted by boat030:
i was hoping for some advice from jetboatguru, but what do you got???
The SKI FLAT class was added to the NJBA program in 1984. I had a Kurtis Kraft runner at the time and ran at the race it was first held at. It was at Lake Cahuilla (say KA WEE A) out buy Indio. (NJBA only ran a few races there) It only took a 105 MPH to win it back then. (I only ran 96). I ran that class until 1993. The record up till then got as high as 126 MPH I think. I called Tom Papp and found that the rules are about the same. You are limited to 460 cubic inches. The carburetors can be no bigger than 2-750s, and you must have 2 seats. They also have SKI JET and SKI HYDRO.
--------
LeE ss13

boat030
02-13-2002, 01:16 PM
ss13, i was actually just harrassing jetboatguru a little bit but thanks for all the info you are a like a regular ski flat encyclopedia http://free.***boat.net/ubb/smile.gif. jetboatguru don't jump to conclusions i'll let you know what's hapening on march 2nd http://free.***boat.net/ubb/wink.gif

Heads up
02-13-2002, 01:37 PM
I heard from a guy at work that Mike Torgeson will be driving a new pro mod built by RBR??? Any truth to this 030?

boat030
02-13-2002, 02:49 PM
no heads up there is no truth to that.

eliminator777
02-23-2002, 07:37 AM
I run a flex plate in my day cruiser. with the clutch disc. for spline drive turbo 400 love it

infotraker
02-27-2002, 08:02 PM
I have a '77 Sanger Pickle with a 60 over 454. I run a flex plate, the balance weight hits the engine mount at about 2800 - 3000 RPM. I had to grind the mount and now hope it does not hit. Will test the boat in the water in about a month.

Costello
02-28-2002, 08:40 PM
Welcome Info, I'm the guy that bought your carb collection. http://free.***boat.net/ubb/biggrin.gif

Infomaniac
03-01-2002, 03:23 PM
Wait a minute! There is only one info around here.