bits and pieces

[Unchained]

Well I guess there's a limit to what these u joints can take.
http://www.***boat.com/image_center/data/500/220driveshaft1.jpg
I took a fellow boater for a ride and was at 7000 rpm/20# turbo boost/ 95mph and pulling hard when there was a hellatious WHAM !!! BAM BAM BAM sound, my first thought was, *uck.......I finally blew the motor. Well the motor was still running and as I was coasting down I shut it off. Smooth and controlled shut down by the way. After it stopped I looked back and seen the driveshaft laying off to the side. Pieces went everywhere and I couldn't find the u joint spider or the part of the u joint the went on the pump input shaft. My first thought was.....It may have broke the front off the pump and shes probably going to sink fast like "Fleetimus's" boat. As it turned out it didn't cause any major damage, the driveshaft loop saved it all. I can see where a couple of the bearing caps shot off like missiles and one made a dent in the top of the pump intake but no other problems. I looked around for a while and finally found the part of the joint that was the pump input. Surprisingly enough the piece was lying alongside the motor. It had to travel quite a path to get there.
http://www.***boat.com/image_center/data/500/220driveshaft2.jpg
From what I can see it broke the yoke, spider, and ubolts too. Pieces must have flew everywhere as I found a bearing cap laying in the right side gunnel 5' forward of the transom with a piece of the spider still in it.
I asked questions from some pump experts as to the capability of the u joint to take the HP of this turbo motor. I was satisfied that it was not going to be the weak link but I installed a driveshaft loop anyways. I'm sure glad I did that.
One pump expert told me right out that there was no way my motor could turn a AA impeller to 7000 rpm even though I recorded 380#+ of bowl pressure and 40 to 50# of intake pressure.
Does this mean that the pump was fully loaded ?? :rolleyes:
A word to the wise, At a certain HP level (over 1000 hp) maybe these things should be changed out every season at least.

[beerjet]

That boat would be a great R&D ride for anyone who thinks there stuff can take beating . Scary but it is a good thing you put the loop in there anyways. Safety first I always say , so now I'm gonna go buy a me a vest.:D
-beerjet-

[DEL51]

I am glad you are ok! Whew, that must have been wild. I will be getting my loop installed this winter. How often are we supposed to grease?

[Unchained]

I am glad you are ok! Whew, that must have been wild. I will be getting my loop installed this winter. How often are we supposed to grease?
Hi Chris, I wasn't much for putting a lot of grease in there, I figured how much use can the u joint get in a boat get as compared to a car ?
The U joint never made any noise or vibration at all or gave any indication that there was a problem.
It's near the end of the season now so I'm likely going to pull the motor and just run the Daytona for any good days that may come along. I haven't had the heads off the TT / Arias motor for 2 seasons so it's time for an inspection.
This Stealth would be a great boat for you Chris.
Did Rick tell you I took him for a ride when he came over for the Hardy Party ? I've got to get him into a tunnel hull. He commented about the smooth ride among other things. :D

[superdave013]

looks like it's time for a solid driveline to me.
Ever think about having Lenco set you up?

[MAXIMUS]

Since the conception of my squirt boat, I have changed my u joint I think 3 times in the last 4 yrs... I inspect it every time I pull the motor to change starters... :rolleyes: It takes a shit load of abuse & scares the hell out of me. I lost 1 in a 19' daytona at about 6400 rpm & it sounded like a bomb went off in the back of the boat. Destroyed my pump & did about 1500 in gel coat damage to the transom... I got hit in the feet with the little needle bearings...
Another area you need to pay attention too is your bolts holding the pump to the intake flange. I had to drill mine out to a larger size, step up to grade 8 & use a back up nut underneath as a result of my pump wanting to come out of the boat!

[olbiezer]

i am suprised that nothing went through the bottom of the boat at that speed .........to the botttom we go.......glad it all worked out.......the guy that build my daytona put a solid drive line in it........i love the what it looks and works great and comes out with one set screw :) :rollside:

[502 JET]

WOW you are very lucky!
Without that safety loop we would be reading another sank the boat thread.
What series u-joints?
There are solid u-joints available (not hollowed out non greasable) that are much stronger than the greasable type.

[Unchained]

I questioned about the solid driveline when I assembled the boat.
Tom Papp said, not for a lake boat. Once around the lake and the spline would be too hot to touch.
I compared the U joint size to what's in the V drive setup and the jet U joints were smaller. I guess looking back, there certainly are many sizes of U joints available. I should have went to something from a truck considering the HP.

[fleetimus]

Damn!!!!! I got the heebie jeebies reading this!!!!! I am starting to wonder if a driveline cover is strong enough???? I would like to think lightning will not strike twice. But, I keep pushing the power.
Glad you are OK!!!!

[kp216]

Well the motor was still running and as I was coasting down I shut it off. Smooth and controlled shut down by the way.
Mark - I'm glad you're OK and the boat didn't go down.
As far as the quote I pulled above, do you think your box underneath your intake had any bearing on the boat tracking straight?

[Duane HTP]

Glad you are Okay Mark. I threw a Lenco shaft out like that one time on a blown boat and it went right through the bottom. Luckily, we kept it from sinking. That's one hell of a noise, Isn't it?

[steelcomp]

Don't circle boats run solid drivelines...lap after lap... blown alky?
You must have had some inclination...or you'd never have built that safety loop. Not many automotive u-joints were made to see 7000 rpm, but...I doubt it was the u-joint that failed. I suspect that you brole the u-bolt that holds the cap in the rear yoke. That's the weak link. You can upgrade to a billet race yoke (like something from Strange Eng. or Inland Empire Driveline)with much stronger u-bolt, or even a billet cap that replaces the u-bolt. Summit and Jegs both sell them. If a u-joint can withstand the impact of a pro-stock car launching with 16"X35" slicks digging 1300 hp into the pavement, I think they can handle the liquid connection in your boat. Try to find some Spicer Gold u-joints. They're pretty indestructable.
Glad it wasn't worse.

[poncho-pwr]

Unchained, the strongest set up I have ever seen as far as the 1350 u-joints go are the Mark Williams #39039(non-greasable) & #39029(greasable) . Their 2nd generation u-bolt kits#39112 are awesome pieces as are their #39110 replacement caps. We do a lot of BIG horsepower pro street stuff where these guys not only run on the strip every weekend, but the also run them on the street with spool rear ends and big slicks. Needless to say we have seen a lot of drivelines break. Here is the Mark Williams website http://www.markwilliams.com/.

[Unchained]

Mark - I'm glad you're OK and the boat didn't go down.
As far as the quote I pulled above, do you think your box underneath your intake had any bearing on the boat tracking straight?
There's no question in my mind that the duct kept the boat running straight.
The nose didn't dive either. It just leveled off and coasted to a stop.
Once I sell the jet boat, that will be the end of the run for the duct. I'm the only one that will ever know what it did for the boat, or kept the boat from not doing. I put three seasons on it and never came up with a negative reason to remove it.
From this I learned that I have to stop giving people thrill rides in my boat.
It's fun watching them and hearing them yell while the boats accellerating, but It may not always turn out to be a safe ride.