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19' Sunkisst tunnel any issues over 100 mph? 480 lb hull

9K views 25 replies 13 participants last post by  pigpenracing 
#1 ·
I see some hints here on my hull on the jet boat speed question. For anyone that didn't see the other thread I bought the boat and it runs solid 85 mph. Heck jet ski's outrun that. I am building a turbo engine and want to go 110 mph. Would someone with some experience driving the 19" tunnel hull Sunkisst please chime in. I did some research on the hull before buying the boat. I know these hulls were built in all different weights and the lighter the more the issue. Ricky weighed the hull at rebuild and it is 480 pounds. I saw some were built as light as low 300's. I did a search and read for weeks before buying this boat. There is a guy close buy that has a big blown motor that runs well past 100. There is one on this site that runs 118 and Ricky has been 100 with his 555 in mine. There are some other fast ones I ran across. The only thing I have found is that they can get ugly if the engine stops. I fly aerobatic airplanes that have the glide ratio of a brick. They can get ugly if the engine stops also. I understand going fast in anything can be dangerous. This is my first jet boat but I have had really fast stuff all my life so kinda got a feel for speed. I spoke to a couple of hardcore guys about putting some power in this boat before I bought it. I am not trying to go 140, maybe 100 or 110 on smooth water. Safety is my main concern so if you guys know of any issues that are really issues with this hull let me know. I can understand it can get stupid if the engine stops or you slow down way to fast. I have made about 10 mid 80 mph runs and it slows down perfect each time, not squirrely at all. I want to hear from someone who has real life experience with these hulls. I do not want to hear from someone that was told by his neighbors uncles nephew that knew someone that had one and got thrown out. Not trying to be a smart ass or anything, I just need to know if I will really have a issue from someone that knows these boats. From what I can tell it is smooth as silk. My Baja outlaw 25 at 65 mph chine walks and feels WAY more dangerous than this boat.
 
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#2 ·
boat

Funny story... Not really but last Friday I went to the lake and made a run that was 84 on the gps as soon as I got there. When I lifted the throttle it was hung open at about 4500 rpm and kept going. No luck getting the throttle to close. I was probably running 60ish??? The only thing I could do is turn the key off. It just settled down and came to a stop. It did not do anything stupid. I had to start and stop it a bunch of tomes to get it back to the trailer. I would crank it and when it would get to 40ish shut it down multiple tomes. I understand 110 is a different story but this was my experience. Something flew in the scoop and was holding the secondary open. Couldn't fix it till I got home with tools.
 
#3 ·
If youve gta sunkist gwing youll be lucky to see 110 before it begins cavitating from lack of keel load.itll be damn quik to it tho!! Its really tuff to get a gwing to stay loading over 105ish. sunkist tunnel and sunkist gullwing are totally diff boats you may get more responses if youll post it correctly ;)
 
#8 ·
Yep... I think you are right. Not sure why I had 19 on my mind. I gotta look at the title.
You can buy a alum blocked ls408 longblock for about 5k thatd handle all that hull can take lake racing with a pair of turbs. i wldnt put a bbc in it if it were me, all the turbo ls cp tunnel style bottom boats out there dont turn or pitch folks;) ive paid attention and all these "dangerous" tunnels seem to be much tamer than runnin with bigblocks. i think the weight loss helps them land softer. i freak folks out the way i land my 16ft cp botttomed tunnel lol. not trying to scare ya but i think keeping it lite as possible is in your best interest. ive ran mine for 4yrs without being pitched or it turning on me. my kids even run it hard.
 
#9 ·
1981 sunkisst tunnel

Ok. I read all your threads and think this one is the most relevant for me to post in. We have been racing this boat for the last 5 years with motors ranging from all alluminum 421 small block and 2 stages of NO2, to a blown 548 big block on race gas. There have been 3 different drivers and all felt comfortable at speed. The boat ran a 8.93 @ 114.8 at Augusta in 2011. We have been flag racing 800ft since then.
I am confident in the hull and setup enough that my 17 year old son is driving now and runs consistent 107 mph pases on gps from an idle in 800ft. This is with a junkyard 5.3 that I freshened with rings bearings gaskets and aftermarket cam. The turbo is a BW S475 and it is set on 13#s. E 85 so no innercooler. 150 shot of gas just until it noses over and he has to grab the diverter.
Now, that being said, our hull is lighter than yours by about a hundred pounds. We found it to very weight sensitive when the blown big block was installed. It does have a jet-a- way and if we ever race farther than 800 again I think it needs a pop off valve. I just hate to modify the transome.
I think you can make a very respectable boat with what you have there. You are starting with a much nicer platform than we did. And FWIW I just pulled a tape and ours is 18.5'
 

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#10 ·
Boat

Thank you :) I am also big into aviation and you get the people that make comments. "Man a Pitts Special is dangerous. I would never get in one of those. Everyone ground loops them, how do you land with no visibility. My opinion is they are the nicest and most forward planes to fly. You better know what you are doing though. They do what you tell them to do RIGHT NOW so you better tell it to do the right thing. Same deal here with the boat. A couple get a bad reputation so now everyone that drives one is a crazy idiot. Right??? Can't wait to get it running, fun winter project.
 
#11 ·
Tom Roland raced a 280# b.h., 18' Texas tunnel (Earl Smith) from 1979-83 +/- and went on to set the ubfj record @130+ with the NJBA. To deal with the shut down/power loss issues of that hull at that time he extended the center pod/keel forward. The leading edge was forward of the sponsons, verticle and fairly flat (knife like) and extended down below the level of the outer sponsons some so that when the hull came down it landed on the keel first assuming it came down fairly flat. The keel widened and flattened out as it went back blending into the orig. keel. It worked very well when tested a time or two. No damage to hull or him. I don't recall seeing any of the other guys running that hull back then with that type of mod. As I recall a couple guys got tossed out from time to time back then but it was limited. Bud Murphy in the u haul boat was the worst injured that I can recall, I believe he ran comp. jet in the 110 mph range. Today there are several different methods to add safety to your pursuits. (jetaway, pop-off valve etc.) Since your a pilot you know the value of redundancy. ymmv. Good luck with your new hotrod.
 
#12 ·
I think these boats do have a bad reputation for spitting out drivers, and much of that is from real life incidents.. I have personally witnessed 3 guys get tossed when the motor shut off at around 100, one guy twice in the same weekend... Much of it has to do with the setup and hardware that gets put in the boat, but to keep one of these loaded with the kind of HP you are looking at, it will need some hardware IMO... Doesn't mean that it can't be a very safe boat, just maybe some safer alternatives out there......

My only comparable experience was with a CP18 tunnel (probably a fairly close matchup) that I had that would hunt all over the place on shutdown compared to my gullwing, and it could have been related to the hardware set up, but it was not a real light boat with an all iron BBC... You never know when a failure can and will occur, and on a lake or river with no rescue boat or medical staff standing bye, it's even more risky....

I think in recent years the performance envelope has been pushed so far that now everybody thinks 110 in a lake river boat is nothing.... That speed can hurt you pretty damn bad if you get tossed...

Just my opinion but there are guys that do it every weekend with success and without getting wet. maybe a pop off? maybe some of the after market landing sponsons? There are some guys on here that have been running them for a long time, so I would contact them to check into their hardware setups and see what has worked and what has caused problems. Tom Bandy would be a good one to check with...

Good luck with it! RD
 
#14 ·
I think these boats do have a bad reputation for spitting out drivers, and much of that is from real life incidents.. I have personally witnessed 3 guys get tossed when the motor shut off at around 100, one guy twice in the same weekend... Much of it has to do with the setup and hardware that gets put in the boat, but to keep one of these loaded with the kind of HP you are looking at, it will need some hardware IMO... Doesn't mean that it can't be a very safe boat, just maybe some safer alternatives out there......

My only comparable experience was with a CP18 tunnel (probably a fairly close matchup) that I had that would hunt all over the place on shutdown compared to my gullwing, and it could have been related to the hardware set up, but it was not a real light boat with an all iron BBC... You never know when a failure can and will occur, and on a lake or river with no rescue boat or medical staff standing bye, it's even more risky....

I think in recent years the performance envelope has been pushed so far that now everybody thinks 110 in a lake river boat is nothing.... That speed can hurt you pretty damn bad if you get tossed...

Just my opinion but there are guys that do it every weekend with success and without getting wet. maybe a pop off? maybe some of the after market landing sponsons? There are some guys on here that have been running them for a long time, so I would contact them to check into their hardware setups and see what has worked and what has caused problems. Tom Bandy would be a good one to check with...

Good luck with it! RD
Very true Jason.
 
#13 ·
Pigpen, is the Sunkist tunnel basically the same as the Earl Smith, CP, etc etc? I think the entry may be a little different, but I think the back half is pretty much the same... I could be way off.....

2Sangers, nice lookin ride!!! Bet it's quick as hell...........
 
#15 ·
The Sunkisst tunnel is a quick boat. Bout 25 years ago i was lake racing a friend in a Sunkisst. I was in a TX-19 and both boats would run about 85 mph. At about 8-900 feet we both hit a sizeable wave. I barely let off and luckily jumped the waves but my friend dumped the pedal. When his nose came down he went one way and the boat went the other. By the time i got slowed down enough to turn around and look, his boat was sinking and went nose up. It was`nt a potato chip but was light. Thats its only drawback. Watch the water very well as far as you can see. Make darn sure you set it down in good water. I know this well as a driver of an Earl Smith TT in the 10 second class and have asked the man on the starting barge twice to wait just a few more than once. Both times the reply was, "Let me know when you`re ready". I`m not trying to scare you away from this good running hull. Just be careful and you`ll be fine. The driver of the other boat escaped with minor cuts and bruises.
 
#16 ·
What type of bottom does Hicks "hot tub" have on it? Is that a tunnel or a gullwing?

Just my .02 on speed over 100 mph. "Building a big block and adding turbos, l would only install a package like that in a known to be safe hull". You have a good looking boat there, why are you convicted to putting 1000+hp in THAT boat? If you recived a killer deal on it, sell it and buy a hull with a better reputation. Hulls (like planes) have the reputation for a reasion. Look at what tt bbc are running in. Or hulls at that power level for that matter. There is a reason for that too.

If its just an ego thing, best of luck.

Be safe, schick.
 
#17 ·
Input

Thanks for all the input guys. The boat is very very nice. The nicest boat I have ever seen. It was not even for sale. I saw it at the lake and asked if he wanted to sell because I liked it so much. I was told it ran right at 100. On the gps it went 84. It lasted 3 trips to the lake and dropped a valve. I pulled the motor all the way down and the rings fell out in pieces. It went 84 with a badly hurt 496. I have put turbo's on a bunch of stuff and I am looking back at how much I had to tinker with it all. It was and still is a thought but I want reliability. Just sick of working in stuff. I am looking at maybe a pump gas 632 with sheet metal intake and 2 dominators. That keeps the cool hot rod jet boat look unlike the turbo deal which is cool but in a different way. I think this option will be fast and 100% reliable without having to tinker with it each time I go to the lake. I would probably sell it as is without the engine if someone paid good money. I am not going to buy a motor till the first of the year. The main objective of this boat is to go to the lake with my son and have fun. Not trying to be the fastest on the waters.
 
#26 ·
Boat

Yes it is the boat that Garry Snow did tons of work on and set up. He couldn't believe Ricky sold it to me. Garry seems to love this boat and made the comment that I bought the best and nicest jet boat in the country. I trust Garry and he told me it is ready for some real HP.
 
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