K&B 3.5 speed?

[Michael Hall]

What would need doing to a k&b 3.5 on a hot shot to get it over 70km/h (45mph)? Ive got a power head that has an ex throttle and when I opened it up it looks like someone has done a few mods

 

[HTV Boats]

Not sure why you set 45mph as a target. With the set up you desribe unless your a tunnel expert I think it would be difficult at best. Not the greatest hull at that speed either. With an exhaust throttle and no tune pipe? Maybe Robin will jump in here as he probably knows the limits of a K&B better than anyone. With a current hull and a good K&B mod motor and pipe I would be happy getting anything over 45mph. I am sure someone will chime in with their Hot Sh*t that runs 50+ but that would be an "Urban Legend".

Mic

 

[Kez]

The origianl Hot Shot (fiberglass) or the Hot Shot sprint (24") ?

I have a few of the original HS in my collection that I do not run anymoe. I keep them for a sentimental reason. The fastest I managed to get those HS to run was probably mid to high 30's. Occassionally you may find an Ebay version that can run 80 mph ;-)

I understand the 24" Hotshot sprint had hit 50 mph using a modified engine and 50% fuel.

kez

 

[John Kubitz]

The origianl Hot Shot (fiberglass) or the Hot Shot sprint (24") ?
I have a few of the original HS in my collection that I do not run anymoe. I keep them for a sentimental reason. The fastest I managed to get those HS to run was probably mid to high 30's. Occassionally you may find an Ebay version that can run 80 mph ;-)

I understand the 24" Hotshot sprint had hit 50 mph using a modified engine and 50% fuel.

kez

Most of the stock 3.5's on ebay with the black carb only run in the high 60's.

Years ago i saw TOD TRIBBIT run 47mph with an air cooled (stock)? 3.5 K&B. Don't remember what boat it was on.

 

[topfuel443]

Weve run 48-49 mph with K&B sport engines on Villains. Its possible, but K&B's dont like to stay together at those speeds for too long. 45 is doable with the engine, not sure about the exhaust throttle set-up, the carsb always worked best for us. Defintely not sure about the hotshot. There are much better hulls out there suited to do what you want.

If you want to run 45-48 mph consistantly without breakage, get an OS...then get a better hull. Probably not what you wanted to hear, but its the honest truth.

~James

 

[HTV Boats]

The origianl Hot Shot (fiberglass) or the Hot Shot sprint (24") ?
I have a few of the original HS in my collection that I do not run anymoe. I keep them for a sentimental reason. The fastest I managed to get those HS to run was probably mid to high 30's. Occassionally you may find an Ebay version that can run 80 mph ;-)

I understand the 24" Hotshot sprint had hit 50 mph using a modified engine and 50% fuel.

kez

I didn't want to burst Michaels bubble but Kez is right on at high 30's. When that Hot Shot hit 50 was it in freefall mode? Maybe off a cliff or in the back of a truck on the hwy?

Mic

 

[Kez]

The origianl Hot Shot (fiberglass) or the Hot Shot sprint (24") ?
I have a few of the original HS in my collection that I do not run anymoe. I keep them for a sentimental reason. The fastest I managed to get those HS to run was probably mid to high 30's. Occassionally you may find an Ebay version that can run 80 mph ;-)

I understand the 24" Hotshot sprint had hit 50 mph using a modified engine and 50% fuel.

kez

I didn't want to burst Michaels bubble but Kez is right on at high 30's. When that Hot Shot hit 50 was it in freefall mode? Maybe off a cliff or in the back of a truck on the hwy?

Mic

I remember reading one of the RC mag when Dumas first released the 24" Hot SHot sprint that the boat had the potential to hit 50 (or high 40's) with a modified K&B and hot fuel.

The best I could do with my fiberglass HS was around 37mph using a stop watch.

kez

 

[topfuel443]

The ONLY hotshot I have ever seen around the 50 mph mark is from John Harter. He is running a piped/modified K&B (that sounds as good as any outboard that I have ever heard). He has the skill and knowledge to do it, and has been running that exact same boat for a LONG time. Its a fast boat for sure, but he had some engine and handling issues at the 09 world tunnel champs. If I remember correctly, he is the only one who has ever run a hotshot at the world tunnel event. (?)

~James

 

[Jim Mamaril]

The ONLY hotshot I have ever seen around the 50 mph mark is from John Harter. He is running a piped/modified K&B (that sounds as good as any outboard that I have ever heard). He has the skill and knowledge to do it, and has been running that exact same boat for a LONG time. Its a fast boat for sure, but he had some engine and handling issues at the 09 world tunnel champs. If I remember correctly, he is the only one who has ever run a hotshot at the world tunnel event. (?)
~James

I could be wrong but I believe Tommy Lee held the saw record with a k&b powered hotshot well over 50 mph for quite awhile. I think it was around 58 mph.

 

[Michael Hall]

The origianl Hot Shot (fiberglass) or the Hot Shot sprint (24") ?
I have a few of the original HS in my collection that I do not run anymoe. I keep them for a sentimental reason. The fastest I managed to get those HS to run was probably mid to high 30's. Occassionally you may find an Ebay version that can run 80 mph ;-)

I understand the 24" Hotshot sprint had hit 50 mph using a modified engine and 50% fuel.

kez

I didn't want to burst Michaels bubble but Kez is right on at high 30's. When that Hot Shot hit 50 was it in freefall mode? Maybe off a cliff or in the back of a truck on the hwy?

Mic

Hey dont worry about it, the nz speed record is 70km/h and was aparentley a hot shot, I would be happy if I got 50km/h

 

[topfuel443]

I could be wrong but I believe Tommy Lee held the saw record with a k&b powered hotshot well over 50 mph for quite awhile. I think it was around 58 mph.

Definitely NOT a hot shot.

~James

 

[moparbarn]

i believe fred lumb or fred jr. has run a hot shot (wood kit) at the tunnel champs. a wood hot shot sprint - 24" with a mod k&b could prolly see 50, but **** sure scary loose to do it............. an ex. throttle can be faster than a carb, but not as reliable on a 3.5 k&b. i've got a geraghty 3.5 mod/piped k&b that's running right up there with the "virginia boys" on top end....... not a clue as to real mph though.

 

[lohring]

A modified ABS Dumas Hot Shot powered by a modified K&B 3.5 engine held the NAMBA 3.5 mod record at 59mph for years. That boat still races at our club and consistently heat races in the mid 40 mph area. It takes really smooth water, the right prop, and good driving to win with this small hull. The same boat was second at the 2000 NAMBA Nationals, beaten by Joe Monahan who also ran a wood Dumas Hot Shot. See http://www.namba.com/content/race_results....&ClassID=17

Lohring Miller

 

[Geraghty]

The ONLY hotshot I have ever seen around the 50 mph mark is from John Harter. He is running a piped/modified K&B (that sounds as good as any outboard that I have ever heard). He has the skill and knowledge to do it, and has been running that exact same boat for a LONG time. Its a fast boat for sure, but he had some engine and handling issues at the 09 world tunnel champs. If I remember correctly, he is the only one who has ever run a hotshot at the world tunnel event. (?)
~James

I could be wrong but I believe Tommy Lee held the saw record with a k&b powered hotshot well over 50 mph for quite awhile. I think it was around 58 mph.

Tommy never ran a "Hotshot" ............you are right about Tommy running K&B's at well over 50+ but all of his SAW boats were "one off" boats he built strictly for SAW.....

The best way to get a K&B powered "Hotshot " to 50 mph is to put the boat in your car and head for a road with a 55+ speed limit........

 

[Michael Hall]

Took it out today and on the back of a lapcat, 25% nitro, x440 prop I got 55kph

 

[GHill]

I ran a extended version of the hot shot that Dad built for me, ran a 3.5 K&B ss on redmax 40% with a Randy Rap X440 2 prop & it ran all day at 43-44 mph, any one in D-1 that raced about 4-6 years ago will remember the pink & purple tunnel i had.

Graham Hill

 

[lohring]

I'd like to correct my post. The NAMBA record by a Dumas ABS Hotshot Sprint was 49 MPH, not 59 mph. The current NAMBA record is held by Jimmy Johnson at 53 mph.

Sorry.

Lohring Miller

 

[DON MAHER]

Loring,

Jimmy Johnson's A MOD tunnel record is over 66 mph set in Nov. 06, He also has the A OPC record at over 54 mph! ( A = 21cc)

DON

 

[lohring]

You're right, I was looking at his stock record. It's also impressive.

Lohring Miller

 

[Grimracer]

I ran hot shots for a few years and at about 45mph they would hit there limit. The K+B will run a good hull up and around 48mph week after week but you have to keep an eye on the upper housing for cracking.

Grimracer