HPBCANADA.COM

GUYS FEEL FREE TO CORRECT ME AND ADD INFORMATION IF YOU WANT TO!

THE BOATS:
The COMPOSITE Critchfield, Allison and the regular Delta are best for the Class.
WEIGHT makes a BIG difference in performance.

PERFORMANCE NON RACE PREP MOTORS
On the hulls mentioned above ALL of these motors below will run 55 to 57 mph.
ON THE OVAL!!
- twin OMC
- twin Mariner or Yamaha
- twin Suzuki
- triple Tohatsu..is a premium fuel high compression stock motor.
- triple Yamaha
- F4 Mercury likely 57 to 59 mph
Mercury 2 stroke triple is on probation.
On production model VooDoo's the two strokes will run 50 ish.

NEW PARTS
Yamaha has everything available new.
Mercury has everything available new.
Tohatsu has everything available new.
OMC has most replacement parts available new
Suzuki has most replacement parts available new.

OMC HAS THE EDGE
With race prep this motor produces 65 to 69 hp at the crank and will turn 6800 to 7300 rpm.
The current world record is held by a Tohatsu on a wing style hull....at 66 mph.
Our OMC's and F4 on our hulls would be close and I believe faster if they were on that record setting hull.
On the oval the OMC has more punch out of the turns and turn higher rpm on the straights.

The F4 Mercury is very competitive on the larger ovals and this is in UNTOUCHED OUT OF THE BOX.
The TWIN Yamahas and Mariners are the same Yamaha motor.
The T750 rules below really help this motor:
- the any tuner rule
You cannot get a 60D....6F1 tuner. There are 2 other stock tuners...the 6F0 2 piece...the common 1 piece.
OR make your own tuner
- the 160 lb compression rule
The yamaha head is big and commercial style in shape.
You need a modified head.

SO CAN SOMEONE GET A YAMAHA TWIN UP TO 69 HP AT THE CRANK?
I THINK SO!
HERE IS WHY.
The 55 hp yamaha 2/3's of the 90 hp yamaha..same sleeve, same rod and same piston.
The 90 hp is 90 hp at the prop.
Rework the 55 hp head to the STOCK 90 hp spec size and the twin is now 60 hp at the prop.
The stock 90 hp head is not 160 compression and you cannot deck a stock 90 hp yamaha head enough to get to 160 lbs.
Hydro Tec sells bolt on kits for the 90 hp yamaha and they do in house testing and dyno work.
A stock match ported [NOT MOD] 90 hp with their billet 155 compression head and their tuner will produce 103 to 105 hp at the crank.

The OMC motor produces 65 to 69 hp at the crank and will turn 6800 to 7300 rpm.
Doing the math the twin yamaha is going to be in the 68 to 70 hp range.....

QUESTION ABOUT THE PAD WIDTH OF THE 13 foot Allison?
The pad on the composite version is the narrow pad.....That is the original pad width on the original 1966 13 foot Allison.
The 1967 Allison had the wider pad.
To be 100% legal you should run the pad as it came from the mold....you should not alter the pad other than blue print it.
If you happen to have an original wider pad Allison it is legal.

I was asked..... Why I don't I promote T850 class as much as T750 class.

REASON:
We don't have as many T750's in the area as we do the T850's.
T750 is growing slowly and the few interested people have just recently got interested in T Class.
So I am educating them.
There are lots of former T850 racers that still have their boats and safety gear, but for many reasons decided not to race or loan their stuff to people who would like to try racing.

This summer we have more T races than we have had in years. I hope the racers support the clubs. Boat count is very important to the events and a large boat count of 15 or more in any T class is important to the T racers in that class. We are able to divide that group into 2 separate heats with boats of similar performance in the same heat. More heats and better races for the fans and more fun for the T racers.

Even though the twin carb 60 Mercury is on probation in T750 . There is still interest in that motor. One of the problems is factory trim for the short shaft. Most think the only option is the side mount twin ram system. I better solution is to use the clamp bracket assembly and mid off the early 90's 40 hp Mercury or Mariner.
http://www.boats.net/parts/search/Merc2 ... parts.html
Just switch the engine bases. Now you have a 60 hp short shaft hidden in the 40 hp.

PROBATION
If you have a twin carb Mercury T boat DON'T be afraid to bring it out to race. The probation only means we look at each boat on an individual bases. So far were have let every twin Mercury race in T750.

The Larry Register Allisons come with the narrow pad (5 3/4") or the wide pad, which is (9"). These are both production boats. Also, Craig Fraser widened his 13ft. Allison pad, as did Dave Elsey with modifications to the pad on his Register closed deck T-850. These all have been considered legal in the past. We should continue to do so, or we will lose boats. Our new T-850 boat is a Register Allison with a (9") pad right from the factory. This should be a legal boat.

Thanks Thom, The 9 inch pad could be better on a T750 than the 5 3/4, especially with a heaver driver.

Yes, that's why Craig widened his pad for T-750. Unfortunately, us heavyweights have to exhaust all ideas that will help compensate for our weight disadvantage. As you know Don, weight is very critical in T-750 with the small, 58-68 hp engines. The wider pad helps us heavyweights in T-850 as well.

I think a good reason to promote T750 is that it is an entry level class. The speeds are manageable. The difference in speed and power is very significant between the two. IMO only a very seasoned high performance boater would show up and race 850. I see 750 as more of a possible stepping stone if one wishes to go faster after some years of experience.
It works out pretty well. You will have all the safety equipment, boat that is rigged, all you really need to do is add the larger engine if you want to step up, possibly a few pounds of ballast if you have a light boat. A motivated individual should be able to convert during race day from one class to another similar to what Hydros do.

Kevi was going to try switching from T750 to T850 on race day same as the stock outboards. The OMC is the easiest. I have a pair OMC's that will work. You need a boat with SST60 thru transom trim and you need to use the clamp brackets and swivel bracket off the triple.
The twin OMC steering arm is longer than the triple, but it is the same diameter. You need to put a bushing in a triple's swivel bracket for the longer twin steering arm. You mount an SST60 ram bracket in each swivel bracket. I mounted steering arm plates on the twin with the same hole positions as the triple. I have a Kevi billet tuner assembly in the triple so the steering arms can be removed on their own.
The remote cables are the same on both motors as is the red electrics plug. They are an easy switch. You remove the pin for the trim ram, remove the steering arms, loosen the outside clamp brackets, slide the motor up and out. Reverse the process for the other motor.
Takes less than a half hour.