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Explanation of Two Unique T 850 Class Rules & Why
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Author:  Hounddog [ November 6th, 2024, 2:19 pm ]
Post subject:  Explanation of Two Unique T 850 Class Rules & Why

It was very difficult to come up with a simple engine spec sheet for T Class because there were so many different combinations of boats and motors run by people who were interested in racing. The engine maximum displacement spec was easy. Maximum displacement would be 60 cubic inches. That size covered ALL of the motors. I didn’t change the title of the class from T850 to T1000 because of the UIM World Wide recognition for that class.

I needed to make engine spec rules that would equalize the different motors performance so all these combinations would be equal. That was a challenge! The “yardstick “ motor was a 100% legal Yamaha 70CES. That was the most common motor raced in UIM T850 world wide and it held all the speed records for the class. Fortunately the 70CES we had in our group performed almost exactly to the record book T850 class records.

The problem motor was the 56 cubic inch OMC. The fishing version under performed and the SST 60 version over performed the 70CES in actual race and testing. Both the 49 OMC and the 60 cubic inch mercury were very competitive with the 70CES.

I decided to try different volume cylinder heads on the 56 OMC motors to see if I could improve the fishing motors and reduce the SST 60 performance. I was also mindful that I didn’t want to change any spec for the 49 omc, 70CES or the mercury 60 cubic inch. I wanted to keep the class stock and simple.

I lucked out....if you ran a cylinder head that produced 150 psi compression on either motor. Both motors were competitive. And oddly enough both the 49 omc and 70CES had 150 psi.

I presented my suggestion to the group. I explained that for this to work the motors would need to be stock other than the cylinder head. Internal port changes would change the compression.
The group decided they would follow the rule, but, wanted it to be 160 psi not 150 psi.
So that is where the 160 psi rule as added.

I wanted T class to expand and allow newer motors into the class. I also worried one combination would dominate the class and that would reduce the number of entries.
So the last rule was:
The fair competition rule......no boat was allowed to dominate the class.

The racers liked the rule and we never had to enforce it. That rule was removed a few years ago.

Author:  Hounddog [ November 6th, 2024, 7:01 pm ]
Post subject:  Re: Explanation of Two Unique T 850 Class Rules & Why

Another unique feature of T Class is it races in the Stock Outboard Division of CBF.. Prior classes raced in OPC division of CBF. I needed a title for the that fit the other classes that raced in stock outboard. So the T classes race under VPR. V Production Runabout

In 2024 we had 10 entries in T850 and their races were very competitive and great to watch.
In the past when be had entries in both T750 and T850 the total number of entries was between 15 and 20 per event.

The current T group are working well together in promoting the class. They are encouraging more people to come out and try racing.

Author:  Hounddog [ November 7th, 2024, 6:17 am ]
Post subject:  Re: Explanation of Two Unique T 850 Class Rules & Why

Question:
Why are there no 59 cubic inch mercury currently racing in T850?

The reason is the motor is no longer competitive compared to the 56 cubic inch OMC.
The same can be said for the 49 cubic inch OMC and the Yamaha 70CES.
Even 56 cubic inch OMC that were competitive a few years ago are not as competitive now.
Competition in the group has raised the performance level.
The performance level didn’t increase overnight in fact one of the top running boats is running a powerhead that was initially raced in 2014.
So it’s not just the motors being more powerful, it’s better props, better setups, more experienced drivers.

Now would it be possible to build a competitive 59 cubic inch mercury? I don’t think so.
There were a couple that ran in SLT class years ago and they were competitive with the 56 OMC. Those motors were likely built by Jeff Dunn or Hydro Tec. They would have been expensive.

The first problem is finding a 59 mercury or mariner short shaft. Jeff Dunn may or may not still have his high compression pistons. Then you need to build it or have it built. Risky and costly if it’s not built right. If T850 was still a 72 to 75 mph class one of these motors would be very competitive. But, T850 is now a 75 to 78 mph class to be a top runner in the class.

The last 59 mercury to race in T850 was Rusty’s. I believe he raced it one season and then switched to running a 56 OMC.

Author:  Hounddog [ November 7th, 2024, 8:49 pm ]
Post subject:  Re: Explanation of Two Unique T 850 Class Rules & Why

If your interested in looking into building a 59 mercury you could look at the 40 hp 59 cubic inch model. There are more of the 40 & 50 hp short shaft models around. Sometimes a modified tiller model will show up on marketplace in the southern US. They were run as part of the drag boat group.

They are surprisingly fast!
https://www.youtube.com/watch?v=0JGyku_oYiY

https://www.youtube.com/watch?v=O4qY3O1lHpM

I just checked marketplace here and this appears to be a 59 cubic inch, 40 hp short shaft.
https://www.facebook.com/marketplace/it ... af58e674f4

Author:  dandrews [ November 17th, 2024, 1:07 pm ]
Post subject:  Re: Explanation of Two Unique T 850 Class Rules & Why

Doesn’t the current dominance of the omc 56 go against the fair competition rule? I would also add any low number production parts that aren’t readily available for any motor that give a competitive advantage also be disallowed. You want as many options on the table to help bring people into the racing scene. Things like specialized motors and gear cases have practically killed stock outboard racing. They are not readily available like production motors. Following your competition model here I would like to see all 15 hp 2 strokes approved for ASH and ASR, raced as is no mods. They are a dime a dozen on kijiji. For TORC I’m thinking about the SeaFlea crowd in Muskoka. It’s a simple numbers game.

Author:  Hounddog [ November 17th, 2024, 3:57 pm ]
Post subject:  Re: Explanation of Two Unique T 850 Class Rules & Why

dandrews wrote:
Doesn’t the current dominance of the omc 56 go against the fair competition rule? I would also add any low number production parts that aren’t readily available for any motor that give a competitive advantage also be disallowed. You want as many options on the table to help bring people into the racing scene


I believe it was winter 2012 or 13. The T Boat racers had a meeting at the Toronto Boat Show to discuss TECH rule changes they wanted make regarding the 3 models of the 56 cubic inch OMC (SST 60, Bridgeport & ovalport). They wanted the ability to be more creative in their motor building. Kevi submitted tech suggestions for the motors and they were voted on and approved by the group. Those rules came into effect for the 2013 -14 season. The fair competition rule was removed from the rule book.
There hasn’t been an issue with low number production parts to my knowledge.

When the drag group started T Class was part of their program. They developed their own rulebook for T Class. It was a little different to the CBF rule book.

It’s the racers racing in T Class that decide on most rules of the class. Tech change rules provided they are not major would not be voted on by other CBF members. That’s why it is important that there be communication among the T racers and co-operation within the group.

Author:  Hounddog [ November 19th, 2024, 8:49 am ]
Post subject:  Re: Explanation of Two Unique T 850 Class Rules & Why

Why does T Class run back to back heats of 5 laps while the other Stock Outboard Classes run 3 laps then have a break and race their second heat 20 to 30 minutes later?

Most OPC events have fewer classes in their program. When FE/EP/FV raced they were part of Outboard Performance Craft Division not Stock Outboard. OPC Division in Ontario Canada raced Sport C, EP, SST 60/75, Mod VP and maybe a second Super Stock tunnel class and Mod U. Most events were EP, SST 60 and Mod U.
Each class would launch for their first heat ...race 7 to 10 laps and come out the the water. The first heats for every class would follow. Then the classes would go through the order a second time. On the second day the schedule was repeated and the 4 th heat was the final for each class and boats raced more laps in the final.

In 1992 Sport C class was started. The Sport C group asked Stock Outboard Division if they could also race in their group as well. Stock Outboard welcomed them and that class raced at both SO and OPC events.
In 2006 there were no OPC races in Ontario Canada. The only option was to make T Class part of the Stock Outboard Group. Their raceday schedule was full already with all of the different classes. I knew having T Class added would be a problem. We would just take too much time out of their schedule to launch twice and race 7 to 10 lap heats.
I suggested back to back heats of 7 laps. They agreed to try it but T class would be last on the program each day. If they ran out of time. We didn’t race that day. The T racers were not happy.
The first event didn’t go well. Two of the boats ran out of gas in the second 7 lap race. Of those that finished both heats many said they were so sore from the pounding that they didn’t want 7 lap heats.
The great news was the fans and the SO group loved the T races.
So we had a meeting and decided on 5 lap heats. It became obvious after a few events that the back to back 5 lap heats worked for everyone.

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