Yamato Cooling Tests

[GrandpaRacer]

Teams from the East coast and the West coast joined together to evaluate cooling ideas for the Yamato in general and the 321 specifically. Two different pickup designs were tested with three boats and three different motors. The external cooling was very effective and the results have been sent to the SORC. The testing suggested further refinements in the design of the cooling water pickup and more testing will be performed before the Annual Meeting in LA. Below is a summary of the tests performed and the results.
Designs tested: Two external pickup designs were tested. One manufactured by Lee Tietze with a ½ inch pickup tube and one home made with 3/8 inch tube. Both mounted to the cavitation plate (see photos) and fed water to the top of the tower externally.
Tests performed: Three motors and three boats were used with 9 total props. The motors were a real 321 blueprinted and ready to race, a hybrid 321 tower with a 302 power head, and a real 302. Tests were run at ½ and ¾ inch prop heights, with a 20ss restrictor and without, with external pick up and without. Water temps were 58 degrees on the East coast and 56 degrees on the West coast.
Results: All three motors overheated (400degrees CHT) or were on their way to overheat without the external pickup in at least one of the test runs. With the external pick up most test runs were below 300 degrees CHT but the highest recorded was only 308 degrees CHT! These tests were not speed tests but we did record some differences. In CSH at ¾ inch prop height the external pickup lowered the max speed 0.7mph. In 20ss with the 321 speed increased 1mph when prop height was raised from ¾ inch to ½ inch with an external pickup(still cooled). The 321 hybrid in C stock increased 1.5mph in the same test but of course a C stock cannot race at ½ inch.The tests also showed handling improvements when the mounting fixture was attached above the cavitation plate vs below the plate.
Refinements indicated: A refined mount was subsequently designed by Lee Tietze to mount above the cavitation plate with a 3/8 tube and crimped opening, See photo attached. Testing to be continued.
Further info can be obtained by emailing: John Adams johnrv7@gmail.com, Lee Sutter lee@kimbele.com or Matt Dagostino mdagger57@yahoo.com
John Adams

[Fastjack]

The proper term for the plate is -- Anti ventilation plate - cavitation is a lowering of water pressure on the propeller usually caused by mechanical damage -

[GrandpaRacer]

At the height we race the only useful thing that cavitation plate does is provide a mount for the adjustable kick out and hopefully a cooling tube bracket.

[ZUL8TR]

That's right on the term anti--ventilation (aka anti-cavitation). Placed on service engines, the plate was run below the rear slip stream of water off the transom to prevent air from being sucked in by the prop which generally cavitated without the plate.

When the high engine race boats are first planed over the ant-cavitation plate does help keep the prop spray from getting on the powerhead.

[flatsmoke]

They will cost around $50.. A lot cheaper then fixing a cooked motor.

[GrandpaRacer]

I hope it becomes available to all Yamatos as an option, but that is the decision of the SORC.

[Ram4x4]

And I hope we're allowed to make our own, or use ones made by others and not be tied to one company as the 'official' and only acceptable manufacturer....

[Matt Dagostino]

Ram 4x4..............the research team is 'suggesting' to the SORC a sole source as to keep the kit identical for all. However the SORC has all the power to do what they see fit.

[bill hoctor]

Teams from the East coast and the West coast joined together to evaluate cooling ideas for the Yamato in general and the 321 specifically. Two different pickup designs were tested with three boats and three different motors. The external cooling was very effective and the results have been sent to the SORC. The testing suggested further refinements in the design of the cooling water pickup and more testing will be performed before the Annual Meeting in LA. Below is a summary of the tests performed and the results.
Designs tested: Two external pickup designs were tested. One manufactured by Lee Tietze with a ½ inch pickup tube and one home made with 3/8 inch tube. Both mounted to the cavitation plate (see photos) and fed water to the top of the tower externally.
Tests performed: Three motors and three boats were used with 9 total props. The motors were a real 321 blueprinted and ready to race, a hybrid 321 tower with a 302 power head, and a real 302. Tests were run at ½ and ¾ inch prop heights, with a 20ss restrictor and without, with external pick up and without. Water temps were 58 degrees on the East coast and 56 degrees on the West coast.
Results: All three motors overheated (400degrees CHT) or were on their way to overheat without the external pickup in at least one of the test runs. With the external pick up most test runs were below 300 degrees CHT but the highest recorded was only 308 degrees CHT! These tests were not speed tests but we did record some differences. In CSH at ¾ inch prop height the external pickup lowered the max speed 0.7mph. In 20ss with the 321 speed increased 1mph when prop height was raised from ¾ inch to ½ inch with an external pickup(still cooled). The 321 hybrid in C stock increased 1.5mph in the same test but of course a C stock cannot race at ½ inch.The tests also showed handling improvements when the mounting fixture was attached above the cavitation plate vs below the plate.
Refinements indicated: A refined mount was subsequently designed by Lee Tietze to mount above the cavitation plate with a 3/8 tube and crimped opening, See photo attached. Testing to be continued.
Further info can be obtained by emailing: John Adams johnrv7@gmail.com, Lee Sutter lee@kimbele.com or Matt Dagostino mdagger57@yahoo.com
John Adams

IT'S ABOUT TIME !

[bill hoctor]

It's about time they get the overheating taken care of & for minor coast!!

[seanp3]

I'm in. I'll order 6 to make sure I have some extras to pass around

[csh12M]

Are we talking about requiring that they be run, or is it an option?

12M

[Adams52R]

It's being proposed as an option to run it or not.

[Big Don]

Just want to be real clear, that proposal of being an option was from one of the test teams. The SORC has not written an actual proposal yet.

[GrandpaRacer]

Don is right the SORC will make the final decision. At our recent club meeting the view of the racers was very favorable and they wanted it as an option. They also wanted one design.

[csh12M]

I appreciate all the work being done and applaud the effort, but I really question if this is the right answer. I feel like it may just add another level of complexity to racing C. Now we will all start testing with heat gauges to find the optimal temp. The problem with the 321 is that the exhaust is not exiting fast enough and heating up the cooling water right? So... shouldn't we work on getting the exhaust out of the tower faster, i.e. cut a small hole in the tower or change make the exhaust fitting larger?

[Matt Dagostino]

Dean................if you wish to view the entire teams report submitted to the SORC e-mail any of the teams e-mails listed in John's initial post on the top of this page and we will forward you one. The presentation was to big to fit on Hydroracer. Our cooling team will be submitting a proposal soon in conjunction with the SORC once Phase 2 and Phase 3 of our program is complete hopefully by mid to late December. To your point of finding optimal operating temps, that complex testing has been in the equation since the 1970's . Look at all the different water tube configurations, water restrictors and hose sizes teams use in 20ssh-CSH and many of our classes etc etc. Job 1 of the cooling team is to make the Model 321 cool. Without cooling the engine is not raceable.

[pav225]

Thanks for the testing everyone!

I'm not saying I'm for an external pick up, but if approved, why put any restrictions on it? All you are doing is adding more water to cool the motor.

[Matt Dagostino]

Mike............everything is on the table for the moment. If you want to see the entire report e-mail your SORC rep or one of the cooling team. In our initial prototype testing we are finding the tubes create a very slight loss in speed. The team wants to present the SORC as part of Phase 2 testing the 'optimal' designed tube that will be the most efficient and create minimal drag in the path of the propwash. Your suggestion is on the table.........

[reed28n]

I actually agree with Pavlick here. Just send the 321 to the Mod category!

Stock problem solved.

[Hydro doc]

Please someone test by releasing the heat . Or enlarging the pick up hole or both

[GrandpaRacer]

These are all good ideas and when I proposed such things on HR last summer I was slammed for suggesting a modification that would change the spirit of the successful 300ss class. This current proposal will allow 321 owners to race 300ss with a sealed engine and also race all the other classes with out over heating.
John Adams

[Matt Dagostino]

Doc............if the SORC in the 1970's would have allowed the Yamato PRO racing foot to be bolted on with it's slick design and water pump we wouldn't be having these issues some 40 plus years later.....the SORC wanted to keep the motors box stock. Look where that path took us.

[Brian10s]

A sealed 300 motor is never going to be competitive in any other class but 300. Why should the change be made to all Yamato's in C & 20, so that a 300 driver can be competitive in multiple classes? Now I am not saying that it should be illegal to get water time but if you want to run your sealed engine, you are forced to run it deep. There are 224 drivers in C & 20 and they should not be forced into changes due to only 49 300 drivers who want a 2nd ride. That is the tail wagging the dog.

If a 321 (unsealed - designated 20 or C) motor can't get close (and I mean within 3/4 below and pump and remember there were less than a handful of drivers who could get a 302 to pump close to 1/2 when it was the height in C), then the change should be obvious and permanent. No going back and forth.

I don't have any problems with either 102 or 302 at 3/4 below on multiple boats and do not require any changes on my behalf. In fact, can't remember anyone burning up a motor at 3/4 below unless something else went wrong.

[Ericwienczak]

When we put our 321 powerhead on our C setup, with milled head we have been seeing faster speeds than what our done up 302 has been doing. So the speed thing is likely false. And this isnt about drivers wanting "more seat time" 80s 102s are obsolete and not a ton of 302s. Wether people want to accept it or not the 321 is the motor of the future and the issues need to be resolved

[Big Don]

Brian, I'm not agreeing with or disagreeing with the following statement. Just sharing what is being said by many.

That while it is definitely an issue with the 321, the other Yamatos have the same problem, maybe not to the magnitude of the 321, but they still have pumping issues.

Here is what is being said and what the SORC is going to have to consider. The argument is that all Yamato's are running too high and we should just eliminate that issue by use of a water pick up. The argument is if most drivers can't get to the allowed height, therefor there must be an issue. One of the other options is lower everything to 1" or maybe lower. I am totally against that, that would destroy everyones prop boxes.

We don't run 302's yet and cannot argue one way or the other if it's an issue. We have people saying you can't run an 80 at 1/2 but we do all the time.

The bottom line is they want to reduce the barriers and put water to a water cooled engines. Hard to argue that fact.

Just to let it be known, I'm not a fan of this, but will most likely support it if we (THE SORC) can come to a pretty good proposal that is not going to cause a bunch of other issues. This may just be good for the category overall and not my own personal opinion.

[Matt Dagostino]

John............great point about the SOA teams and the burnt up 302's. Your SORC reps should present those incidents in Los Angeles as part of the discussion. As you point out many 302's run on the edge currently and often suffer meltdowns.

[Big Don]

All... don't wait until LA to present anything, get that data and info to your reps now. We are discussing this issue now. If we hold stuff till LA we will never resolve it.

I'm shocked about the 50% with 302's are cooking their engines. Not saying it's not true, just that I would have never guessed that.

[GrandpaRacer]

Don, it was about 1/2 our drivers overheated an engine in 2016. There are probably more engines than drivers here. We have a little over 30 Yamato drivers.
John

[reed28n]

302's over heating in what class specifically? GrandpaRacer can you provide a break down of what class and how many motors overheated? it would be great to see data for your 302 claim.

[GrandpaRacer]

We have the names of all the drivers who overheated but did not slice it 20ss vs CS. But just by observation as you would guess there are probably more 20ss over heats than C. But the C at 3/4 inch does definitely have problems. It should be that they never over heat, like OMC, Mercury, Tohatsu, and Sidewinder.

[dholt]

Scott,
I'll give you some data. I can't run at 1/2" and many times stop pumping water below that height with 302.

[Brian10s]

And we all know how slow Holt is.
So, just for the record, you can run below the legal height limit, be fast and yet not burn up your engine. Full disclosure - here is one of Holt's trademarked speed secrets, extent the hose down the cockpit so you can visually see when it is pumping or not. Another barrier reduced.

[Big Don]

Dana, drop that thing to 1 inch, you will be ok.

[Lee Sutter]

Overheating is an epidemic in Region10. It's so bad we actually started making a list. Ugh...And, that's with the Y302. Imagine how bad it would be running the Y321. This is why we are doing all the testing and development work. We just want the engines to stop cooking!!!

[Big Don]

Brian, that is their main point, you should not have to work on pumping.

[adamallen]

If "not working" to get it to pump then why not set the height to a lower level? Everyone would be reset with props, is that a bad thing? You're still gonna work just as hard to be at the top of the field.

[Brian10s]

Don,
You have to work to get either the 302 or the 102 to NOT pump at 3/4. I have run both for years on several different boats and pump like a fire hose. At 3/4, I never even worry about pumping anymore.