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| Sponson Mounted Low Water Pickup System For S850 & F4 Tunnel https://hpbc.ca/viewtopic.php?f=37&t=4601 |
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| Author: | Hounddog [ July 25th, 2024, 9:10 am ] |
| Post subject: | Sponson Mounted Low Water Pickup System For S850 & F4 Tunnel |
The S850 system is the one used with the 70CES Yamaha. The F4 system is the one used with the Mercury Formula 4 60 hp 4 stroke.. I am looking for a supplier contact or information directly from S850/F4 racers themselves.on what parts they use. They could be exactly the same ?? https://www.google.com/imgres?imgurl=ht ... bme%2Ctrie By having the tested and proven system it will eliminate any chance of failure. For years I have wondered how the kilo record for S850/70CES was 103 mph and the SST 60 is 96 mph. What would happen if you put sponson mounted water pickups on a top running SST 60...my guess is I will run faster....how much faster?? Lately there is a little more interest here in trying different ideas that have been done overseas for several years. Their class entries are growing and younger people are the reason. HRL (Hydroplane Racing League) in Quebec has a Novice Class as part of their Events.... Restrictor plate A Stock Hydro ....they have rules for the 15 hp Mercury/tohatsu fishing motor as a separate rule section. At this time there are no measurements for driveshaft below the bottom etc they want people try different setups and see what works. Just having a 4 stroke is a positive starting point. https://hrlhydroplane.com/wp-content/up ... 024_V3.pdf |
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| Author: | Hounddog [ July 25th, 2024, 1:42 pm ] |
| Post subject: | Re: Sponson Mounted Low Water Pickup System For S850 & F4 Tu |
In 2016 I asked about these water pickups. http://www.hpbc.ca/viewtopic.php?f=19&t=3577 8 years later people are starting to show some interest. |
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| Author: | Roflhat [ July 30th, 2024, 5:20 am ] |
| Post subject: | Re: Sponson Mounted Low Water Pickup System For S850 & F4 Tu |
Rolf ran a hull mounted pickup for the 101.3mph record. He told me he had to back off on that run because the sponson with the pickup lifted out of the water, he had 104mph in testing |
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| Author: | Hounddog [ July 30th, 2024, 9:59 am ] |
| Post subject: | Re: Sponson Mounted Low Water Pickup System For S850 & F4 Tu |
I have learned a lot about the transom mounted water pickup systems. First off the Canadian winter plays a serious part if you use either the transom or nose cone pickup. You must be able to drain the system of water for the winter. The common mistake is completely sealing up the stock water pickups on the sides of the gearcase. You must leave a small hole at the bottom so that chamber will drain. There are two types of boat mounted pickups. One is called “high speed”. Those are the ones you look at. Not one size of pickup suits every application. Bigger motors required larger pickup size and in some cases multiple pickups. An offshore style system is going to be too large for your 2 or 3 cylinder outboard. Some of these transom mounted pickups are hundreds of dollars. The larger the head on the pickup...the more drag it causes and the more likely it is to pickup floating junk and possibly plug. The diameter of the water tube in your midsection will tell you the size you need for the pickup and the hose If the water tube is 1/2 inch you don’t need a 1 inch pickup . On a T boat the best pickup location would be beside the pad right where the pad meets the hull. Use a 1/2 drill and round out the corner. Extend a slot about 2 inches forward. Take the drill and lay it in the slot. Fit the end of the water pickup over the drill and that will line the pickup up. Check the size of the water flush hole on the gearcase. If it’s smaller than the water tube then install a larger fitting. Test run the pickup before attaching it to the motor. You will be surprised how much improvement there is over the stock system. Once we get a few T guys playing with these systems we should come up with a proven system. At that point there should be enough interest that Kevi can manufacture a billet aluminum system with custom fittings that we can purchase. |
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| Author: | Hounddog [ August 2nd, 2024, 10:23 am ] |
| Post subject: | Re: Sponson Mounted Low Water Pickup System For S850 & F4 Tu |
There is another way to have low water pickups on your outboard without adding a nose cone or using a separate transom mounted system. This involves modifying the inside of the lower unit. You seal off the exhaust passage in the gearcase that directs the exhaust thru the propeller. You have the exhaust exit out the side of the gearcase or out of the midsection. You then cut a passage from the exhaust chamber into the water pickup chamber. You seal off the stock water pickups on the gearcase. You need to modify the carrier by sealing up the exhaust ports. You drill new water pickups under the bullet so the water enters the modified exhaust chamber. The water will now enter through the bottom of the bullet, travel up through the former exhaust chamber and to the water pump. Some gearcases are easier to modify than others. You see this mod on many of the small racing tunnels. It works very well. At a race you see these small tunnels arrive just like the Stock Outboards. The racers mount their engines and do the rigging in the pits. Here is a video of a gearcase being modified https://www.youtube.com/watch?v=0eUs19my-VM |
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| Author: | Hounddog [ August 3rd, 2024, 6:27 pm ] |
| Post subject: | Re: Sponson Mounted Low Water Pickup System For S850 & F4 Tu |
Actual transom mount water pickup system attached to an SST 60/nitro gearcase. This very short video has the motor drawing water from a pail. It has no problem drawing enough water even at idle through the hose. https://www.youtube.com/watch?v=B4ha5iCloOQ The water pickup head on the transom will produce much more water pressure even at medium speed. We know that the larger the head on the pickup, the more drag it will produce. The larger the hole in the pickup head, the more chance there is of debris getting into the tube. So wouldn’t a 1/2 “ tube sized pickup with a adapter fitting on it so you could attach 3/4 in hose be a good idea? The 1/2 should be able to fill the system with adequate water. Then to protect the system from plugging and give the system additional water capacity why not put an inline garden or pressure washer canister type filter the system just in case debris gets into the system. |
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| Author: | sharpeye Mike [ August 3rd, 2024, 7:46 pm ] |
| Post subject: | Re: Sponson Mounted Low Water Pickup System For S850 & F4 Tu |
I would build the pickup with a grill like some I've seen built. Weeds should skip right pass the intake. |
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| Author: | Hounddog [ August 3rd, 2024, 9:45 pm ] |
| Post subject: | Re: Sponson Mounted Low Water Pickup System For S850 & F4 Tu |
Just shows people do read this thread. Mike thanks for the reply....I like that style of pickup as well and I think it is worth a try. https://www.ebay.ca/itm/304594984371 Here is another idea which is very similar to another suggestion I mentioned. https://www.offshoreonly.com/forums/gen ... ickup.html I was surprised to get this picture...it’s a Bobs setup on a small motor and it appears to have the inline filter https://www.refugeforums.com/media/view ... prop.1536/ |
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| Author: | Hounddog [ August 5th, 2024, 10:40 am ] |
| Post subject: | Re: Sponson Mounted Low Water Pickup System For S850 & F4 Tu |
There is not a lot of video in the Malaysian tunnel boat races that actually shows the motor and the water pickup. The first 5 minutes of this video is very good. https://www.youtube.com/watch?v=8tFN7SA0hQ4 From watching many of these videos this is what I have noticed. The transom pickup system is very simple...the hose varies in diameter from 3/8 to 1/2”. The transom is very tall, the bullet of the gearcase lines up with the bottom. It barely enters into the tunnel. The skeg on the motor is very large. They run 3 and 4 blade props. Many appear to be 11-11.5 diameter Ron Hill thru hubs Some run the larger 40-50 hp Yamaha clamp bracket. There are different sized nose cones. The timing on some of the motors is advanced and the idle is about 1500 rpm. Others idle like a stock motor. Boats are constructed very light....appear to use 1/4” plywood...some looked like 1/8”. The fuel appears to be pump gas with regular outboard 2 stroke oil. The cylinder heads don’t appear to have extra washers so they’re not running super high compression. Something is going on with the carburetors but you can’t get a good or long enough view. The motors are turning over 7000 rpm...I think 7000-7300 but again difficult to tell because they run different exhaust on the same model motor. Yamaha outboards are the most popular. |
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