Try some IMCO lowers, have had great luck with them and if they don't work for you they are very saleable.

Interesting
 

Wow...If I could get rid of the pickups on the bullit I know I would definatley pick up speed. I'm going to make a call. Treadwell, I'm going to try a little of your speed cote this weekend. keep your fingers crossed.

Cat- Probably not a flaw performance wise but they look like ****. especially for all that dough (aesthetics do count). look at the lower in june-Hotboat (pg 108) and you will see what I mean. Looks like chicken pox, Polka dots.

Maximus

Max
 

Max- I'm pretty sure what you are referring too is a form of corrosion which will happen to any raw aluminum product, even in fresh water to an extent.

Imco does offer painted versions too. If merc's is raw aluminum it will also corrode in time. I could be wrong but that's what it looks like to me. You may want to look into that and clear coat them next chance if that's the case- (no pun intended). Good luck!:D

yes but
 

your right that happens with all aluminum, but the putty spots, two different colors of oxidation???Not on the Merc product. My friend has a brand new 36 daytona. the best of everything...and filler spots. In person it looks funky. Lake water you can keep them shiny(r).

Paint and clear wont stay on over 100mph....will it?

Maximus

Tread - Maybe you just answered my problem! I'm running a twin step cat that I'm having trouble pulling in water on the starboard transom pickup during an extended high speed run. Should I put pickups on the front step, the rear step, ??? What kind of pick-up would I use?

Sorry for getting off topic, but I just had to ask. I've been looking for an answer for some time!!!!!:D :D

depends on how flat the cat run's. uassally on a cat you put the pickup's on the trim tabs. best place for clean water. try there or put it in front of all the steps and run a large sea strainer. in all honesty on a cat they are all diffrent. just takes a little time to R & D. best place is most likley tabs. drill a hole at the end of the tab and plumb it from there.

max.

if you spray the hyspeedkote on the drives they will not corrode. problem solved. when you test your boat you may not be able to see speed increase because it's getting hotter an everday you lose a little. but drive it for a while, take it through the paces. even go in rough water. i promise you will fell a diffrence there. it will land softer, handle better and give you better gas milage at the very least. email me if you have any questions over the weekend. rermember to follow the directions to a tee or it will not work. also spray tabs.

Treadwell

Thanks Tread!!
 

Sounds like I've got some work to do.:)

Man JR you have been trying to solve that issue for a while. I would have never thought about the tabs but man it does make a lot of sence!!!! :D:D

Dan,
Are you thinking you need spacers because Pat raised the X dimension higher than on other 37's he has done or strictly because of the slip numbers? Has AT put lager power than 500's in the 37' before? What is the top speed Pat has gotten out of a 37' so far? I wonder if it is the hydrodynamics of the gear case that is causing your high slip numbers. With a little time your boat should be flying.

Dan

The spots on the imco are welded up holes that are there from core support. The core is made of sand or wax and after casting it is removed through the holes.They are sand cast and not dye cast. The holes are welded shut after casting and before heatreating.
Audio, bottom pick ups are the best with accumilators(sea strainers). If you pull the tabs up or forget to put them down you will be looking for a good bilge cleaner. Lack of lube (water) and no more rubber impeller, it takes a nano second. Remember there are turns.
good luck.
pat W:D

Audio - Yeah, It's been a battle. I've modified the existing pick-up so that now the only time it's not pulling enough is when I run for awhile at 90+. It's pulling some water, but the temp slowly rises.

Shifter - I thought about the same problem with tab pick-ups. But it may get cleaner water than right off the transom.

shifter.

tabs are always in the water on a cat. v hull i would agree. bottom line i said was you have to test it becaus each boat is diffrent. the ideal place would be before the steps then it's 100% clean water.

Treadwell

I agree with the testing 100% also taking good notes.
I was thinking vee on the tab pick-up. Some of the cats we have played with had no tabs.
Fluids do not like making 90 deg turns. Every 90 is worth 3 feet of hose. Thats why I like bottom pick-ups. It is the hardest to do right and should be done when the boat is manufactured. There are some really good transom pick-ups that I have seen but I don't know who makes them. Yet. I'll check at the next race.
pat W

A good way to test locations for the water pickup is to temporarily mount a basic speedo pickup and read the speedo in different water conditions, if the reading is stable then that location will probably be ok if it is not stable then try another location. Good luck The Ironman.

Water pickups thru the bottom are harder to place, Clutter the bilge, but can be made to work well after using the first running boat for feedback! For me I personally like the Transom mounted pickups, Also a properly designed Catamaran has a tendency of carrying or floating its front step at times.:)
Best Regards

Pat thought that we needed spacers because of the slip. Pat told me the x is in the same spot as all of the other 37's. The largest power that was in a 37 was 600sc, and that boat ran 96 on gps.

We are going to look at the hydrodynamics of the lower gearcase, because something is not adding up.

I am getting very, very frustrated. :(

We WILL have it dialed in tomorrow. We are going to the famous LAKE X to finalize our testing tomorrow. I will keep you posted with the results.

The Skinney! On the new Sportmaster lower
 

FYI

I was just advised the Mercury Racing does not offer the new "Sportmaster" lowers without low water pickups. The pickups serve a dual purpose. Drive cooling and clean water pickup for raw water engine cooling (obviously).

I am curious to learn Mercury Racing's thoughts on drive coolers. If they were that effective wouldnt they incoporate a design into the drive itself???

Maximus

Merc Racing response- drive coolers
 

I asked them that very question about a year ago....

They claim you don't need them- their oil is great, change it every 20 hrs, proper drive for the application etc. etc.

It's no mystery that water cools better than air and that cooler temps= happier oil, less thermal expansion differences between aluminum and steel parts and the related effects on clearances etc.

It's probably fair to say that good drive showers hurt their spare parts biz.

We are looking at trying the sportmaster drives. I also called merc racing to find out about the water pickups and they told me the drives did have low water pick ups.

we rescheduled until Wend. :( But this way I can now fly out on Wend am, drive to the lake for the testing.:) I am flying into Orlando, anyone have great directions or an aproximation on how long it should take????

Dan,
Good luck with the testing. I bet your going to have to go with shorter drives. Make sure you bring your digital to take a picture of the Speedo for the skeptics. :D

Dan

jessie james,

that is ok, i will get directions.

candyman,

believe you me i will.g