modified 250 efi for the 21 trick

[mrcrsr]

here's a couple of pics of a build i just did, engine started life as a garden variety 250 efi. a lil quick history on this engine, built it and modified a few years ago, after it was running for a while we swapped out to a milled set of heads, anyway, the guy who milled them and cut the o ring grooves screwed up, there was an .008 variance side/side in the depth of the grooves and the engine got water in it. this engine is going on a 21' trick. it originally pushed the trick to 100 on the limiter using 1.75 gears and a 30 p pro et. we were looking to modify the exhaust chest, the production 3 litres have bumps in the chest like a production 2.5 that obstruct exhaust flow, whereas the 300x block doesn't have them. the only answer has been to cut the back covers off, grind the bumps out and weld both covers back on. this is a recipe for water leaks and engine damage. with the heat cycles and vibration welding is not a good long term way to do this. we came up with a way to do it without hacking the cover off. here's what it looks like stock http://i59.tinypic.com/30vf8kz.jpg

[mrcrsr]

here's the exhaust chest after being machined out. the exits out of the cylinders all look pretty decent and really don't require any work. http://i60.tinypic.com/29bljev.jpg

[mrcrsr]

on a side note concerning 3 litres and poppet valve diverters, all that water now gets pumped out of the mid, which isn't a bad thing but what is now cooling the gearcase??

[mrcrsr]

here's a pic of the engine built and ready to go on the boat, notice the flywheel. we took 3.5 lbs out of that. we also make our own 1" spacer plates.we are not running oil injection on this engine and the ports are blanked off by the spacer plate. we ran the boat yesterday and put 3 hours on it. everything pictured here we provide as a service, pm me for pricing. http://i58.tinypic.com/2ldj8de.jpg

[captainsteve]

We had a great day of breakin yesterday. As always when Charlie builds my motors we mount it on the boat it fired right up.
I always love telling people I'm running a fishing motor on the boat. Can't wait to get it broken in all the way to see what a difference the new modifications made

[R.grover]

The pipe you have installed dose that mate up to the brass barb on the outside and do you use the standard poppet valve? and where are you pluming the water from?

[Liberator*21]

Nice job Charlie, and great idea on the water dump tube......:thumbsup:

[mrcrsr]

Uses the stock poppet valve. Welded the dump port on the bottom closed, drilled and tapped it and the tube runs to that. The hose barb intersects that passage and dumps excess water.

[Liberator*21]

Uses the stock poppet valve. Welded the dump port on the bottom closed, drilled and tapped it and the tube runs to that. The hose barb intersects that passage and dumps excess water.


Charlie version of the 3L dry exhaust............:thumbsup:. Love it....:D

[mrcrsr]

Makes the 3 litre even louder another added bonus! Not to mention increased power and a cooler running gearcase

[specboatops]

Subscribed !

[mrcrsr]

my boat has run that setup for awhile, i've updated it a couple of times as i've learned what stuff works better. my gearcase never loses any oil and oil always comes out unburned, but initially i did it looking for more power and to try and save some water pressure. it'll be interesting to see how steve's boat runs with the fresh engine with additional mods. his boat is easily 3-400 lbs lighter then my skater.

[Liberator*21]

Me too...:thumbsup:.....Subscribed, next time I have to pull the P/Head I'm going to make the change as well, it makes perfect sense to to it. Good job Charlie and thanks for share'n.

[baja200merk]

Hang on a second.... Fishing motors cannot go fast :D

[R.grover]

sounds like what I need

[mrcrsr]

Hang on a second.... Fishing motors cannot go fast :Dyou should see the next engine that is going together I am going to "ungreen" a 225 optimax!

[Liberator*21]

you should see the next engine that is going together I am going to "ungreen" a 225 optimax!


:eek::eek::eek:.....Charlie, the tree huggers are pickett your house now.................:D:D.

That project will draw allot of attention as there's lot's of them out there that would appreciate a new life in the fast lane, good luck on the project and PLEASE keep us in the loop on the project.....

[captainsteve]

The boat was originally built with twin 250xs motors. I never ran it with them but I believe it's a much better riding and balanced boat with the single engine. 300570

[Liberator*21]

The boat was originally built with twin 250xs motors. I never ran it with them but I believe it's a much better riding and balanced boat with the single engine. 300570

Very, very nice.............:thumbsup:

[R.grover]

hows that new 3.0l going strong?

[mrcrsr]

He hasn't had it out again. Was hoping to run it today but the weather here has been dicey, and now there is a tropical depression right off the coast

[baja200merk]

Thats skater weather :D

[captainsteve]

It's the lightning that bothers me when my head is the tallest thing out in the ocean!

[R.grover]

Charlie by fitting the pipe to the poppet what do you gain by doin this over running the standard set up?

[gorillapowered]

Damn Charlie!! You know I have a 250xs that might need some juice.....lol;)

[mrcrsr]

Damn Charlie!! You know I have a 250xs that might need some juice.....lol;)
get that thing going dan, i can imagine you're itching to go for a ride:D let me know if you need any help

[mrcrsr]

Charlie by fitting the pipe to the poppet what do you gain by doin this over running the standard set up?
directing water to where it is needed most, to cool the gearcase, and also taking water out of the midsection, in simple terms, it actually does more then that

[R.grover]

any up dates on performance?

[captainsteve]

Not yet. Haven't had a chance to finish the break in yet. The weather hasn't been too good and I have had to work a lot.

[Velocity72]

Any updates? Had a chance to finish the break in yet?

[mrcrsr]

He's been slacking off I think he's got 8 hours on it

[Liberator*21]

Any updates ..............:confused:

[mrcrsr]

He ran it up to 5500. I believe once it hit 5000 he said it woke up and started climbing

[specboatops]

you should see the next engine that is going together I am going to "ungreen" a 225 optimax!

I had a guy build me a "Ungreened" as you say 225 Opti, one of the best running, longest lasting motors I have had, ported like a drag, really curious to see what you do with the one you're building.

[R.grover]

same here waiting to here updates

[firebird]

Subscribed !

[mrcrsr]

i'm waiting for updates myself! i know he has been busy with charters right now

[captainsteve]

8 1/2 hrs on it. It's pathetic I know. I can't wait to really get more time on it and have Charlie adjust the fuel. It is still running on extra oil and richened up fuel. Last time out had 4 people and half tank of fuel with my 32 pro et, over 5000 rpm it pulled up to 6k very fast into mid 90's with more to go.

[R.grover]

Any more hours on it yet?

[mrcrsr]

no, captn steve has been busy with charter season. on a brighter note project optix(opti block converted to 300x specs) is done, its going on a friends 21 skater(and breakin and full power runs will happen alot faster on this one). went to put the midsection back together yesterday and there is all sorts of play in the swivel housing, had to take it all back apart. the customer just paid last year to have the swivel fixed by the man in palm city, and apparently, he bushed the bottom and never replaced the bearing in the top(this one is shortened to 15" and cut down), so needless to say it tore up the bottom bushing. it only lasted aprox 20 hours. going to bore the bushing that was installed to accept the factory mercury plastic bearing, and install a new one on top(that should've been done in the first place) which would've avoided all this.you think for what he charged he could've spent an extra 10$ and replaced the torn up original upper bushing, and we never knew it as we got it back all assembled.

[captainsteve]

Charlie had my trick at the Swanee. I'm sure he will give you guys some updates on it soon. I'm still so busy haven't had time to use it but I'll be at river ranch with it.

[mrcrsr]

ran the trick at the suwanee run, its broken in now, finally! its pretty amazing how quick it is, punches thru the hop in milliseconds. only ran the 30 p pro et on it, actually hit the limiter twice at 100 mph, and gets there quickly as well. we have the 32 but i didn't run it. the ecm on this engine is weird, it actually shuts off when it hits the limiter at 6850. the second time it did it i shut the ignition off and kicked it back on while on plane still, at least the boat doesn't do anything stupid when it loses power

[vnemous]

subscribed

[mrcrsr]

Also ran the optimax/300x patterned engine this weekend, got 6 hours on it, it's on a fairly heavy 21 skater, have the engine rich rite now, and it goes through the hop faster than the 300x that was on the boat. Should have that engine fully broken in this weekend

[R.grover]

thanks for the updates any pics on ya ungreen opti?

[mrcrsr]

i'll get some up today, actually going out later on to do some tuning on it

[Da Bull]

So how did the tuning go?

[mrcrsr]

excellent but weird! the new engine bangs the limiter(7k rpm on the new 300x computer) with ease and pretty quickly, that is with his 30p pro et. the other thing is it goes thru the hop way faster, acceleration is way better. this is the weird part though. the speed is only 87 mph with the 30 pro et on it, i put a 32 pro et on it and the boat bangs the limiter at 90 mph. the owner used to see 89 mph with 2 people in the boat with the 30 at aprox 6700 with the old powerhead. nothing else has been changed other then the powerhead. i am at a loss to explain this one! his boat is an '86, mine is a 91, my boat is definetely much lighter which would explain some of the speed difference between the pair,and his hull has asome differences(has an additional strake) but it still makes no sense the loss of speed and gain in rpm, using his old prop. my prop guy feels that it is due to the increase in torque, that it is causing an increase in slip,but still, if you spin it faster it should go faster. comparing his to mine also, at 6k rpm his boat is doing in the lo 80's, on mine i'm in the 90's, setup and props on both boats is identical. Checked gear ratios this morning and found he has a 1.87 ratio, apparently mercury offered it as a high altitude ratio! Just ordered a 1.75 gearset and will change it. Still doesn't explain the loss of speed and gain in rpm though, as nothing was changed other then the powerhead at this point. Just rechecked the gear ratio in daylight and it is a 1.75. going to try my 1.62 case on it next

[R.grover]

I Had same type of issue 28 30 and 32 et stock 300pm vs a 300x prop slip was massive lowerd motor. how high are you running it?

[mrcrsr]

it has a hydraulic jackplate, typically the higher you raise the jackplate the faster you go until you run out of water pressure. i held the throttle at 6950, lowered the engine while watching the gps , speed started to fall, raised the motor and speed climbed. also played with the trim doing the same thing, you can really fly the bow but the speed falls when you do it. its weird, the setup is identical to my boat. even at 6k rpm, his boat is doing 80, i'm running in the low 90's at the same rpm, even tried my 30 on it. i'm going to try my 1.62 gearcase on it next. kinda at a loss with this one, the slip numbers are over 20%

[Da Bull]

I can understand the speed loss with increased torque creating more slip but i don`t get why your boat is faster at the same rpm with the identical set up. Weight being the only difference could be the culprit. You may find more speed with your 1.62 but i don`t think it will match the speed of your boat. I agree with you Charlie. It`s a weird thing.

DB

[baja200merk]

The gear difference is the speed difference between boats. You will have to turn a 1.87 8000rpm to get the same prop shaft rpm as a 1.62 turning 7000rpm (everything else being equal).

the increase in slip on the same boat back to back is strange. The increased torque might make it slip on acceleration but you'd think once you hold it there a minute it would catch up and slip would drop. Strange

[bigtis]

Two identical used boats will NEVER run identical in terms of a high performance setup. The bottom on the unexplainably more efficient boat is without a doubt truer and sharper where it needs to be.

Unless I'm reading it wrong. There is two identical boats, setups, and using each others props correct?

[mrcrsr]

Two identical used boats will NEVER run identical in terms of a high performance setup. The bottom on the unexplainably more efficient boat is without a doubt truer and sharper where it needs to be.

Unless I'm reading it wrong. There is two identical boats, setups, and using each others props correct?
Everything identical down to the propellers. His boat is definetely heavier, and his sponsors have an additional strake compared to mine. The weird thing is that just changing the powerhead caused a 3 mph loss, but a drastic increase in rpm, and acceleration. One thing I did just realize, he has a cut down 15" mid, I have a factory 2.5 15" clamp, so I have a Lil more setback, still doesn't explain the speed loss from a powerhead change.

[mrcrsr]

The gear difference is the speed difference between boats. You will have to turn a 1.87 8000rpm to get the same prop shaft rpm as a 1.62 turning 7000rpm (everything else being equal).

the increase in slip on the same boat back to back is strange. The increased torque might make it slip on acceleration but you'd think once you hold it there a minute it would catch up and slip would drop. Strange

Kevin, initially I thought the gear ratio was 1.87, took the gearcase apart last night and it is 1.75.

[mrcrsr]

ran the boat yesterday,the 21 skater with the modded opti block, 1.62 case with his 30 p pro et, it basically took alot of the fun out of driving the boat. it planes off much quicker, but once the boat lays over and hooked up it was sitting at about 2200 rpm, you give it some throttle and not much happens for a little bit, first time i planed it i looked back at the engine and checked the guages thinking something was wrong, but it was just under hi load at lo rpm, once you get up to 3500 it is fine, acceleration was ok, not great, and top end was 89.5 at 6800, about the same as running the 32 with the 1.75 gears, and the 32 /1.75 accelerated way better and was fun to drive, and didn't lug at lo speed. the 30 did have a little bit of cup added to it, so that may have contributed to the bog at lo rpm, and i didn't have time to run the 32.

[R.grover]

you tried it again?

[mrcrsr]

you tried it again?
the results are a post above your question. the one thing i find weird with the 1.62 case is it spins the 30 to 6800(not to the limiter) at the same speed as the 1.75 case with the 32 at the limiter, and the 32/1.75 combo totally out accelerates the 1.62/30p combination(89.5 mph) i think he is going to have to play with props. his boat is definetely much heavier(earlier 21 skater) and the slite difference in the sponsons.

[R.grover]

any new updates?

[mrcrsr]

both engines are running strong, the opti block skater's fuel mileage is much better then it was with the 300x- the x used to get 2.2-2.5 mpg, the opti block gets 3-3.5 mpg,i think mike was happier with that part of it more then anything else, and makes more power. as far as the trick(modded 250 efi) haven't gotten to string it out yet with the 32 pro et.

[R.grover]

you been back out on the water hows testing goin?