Finally pulling the trigger
 

I finally decided to upgrade my engines. Am pulling out 496 mags (375hp) each & replacing with 650hp 540s. Anyone have an idea what I can expect speed wise? The boat is a 2007 Kachina 34 Bolero with 1.50 Bravo xr's & -2 speedmaster shorties with a 1" spacer Bravo1 4blade 28p labbed props. The boat will run 70mph @ 48-4900 rpms. BTW I remembered why I dont fix boats for a living anymore. LOL. Randy

did you get 540s already

Not in hand yet, I will be trading my 496s when I get them out.

RANDY,i would look for 13 to 15 mph gain after it is proped right,enjoy.ps,this is asuming the new engines make the 650 hp.

Mike, what would your guess be for props?

i would start with out of the box 30p bravo ones.

Thats about what I figured, was suggested to try maximus 5 blades labbed but I've heard they are hard on the drives

i agree,but it also depends on how u drive it.

Well......I learned the hard way about hole shots so I dont do that but with the current setup I have a lot of prop slip until it planes but I can throttle back & cruise at 28-3000rpms where as I couldnt with the stock bravo28s. I do like to hammer down once in a while but the oil companies are keeping me in check. LOL. Randy

Cleaning
 

The engines are out & the bilge is filthy go figure, after scrubbing with dish soap & a pressure washer I was only 1/2 way there. Went to the parts store & asked for the best degreaser they have. Its called Super Clean & WOW does it work! Ran out of daylight but I got most of it, will finish up tomorrow. Randy

Nice looking clean up. Good luck. Those 540's are going to be rough on the XR's so go easy haha.

After cleaning the crud & looking things over I decided to sand out the rough spots & runs in the paint or gelcoat whatever the stuff is. It chips like gel but seems too soft in a way, any tips on paint or gel & how much trouble it will be? I will post some pics of what I have done tomorrow, ran out of light. Thanks Randy

What did you do with the 496's

Chris

Sold them to help pay for my new power.

Pics of my bilge
 

Here is what I have done so far, I applied some grey primer so I could see the high spots better.

More sanding
 

When I removed the engines I found the adjusting nuts loose by at least an inch each on all 4 mounts!!! Real nice since 1 engine was replaced under warranty for a starter issue that took a chunk out of the block. The mercruiser certified service center that will never see this boat again should have seen that especially since they would have to have lined up the new engine. I guess they were more interested in replacing a new bilge pump with a newer pump. Anyway the engines bouncing around in there bent the stringer bolts & egged out the holes causing me to have to make repairs. Thats why I am doing this, If I have to fill,drill, & sand might as well make things look a little nicer. Randy

I cant wait to see your new power plants in that clean bildge!

Jeffro, I cant wait to try your props out with some new power!!! LOL Randy

Where we at on this upgrade? Did you get the new power yet?

It wouldnt be a project if I didnt find more to do would it? I redrilled the stringer holes to 1/2 inch & bolted the mounts up but they arent quite level so Im filling them & redrilling them with the mounts clamped in place as a template. I have bilge paint on the way, headers got ordered after I did the measurements for them. Assorted hoses,clamps,etc. Am going to add some indirect lighting so show all of my work. I think I am going to be moving the boat indoors as the weather gets colder so stay tuned I will post some more pics when I make some more progress. Randy

Adding that much power I would upgrade your front motor mounts to solid offshore mounts directly to block. As far as props, what rpm's do you plan on running the 540's? My 353 fastech ran 5200 rpm's with labbed 31's on 500 hp's. (a little over 80 mph)

supercat, I am upgrading to (3) 1/2 inch stringer bolts per pad with solid stock style mounts from Eddie Marine if you or anyone else thinks that is not sufficiant nows the time to change things. Where do I look for true offshore mounts? As far as props the engines are supposed to redline at 5400 I was planning on trying some 30 & 32 pitch 4 blade bravo 1s to test & get a baseline & go from there. Randy

Looking at your pics, I think your mounts will be adequate as long as you have backing plates on the other side of the stringer. They are pretty much a combination of the adjustable mount and true fixed offshore style mount.

They have large washers on the outside of the stringers but I do have the material to make plates if needed. Randy

Got some paint put down today, what a difference! I am not stripping everything Im going to tape around the transom plates these pics show just the floor but I have the starboard half painted with 1 coat the floor has 2. How many coats should I put down? I mounted some lights while in there & they are cool. Engines & exhaust are on the way, will update when more is done. Randy

Looking great. Keep up the good work. Artie

Got some more painting done, if anyone ever tells me a body man/painter doesnt earn their money they might get a punch in the mouth,LOL even with all of the sanding I have done it still isnt really smooth but shouldnt be a problem as the water just beads up on this paint.

:party-smiley-048:Engines & exhaust were delivered today I guess I had better get busy

randy,engines look good,did you get them from a member on oso?

Not sure if he is a member but they were advertised in the classifieds. Bullet Engines, Ontario,Canada. He is very easy to deal with & does a nice job these things are ready to drop in & go. Seeing them up close they are purdy!!!! Should look even better with new CMI exhaust I got setting in my garage. Randy

Test fitting the exhaust, looks pretty nice! Looks like I will have to do something with the shifter bracket but it wouldnt be a project if it came with instructions. Lol. Randy

:party-smiley-020::party-smiley-020:New bilge pumps, fuel filters, drive reservoirs, battery charger, depth sounder, solid mounts, gimble bearings, scrubbed & painted, bling lights. I think I am ready to mount some engines. Randy

Your shift linkage assembly should bolt right up to that plate. Its is identical mine and the plate is tapped where it needs to be.

Shift bracket
 

:poopoo:The problem is that the bracket is too close to the breather, If I redrill the bracket to move it back a couple of inches that might do it or just make a new bracket altogether. Randy

Why not just mount the shift assembly under your engine on the stringer , that's where mine is . Makes for a cleaner looking engine , gets rid of some spagett . By the way , really looking good Randy . Nice work !

1 down lookin good!
 

Got 1 engine bolted in so now I can finish mocking up where I want things to be. I cant believe how much room there is compared to the 496's. I might take the deeps suggestion to mount the shifters on the stringers if I cant make up something to make use of the mounts that I paid extra for. Randy:bong::daz::evilb:

I agree - huge difference.
Keep the photos coming.
Good luck with he build.
Remember to post the before & after results after you get her dialled back in again.

If they don't have them already I would put gussets on the engine mounting plates, for the simple fact that the weight of the engines will bend those mounting plates!! You could also box in the end of the mounts... I know for a fact they will bend, been there done that!!!

Gill Offshore Cradles = Ties the stringers together with steel and will not allow any flexing , bending or breaking due to horsepower or rough conditions . Cheap peace of mind . Not criticizing , just an honest suggestion . Peace out , deep

Earlier in this thread I posted some pics of the loose mounts I found when I pulled the 496's. The engines bounced around enough to pull the exhaust apart, I thought the mounts were bent from that but they weren't. The mount bolts were stretched & bent but not the mounts, I redrilled the mounts & stringers to use 1/2 inch bolts instead of 3/8 & double nutted the bolts to make sure they won't loosen up. I will look into gusseting these mounts as I don't feel real confident about re engineering the mount system the boat came with. Don't worry about criticizing I see that as an opportunity to learn as a lot of you have more experience at this stuff than I do. Keep the suggestions coming. Randy