Complete repowering of a brick
 

The title was from my last post about is it worth it to build my 27PC. Most but not all basically said no. So this thread is to document what the plan is and in the end guess I'll find out if it didn't work.

Boat 1994 27PC with a single 502 and B3 drive. Talked with Marine Kinetics (bob) and he recommends boring .030 over, aluminum heads, custom head and cam work and Bravo 1 XR drive. I would like to use a B3 for docking and slow moving my cruiser but have yet to buy one. Just picked up an HP transom from Costal Marine Export.

Previous engine always ran rich and top speed was around 45 to 47 (on a good day) with a GPS at 5200rpm.

http://i609.photobucket.com/albums/t...psf03f3cb8.jpg
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Intake
http://i609.photobucket.com/albums/t...psd71c2bb6.jpg
http://i609.photobucket.com/albums/t...psa2656e47.jpg

Intake was oily
http://i609.photobucket.com/albums/t...ps5b56c633.jpg

There was a guy at our marina that had a 27pc with twin 454s and he said it did sixty. I dont remember what drives he had on it though. He has since traded it in on a new 31pc that also has twin big blocks, 496s i think. We have a 31pc also, the model before the current one and have 6.2s, i wish we would have got big blocks.

Didn't think there was enough room for twin BB in 27PC. I have to hang upside down to work on the starboard side most times. Ones there building today you can get twin 5.7HO. I'm not looking for top end as much as coming out of the whole and fixing my overly rich running engine. Have a couple other things also but that's boats

One thing that I see is you have the small corsa tips that are meant for 300 hp and under applications, even when diverting some of the volume through the y pipe. So, you have a VERY RESTRICTIVE exhaust there. Without running anything through the prop, your engine is being choked to under 300 hp. The boat probably ran a 454 (300hp) originally with a silent choice and no one has addressed the tips. Fixing your exhast restriction will more than likely fix your running rich condition. Bravo 3's are great for everything under 60-65 mph, especially if your boat responds well to stern lift....sounds to me like you really want a B-3. good luck!

Appreciate the input and will pass it by Bob prior to completing the build. Formula never installed thru hull on PC's that I know of. Boat originally came with a carb 7.4 and B3. I installed the thru hull and the silent choice when I put in the 502. Have EMI thunder headers that come out as 4 inch, then into the diverters, then thru 4 inch corsa muffler tips. Always figured 4 inch was plenty big enough for more then 300 HP.

Hey AllDodge.. Your project looks very interesting. I do not see any problem with your exhaust as far as HP is concerned. The oil in the intake looks bike blow by /blow back at idle to me. Prob have valves that are past their prime.. My guess is this is due to the transom exhaust/ flapper situation and maybe need for taller risers. First you MUST HAVE internal and external flappers in the transom exhaust. Lift up the external flapper and look inside. If no internal flappers are present or they are badly warped, then thats why your valves are toast and there is oil in the intake. MUST FIX this first. Personally with a single engine on that boat, I dont think you are going to get in the 60's without major horsepower. And if you do, it will be a ***** to plane off. But all boats are different and I will be watching closely. Bob Madera is definitely your best bet to build HP on that motor.. Good luck and keep us posted.

Chris

Seems like a lot of rpm on a b3 on a 27 ending with mid 40's please do tell how this plays out , think.your gonna find a little something somewhere that gives you some major speed increases ,remember to share

Makes no sense to me to spend 6-10k on a 15k boat to pick up maybe 4-5mph. Its your money though.

The engine has around 275 hours on it and it's been through a bad spot. When new (crate motor) it had a valve issue which I sent it back. Was told I was getting a new motor but after reinstall and about 20 hours it still was running like crud, almost as bad as the 454 I pulled out. Did a compression check and found some problems. Pulled just the heads and found out someone had installed 454 valves in the 502 head (to small). So new Icone valves and head work and has been running pretty good but rich. In hind sight when I found the valves I should have pulled to motor and gone through it. This is another reason to do everything this time. I'm seeing some blowby and the exhaust flappers were replaced when I installed the 502 and they still look in good shape.

Don't plan I trying to hit 60, 50 or 55 would be more then enough. Still may go with the B1 over the B3 but docking is a lot better with the B3. As for the risers, I mentioned it to Bob on the first call. The EMI risers are higher then the stock but not much. Had to send the diverters back to Corsa to have them lengthened because of the risers. May need to go get a high set for insurance. Will also need to have a bung installed for the Holley EFI. Bob did say I could use all mu internals if they check out

Griff has a point .if that motor has good compression and the boat doesn't have soaked foam or twisted hull you should have 55 already sitting there waiting to be found .we have a formula 496.b3 does 60 and a big pig 26 bayliner 305 mpi b3 runs 47 still think something is hiding in there somewhere ,

Do you know what ratio your B3 is? May try just changing the lower and bolting on a B1 lower. Be aware though if you do A B3 2.0 is a 1.50 B1. You may have a 1.81 or 2.2 B3 (1.36 or 1.65 B1)

I see it more as a HP to weight thing. The boat is listed as 9500 pounds dry. Then add the generator and other stuff and your close to 11000. One thing I found about Formula they build some of the heaviest boats out there. There are several folks at the bock with other brands and none are as heavy as this one for a 27 footer. My 27 weights as much as the guys next to me having a twin engine 29 foot searay (owners words). Either way I appreciate all the comments, it will make sure I look at everything while going through the rebuild

My current ratio is 2.0. I have four sets of props , 20, 22, 22 cupped and 24. This is why I was looking at the 1.81 ratio B3 so it would give me some options and may not have to buy another set. I have a 1.5 B1 in my Rinker which I could try (nice and easy) once the engine is back in.

All the more reason, that adding more HP will have even less of an effect. It will prob take 30hp for every 1 mph gain

Good luck with the rebuild and keep us informed on the progress and results... I'm very curious.

Waiting for a friend to show up Saturday to help me pull the motor. Been looking around trying to get more info on best course of action. Looked at some threads from Eddie Young at his website. This got me thinking about a 540 engine. Found new crate 540's along with several building them, both here and on the web. Will a 540 mount where a 502 use to be? Don't know if the exhaust manifolds are the same, just trying to understand the whole make up?

Stroker crank 502 version swap right in , ran one with aftermarket heads roller cam modded mpi intake.and pcm did 670 with tubular exhaust .traded the heads for a 454. Getting ready to reserect it with modded 088's Cutler mpi and headers going in a Taylor sj with a dominator pump ,engine cover and swim platform ,going to go for the sleeper theme

Sounds good thanks, wanting to explore all options. Looking into Dart 540 blocks and heads, maybe buy a turn key setup.

y
that 540 with 650 hp from eddie young looks real tempting, I wish I could afford one

A 540 is a 502 bored .030 over with a 4.25 sroke crank.
You can turn your engine into a 540 with bout 3k in parts.

You should also realize that significantly more HP and torque is going to explode your Bravo3 drive, especially in a single engine 9500# boat.

Seems like a lot of the gen 5 502 's get opened up to 540 s around here ,and its not too expensive for someone thats already rigged for a 502 then there is the merc tall deck 540 ,your prob looking at flywheel dist oil pan manifold or spacers that stuff adds up .worth it if you have the bucks though

Better to buy the 650 hp 540 frpm eddie young its turn key

Thanks, probably should have mentioned the 540 I was looking at was the Dart block. I'm guessing the Dart block would be new and could be bored out in later years, wondered if it was the same outer size as the GFM 502. That is if I still have the boat. Agree if I went this route I would do the B1 and get better at backing up

You got me with the flywheel distance, manifold and spacers.

I sent Eddie an email but looking at the engine he has it built very well. Wouldn't mind the same setup with a bit lower compression so it will not need 93 octane, 90 would be fine. Just don't want an engine I have to do head work every 300 hours or so.

Docking aside, that boat will be a b!tch to get on plane with a Bravo I. A Bravo III can be beefed up just like a Bravo I (except the propshafts). NFW I'd run that boat with a single Bravo I. Of course, NFW I'd be doing what you are doing now but as Griff said it is your coin and I'll be curious as to what the final outcome is. Good luck.

I 'm still getting the ever so slight hit of condescension, but you are providing me some actual input, and with that thanks.

Agree it's my coin and over the years I have done some dumb stuff. Many times by accident and others by not knowing, hence the reason I'm asking questions.

Not trying to be condescending. I've attempted to do similar things to "bricks" in the past and knowing what headaches you are likely to encounter down the road I'm only saying that I would not even take the first step. That said, I still am interested in how this turns out as many times we think we know the ending to a story only to be surprised at the final outcome. Best of luck.

Pulled the engine
 

We pulled the engine and started disassembly. Everything is looking good but do have a couple shinny spots on a couple pistons, maybe a bit of water go in. Took some pics but they didn't come out. Will take some more and post later.

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What did u decide on for power

Heads look good
http://i609.photobucket.com/albums/t...pscda2f6ee.jpg

Have some light discoloration on the top of a few pistons
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http://i609.photobucket.com/albums/t...ps51e1a39d.jpg

Pistons
http://i609.photobucket.com/albums/t...psf4843ebf.jpg

Cylinders and cam
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Talked to Eddie Young today at length and he advised that (paraphrasing) if I had a go fast then I should go for the Holley EFI. Since I need torque more then HP he recommends I need to keep the intake I have and have it worked. The intale I currently have will produce a lot more torque then the single plan intake at low er rpms/ Change from a EMFI-1 to a EMFI-4 and do some mods to the fuel rail, pump and intake. Suggest to stay with the B3XR. After about an hour of discussing what I would like and what he recommends I thought I should not have taken the engine apart. So current plan is to strap everything to a pallet and send it to Eddie and let him work his magic. Current plan is to build the motor for between 525 to 575HP and 600 ft lb torque.

Should have just left the motor together and let him take it apart. So now I have to box it up. Sure looking forward to it coming back an d next seasom

nice choice im gonna follow this thread for sure,

Eddie is a good egg. My buddy Rob has been tickled pink with his YP blown 540.

Drove to see YP today and dropped off my engine. You know the engine takes up a bunch more room when you take them apart. Easy enough drive and now I can start working on getting the boat ready for when it comes back.

http://i609.photobucket.com/albums/t...psd79bd624.jpg

Are you upgrading the existing BIII or are you looking for a BIII that started life as an XR?

I plan to buy a brand new B3XR,

Issues I'm looking into for the answers are can I use a 1,81 ratio?
Want to go that route so I don't have to buy other props. Currently have 20 thru 24 pitch sets.

Other is can I use the B3XR with the power being built.
Eddie already answered this one, but want confirmation once he has time to look through the engine.

Looks like the brick is getting some serious love . I know of a guy who wants that old cam ...

Yep lot of work to do before the engine comes back. Started taking the transom assembly off. Sure is a mess in the bilge,
http://i609.photobucket.com/albums/t...ps7deec9cb.jpg

Don't have a current plan for the cam yet but thinking I could use it for a refresh on my Rinker. The Rinker's motor has more then 600 hours on it and could use a some love it self. Will think about it

Not done but looks a lot cleaner
http://i609.photobucket.com/albums/t...ps45bbdc37.jpg

Transom assembly is out
http://i609.photobucket.com/albums/t...pscc3ae15e.jpg

New stuff
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Kind of thick
http://i609.photobucket.com/albums/t...psa6fba0bd.jpg

what will you use for exhaust?

I have 4-inch thru hull and silent choice installed. Second pic down in post above shows the bottom of the muffler tips. My first post has a better pic of the tips.