Out with the old, in with the new!

wca_tim

Lieutenant Commander
Joined
May 28, 2007
Messages
1,708
finally had time to get into my engine swap yesterday... (replacing 4.3 with a fresh built 383) 4.3 is out, 383 is done with only a little "dressing" to do with some of the things needed from the v-6. after I got it out, test drilled flotation boxes, etc... figured if I'm going to completely redo the engine compartment today before putting the engine back in, better check.. thank God no water or wet drillings anywhere, so I get to glass in the new engine mounts, fill all the fastener holes and shoot paint this morning / early afternoon. touch up paint a couple little things on engine parts and put the new engine in.

finished final polishing and buffing of new imco powerflows, filled lettering with red metallic to match engine colors and then clear coated with por15 glisten, they look awesome!

Where there are old fasteners or other holes that ave been drilled anywhere in the engine compartment, I'm going to drill out larger and fill with peanut butter, then spray the entire thing. Still not sure exactly what paint going to use on the engine compartment. have several options on the shelf. am going to stick with the original black, and think I want more gloss. I'm very tempted to lay a coat of thinned epoxy first and then once cured, cover with two part polyurethane, maybe auto paint like nason fullthane (have had very good luck with that on several projects now and it seems to hold up great even on engine paint...). I've read a lot on here about different options for coating the bilge... I'm planning to do the sides and front (not very visible) with ruberized undercoating for a little sound dampening and am very tempted to top coat the whole thing in undercoating - it is tough stuff and what my engine builder had me coat the bottom 3/4 of the oil pan with to help with corrosion. Any thoughts here would be apopreciated, but I'm sure any of the above will work out fine and can touch things up as needed once the engine is in... have a good amount of room.

I'm not realy liking the degree of movement in the rubber engine mounts, but they lok like they're in good shape for what they are and will go with em for the time being. I'm a little tempted to chain engine down and use turnbuckles to tighten / adjust for a little added rigidity, although this would most likely transmit a lot more vibration noise through the hull...

Was also nice that when I pulled the outdrive, there was no water or any signs of it anywhere... don't think I would have gotten the bellows changed succesfully without the input and information from people on here... that and some other things that I've done since.

Wth a little luck and assuming I get the carb jetting right on the first try, I'm hoping to be ready to test run / break in cam on the new engine tonight, and have the boat in the water for shakedown onf the new set-up by Sat...

Assuming all goes well, can put the 4.3 up for sale next week (fogged it took movies of running etc... yesterday before changine oil and pulling it..) and get the interior done in plenty bof time to spend the summer on the water instead of in the shop...

so on outdrive... not sure which to try first... 1.84 gear ratio with 28 or 30 pitch prop or 1.5 gear ratio with 21 or 23... (I have both upper outdrives and either already own or have place to borrow the props to try) the 1.84 is installed and may get the nod for this weekend just due to sheer "laziness"

headed out to get a couple plugs for the water jacket openings on the heads, and a few other misc. items and then back to work... beautiful day for it. Have a great day and thanks (to those who have been helpful) for all the information / perspective...
 

fixb52s

Chief Petty Officer
Joined
May 14, 2004
Messages
463
Re: Out with the old, in with the new!

Using a rubberized undercoating would be a bad idea because gas and oil will attack it, leaving you with a gooey mess.

I would go with a rhino liner type coating that would hold to chemicals.

The V8 would be better off with the 1.5 ratio. From what I researched, the 1.84 is used with the V6 engines, and the 1.94 for the straight 4. The torque of that stroker motor would be much happier with the 1.5 drive. Changing the prop around will not move the torque curve much as would the gear change.​
 

wca_tim

Lieutenant Commander
Joined
May 28, 2007
Messages
1,708
Re: Out with the old, in with the new!

Hear you on undercoating.. I'll see when i get home if the two kinds i tried have held up to gas and mineral spritis... (I left test pieces soaking and have my own doubts). In the absence of something really compeling, I'm currently planning to go with catalyzed urethane for top coat. once set up it is tough stuff with respect to solvents, and others and it is an animal that I'm comfortable dealing with...

on gear ratio... have been throug this all to the point where probably sick of hearing about it... and I do understand about the torque curves, etc... I'm going to try both over the next couple of months. The ratios spec'd by merc are for the average / broadest band of aplications. In reading some older magazine articles on set-up, I understand that props that are in the range of 2:1 pitch to diameter ratio are best for getting top end out of boats from 60 - 100+ mph. Which would indicate that for 14-15 inch prop diameters, I may do better with a 28-30" prop behind the 1.84 than a 21-23 behind the 1.47 gears... (obviously there is more to it with respect to prop specifics, etc...). I'm running in the 55-60 range with the 1.84 gear ratio behind the v-6... depending on where top end will play out, either of those combo's should give a starting point for wot rpm somewhere near peak engine horsepower of 5200-5300 rpm... will just run props with a little lawer pitch for general use / water sports if it's a dog out of the hoile with the initial set-up...
 
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