4.3 water intrusion in oil with cracked intake and performance mods

[daughtryd]

May need to completely loosen the front motor mounts and hang the front of the motor. Then raise lower the front until you achieve perfect alignment, see where the motor mounts want to be attached.

Rick, Thank you for getting back to me. BLUF: Took it to the shop and they did it for me.
After 2 1/2 days of hanging, rehanging, checking double wound washers twice, I basically just gave up and tossed in my Man Card. It is all back together now and I'm doing the carb tuning. More to follow when I am complete, with a total wrap up.

 

[daughtryd]

If you are calibrating for a Vortec, start where I ended. Don't get the Edelbrock calibration kit. It is not made for Vortec.

http://forums.iboats.com/forum/engin...k-1409-4-3l-v6

Rick, I looked at your post and have those jets, rods, and springs. I also ordered the larger pump nozzles. I put her in the water for a initial leak check and shake out, only noting how the engine reacted to off idle to WOT and mid throttle to WOT. Vast power improvement all around the RPM's with a hesitation off idle. So now for the meat of my question with background. You said the 1409 is very lean and you had to richen it up for your application. Has Edelbrock changed how they deliver the carb now that we are in the Vortec hayday?

The Carb delivers with(stock config):
.098 pri
.101 sec
.068 x .047 rod
orange spring (5"mg)
.028 nozzle

you ended your carb tuning at:
.095 pri
.092 sec
.065 x .057 rod
pink spring(7"mg)


My look at the chart is that your numbers are much leaner than stock( as delivered today). My assumption is Edelbrock has changed its stock config for delivery since your original post. Am I reading all this info correctly from your April 2016 post? Please don't misunderstand, I'm not throwing darts. I'm just getting my head wrapped around all of this.

 

[Rick Stephens]

The 1409 I did was last year and came from the factory calibrated for a 5.0L motor, which is way too rich for the 4.3L. I believe the carburetor still comes that way.

Where I started my testing was with the 1485 Edelbrock Calibration kit made for the 4.3L installed and had to richen up a bunch from there. Edelbrock does not appear to make a Vortec calibration kit, hence the start point for you would appropriately be the end point for me.

Rick

 

[daughtryd]

So some of you followed this and gave me some great advice. Chris gave some great advice and got me started on tuning my carb without wasting money on the Edlebrock tuning kit. I?m going to give a closing write up and make some statements that some will disagree with. I know that guy is going to say. You coulda had a V-8. Sure could have. But not even close to the 800 bucks I have in this little motor. So lets get started:
I did crack the intake and the block was in excellent shape. I have always had my suspicions that a 4.3 Mercruiser was a repackaged Chevy 4.3 from a S-10. I AM NOT discussing, distritributor, alternator, starter, starter solenoid. The block. I can see no evidence of anything other than a standard block. It does have a coating on the outside that has a striking resemblance to POR-15, a coating to inhibit corrosion. The casting plugs (freeze plugs) are brass. That is needed for saltwater. Your call on a fresh water boat. Crank, rods, pistons, valves, and springs appear to be the same. So what did I find different? Oil pan, intake, carb. The oil pan being different is a mystery. The intake needs to be different for salt water, and the carb needs to be different for the fast idle and most importantly the fuel drain in case of a stuck float. In my opinion you can ignore the marine price tag on a few things, but don?t cut corners on the carb. Venting fuel into the engine bay could cause a fire.

Lets talk cam. That great mystery stick that is shrouded in secrecy. I took the part number off my stock mercruiser and you guessed it. S-10. So I had a call with 2 cam companies. I ended up with Lunati. The tech knew my concerns and could discuss with confidence, reversion.

I ended up with a
1409 Edelbrock carb, with 95 main jet, 98 sec jet 068x.047 rod, with plain spring (8hg, .043 pump jet)
2114 Edelbrock intake
Lunati Cam .447in-.447ex lift at valve, 207in-207ex dur at .050, 266in-266ex advertised duration.
(not a big departure here from stock just more lift)
19p14dia Nemisis prop (gearing is 1.81 alpha one)

My goal here was 250HP. Will I know if I?m making that? No. Not gonna put it on a dyno. But here is what I do know. I had a 17 pitch prop and the motor would only hit 4800rpm if I were alone and light on fuel. First time in the water with the upgrades. Spun the 17 prop into the rev limiter quickly. With the 19p prop I can get above 4800rpm with 4 souls on board and ? tank. Yanked the skier out of the water and planed very quickly with excellent stern lift. Yes stern. The boat can plane and hold 17mph for wakeboarding now. That a good improvement from the 17p prop.

Testing numbers as follows:
Boat weighs 2750, 28 gal fuel, 450 gear/people
95 deg, 60% humidity, 600+- ftMSL

19p nemises:
3000rpm, 11invac, 22 mph, 26 prop slip)
3500rpm, 10invac, 29mph, 17 prop slip)
4000rpm, 8invac, 34mph, 14 prop slip (4000rpm, 10invac, 34mph, trimmed) trim didn?t make a difference in speeds below 4000rpm, as I trimmed I maintained 4000rpm and throttle was reduced to maintain rpm)
4500rpm, 5.5invac, 36mph, prop slip 20 (4500rpm, 8invac, 38mph, trimmed, prop slip 15)
4800rpm, 3invac, 39mph, prop slip 18 (4800rpm, 5.5invac, 41mph, trimmed, prop slip 14)

I had a 19p, banged up 3 blade prop that is my spare. It does not plane nearly as quickly as the 19p, 4 blade nemesis.

19p 3 blade:
3000rpm,22mph
3500rpm, 32mph, 8 prop slip, not trimmed
4000rpm, 36 mph, 9 prop slip, not trimmed
4500rpm, 38mph, 15 prop slip, not trimmed
4700rpm, 44mph, 6 prop slip, trimmed out

 

[Rick Stephens]

Nice. Sounds like you are on the money. How do the plugs look in mid and high range? I ask because I worried about that on my own tuning. Pulling plugs is the only way to be certain we aren't burning pistons.

I had the same kind of results, which, like you, I will never verify on a dyno. Boat runs better than ever before and faster than I need it to run. I very seldom open the throttle into the secondaries.

I really like your cam choice. I already knew that the Mercruiser V6 is just a Chevy pickup motor pulled off the line with a few different parts. Different parts must include the brass core plugs even in fresh water - the galvy ones will rot out in no time. Plus water pumps, the stock automotive ones rust out quickly unless run with antifreeze. We could probably get away with stock head gaskets in non-brackish water for years. Ignition, carburetion or injection, alternator, starter, all need to be marine rated, which isn't all that difficult - seems sensible that even automotive electrical components should have the simple non-spark source protections built into marine components.. many don't though.

Enjoy your boating. Been a long road to building your new motor. Congratulations.

 

[daughtryd]

Agree on ALL the external components. Plugs: I am still a little lean and will be changing out rods for more fuel in power and cruise mode. Then I will start to look at jetting again. I did make a run with the stock jets, 98/101 and they gave the same readings on the plugs on short 20 minute runs at 3000rpm.My current plan is leave it as is and put 10ish hours on this these settings 95/98 and check them.