Nola Mike's 3.7/470 --> 4.3L swap thread

[Scott Danforth]

with a single plane manifold, an open adapter simply adds some plenum volume.

 

[kenny nunez]

2Xs with Scott on the single plane manifold. Keep in mind however that they are designed for high 3500-8000 rpm. So if the boat is not too heavy and the engine has enough torque to get past the lower rpm then it just might work out.
Check out page 21 of the current Summit catalog .
Sometimes it is easier to start with a new length of flared tubing from NAPA and carefully form it to fit then cut and Re flare the end to the carburetor. Start with a length of coat hanger wire to get an idea what the line should look like.
Also if there are any performance shops in your area get the flex braided or equivalent like Earl’s ,Aeroquip Or Russell. PEP BOYS usually has some of this stuff.
Glad to hear that is the only damage your house got from the hurricane. When they hit down here it gets interesting.
I just had a 25KW generator installed so I am somewhat ready for the next one.

 

[nola mike]

Hmm. I don't like the loss of low end. Didn't know anything about this stuff until I started getting into it, but it appears that I should have gone with a dual plane setup. One of the main reasons for going with the v6 was to pull me and my fat *** friends out of the water on a slalom ski. That said, my tired 3.7 was able to do it with difficulty, and was able to hit mid-upper 40's even last year (50 mph when I first got it). So at this point, is it worth getting the 4 hole adapter?

Water back on, can't find my shed roof, still low on co2 and it's just about beer o'clock.

 

[Scott Danforth]

the V6 will have more low end than the 4-banger.......even with the single plane

 

[nola mike]

Hopefully will be able to overcome the weight penalty. No way I could get up with an extra 200# with the 3.7.

 

[Scott Danforth]

Hopefully will be able to overcome the weight penalty. No way I could get up with an extra 200# with the 3.7.

Is it the engine that weights 200 more.....or you?

 

[nola mike]

Is it the engine that weights 200 more.....or you?

So rude.
got a flaring tool, cut about 1" off the carb side. Fits nicely.
need a coil, a couple of coolant hoses, figure out how to mount this thing on the driveway, and fire her up...

 

[Scott Danforth]

The way you wrote it was nebulous...... Wasnt intended to be rude

 

[nola mike]

The way you wrote it was nebulous...... Wasnt intended to be rude

Ha ha. Any weight gain on me is almost certainly all muscle. And my hair is getting blond, not grey.

 

[nola mike]

Ok, finally some progress!
got everything hooked up. Planned on using all the wiring from the donor to just plug in and start, but I need the wiring from the throttle, which isn't here.
So just jumping wires, and noticed that all wires had some degree of continuity with the purple wire in the harness, including the ground wire. I started a different thread on that, but with the thunderbolt module disconnected, the continuity disappeared. So I don't know if that's normal behavior or not. At any rate, the fuel pump seems to be working, no leaks at my flared fitting at the carb. I tried to hook up the electric gauge from the donor boat to the oil pressure sender. When I turn the engine over though, I got no reading at the gauge. Disconnected the sender, and I did have oil spurting from it when I turned it over, trying to decide whether to get a mechanical gauge before trying to start. Other good news is that everything turned over smoothly, no weird noises. I wasn't sure if it was turning over fast enough, see the video. No plugs in.
Checked compression, 140's in 4 pots, 1 at 130 and 1 at 160.

https://youtu.be/H4-f2Dig8A4

 

[nola mike]

It's alive! FINALLY started it today, and nothing exploded, screeched, leaked, smoked, knocked, or burned. I managed to get it idling for maybe a minute. I couldn't check timing since I needed to work the throttle. Gonna need to figure out how to do that. Couldn't get it running smoothly though, and it wouldn't rev. Oil pressure was 40 psi. No water hooked up, and I have the PS disconnected for now (no belt).
Shut her down (aka closed the throttle) and noticed fuel pump still running (not sure how long the oil pressure stays up enough to activate switch). Also noticed fuel dumping into the carb.
Checked fuel pressure, which was upper 7's-8 psi. Edelbrock specs a max of 6 psi at idle. I'm guessing this is my culprit, but want to make sure that those high numbers are enough to flood the carb before I open it up again. I ordered a new fuel pump. Really don't want to have to install a FPR, since I'll be at square one in terms of my fuel lines and mounting location.
But overall good news!

 

[Scott Danforth]

buy this https://www.amazon.com/Carter-P4389...ocphy=9012149&hvtargid=pla-436786530421&psc=1

 

[nola mike]

buy this https://www.amazon.com/Carter-P4389...ocphy=9012149&hvtargid=pla-436786530421&psc=1

That's what I have. Ordered a new one.

 

[Willyclay]

It's alive! FINALLY started it today, and nothing exploded, screeched, leaked, smoked, knocked, or burned.....But overall good news!

Attaboy!

 

[Lou C]

Since you have a single plane intake I think you can use the open adapter, I posted up above the one OMC and Volvo used on the V6 when they switched from the Quadrajet to the Holley. Might want to look in the instructions for the 1409 to see if Edelbrock had any objection to the open adapter. I think that when Michigan Motorz sells their engine packages with carbs they used some kind of plate with the Edelbrock to cover the gap left from using a square bore carb on a spread bore manifold.

 

[Lou C]

PS I know Merc used the similar Weber 4 bbl on the spread bore manifold on these engines why not take a look at their parts catalog and see what they used?

 

[Lou C]

Answered my own question, I looked in Edelbrock's instructions for the 1409 and they say to use the 4 hole adapter not the open one. But they don't say if this is for a single plane or dual plane manifold. The adapters are cheap you can buy one of both and see which way it runs better.

 

[nola mike]

We're going to move on from the adapter for now. I really can't see what the difference would be on the single plane, but I'm not an engineer. We'll see how it runs. While waiting on the new fuel pump, discovered that my steering cable is frozen. Because, why not?

 

[Lou C]

Its always something eh? One day I will have a nearly new (OUTBOARD) powered boat. As my old I/O mechanic used to say I love small block Chevrolets I prefer them to be in a hot rod than a boat though!

 

[Scott Danforth]

Remember, boats are designed to last 15 years and be replaced or rebuilt....... Had to replace my steering cable and the shift cable from them sitting during the restoration.