Well She Works!

[GregH]

Finally was able to take the boat out for it's first test. The engine overall worked beautifully is what it felt like !

There are of course some tweaks and mods to be done to help it along.

Running a 2 bladed prop but I forget it's dimensions. The top speed is about 5.4kn at 1500 rpm. Any more throttle and there are no changes.

Moving along at 1500 the temp creeped up to about 190F. At about 1000rpm temps hovered between 160-180F.

Oil pressure hovered +/-40 PSI from cold start up to running hot.

My thoughts are

- need to close off more of the water bypass to thermostat so more flow to block?

- the oil pressure, the system needs a good oil change, will that affect the oil pressure? I admit I did not monitor the oil as much as I did the water temps. Should the pressure be changing more than it did ?

Feedback more than welcome !

[Dave Neptune]

Greg, those oil numbers are excellent indeed.

The temps depend on the set up. What kind of water are you in, raw water cooled or a HX?

If you are messing with a "bypass valve" be sure the t'stat is removed and/or the correct type of t'stat. Many variations out there. How is yours set up?

Dave Neptune

[ndutton]

In addition to Dave's questions I'd like to know more about the prop. 1500 RPM max is below the recommended minimum RPM for hull speed (1800 is minimum, 21~2200 is sweet).

[GregH]

Greg, those oil numbers are excellent indeed.

The temps depend on the set up. What kind of water are you in, raw water cooled or a HX?

If you are messing with a "bypass valve" be sure the t'stat is removed and/or the correct type of t'stat. Many variations out there. How is yours set up?

Dave Neptune

Well bit of confusion here on my part - I have the bypass valve off the old engine but apparently I did not put it on this engine - so right now there is no adjusting valve. Easy swap out but didn't do it. Must have gotten my "to do" list and my "finished" list mixed up!

The T-stat is a 160 '3 spring" one that worked nicely in the pot of boiling water. I'll see if I don't have more info on it or pics. And I'm running raw water.

I'm in Fresh water of Lake Ontario.

The prop I'll have to get back to you; I have the notes somewhere but I think it is 13 x 9 (2 bladed) on an Alberg 30

[sastanley]

13 x 9 sounds too big. That may account for the low engine speeds. You are probably faster than you'd like to be at idle forward too.

glad to hear she runs and pushes the boat..all the other stuff will come in time!

[GregH]

Last Sat had her out in calm (can you say glass?) conditions and at 1500 rpm and she was pushing 6.4kn. did a run around the bay for an hour and the temp never went over 180 (haven't replaced the bypass valve yet that is stuck). So will be doing that replacement this weekend and the thermostat removal as well - just have to make sure I have an extra gasket or some permatex handy just in case.

[tenders]

This would be a good time to install a vacuum gauge on the intake and take a bunch of measurements at various RPMs and speeds so you can tell when your prop or your bottom starts to get fouled up.

[GregH]

This would be a good time to install a vacuum gauge on the intake and take a bunch of measurements at various RPMs and speeds so you can tell when your prop or your bottom starts to get fouled up.

It is on my list for 2019

[sastanley]

tenders is right, but I agree that is getting into fine tuning. Enjoy it running for now, but maybe report some idle speeds if you can so we can help decide if it is overpropped or not, and maybe get technical with vac loads and stuff later on. It seems most direct drive A-4s are overpropped (but I am not an expert)..and they struggle to push the boat at low (1700 RPM) and high cylinder pressure etc., And, on the back side of that, you might be running 3 knots + at idle with direct drive and too-steep prop.

I have a direct drive and the 10" x 7.4 pitch Indigo prop on my Cat 30 sings wonderfully at 1,950-2,000 RPM.

[CajunSpike]

My E27 has a 12x8 foldable prop.
WOT is about 2000rpm and just over 5.5 knots according to navionics on my cell phone.
Running at 1500 rpm gives between 4.5 and 5 knots.

[sastanley]

Just to follow up on cajun's post..my WOT is about 2,300 RPM with the Indigo. My cruise is 1,950 RPM. If I were going with a Martec or similar folder, I think I'd ask for 6" or even 5" pitch to get the RPM's up and unload the engine a bit. My 7.4" pitch is a calculation made by Tom at Indigo coupled with the 10" diameter. I am not a fluid dynamics expert either...my boat came to me overpropped with a 12" d x 7" 2-blade fixed prop..it was awful.

I really like the feathering props available that are adjustable, but they cost about what the boat is worth.

[GregH]

tenders is right, but I agree that is getting into fine tuning. Enjoy it running for now, but maybe report some idle speeds if you can so we can help decide if it is overpropped or not,

So when I go out this weekend, set it to my idle revs and put it in gear and see what spd I get?

Or do you mean idle rpm?

on a side note, ordering in my vacuum gauge and kit after work tonight.

[sastanley]

Yes, the former..it is just a balance we need to find with a direct drive motor. A steeped pitch prop at 700 RPM might move the boat at 2.5-3 knots.

If I am coming into an unknown area, I don't want it to be at 3 knots. I gotta take it in and out of gear and coast. Same problem an out board motor has, except they run 5,500 RPM WOT, and our range of motion is less.

[GregH]

Yes, the former..it is just a balance we need to find with a direct drive motor. A steeped pitch prop at 700 RPM might move the boat at 2.5-3 knots..

So in the marina today which is basically calm ( wind F3 gusty) as soon as you get past the breakwall, engine rpm about 700-800 and in forward gear we were moving almost 3kn. Checked again when came back in and the same.

In and out of gear to keep it down to 1-2kn.

[Mo]

So in the marina today which is basically calm ( wind F3 gusty) as soon as you get past the breakwall, engine rpm about 700-800 and in forward gear we were moving almost 3kn. Checked again when came back in and the same.

In and out of gear to keep it down to 1-2kn.

Greg, I have a 3 blade 12/7 pitch prop. I have to do the same thing. I come into the marina make my last turn into my row and go to neutral...coast dropping off speed and turn for my slip at 2 kts...down to 1.5 to 1 kt coming into the slip...a shot of reverse, she kicks port and is there...on a good day