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]

Originally Posted by 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

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]

Attempt #2

The bypass I put in recently was from the Atomic 4 sitting in the garage at home waiting to be rebuilt. Problem was (for me) the valve on it was an old "gate valve" and it was tough to know how much was closed off etc. So last night re-plumbed with ball valve.

Soooo much nicer.

Now for a weekend of light air sailing huzzah!



by the by - the pic was taken just after I installed it... I know the valve is set to full bypass

AND ... the thermostat is most definitely out...

[GregH]

So I've been running the new bypass about 50% closed and on avg cruising about 20-30 minutes. From reading this isn't enough to get the engine fully warmed up.

The temp gauge is working but it hasn't moved from the lowest 120F point. Water temp in lake Ontario is about 13-18C.

Keep closing down bit by bit until I see temp react I am assuming is the next step? I don't like the idea of running it too cold either.

[Peter]

Greg,

The bypass controls how much coolant flows through the block versus how much goes straight up to the t-stat housing.

Closing the bypass forces all coolant through the block - hence the engine runs cooler.

Opening the bypass reduces block coolant flow by allowing some flow to go straight the the t-stat housing - hence the engine runs warmer.

So, opening up bit by bit until you see temp react is the next step.

Hope that helps,

Peter

[GregH]

Originally Posted by Peter

Greg,

...
Closing the bypass forces all coolant through the block - hence the engine runs cooler.

...

Peter

Yes of course.. closing would force more water through the block.. silly me.

That's what I get for rushing my message this morning! LOL..

thanks for setting me straight,

[GregH]

Just a quick update - the Indigo Prop (and crankcase system) has finally been ordered. Now for Spring!