[Tom Bartolomei]

Hello all. Is there a part number and general procedure for this replacement? I also have a weeping leak that I’d like to rectify.

Thanks
Tom

[Tom Bartolomei]

Thanks Tony. The flange connection is air tight and no issues there. Its just the hose connection with those constant torque clamps that is giving me some grief on only the one aftercooler. The other engine, all is good and well. I will fiddle some more with it and apply rectorseal as well which I did not do initially.

As usual, thanks for the tips.

Tom

[Tom Bartolomei]

This is the part I’m referring too.

Tom

[Tom Bartolomei]

Thanks Corey. I removed the silicone strips. As an old mechanical engineer myself, I can’t understand their intended design purpose frankly. As to the pitting, its location was on the inner bore surface of the housing and was minor compared to various photos I looked at on SBMAR. The actual sealing surfaces of the housing and the cores themselves were very smooth and clean. Greased them all up, o-rings on, aluminum sealing rings in, and done.

I did run the engines up to 1100 RPM with the manifold hose disconnected. Wrapped an industrial paper towel around the aftercooler discharge to see if any water spray or drops were evident. Saw nothing.

Deemed all was okay and back together again.

Tom

[Tom Bartolomei]

Is the current thinking still to remove (and discard and not replace) those 3 silicone strips that run along the length of the cores?

The cores cleaned up nicely, pressure tested checked out. I do have a concern at the bore of the aftercooler housing as there is some localized pitting. I will try to get a picture but any rough guidelines as to what level of pitting on the housing bore surface would be problematic?

Tom

[Tom Bartolomei]

Thanks Corey. Will see what condition mine are in once pulled apart. Are those aluminum rings a sort of compression ring?

I also presume that upon re-assembly, all of that should get plenty of grease.

Tom

[Tom Bartolomei]

With my M7 prop set @2600RPM, I was getting 27-28kts at slack tide with 50% fuel, full tools/rations, 2 adults, a 12′ AB dingy w/40HP outboard on the Freedom Lift, clean bottom, and 100′ (~150lbs) of 5/8″ chain up in the front anchor locker. I believe the Sabre 48 hull #1 sea trial was conducted with M7’s, 100% Fuel, 100% water, no waste, no dingy, clean bottom, 6 adults, no tools or rations.

With the M2 prop set @2600RPM, I now get 23.5kts, at slack tide, 100% fuel, waste, 100% water, full tools/rations, 2 adults, same dingy configuration on the Freedom lift, clean bottom, and now 300′ (~450lbs) of 5/8″ chain up in the front anchor locker. Lost some speed but lower fuel burn on the engine at that cruising RPM. 23kts is still hauling in my book for this boat.

I’m pretty happy with it now and I don’t think I can do much more. Sold one pod worth of M7 prop sets to a marine shop in FL. One more pod’s worth of M7s to get sold. Going to hold on to my set of M5’s as spares since these things are so expensive and hard to source with any reasonable speed.

Tom

[Tom Bartolomei]

Hello all. Been some time. After an open heart surgery and some new plumbing and a valve. I finally got around to recording the performance data on my Sabre 48 Salon Express with a set of M2 props. See the attached graph.

I cruise at 2600 – 2700 RPM and with the M2’s, the fuel burn @2600 RPM is 40.2GPH. Spec @2600 RPM is 38.6GPH. Only 4% over spec at this RPM which is much improved versus the original M7’s propsets where it was some 17% over spec @2600RPM.

Still over the spec curve in the RPM range of 1700 to 2500. The boat doesn’t get up on plane until about that 2450 to 2500 RPM range. The max deviation from spec is at 2000 RPM where its 32% over the spec fuel burn.

Tom

[Tom Bartolomei]

Hi Bruce –

Apologies for the delay. I had a medical setback which dominated the last few months for me. The good news for me is I’m on the green side of the grass but the bad news is that I haven’t yet had the chance to get the M2’s props put on. Hope to get that done in February and will post the results here for sure.

I will send you a direct message with my number as well.

Tom

[Tom Bartolomei]

Hi Rob –

I am not anticipating much change with the dingy replacement as far as my attempt to dial in the props go. I do think the best yards gained will come from the prop pitch adjustment. My initiative on the dingy is really prioritized because its weight is just a tad over the spec recommendation for the maximum lift capacity of the Freedom Lift. As you know, on such a cruiser as this, I’m either at hull speed 9kts or up on plane @25kts. No in between. Its unnerving while bouncing through or over chop @25kts and seeing that dingy ‘bouncing’ around on the lift. I have run the vessel without the dingy and the result in terms of my need for trim @cruise is significant. Reducing the weight on that aft end by my math drops the moment arm on the vessel from its lateral CG by almost 50% which is a bid deal. That combined with lower stress on the lift and finally, the current dingy is like a Mercedes Benz when what I really want is a more functional dingy to haul a few crab pots and run the dogs to shore for their routine biz.

I’m looking forward to seeing what these M2 props do. I have a feeling that I’m approaching the situation of “I got what I got” in terms of power and how this boat performs.

Tom

[Tom Bartolomei]

I haven’t spoken to Sabre yet about the performance. Once I get the M2’s on and tabulate the performance to see what that gets me, I will share the results with them and various profiles along the way with the different prop sets.

I do know that Sabre did not take into consideration the added weight on the backend resulting from the freedom lift plus a very heavy dingy. This represents an additional 1300 lbs in total basically cantilevered on the very aft end of the vessel. This additional weight is not insignificant. Even without the dingy though, the fuel consumption is still over spec right in the mid range.

In addition to the prop adjustments I’m working my way through, I am selling the dingy and moving to a lighter aluminum version which will take about 400lbs of weight off and out of the equation. Hopefully after all that, I’ll be closer to the spec fuel burn. Will keep the forum posted for those interested.

Tom

[Tom Bartolomei]

I just received M2’s and will be putting them on in short order. Mercury doesn’t produce a M3 propeller and I felt a move to M4 just wouldn’t be enough.

As to repitching these all SS props, I’ve heard more opinions about the potential to weaken the blade root during the repitching process thereby increasing the possibility of tossing a blade under operation. True or not, I really don’t know but for the amount of inches I am seeking to remove, I felt it was the better move to buy in lieu of repitch with these seemingly fussy props.

I will post the results with the M2’s when available. Mercury still won’t tell me the pitch. Crazy.

Tom

[Tom Bartolomei]

Likely reply here is to post more pictures further back allowing a better view of the entire setup along with a bit more history and nameplate of the engines that you have available. 2850 RPM at WOT is quite a bit short. I’m a previous owner of a vessel (2005 Sea Ray 390DA) that had QSB5.9 380’s for the power package. Re-propped twice to get it dialed into 3065 RPM at WOT, fully loaded vessel, and at about 93% engine load.

You will definitely get the right guidance here but need to supply some additional information.

Tom

2 users thanked author for this post.

Daryl Keyser, Rob Schepis

[Tom Bartolomei]

The pitch difference between the M7 and M5 is a little over 2″ as I understand from Mercury. There are two props (counter rotating) per pod. The front prop is a five blade while the rear prop is a four blade. The pods also have an integrated trim tab system which automatically regulates the position of the trim tabs. I did all of these runs (except Sabre Hull #1 which is their first release of this vessel back in 2012) with the trim tab system on ‘auto’ but frankly am not impressed with the auto trim tab system. I have noticed that I can dial in better vessel performance with the tabs in manual mode. “Better performance” meaning lower fuel flow, lower load, and more comfortable ride/bow rise.

After a few calls, I may be able to try out a set of M4 props. These suckers are $1,900 per prop.

To Tony’s point on …”Engine achieves or exceeds rated rpm when accelerating from idle to full throttle”. So I can be sure I understand what this means in practice; do you guys recommend I do a run starting at say 800 RPM and push the throttles straight to the stops and monitor/log the RPMs generated as the vessel accelerates through to its top end? This would confirm what the graphs are indicating which is while the new prop (M7) has helped a bit on the top end, albeit still above target GPH, the more troubling area is cruise rpm where a still much lower pitch is warranted. If M7 to M5 was worth about 2″ of pitch and bought me 120 RPM on the top end, I’m thinking M4 (another 1″) won’t cut it.

The engines are really working in that 1600 to 2300 RPM range which is that point where the boat is trying to get on plane.

Tom

[Tom Bartolomei]

Thanks Tony –

There was a graph attached that included performance with the new props (M5 versus my original M7 props) but that graph is somehow missing now from my post. I’ve reattached it here.

I’m at 3020 now at WOT with the vessel and new props but not quite achieving that easily as you say and as I’d like. Clearly still working hard over the entire RPM range from say 1200+ RPM.

I may have a source to try out the next pitch size down on these Mercury Zeus props. They are not easy to come by to say the least.

Tom

[Tom Bartolomei]

Bruce –

Not sure you are still monitoring or not. Finally received new M5 prop sets and ran the tests. Attached graph updated. Getting 3020 at WOT now with vessel fully loaded. Compare that to the other runs where vessel wasn’t loaded quite the same (will do that in future though to really nail apples to apples). Somewhat puzzling in the ‘fat’ or off plane range where I see no difference between any configuration of boat loading or prop set. Maybe Tony or others can chime in. I start out close to the cummins curve then diverge from it quite a bit between 1600-2400 rpm then it gets a little better from then on up until finally converging at the WOT point.

I either run in the green zone or run in the blue zone. Makes sense, either on plane or at hull speed for this cruiser. Anything in the middle is really hard work. A break down of my load factor is below. I chart every trip and log the hours and the fuel burn. Also don’t tend to cruise at the high RPM with full fuel (520 gallons for my boat).

56% of overall hours with <15% load factor
27% of overall hours with 16% to 30% load factor
15% of overall hours with 31% to 45% load factor
2% of overall hours with 46% to 60% load factor

Have 354 hours on this vessel and my average load factor is 17%.

Not sure I’m going to chase further prop changes at this point.

Tom

[Tom Bartolomei]

Attachment…

[Tom Bartolomei]

Bruce – Attached is a graph of my vessel’s performance compared to Cummins Spec and Sabre’s own Hull #1. The props on my boat are M7’s as I mentioned above. The props on Sabre’s Hull #1 also M7.

Sabre Hull #1: 100% Fuel, 100% water, 6 adults, 0% waste, clean bottom, no dingy
My Vessel Loading: 50% fuel, 75%, water, 50% waste, 2 adults, tools & rations, 12 months on the bottom, Dingy on freedom lift (800 lbs dingy only). Freedom lift weight not known but significant.

You can see how much harder my engines are working with these props across the RPM range. New props arrived finally (they are hard to source) and boat is being hauled tomorrow. Should have her back in the water next week and will add a 5th line on the chart for the vessel performance with M5 props. I didn’t breakout fuel flow between engines as they were within 1 gph of each other at each setting. WOT performance on mine for each run was 2900, 60 GPH, and 100% eng load.

Tom

[Tom Bartolomei]

Bruce –

Not sure where you are in the process of looking at that Sabre 48. I am due to receive new props on mine in a couple weeks. I dropped from my current M7’s down to M5’s. I need a good 200 RPM at WOT. Will get her on out and test with the new props and report results here.

Tom

[Tom Bartolomei]

Bruce-

I have the same 48 Sabre with the same engines, although mine is a 2014 with 150 hours on her last year Feb when I bought it. 330 on the clock now. Had a prior searay(390DA with QSB’s) and set her up with many if not all of the recommendations on this site. That paid off in performance and re-sale value.

On the Sabre, I also have a 800# dinghy on the back. I’m coming up short on WOT RPM’s fully loaded and am in the process of dropping pitch. Zeus pods and the prop sets are a bit more unique than conventional straight shaft or v drive set ups. I suspect you have the M7 prop sets. I’m 200RPM short of where I want to be and dropping to M5 prop sets. I wouldn’t be surprised if you’re short on rpm as well and may be looking at M6 or M5. Sabre itself makes a great boat and you won’t be disapppointed. Engine maintenance and pod maintenance is what it’s all about. Your riser set up is fine. Do get those aftercoolers off and serviced and fill out the info requested above but again, I won’t be surprised if you are short on RPM fully loaded.

I also replaced pod hydraulic filters…again, a bit unique compared to conventional setups but so far I’m happy with the vessel and power/drive train.

This vessel of mine was from Newport Beach CA. I pulled the aftercoolers and all was well with them. I wouldn’t get hung up on oil analyses unless you have a trend showing something off.

Happy to help where I can on this specific boat configuration.

Tom

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