[Ethereal]

I am considering a 35 Open with 8.1 Crusaders. Some say it is not enough power, others say it is. Some say they are fine for the Open but not enough for the Express. I noticed that the Open weighs only 2/3 that of the Express (14,000 compared to 21,000 plus). Is the 8.1 package enough power?

[ReelMagic]

In my opinion the 35' open requires diesel's. I had a 31 open w/454's which ran at 24.5 knots @ 3200 (~32 gph). My friend had a 1998 35 open w/same power (twin 454) and cruised at 18-19 knots @ 3200. Ran at 3600 to get to 21 knots. Fuel burn was nearly 40 gph @ 3600... If your not planning to take long trips it would be OK.... . My 2 cents

[Uhehner]

I have 8.1's in my 36 convertible that weighs in at 18,300 empty. Read my previous posts about the performance. The cruise is about 24 at 3400 and WOT is mid 30's. I figure 1.2 MPG, nothing like the old 454's that got half that. These are quite, efficient, easy starting, smoke free and smooth running engines. Capt. George

[mikefromlb]

I have 8.1's in my 1989 Open, re engined in 2004. Run on trips to Catalina at 2800 rpm's, 18 - 19 knots when we'll trimmed. Estimate fuel burn 1.2 mpg. Wt. at 2013 survey at boat yard was 21,000 # with 3/4 full tank. Based on recent cost to replace risers and manifolds, I would prefer diesel over gas.

[Ethereal]

At 14,000 lbs and 35 feet, this seems to be a borderline vessel. Despite higher cost, I think I'll error to the safe side. I've never had anything this large (only 24 to 30 foot center consoles). I would be really bummed out if I owned it and felt it was under powered, too late at that point. Thank you all for taking the time to share your experience.

[Uhehner]

If you slam the throttles forward, your passengers will go out the back of the boat. Don't think you will be under powered. These are not 454's. And think about the operating cost. Oil and filter change is about $ 25.00. Can you do that on a diesel? I had to change the elbows on my Volvo diesels at 5 years and they were not cheap. Capt. George

[Fiddlehead]

Sorry for bumping a 4+ month old thread, but as someone who struggled with this exact decision before I bought my boat I wanted to weigh in.

I've had my 2002 3500 Open with 8.1L Crusaders for a full season now - taken it offshore for day trips as well as several overnights up the Maine coast. I don't regret the choice one bit. The boat has terrific power, handles everything we've thrown at it with ease(and we've found ourselves in some pretty nasty seas, not by choice!) and the fuel cost is nowhere near as bad as I'd feared. I cruise easily at 23-24 knots and 3200-3400 RPM, with two adults and a half load of fuel/water/gear, and I'm burning right at 1mpg.

I can't help but thinking some of the old recommendations for diesel in the 3500 Open were based on the earlier years where Tiara was using the 7.4L Crusaders ... before they went to the 8.1L's.

Taking everything into account ... upfront cost, maintenance, fuel cost, performance ... I couldn't be happier.

[sluggo]

I have a Sovran 3600 (2006) with 8.1 Crusaders, this is the spec sheet and I have found it to be very true. I ran 4000 rpm for several hours right at the 26 27 knot range vs the river current. Hope this helps.

PERFORMANCE REPORT

Date: 6/23/2003
Model: Tiara 3600 Express Engines: Crusader 8.1L MPI
Location: Holland, MI - Lake Michigan Test Engineer: Jack Funkhouser
Hull Number: SSUM6001C304 Gear Ratio: 2.48/2.53:1
Propeller: Federal EPX-300 22x23 #5 Cup Nibral No. of People on Board: 3
Weather Conditions: 1 ft. Chop/Wind 10 kts Out of South Fuel Capacity, gallons: 325
Acceleration: 5/24 seconds to 3600/WOT RPM Water / Air Temperature: 58 / 69
Fuel/Water/Waste: 100% / 100%/ 75% Gear on Board: 200 lbs.
Optimum Cruise Speed: 25.3 mph Range at Optimum Cruise: 214 miles

Trim Angle Est'd. Range
RPM MPH Knots GPH MPG dB, A degrees Statute Miles

646 4.6 4.0 2.3 1.97 63 0.0 576
1010 6.7 5.8 4.1 1.65 68 0.7 482
1512 8.9 7.7 6.9 1.27 74 1.0 363
1998 10.6 9.2 12.4 0.86 78 3.3 251
2508 12.4 10.8 19.4 0.64 80 5.6 187
3012 17.6 15.3 27.1 0.65 82 6.9 190
3199 19.9 17.2 30.2 0.66 85 7.5 192
3416 22.6 19.6 34.2 0.66 86 7.9 193
3632 25.3 22.0 39.0 0.65 85 8.3 190
3826 27.8 24.2 43.4 0.64 85 7.5 186
4023 29.9 26.0 50.0 0.60 87 7.1 175
4195 31.4 27.2 55.9 0.56 88 6.5 164
P 4488 / S 4456 33.5 29.1 67.0 0.50 90 6.1 146

[sbw1]

I have a 32 Open with 8.1s. The 35 is actually slightly faster and more efficient than the 32 due the extra water line. It is not at all underpowered with the 8.1s. 8.1s are more common on the great lakes than in Florida and other ocean venues. They perform well and are much cheaper to service than diesels. I would go with gas on the great lakes and diesel in other markets for the 32 and 35 opens.

[NYMarine1]

I am running a 2003 Tiara 35 Open with twin 8.1L Crusaders - Captain's Choice.  This is my second season with the boat and it has never felt underpowered.  Gets up on plane quickly and the engines are quiet.  I cruise at 3200 @ around 22 kts with full water and fuel.  I don't have flowscans so I am not sure of the GPH, however, I believe the spec sheets says its is around 30 GPH.

I have another boat as well so I do not (in my humble opinion) put enough hours on the Tiara to justify diesels; but if I had found a boat in my price range with diesels, I would have jumped on it.  Some of the benefits of the diesel that appealed to me were: safety (no gas fumes), efficiency and longevity.

As I am sure you have found on other forums, there is one problem with the 8.1Ls on the 35 open: they are no longer made.  While I have heard many people say the 8.1Ls are ok for the 35 Tiara open (as my experience so far confirms), if these engines go there is not a sufficient replacement because GM stopped making the long blocks.  I believe there is a HO version but I have heard it will not cut it. 

Best of luck!