Trojan Boat Forum

mac32's really haulin. i cant get near that speed on my f32 either. maybe hes added a hydrofoil underneath?

I have a 1977 Tri Fly with Chrysler 400 CID engines and Walter V-Drives, 20x21 props. She pops up on plane at about 15-17 mph maybe a little earlier (on the GPS), at 3000-3100 she is cursing at 22mph and WOT, 4000-4100 she is topping off at 27.2. Not bad for original engines. I brought her from Saugatuck, MI to Alpena, Mi (about 350 miles) and she ran like a champ, averaged 22mph, not bad on fuel either, did not care, just wanted to make the destination

g36 wrote:mac32's really haulin. i cant get near that speed on my f32 either. maybe hes added a hydrofoil underneath?

Really.. I was thinking that his speeds are right but his rpm readings were low.
What size are your props? Is your boat unusually heavy?

Trojans specs for the 318 with 16x15 blades had the WOT around 30/31 mph.
I get his numbers for speed but need to push his rpm list down a level and add 4000+ for the top speed.... I think his tachs need calibrating
so in general I agree with
15 knots at 2300
20 knots at 3200
27 knots at 4100

Sherman , The Internationals are slower (for equal power) and do burn more fuel due in part to the deeper V and I believe they weight more . But they also Ride better in heaver seas . Its a trade off . Diesels are the way to go for sure.

Paul ....did your F36 have diesels when you bought her or did you do the conversion?

I think we should all go out and run a real speed curve and do it the old way without the use of a GPS

Will ,the diesels were in there went I got it. (installed in 99 )


Willietrojan, a real speed curve with out a gps ? I would think the speed curve with a gps would be better, running to and from so tides would not alter the out come .

S.A.M. pull up your 10m on boat test, the did a repower w/ yanmars. They also have your boats results w/ the 454's in there. Sounds like yours may be missing a little compression or in a need of a good tune up while getting a closer look at your inginiton system. Check out the site and tell me what you think

Butch I

No kidding, those are great numbers. When I had two good engines in my 30 foot Flybridge Searaider (merc 350's, 330hp ea) I got about 18-20 knots at 3100rpm with clean bottom and gear......however at 4800-5000rpm I got 33knots on the GPS.....only did that one time and I hurt the starboard motor.
Needless to say, going forward I will be happy at 3100rpm.............John

I read the test and I am realy haveing a hard time beliving those numbers ,Is anyone with a 10 meter getting anything close to those numbers ? I belive S.A.M.S, numbers are much more realistic. from the folks I talked to and posts I have read .Real world number are often much diffrent then magazine numbers

What is the weight of the 10 meters ?

Went to the boat yesterday and checked the wiring that I removed to the engine syncronizer and found I still had a loop going up to the bridge so after changing that then the starboard tach does not skip or drop anymore and both engines run at the same. Also confirmed I have 1.52:1 velvet drives.

Did another trial yesterday on the lake with calm glass like water and found or confirmed the exact same thing (had a few people on the boat this time so a little slower) Max speed was 25knots (29mph) at 3300rpm WOT (also had 2 different GPS units to validate the one on the boat). And she seems to run very smooth (insert happy here)

So this sounds like my tachs are off both upper and lower helm. How do I go about correcting this (with out buying all new gauges)?

May have ajust ment on the back of the tach . check them with a photo or lazer tach . shop around you can find them under 50 bucks. a very useful tool.

Wow, those numbers are sure different than mine. The best performance I can get with my twin 351 Mercruiser 233hp is 17 knots at 3200 rpm, .8 mpg, 15 gph, 15x15 light cup props, with a fully loaded boat.

wowzer52 wrote:Wow, those numbers are sure different than mine. The best performance I can get with my twin 351 Mercruiser 233hp is 17 knots at 3200 rpm, .8 mpg, 15 gph, 15x15 light cup props, with a fully loaded boat.

"Fully loaded boat" is the key I know I have lost 3 knots at cruise ,from when I got the boat ,in my case fully loaded may mean over loaded in my case

Twin Cummins 6BTA5.9 diesels
Velvet Drive 1:1
17x20 Bronze Props
23knots max around 2300RPM