bertram31.com

Hey guys. Quick question thinking of a 37 Bertram and see them with different power options. Which would be the preferred power for the boat, Detroits 450 hp or Cat 3208 375hp? Would like the boat to cruise 20-22knots loaded for 100 mile one way NE Canyon run and anything over would be a bonus. I have heard so many different cruise numbers my head is spinning and figured you guys could give me the real world numbers, ball park anyway.

waggles02673 wrote:Which would be the preferred power for the boat, Detroits 450 hp or Cat 3208 375hp?

If these DD's are the Johnson & Towers (a.k.a. Junk & Trash) souped up 6V71's I'd stay away from those... Not sure the Cat's are better but these DD's are high maintenance...

Hi Waggles ,

I have a Bertram 37 with 2 x 6 V 92's except for the exhaust noice i am very happy with those.
You need the HP because it is a heavy boat.
Fuel consumption is 30- 35 gallon per hour doing 20-23 Knts.
if you have more questions feel free ! :)

I seriously looked at the 37 a couple years ago, the cat boat was a 18 kt. Boat, the 6 92 boat was better, yet with the inherent mx, fuel usage , and noise probelems. I found an older 38 with 450 cummins. 21-22kts, 28 pins, but much more space in salon, engine room, bigger cockpit. Just not those sexy lines.

Gert van Leest wrote:Fuel consumption is 30- 35 gallon per hour doing 20-23 Knts.

That's about what I'm getting... From a 46' Berty with 4 more cylinders... And, compared with the 6V71, each of my cylinders are 21 cubic inch bigger... That's a total of 310 cubic inches more per engine... 426 CBI for the 6V71 and 736 for the 8V92... The 6V71 has 42% less displacement then the 8V92... Obviously the much smaller engines are worked a LOT harder... Which explains why these engines are notorious for their significantly lower life spans... Even when maintained better then specified by the manufacturer...

The 6V92 souped up versions are better then the 6V71 versions but, sadly, not by much... Again, look at your fuel consumption and mine... Practically the same but my Berty is a 46 and yours is a 37... My Berty is a bigger, heavier boat with bigger engines (non souped up version) yet the same performance and fuel consumption...

There are additional differences between these engines... My charge air is (seawater) cooled outside of the block by an intercooler... Your charge air is (coolant) cooled inside the block (the aftercooler is located under the blower in the V space)... If my intercooler leaks I can see it and water doesn't get into the engine... If your intercooler leaks the first you'll know about it is when your oil has become emulsion (emulsion doesn't do a good lubricating job)... Your blower is a so called bypass blower... Mine isn't... Bypass blowers are more complicated and less reliable... The only thing I really like about these engines is their "wet" (cooled) turbos... But that, again, should tell you something...

The best way to measure engine load is exhaust temperature... The fact that these engines can't work with "dry" (non cooled) turbos is because their exhaust temperature is significantly higher... Higher exhaust temperature means higher load... All things being equal, higher load translates directly to a lower life span... But things aren't equal... I have 25% more cylinder displacement... This translates directly into an even lower life span...

Speaking for myself, I'd rather have a slower boat with more reliable and longer lived engines then a faster boat with less reliable and shorter lived engines... And I don't have to pay $100-$140 per hour for the DD tech... Just the parts and my time...

And, in case I haven't said so before, I absolutely love what you've done with that 37... Next time I'm in The Netherlands I'm going to look you up... If only to see that beauty... I'll make it towards the end of the day and I'll bring the Heineken (or the Grolsch - my preference)...

My Dads 37 runs 3208 375 hp Cats and has made many canyon trips without a bladder, the detroits are faster but thirsty as well..Great boat been in some nasty stuff kept plugging along at 19-20..repower with 450 cummins and you should have a rocket ship. BH

Not to hijack the thread, but Gert, you did it again.

I have a 37 with the 450 hp 6V92s and at 1950 rpm I'm cruising 22 knots and burning about 35 gph. The Cat boats are decidedly slower. I've had great reliability from the Detroits. It's true they like fuel, but I've put a lot of hours on mine without a single major failure, and the 37 is a truly great rough water boat for its size. I had a 35 before this one, powered by B Series Cummins, and that thing would scare the hell out of you in a following sea. This is a vastly superior boat.

Navatech, I'm curious what horsepower your 8-92s are. It doesn't seem plausible that you can burn the same fuel as a 6-92.

John Brownlee wrote:Navatech, I'm curious what horsepower your 8-92s are. It doesn't seem plausible that you can burn the same fuel as a 6-92.

My engines are bog standard (i.e. not souped up) 8V92TI's.. I haven't actually put them on a dyno but they're supposed to put out 575 HP each... At WOT they'll eat up 27-30 gallon per hour each... A souped up 6V92 will consume close to that... Fuel efficiency is directly related to the HP the engine puts out... The efficiency of the 6V92 and the 8V92 is practically the same (give or take a fraction of a %)... IOW, when both put out 400 HP the fuel consumption will be practically the same... The difference being that the 8V92 isn't working as hard... Not working as hard translates directly into longer longevity of the engine...

What you have to understand is that the original NA (Non Aspirated - blower only) versions put out a lot less HP... Then people wanted to increase the HP and started putting in bigger injectors... When you spray more fuel into the cylinder you need more air (oxygen) to facilitate the combustion of that additional fuel... Hence the turbo(s)... Hence also the bypass blower...

The original function of the blower (similar in design to a super charger) on these engines was to provide extra air to scavenge the cylinder of burnt fuel products... NOT to provide more air (in order to burn more fuel)... At a certain point the blower actually hampers the airflow from turbo(s)... Hence the so called bypass blower...

Souping up these engines starts with increasing the amount of air in the cylinder... The top level souped up engines will have wet turbos (results in cooler - denser - charge air) that are bigger (in terms of the air volume that they can push), intercooler (between the turbo and the blower) AND after cooler (under the blower)... It's the amount of air (oxygen) available in the cylinder that limits the amount of fuel (size of the injector) that is useable... These souped up version can deliver about 750-800 HP from what's essentially the same package... That's about DOUBLE the original design HP...

My 8V92 puts out 0.78 HP per every cubic inch... All things being equal the 6V92 will put out about 430 HP... The 8V/71 will put out about 443 HP and the 6V71 will put out about 333 HP... Obviously the 6V71 that puts out 430 or so HP is souped up... It can (and, obviously, is) done... The trade off is less longevity and some additional complexity (after cooler, bypass blower, wet turbo)...

As far as fuel consumption goes, roughly the same amount of fuel will be consumed for each HP put out by the engine... IOW, the souped up versions do not have significantly different fuel efficiency... Of course, we're talking boats so the HP/(engine) weight relationship will impact the boat's fuel efficiency but that's another matter...

i vote for Bob H ------remove 1 ton of engine weight and buy 480 cummins recon for chump change ,28 knots,no smoke what so ever and sooooooo quiet---whats not to like old technology is just that old technology! yes 38' with windshield covered and 1 piece side windows looks great at 60,000 to 80,000 repowered with cat 3126 or cummins 480hp.

bob lico wrote:i vote for Bob H ------remove 1 ton of engine weight and buy 480 cummins recon for chump change ,28 knots,no smoke what so ever and sooooooo quiet---whats not to like old technology is just that old technology! yes 38' with windshield covered and 1 piece side windows looks great at 60,000 to 80,000 repowered with cat 3126 or cummins 480hp.

Granted, a modern engine WILL provide better specific fuel efficiency AND more HP for a lesser weight... Unfortunately, the ROI in terms of fuel savings is such that you need to do an awful lot of hours at sea in order to make it worthwhile... $70K will get you 23,333 gallon of diesel at $3/gallon... That's 777 hours at 30 gallon/hour...

As for smoke, there's always smoke... Once DD's are up at working temperature there shouldn't really be any of the soothy black smoke everybody hates (with good reason)... As for speed, even on a long voyage (say PR to FL) of roughly a 1,000 miles, the difference between running at 28 knots or 22 knots is roughly 10 hours... Does it really matter if you're taking 36 hours or 46 hours on such a long voyage?!...

Thanks for all the info guys

absolutely incorrect when i say no smoke i mean not a trace or they take them back!!!!!!!!!!! cannot make it any clearer then that. 80,000 FOR THE ENTIRE BOAT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! with the 480c cummins,shafts,structs,props. Jacksonville fl. low hours

Super NIce Gert!

Bob:

What do you mean by "chump change" when buying 480C's?

David

they are used to power 90% of 18 wheelers and the only one adapted to LNG so in years to come with lng station across route 80 already you go double the distance of old diesel cummins. there are building them like crazy. due to the huge availability of the 450c block cummins sell the recons for damn near 6bta prices. these are mother engines (liners) and simple to rebuild that is why the truckers and commercial boaters love them. too big for 31 Bertram but perfect for 38' bertram in the updated common rail injection version starting at 480 hp and running up to 600hp. parts are dirt cheap and available in all 50 states. tier four compliant. three cummins/38' bertram have appear on yacthword .

for those whom want technical ; for 37, or 38' Bertram re-con DR6508RX 6CTA-TIM 450HP @2600 (very inexpensive) or upgrade to 480hp and for husco cummins re-con DR6489 6BTA TIM 330 ID/HOR this is 330hp @ 2800 version 270 hp cost more!!!!!! availability upwards of 90 engines on 2/3/16 can be exported to PR. for repower only. better if you have cores

bob lico wrote:for those whom want technical ; for 37, or 38' Bertram re-con DR6508RX 6CTA-TIM 450HP @2600 (very inexpensive) or upgrade to 480hp and for husco cummins re-con DR6489 6BTA TIM 330 ID/HOR this is 330hp @ 2800 version 270 hp cost more!!!!!! availability upwards of 90 engines on 2/3/16 can be exported to PR. for repower only. better if you have cores

The 270 has become so popular, that the 30 and up has become cheaper. Go figure. I got a deal in 2008 compared to todays prices.

tony they are a good deal either way 270.330,370 cummins re-con. i sold my 250 hp Yanmars in 2005 and purchase a pair of 330 hp cummins re-con for $32,000 in 2006 . i transferred the port engine fuel filter to opposite side of block to have conviance of both engines having oil dip stick,fuel filters,oil filters facing companion way. then routed the 7/8" threaded hose line from bottom threaded bulb outlet in bottom rear of oil pans to side of block so i can remove cap and thread on oil removal hose to pump and five gallon pail. maintenance is a breeze. i have one oil filter relocation kit ( one needed for starboard engine only) for anybody installing a cummins in 31 Bertram. off the record when i first uncrated the engines for oil removal upgrades i notice the ribs in the block indicating they were storm blocks then check other re-cons-----------HOOD WINKING THE FEDS laugh my ass off my engine were brand new storm blocks and brand new engines dated two months prior to receiving. think about it, cummins gives same warranty as new why take a chance on faulty existing conditions inherited in rebuilding so they give you brand new engines but they run Bosch fuel injection pump thru assembly line twice and call engine recondition mainly because this loophole lets them skirt tier four EPA. standards but must only go in repowered boats this applies to 6BTA,6CTA,QSB,QSM and all other RE-CON engines.perfect for 31',37' and 38' Bertram. for those whom want to "run with the devil" QSM cummins in 37' will put you i the 34 knot range.

Bob, I don't think QSMs will fit in the 37. I looked at repowering mine with 450C recons and even that was a very tight fit. Length is the issue: the engine room in the 37 was designed around V-block engines and is short. To put in the 450Cs, we would have had to cut 7 inches off the shafts and the couplers would have been tight up against the shaft seals. QSMs are even longer than the C blocks.

john i spoke with phil from east end marine and you will have to bring your 37' Bertram to Mattituck, long island sometime in next two months and he will install Cummins QSM`S . you will have a mid 30kns. boat with 110% 5 blade props. pm me i will give you shop phone and estimate.----------BOB

Anybody have an idea what a pair of QSM11's (about 600 HP) with gears goes for?!...

QSM-11------715hp ---meets tier four or the QSM-11 re-con 661 hp only for repower does not meet even tier three EPA. which one meets your criteria?

bob lico wrote:QSM-11------715hp ---meets tier four or the QSM-11 re-con 661 hp only for repower does not meet even tier three EPA. which one meets your criteria?

They would be going into an 1985 Bertram (if it ever happens) so the 661 would be good... Don't even mind getting a pair that needs rebuilding...

lets begin by saying a qsm-11 or qsc is not routine in a 37' but no problem in 38' (make sure you move gen foward between engines) balance, balance! a sport fishing boat of 37',38' moving 35knots in 4' seas takes a little move talent then a barge at 20 knots ,be prepared!!!!
(2) QSM-11 670 hp 70,000 Shawn Johnson 504-400- 2725. reality -6cta 450 hp 867 hours 12,500 ea. --------------husco; 6BTA pair 330 hp re-cons Doug 608-783- 2766
i had a long conversation with DR. Ira Trocki owner of Buddy Davis Thursday for a good friend. building a 52' buddy davis express does 52 knots in 4 to 5' seas . i will test drive when completed, right now looking at buddy davis 34' center console triple 300 hp and will be at miami boat show for test if financing goes thru corporate.

Bob:

You are a salesman......a 37 sounds feasible with your plan!

hueso a 38' sounds so much better . very easy to enclose front window and remove side window and replace with one piece.interior has perfect layout and a simple job to cover bogus walnut color crap with book match teak panneling with teak molding on top. 38' Bertram availuble for $ 80,000 every day of week some with repower like the 38' near Jenson beach florida with Cat 3126 420hp. interior upgrade.look at 37' then 38' and visualize the easy upgrade at $50,000 less even better with repower upgrade. considering family needs and great layout with huge cockpit i would have built a 38' instead of 31.

I have always loved the 38 Special. I know its not a flybridge boat but what a beauty!

Repower one of those and you truly have something special!

i agree Doug you might say the boat was way ahead of the boat design in that era . now express is the norm and being used on large center consoles.

Bob:

When you talk about the 38' are you referring to the wide body version or newer version (II, III, etc.)?

Hueso wrote:Bob:

When you talk about the 38' are you referring to the wide boy version or newer version (II, III, etc.)?

Hueso - the 38 Special was a lot like me, not really big, but heavy, solid and needs a lot of power to get her moving - but you won't feel much as she displaces a lot of water!

Tom

Tom:

It took me about 20 seconds to figure out your comment! LOL

David

P.S.: Some editing done.

Hueso i really don`t understand the strategy here. lets do this; Yacthworld 38' Bertram in Wilmington NC. a 38' Bertram with perfect updated cockpit teak sole, head,v-berth area is perfect,teak and holly cabin sole. salon and galley a simple job as stated above in teak.boat has 3126 caterpillar at 420 hp each ,these are great motors with world wide parts and service along with updated generator moved forward .new cruise- air A/C .she is a 38' by 13.3" beam masterpiece by Raymond Hunt and COMPLETELY lay up in glass as 31 Bertram a 37' has cored hull sides with a vent cut right into it (ouch). the 37' is more sleek but you can change side windows and glass front window for same effect. they are asking $49,000 do the math----------------------3126--420hp,gears,shafts,rudders,generator,$10,000 worth of A/C and throw in the Furuno Nav-net and the boat is FREE .i am loss for words. i am not even going to comment on any detroit diesel powered boat . Oakdale yacth,Jackson marina,Spelman marina they are worth minus $650.00 (the cost of dumpster)if sent to junk yard a penny a pound,do not allow to touch bare ground must be put on a trailor with tarp under and junk man takes for free and save dumpster fees.like it or not the EPA. are a bitch and always snooping for $25,000 fine. you have no idea!!!!!!!! this is fact and not my opinion .