Opinions of 6V53's in the 31

Carl · Post by **Carl** » Dec 29th, '06, 16:50

If whaler1777 can take out 6V53T's from a 31, I can put 6V53's in, correct. Didn't think they fit so never looked, thought the 4v53 was the only old Detroits that fit. So why shouldn't I put them in.

Not an easy install, very heavy and they leak, smoke and are noisy anything else that can be thought of please let me know. Maybe too fast for inshore trolling.

Up side, a decent cruising speed plus the economy and range are what I would like, 22knt's @ 15gph from Capy's posted numbers. I have been pricing parts, motors and speaking with guys that service them, not overly high numbers and seems to be a reliable motor.

If pricing was in my range I would go Steyr, Yanmar, Cummings then 3208 Cats and finally Detroit's, pretty much in that order. Am I overlooking another quality motor with good service parts and reliability.

Otherwise I stay with the 440's.

Thanks and Happy New Years to you All!
Carl

scot · Post by **scot** » Dec 29th, '06, 18:43

I like DD's. Basically the American original diesel. The 6V53 is as good a version as they ever built. Spend your money with a MOH and they will out live you.

You already know the down sides.

The up sides: Wet liners, economical injectors, No massive/expensive injector pump, More HP per cu inch than 4 strokes, good low end torque. Buy parts at Kmart... practically. Lots of guys know how to work on them.

The 6V53'2 aren't all that heavy...1,800lbs. Actually a little bit lighter than the 3208 CAT's. I think you'll like the smooth ride.

$.02 cents from a "old school" guy

Whaler1777 · Post by **Whaler1777** » Dec 29th, '06, 19:55

Heres a shot of what they would look like in the b31... Theyre out of the boat now...

As you can see the engine boxes have been moved aft and an extension has been added to the bulkhead (the teak strip) for the edge of the box to rest on... The engines that I removed are actually 400HP twin turbo supercharged 2 stroke diesels, I never ran the boat with the dd's but I was told by the prev owner that they gave him no problems and that the boat did close to 38kts and that he would have to run on one engine when in canals/creeks... the props on the boat are 3 blade 22x23..

Harry Babb · Post by **Harry Babb** » Dec 29th, '06, 20:12

My opinion of DD is the same as Scotts.............Good reliable inexpensive engine to rebuild and maintain. I have considerable experience on Detroits infact the 653 is the first diesel engine that I ever overhauled..........but......I would look REAL HARD to try to find something else to use to repopwer a 31 or any other small boat like the 31's.

The engines are really LOUD.............Its like running with Yamaha dirt bikes in the bildge.......LOUD.

Although I am working towards a repower with 6B Cummins I really favor the John Deere because of the low noise level and the smoothness of the engine.

Any of the 4 stroke inline engines I believe are better suited for our Bertrams.....They will be easier to service and give room on the out board sides for a genset, they are cleaner and quieter.

Harry Babb

Whaler1777 · Post by **Whaler1777** » Dec 29th, '06, 20:14

Yea theres no way you can fit a gen next to one of these engines...

Rocket · Post by **Rocket** » Dec 29th, '06, 20:26

Did Harry mention that they are loud? Not the kind of throaty V8 gas motor loud or the really low tourqey 3208 loud, but screachy loud like a haywire outboard on steroids kind of screaming loud. Great motors though they'll still run even if the skidder is lying on its side with no wheels on the ground. Very hard to kill and cheap to run. Not sure if I'd want them on my boat, though....

scot · Post by **scot** » Dec 29th, '06, 23:03

Whaler177,

I noticed that those engine boxs have ZERO sound control material...I bet that boat was REALLY loud. If your going to run DD's you should make every effort to muffle them as best you can. Stuff sound control everywhere! Forward bulkhead, the box, between the engines, etc. etc. Just find every hole a DB can escape and baffle it or plug it.

Basically to live with them you have to design around their nasty habit of making boo-kuu noise.

I've got one going in my B25 as a single and the entire engine bay design is based around controlling the roar, or attempting to at least. Hope I only get 1/2 the noise a 31 twin would have!

Harry...I'm rebuilding my engine myself and I'm glad to find you for a resource, hope I don't drive you nuts with questions.

What all have said about DD's is true...the good and the bad.

Whaler1777 · Post by **Whaler1777** » Dec 30th, '06, 03:05

Just had them pulled last Tuesday... Had to literally go from yard to yard to see who had the right size crane to fit in my driveway and clear the electrical wires overhead... 100 Bucks later Theyre out...

Harry Babb · Post by **Harry Babb** » Dec 30th, '06, 22:16

Hi Scott
Tell me about the Detroit that you are rebuilding. Its been several years since I have turned a wrench on one but I remember a good bit about my "Diesel Years"..............Mostly DD's and Mack's and Cummins. I will never forget the "Rush" that I get when I clamp a pair of visegrips onto the rack of a Detroit and then hit the starter button. One of the first ones that I ever tuned up ran away with me...........just to governer speed.. and scared the living crap out of me.

I am also in the process of rebuilding a pair of diesels......... ..6BTA's..These Cummins have me more spooked that any detroit ever did. I was very tempted to purchase aftermarket parts, for cheap, but I have now decided to purchase Cummins OEM parts. I cannot believe how expensive OEM parts are but the consequences of an engine failure are far greater than the money saved.

Harry Babb

scot · Post by **scot** » Dec 30th, '06, 23:28

Harry...just sent you a PM.

Carl · Post by **Carl** » Dec 31st, '06, 11:46

Thank you for the responces.
38 knots, I'd like to take that boat out at least once. If they only idle down to 600 rpm you would do about 9knots in gear, thats crazy. 20 knot cruise with a burn of 15 or better is all I am after, don't want to think about turbos. It is impossible to have a turbo issue without turbos.

What do 6v53's idle down too? I really want diesel to go offshore more, 20-40 mile runs which are just too costly now with 440's, but I still want to troll inshore for Bass, 3knots is about right, am I going to be able to still do this? One engine and tabs down? Tossing a sea anchor Id rather not have to deal with, too easy to tangle rope in wheels. Trolling valves? I really don't know anything about them or how they work, if they allow the tranny to slip as I sought of think they do then how long till it craps out?

I believ the 6v53's are a couple hundred pounds heavier then the 3208 naturals, but not a huge difference.

I agree, not a great first choice. But I want to go a further distance with my available funds. I need a reliable power. I need to be able to service economically when the need arises.

I can do the install so time is the main issue (besides funds), most things would be required down the road if and when new 4 stoke engines become a possibility. Engine beds, exhaust and underwater hardware plus strut beds.

Thanks again.
Carl

In Memory Walter K · Post by **In Memory Walter K** » Dec 31st, '06, 13:17

Carl- Although I am not familiar with the engines you are considering, I was in a similar position as yourself a while back with tired Chrysler 440's that were sucking gas like crazy. I, like you, wanted to be able to run 20-40 miles offshore for Tuna and Shark, yet almost all my inshore trolling was for bass and bluefish. I never even considered diesel until we discovered that Chrysler wouldn't warrantee their new engines unless I enlarged my exhaust system, and their new engines were also a bit wider so my boxes had to be modified. The cost of all that drove a gas repower higer than installing brand new Cummins 6bt's @ 210 hp each. I could keep my 1 3/8" shafts, did not have to enlarge my exhaust system or make any box modifications. The performance met my needs perfectly. I cruise at 21 kts @ 2400 rpm with 20X20" 3 bladed props with light cups. On the Bass trolling side, the engines idle at 650-800 rpm. I normally troll against the tide on one engine and catch fish. My fuel consumption has gone from the 20+ per engine on the 440's to 7 gph per. Overall, normal for me on mixed fishing/running/trolling etc is about 1.5 nautical miles per gallon. I probably could get more speed but I opt to underprop so as to both extend the life of my engines and to allow me to run slow through my marina, docking etc. Hope this is of some help. Walter

scot · Post by **scot** » Dec 31st, '06, 16:10

The 6V53's are NOT heavier than 3208's. Actually a bit lighter by 150-200lbs. Now, the 6V71's are about 300lbs heavier than 3208's. These engines are lower RPM engines than gas or 4 stroke diesels. WOT NL 2800PRM on the 6V53, criuse around 2300 - 2400 RPM... this typically results in designers using higher gear ratios to match the engine power curve. Often 1:1, 1:2 etc...some 1:5

High ratio gears are spinning the props at high RPM...even at idle. Not sure what gears are in the boat??? Dun-know.

You can't take the turbo's off, the DD has a different piston for turbo / non-turbo engines. These engines only have 318 cu inches and turbo's are required to get that little guy up to 400 hp, which is pretty high for the displacement.

I agree that 38 knots is really moving in a 31....if only they didn't sound like (2) 300 cu inch chain saws on steroids.

Harry Babb · Post by **Harry Babb** » Dec 31st, '06, 17:57

Sim
It sounds like these engines will do just what you want and I am sure that the DD's are very reliable
To my knowledge these engines will idle down to 550

Let us know how it all turns out
Harry Babb

Whaler1777 · Post by **Whaler1777** » Dec 31st, '06, 17:58

They are the twin disc... Not sure of the ratio... The Id tags on the trans are scratched.. Only thing I could make out was the "Twin Disc" Logo

Carl · Post by **Carl** » Dec 31st, '06, 20:45

I must have got my weight numbers incorrect on the 3208's. Thanks.

Turbo, I was not thinking of removing turbos' just looking for naturals to begin with. However I would have loved to take setup Whaler 1777 had for one ride. Kind of like I would love to have a go-fast cigarrette boat for a weekend, no longer I'd get board.

Walter, yes if I did not have two young kids, mortgage and trying to re-establish my business I would take the plunge and do the right way by buying a pair of the new lightweight high reving motors such as Yanmar, Cummings and Steyr. Not the case for me. Either I stick it out a few more years with gas, cross my fingers and buy some running takeouts and hope I can get by a few years without problems or look for some old tech motors with issues I will have to deal with till I can swing the ideal setup. At least I may be able to use the boat in the manner I bought it. Hell if I am going to fish inshore I can go back to a Bayliner, yes I had one and it served me well.

I have been looking for a good deal on Cats for years, just do not see many in good condition in my range.

Thanks again for input.... 550 rpm that may do.

Carl

Whaler1777 · Post by **Whaler1777** » Jan 1st, '07, 03:26

My boat sat on land for approx 15 years... I would have loved to see how the engines performed but I already had an image of what I was looking for in my mind. If I was to make the boat seaworthy it would have been a waste of money (steering system, rudder bearings, electrical) I would rather do it all once and know that it is done properly.
-John

In Memory Walter K · Post by **In Memory Walter K** » Jan 1st, '07, 11:21

Carl-My point was that by the time I did the modifications forced on me by replacing my 440's, it was actually cheaper to put in the diesels and not make the modifications. You might want to look into factory rebuilt/waranteed engines. My big surprise was the difference in how the boat handled with the change. I was perfectly happy (I thought) until I suddenly discovered I could maneuver the boat into the tightest spots like a pro, never need to hit the throttles docking, stopped being affected by winds etc. I hope 2007 finds you a set of diesels at the right price so you can both enjoy their benefits and stay within your budget. Walter

scot · Post by **scot** » Jan 1st, '07, 21:07

Need tp correct MY error. Happens to me all the time.
The CAT 3208 IS lighter than the 6V53.

OEM literature for both list the weights as follows:

6V53N @ 1830lbs w/ gear (too many HP variations to list)
6V53T @ 2200lbs w/ gear (too many HP variations to list)

3208N / 210hp @ 1740lbs w/o gear
3208T / 325hp @ 1800lbs w/o gear
3208TA / 375hp @ 1880lbs w/o gear
3208TA / 435hp @ 2,080lbs w/o gear

Add the gear weight and compare "hp to hp" and it's a dead heat at the 400hp level. Considering the CAT is 636 cu inches and the DD is only 318 cu inches, or exactly double the displacement it's no wonder the CAT was more popular at these power levels "in the old days"

bertram31.com

Opinions of 6V53's in the 31

Opinions of 6V53's in the 31

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