Struts and running gear placement
Moderators: CaptPatrick, mike ohlstein, Bruce
Struts and running gear placement
Anyone running 11° struts and by chance 315hp Cummins? I’m curious to how the boat rides with that setup, I have a pair of 11° struts I’m fitting to our Bahia Mar. shaft logs are cut out and for some reason the guy who did a lot of the fiberglass work for the overhaul, removed and filled in the rudder ports. So I have a lot I can play around with.
Re: Struts and running gear placement
Not sure if you are rebuilding your rudder shelf--but if you can move the rudder port---I would suggest to offset so you can remove shaft without dropping the rudder.
Re: Struts and running gear placement
i posted the entire step by step process many years ago so look it up and absolutely no help from your yard marine mechanic. this is a differant approach to the job to eliminate wet ride,rolling and added performance (fuel economy) only special tools are a quality LED pin point flashlight with red or green lens. and a small block chevy freeze out plug with 1/8" hole drilled thru center.
capt.bob lico
bero13010473
bero13010473
Re: Struts and running gear placement
Craig, yes, we are rebuilding the rudder shelf, have blank canvas to work with. And from what I’ve read on this site I was planning to offset the rudders. Wondering if anyone has tried moving rudders and struts further aft.
Bob, I will definitely give it search. I think I’ve read about your setup before in another post, just not the actual process. Do you have any opinions on running shaft tubes from the shaft logs down to the struts like some of the newer bigger boats are doing? A captain I know locally who has a lot of experience is trying to talk me into it.
Thanks for y’all’s input.
Bob, I will definitely give it search. I think I’ve read about your setup before in another post, just not the actual process. Do you have any opinions on running shaft tubes from the shaft logs down to the struts like some of the newer bigger boats are doing? A captain I know locally who has a lot of experience is trying to talk me into it.
Thanks for y’all’s input.
Re: Struts and running gear placement
yes i have the experiance. before you start this project you must look in the mirror and say I MUST MAKE THINGS HAPPEN nobody else. you are lucky we have two precision machine shop owners on this site which are essential to this new concept installation. CARL and HARRY both can take the two propeller shaft couplings along with output flange of gears and machine the face to within .001 runout.the ID. and the matchinf face of coupling and output flange of gears must be perfect in this installation THERE IS NO SHIMMING after engine and shaft are allign after engine installation. actually gears and shaft are one piece the variable is the fiberglass shaft log and struct angle to bottom of boat. 31 bertram Phoenix has a cruise of 29 knots in 4 to 5' seas on a regular basis and super fuel economy cruise of 27 knots at 1.85 mpg.but you must take the unusual steps in installation. let the 1/2" space between rear of gear oil pan and bilge be a guide the lowest center of gravity possible.
capt.bob lico
bero13010473
bero13010473
Re: Struts and running gear placement
Curious as to where you came across 11 deg struts for the 31. The stock 10 degree struts from what I know are for 1-1/4" dia shafts with no room to bore open for larger bearings. Then they only have clearance for a 15 or 16" wheel, just not enough wheel diameter.
I'd add to how the boat rides or performs, but not up to that point just yet.
What I can say for sure...the closer the shaft/prop angle to the direction of travel the more efficient the setup. Outboards and I/O's and pods are most efficient for that reason. I'll also equate efficiency to speed.
Handling- - All I can say is I see no good handling characteristics coming from a prop pushing water at a downward.
For that reason I spent ALOT of time dropping the motor several inches for a lower shaft angle. Stringers cut down, changed location of shaft log, glassing in fiberglass log and making 11 deg struts.
As to why they glassed over the rudder ports...I believe some boats had the ports placed a bit off. If going up a shaft size or two the shaft Will Not pass the rudder in stock location. So either motor and shaft shift or rudder placement changes. Could also be to move rudder back a hair...you can move strut back a hair for a longer strut and a larger wheel.
And unfortunately when I'm done and finally running, I'll have nothing to compare my numbers to to see if there is a benefit from all the work I did.
It would be nice if I had motors setup with 15 deg one year, got my numbers then modified to 11 and saw the difference.
I'd add to how the boat rides or performs, but not up to that point just yet.
What I can say for sure...the closer the shaft/prop angle to the direction of travel the more efficient the setup. Outboards and I/O's and pods are most efficient for that reason. I'll also equate efficiency to speed.
Handling- - All I can say is I see no good handling characteristics coming from a prop pushing water at a downward.
For that reason I spent ALOT of time dropping the motor several inches for a lower shaft angle. Stringers cut down, changed location of shaft log, glassing in fiberglass log and making 11 deg struts.
As to why they glassed over the rudder ports...I believe some boats had the ports placed a bit off. If going up a shaft size or two the shaft Will Not pass the rudder in stock location. So either motor and shaft shift or rudder placement changes. Could also be to move rudder back a hair...you can move strut back a hair for a longer strut and a larger wheel.
And unfortunately when I'm done and finally running, I'll have nothing to compare my numbers to to see if there is a benefit from all the work I did.
It would be nice if I had motors setup with 15 deg one year, got my numbers then modified to 11 and saw the difference.
Re: Struts and running gear placement
Carl, I wish I would have gotten on this forum sooner so I can write about the whole story on our boat lol. There is so much I have yet to add to it. So here’s a little taste... as to where I got the struts, another mariner’s miss fortune with a rotten wood core boat, became a jackpot for our overhaul.. we got a pair of 315hp 6BTA’s mated with ZF 220A’s, 102” of 1-3/4” shafts to work with, stainless 11° struts, over sized rudders, 4 blade props 20x24 with cup, and a center pod station for the controls. I will add that we ditched the engine boxes on our Bahia mar and elevated floor at the start of the aft bulk head to create an engine room...
So I happen to be a marine aluminum fabricator and I can weld stainless, the struts the boat came off of do not have the correct angle to be inline with the shafts, so I just have to cut and weld to make them work for our boat.
Now here’s what sucks, we originally bought a 32 cary for the 250hp Cummins she had in her for this overhaul. So I built engine beds and what not for the 250’s with the stock struts, which are the 15°.. it wasn’t until recently I actually measured them and after further inspection come to find out that they had been shimmed up to 17° why? I have no idea lol. But with the new struts all that work I did setting up the 250’s was for nothing haha. Oh well, I’m kinda very exciting to be reworking everything. Every thing I’ve been reading on this forum and others is fantastic, and has me very motivated.
So I happen to be a marine aluminum fabricator and I can weld stainless, the struts the boat came off of do not have the correct angle to be inline with the shafts, so I just have to cut and weld to make them work for our boat.
Now here’s what sucks, we originally bought a 32 cary for the 250hp Cummins she had in her for this overhaul. So I built engine beds and what not for the 250’s with the stock struts, which are the 15°.. it wasn’t until recently I actually measured them and after further inspection come to find out that they had been shimmed up to 17° why? I have no idea lol. But with the new struts all that work I did setting up the 250’s was for nothing haha. Oh well, I’m kinda very exciting to be reworking everything. Every thing I’ve been reading on this forum and others is fantastic, and has me very motivated.
Re: Struts and running gear placement
why 1 3/4" shafts???????? something radically wrong here i have 83" shafts. Carl stay away from yard people WHO says 1 3/8" structs fitted to 1 1/2" have to sit flush to hull . the shaft gives you the angle with 10 degree down angle of IRM 220 ZF gears than you fit the struct accordenlly disregard F/G shaft log until you are perfectly inline then slide shaftlog down and glass in
Last edited by bob lico on Mar 5th, '20, 21:46, edited 1 time in total.
capt.bob lico
bero13010473
bero13010473
Re: Struts and running gear placement
Bob, all I wanted to run was 1-1/2” but the salvage boat we got the motors and running gear & motors from had 1-3/4” shafts. The shaft diameter may be way over kill, but I don’t see how it could hurt performance wise? I’m not going to use all 102” of shaft either. I’m just working with what I got.
Re: Struts and running gear placement
the only reason the 1 1/2" to 1 3/4" shaft will make a differents is the enormous barrel used with the 1 3/4 struct compare to the streamlined 1 3/8 " struct modified by boring struct barrel AND cutting down the cutless bearing to fit using the full 6" without cutting off excess as a watershear in front of struct barrel. this is how you get that unbelievable fuel economy , a little here and a little contouring here adds up.
capt.bob lico
bero13010473
bero13010473
Re: Struts and running gear placement
I see where you’re coming from, I yanked the old original structs off this evening and had them side by side with the new ones and boy is there a size difference.. lol.. but I think I can make them work.
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Re: Struts and running gear placement
To help simplify things for you, what Bob did was lowered his engines so that they are only about an inch off the hull. The shaft log is the same size as the original except that he adjusted the barrel so it matched the new shaft angle.
This allowed him to maintain a 20 or 21 inch prop and gain some thrust efficiancy due to the decreased shaft angle.
This allowed him to maintain a 20 or 21 inch prop and gain some thrust efficiancy due to the decreased shaft angle.
1975 FBC BERG1467-315
Re: Struts and running gear placement
Bob gets a pass on calling them "structs"...
Everybody else, please, they are Struts, not structs.
Sorry iddy biddy pet peeve... but I'm ok now.
So yes, you don't have to have the STRUT base fit flush to the hull, but I wanted them to and mine do.
To use my original struts, I would have needed a several inch spacer to swing a 20" wheel, then the barrel would have to be bored out to a paper thin wall with paper thin Thordon cutless bearings at a 1/16" wall, just too thin for diesel, even low hp ones like mine.
Then I was going to buy original Bertram 15 deg struts, but didn't want to spend all that coin and have to tweak and shim 4 degrees then be stuck putting them where they had to go instead of where I wanted them to go to fit prop and squeeze by rudder. So I started looking for stock products that might work, no dice. Then started talking to the foundry about pouring me custom struts. But soon as I started taking measurements I knew I was in over my head going that route with compound angles...much easier to just make n fit em.
Everybody else, please, they are Struts, not structs.
Sorry iddy biddy pet peeve... but I'm ok now.
So yes, you don't have to have the STRUT base fit flush to the hull, but I wanted them to and mine do.
To use my original struts, I would have needed a several inch spacer to swing a 20" wheel, then the barrel would have to be bored out to a paper thin wall with paper thin Thordon cutless bearings at a 1/16" wall, just too thin for diesel, even low hp ones like mine.
Then I was going to buy original Bertram 15 deg struts, but didn't want to spend all that coin and have to tweak and shim 4 degrees then be stuck putting them where they had to go instead of where I wanted them to go to fit prop and squeeze by rudder. So I started looking for stock products that might work, no dice. Then started talking to the foundry about pouring me custom struts. But soon as I started taking measurements I knew I was in over my head going that route with compound angles...much easier to just make n fit em.
Re: Struts and running gear placement
Thanks, tony. I’ve definitely been soaking in all the info y’all are feeding me. I think I’m going to completely rebuild my engine beds and try to get the motors as low as possible. I built mounts that bolt onto the bell housing so the transmissions are floating.
Carl, Bob had me second guessing if I was spelling strut right, Hahaha.
Also Carl, I notice your new struts aren’t the same angle as the originals. My new struts look very similar, I was gonna cut the welds at the base plate on mine to match the angle and then weld it back up. I would post pictures, but I’m not sure how to with my phone. Is there a reason why you didn’t match the 23° angle?
Carl, Bob had me second guessing if I was spelling strut right, Hahaha.
Also Carl, I notice your new struts aren’t the same angle as the originals. My new struts look very similar, I was gonna cut the welds at the base plate on mine to match the angle and then weld it back up. I would post pictures, but I’m not sure how to with my phone. Is there a reason why you didn’t match the 23° angle?
Re: Struts and running gear placement
In that picture the angles look very different, but they are pretty close. I just adjusted the angle a hair to let larger shaft pass by the rudder.Dimmer wrote: Is there a reason why you didn’t match the 23° angle?
Re: Struts and running gear placement
Carl, since you mentioned it first, about structs vs struts..etc, let me also add what I see often in this forum, that “then” is different from “than”, also Bob’s name is Lico, not Lilco, and more!
I would have never started this on my own as I’m the least authorized to do so, but what the heck, I found the opportunity and jumped in. I hope no one takes it personally.
I would have never started this on my own as I’m the least authorized to do so, but what the heck, I found the opportunity and jumped in. I hope no one takes it personally.
1973 B28 FBC/2007 4LHA STP's - "Phantom Duck" - Hull "BER 00794 1172"
Re: Struts and running gear placement
let it also be known i have shut off spell- check and not the least bit concern because this is not high school.
capt.bob lico
bero13010473
bero13010473
Re: Struts and running gear placement
I second that, bob.
- PeterPalmieri
- Senior Member
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- Location: Babylon, NY
Re: Struts and running gear placement
I was under the impression structs were a special device that is used with Cummings engines.
I really don’t care about anyone’s grammar but when I see a boat listed by a broker and it says Cummings engines I really want to vomit.
I really don’t care about anyone’s grammar but when I see a boat listed by a broker and it says Cummings engines I really want to vomit.
1969 31 Bertram FBC "East Wind" hull #315939
Re: Struts and running gear placement
When a person can forget more then most people will ever know about a subject, that person gets a pass on using the exact terms and spelling. I say this cause everyone knows that person knows exactly what they are talking about.
For the rest of us, if we start tossing out the wrong terms it can be an indicator we are not quite up to speed on the subject, as such can become fresh pickins.
For the rest of us, if we start tossing out the wrong terms it can be an indicator we are not quite up to speed on the subject, as such can become fresh pickins.
Re: Struts and running gear placement
Anyone who can only think of one way to spell a word obviously lacks imagination.
Mark Twain
Mark Twain
B28 "NINA PETER SANTA MARIA"
Re: Struts and running gear placement
thank you carl ,as i remember my college days when a paper was graded with a letter over a letter as in A/B .top letter was for content and bottom letter for spelling ,grammar.with this being said i should think this site is 100% content and if you cannot decifer spelling asked.
capt.bob lico
bero13010473
bero13010473
Re: Struts and running gear placement
Hi bob ,
Good to see you are still on the board . I read that your wife had suffered a stroke . Please accept my condolences . I was concerned that it was you that was ill , i recall you talking about the Cancer that runs through your family history . I see you are on Long Island , I have a friend who is a well known oncologist who helped set up a Sloan Kettering satellite hospital on Long Island . He would talk about Certain cancer "hot spots " that are not disclosed to the public . He mentioned a place called West Islip in Suffolk County that had the highest Breast Cancer rate in the country years ago and an adjoining village of Babylon ( i remember because it has a Biblical name ) that is horribly contaminated due to the fact that there is a lot of light/ medium industry north of those towns that contribute to the problem . I hope you do not live near those areas ! My friend retired and moved out to Vail ( he lives down the mountain from me ) and spends his time fly fishing & free climbing . He always says how glad he was to get off of " Plume Island " . Good luck with your wife and her rehabilitation !
Good to see you are still on the board . I read that your wife had suffered a stroke . Please accept my condolences . I was concerned that it was you that was ill , i recall you talking about the Cancer that runs through your family history . I see you are on Long Island , I have a friend who is a well known oncologist who helped set up a Sloan Kettering satellite hospital on Long Island . He would talk about Certain cancer "hot spots " that are not disclosed to the public . He mentioned a place called West Islip in Suffolk County that had the highest Breast Cancer rate in the country years ago and an adjoining village of Babylon ( i remember because it has a Biblical name ) that is horribly contaminated due to the fact that there is a lot of light/ medium industry north of those towns that contribute to the problem . I hope you do not live near those areas ! My friend retired and moved out to Vail ( he lives down the mountain from me ) and spends his time fly fishing & free climbing . He always says how glad he was to get off of " Plume Island " . Good luck with your wife and her rehabilitation !
Re: Struts and running gear placement
My concern - I do not want our people going out and sounding like they do not know what they are talking about by using the wrong terms.
Bob...you've been typing them up as structs for years, I noticed but didn't care, didn't correct because it didn't matter. It is only when others started calling them structs I mentioned it. AND if everyone here knew they are struts, but felt like calling them something else...or if they got the spelling wrong I'd be back to - so what and who cares.
...and I mention it as saying and calling as the way its being spelt will change the way it is pronounced, unless that c is silent.
Bob...you've been typing them up as structs for years, I noticed but didn't care, didn't correct because it didn't matter. It is only when others started calling them structs I mentioned it. AND if everyone here knew they are struts, but felt like calling them something else...or if they got the spelling wrong I'd be back to - so what and who cares.
...and I mention it as saying and calling as the way its being spelt will change the way it is pronounced, unless that c is silent.
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Re: Struts and running gear placement
Carl
You are not taking into account that in todays world with all of the over weight people we have that it is not just do to fat fingers, or automatic spell check changing what you are typing. Man do I hate that function, it tries to out think you.
You are not taking into account that in todays world with all of the over weight people we have that it is not just do to fat fingers, or automatic spell check changing what you are typing. Man do I hate that function, it tries to out think you.
1975 FBC BERG1467-315
Re: Struts and running gear placement
Tony Meola wrote:Carl
You are not taking into account that in todays world with all of the over weight people we have that it is not just do to fat fingers, or automatic spell check changing what you are typing. Man do I hate that function, it tries to out think you.
This subject has been beat to death...but one last kick.
My issue was never about the spelling, it was about clarifying the terminology.
ok...I may have told this here some time ago...but its a good one and I like it...Sooo
Customer is kinda tech savvy and has been sending texts by dictation for some time with pretty good results.
One day I get a message that starts off ok then goes extremely strange with some risque innuendo with cars and...well I'd rather not go there.
Debating if I should respond...my hands typed out "Did we have a Liquid Lunch today ?" and hit send.
A few seconds later I have an irate customer on the other end of the phone.
He's pissed at my accusations...I try to calm him down a bit, then ask him to please take a good look at the message he sent me.
Annoyed but he agrees...Oh! Oh no! what? No....Now I have a very apologetic customer on the phone.
It was a New car with Bluetooth that takes dictation, he didn't proof read it as he usually does before sending.
He's so sorry, didn't mean anthing by it, thanked me for letting him know.
I tell him no worries and we crack up laughing. I ask if he sent out any others...laughing slows on his end.
Then stops...and an abrupt "Gotta go"
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Re: Struts and running gear placement
I hate blue tooth. My phone while in the car never calls the right person.
By the way, my comment was tongue in cheek.
By the way, my comment was tongue in cheek.
1975 FBC BERG1467-315
Re: Struts and running gear placement
Bluetooth when it works right can be real nice...when it works right.
Call D o r e e n
Calling Jack from State Farm
NO! CALL D O R E E N
Calling Maureen
NO, DON'T Call MAUREEN! I SAID D O R E E N, Doreen my wife you jack aRse!
Hello, Maureen speaking-
Yeah, Its Carl, my car called you, sorry.
No problem, say hi to Doreen for me
Wish I could...
Between my spelling, auto correct, fat finger typing and diminishing eyesight, I'm surprised anything I type is right these days.
Call D o r e e n
Calling Jack from State Farm
NO! CALL D O R E E N
Calling Maureen
NO, DON'T Call MAUREEN! I SAID D O R E E N, Doreen my wife you jack aRse!
Hello, Maureen speaking-
Yeah, Its Carl, my car called you, sorry.
No problem, say hi to Doreen for me
Wish I could...
Between my spelling, auto correct, fat finger typing and diminishing eyesight, I'm surprised anything I type is right these days.
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Re: Struts and running gear placement
Carl
Been there with the Blue tooth. Sometimes it is not just worth it. LOL
Been there with the Blue tooth. Sometimes it is not just worth it. LOL
1975 FBC BERG1467-315
Re: Struts and running gear placement
By the way bob , you spelled decipher wrong .
I could not help myself lol -
p.s. How is your wife coming along ?
I could not help myself lol -
p.s. How is your wife coming along ?
Re: Struts and running gear placement
I once sent a dictated text to my sister that was supposed to say "I am standing in the kitchen talking to Mom." It came out "I am standing in the kitchen naked with Mom." Needless to say that got a phone call from my sister! LOL!
Rawleigh
1966 FBC 31
1966 FBC 31
Re: Struts and running gear placement
Rawleigh wrote:I once sent a dictated text to my sister that was supposed to say "I am standing in the kitchen talking to Mom." It came out "I am standing in the kitchen naked with Mom." Needless to say that got a phone call from my sister! LOL!
LOL...Yes Rawleigh that sounds kinda similar to the message received by me...
I wonder if the people who put these dictation pieces of software together have some sort of weird perversion that ties seemingly innocent words into...well, naked with mom. Even typing that - - my fingers know its just sooo wrong.
Re: Struts and running gear placement
Any progress with this boat? Would love to see pics if so.
Devin
31 Bahia Mar
31 Bahia Mar
Re: Struts and running gear placement
Apologies for the super late reply. Had some things come up and hadn’t had a chance to work on the boat for a while. But, just got the engines sitting in the engine beds this past week. Once I get a little bit further along I’ll post some pictures. Going to be running a shaft tube from the hull all the way to the Struts with 2 cutlass bearings. Have a blank canvas, so could take me a while to get everything squared up. Goal is to have the boat on the water by summer!
Re: Struts and running gear placement
There are lots of priorities over boats...
Glad to hear you are back to making progress on the boat. Get to it as summer comes up real quick. At least it did for me...then summer went into fall, winter, spring and finally by mid-summer of the following year she was splashed, even though not quite done, but done enough to run.
Glad to hear you are back to making progress on the boat. Get to it as summer comes up real quick. At least it did for me...then summer went into fall, winter, spring and finally by mid-summer of the following year she was splashed, even though not quite done, but done enough to run.
Re: Struts and running gear placement
Haha, I heard that! I’ve already got the new Marlin tower started, once engines and running gear are in place, I think everything else will be downhill and shady! Gonna be a pretty interesting setup. We raised floor height starting at the aft bulk head going all the way to the v-birth. The floor is the height of the old engine boxes. So now we have an engine room. Will be putting a center pod up on top of the floor, with seating all around it.
Re: Struts and running gear placement
Sounds interesting to say the least...love to see some pictures posted when you can.
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