Engine Installation Questions?

Vince Luciani · Post by **Vince Luciani** » Feb 13th, '07, 11:39

I am interested in hearing from those that have repowered with Cummins 6btaâ€™s, but have not modified their engine boxes. I know there are some of you out there (uncle Vic, walterk, others? ) because you have responded to an earlier post on the subject of engine modifications.

I am interested in determining how you routed your exhaust without modifying the engine boxes. I am assuming that you went with a crossover exhaust riser on the port engine. Am I correct? If not, can you describe how you ran your exhaust.

Also, it would be very helpful to learn the dimension from the front bulkhead to the pulley on the front of the engine. Uncle Vic you had indicated in an earlier post that yours is about 3 to 4 inches. How about others?

I intend on constructing an installation jig using the drawings supplied form Cummins. (I have access to a plotter and can plot the drawings at full scale). I am going to use the jig to fabricate my engine mounts. It would give me a nice degree of confidence to know that if I stay â€œxâ€ inches back from the bulkhead, that the engine will fit, my boxes will close, and the exhaust can be routed (without major demolition). I am trying my best to avoid that situation. I donâ€™t have unlimited access to a crane where I can use a â€œtrial and errorâ€ process of getting my mounts correct.

I would welcome any thoughts on my approach. I think Iâ€™m on the right track, but multiple heads are better than one.

Thanks guys,

Vince Luciani
1968 Sportfish

In Memory Walter K · Post by **In Memory Walter K** » Feb 13th, '07, 13:43

Vince- Mine too is a Sportsfisherman but of an earlier vintage than yours because I have the 2-piece engine boxes. She's all sealed up now so I can't take measurements. The installation was a while back (and I had it done), but here are a few things I remember. We took the covers off the fanbelts to give us some more room and ease of belt changes up front. My port engine's exhaust does cross over to the outside stringer area and runs down under the cockpit to the stern. Mine's he 210 and was told it had a slightly lower profile. Wish I could be of more help. Walter

Vince Luciani · Post by **Vince Luciani** » Feb 13th, '07, 14:14

Walter,

It all helps! I was planning on removing the belt covers. My drawings (done on AutoCad) show that the motors fit, but the drawings are only profiles. In fact, by my drawings it looks like I can keep the pulley about 3 inches from the bulhead and still fit the engines in.

My concern is the exhaust, especially on the port engine. The drawings from cummins don't show that custom made item. It's good to know that if somebody else was able to find a way to route things, then chances are, I will be able to also.

Thanks again.

In Memory of Vicroy · Post by **In Memory of Vicroy** » Feb 13th, '07, 14:37

Vince - I have the 250s and the port exhaust out of the turbo sweep goes down about 90 degrees, then there is a custom welded s.s. 5" pipe with about a half dozen angles that takes the exhaust out along the stringer with a big f.g. muffler. No 'crossover', its all below the rear of the engine. The fit of the turbo exhaust sweep and the joint to the s.s. pipe is real tite against the lower companionway panel on the prot side, but it works without mods to the engine box. I may have some pix of it at home, will look. Mikey has some pix of my 'tower' aluminum engine mounts and may help, and I probably have some too.. Yes, take the belt covers off. The 6BTA is a nice easy fit into the B31.

UV

JP Dalik · Post by **JP Dalik** » Feb 13th, '07, 15:33

Vince,
We pulled out our Cummins to redo the engine beds and bilges as part of our restoration. Depending how far you are going with your refit there are a few options. The fuel tank is your enemy here.

A) You can go over the top with dry exhaust and join up the water on the outboard side, which means you will need to insulate the stakc pipe.

B) You can slide the fuel tank back 3 inches to give the exhaust more room to fit between the engine and fuel tank.

C) If you are building a new tank you can leave the port forward corner "cut off" so the exhaust fits (you don't lose much fuel)

D) Fit a custom stainless exhaust like UV stated

E) Move your engine mount on the port inboard side to the bell housing (not recommended, but still approved) which gives you enough room to use store bought elbows and fiberglass tube to fabricate your crossover and surge tube. The further you keep the engine forward the more room you will have.

We are using option D cause we already had stuff that worked and I found a welder who is capable of making some changes to it if needed. No matter what you do its going to be tight. We have the ZF 220A transmissions with trolling valves and it if you desire to use your original engine boxes and go out under the deck it will be a tight fit. I'll try and post some pics (if I can find batteries for the digital).
Everyone has different ideas and they all work. Hope it helps.

Vince Luciani · Post by **Vince Luciani** » Feb 13th, '07, 21:19

Thanks guys for the replies! Uncle Vic I like what your telling me and pictures would be great. I was leaning towards the crossover top exhaust, but I may have to rethink.

JP, your explanation of the fuel tank as the enemy makes things a little clearer for me. It is easy for me to understand that if the fuel tank is moved back, there is a lot more room to route that exhaust (but I really don't want to get into moving the fuel tank).

I orignally had thought about installing the engines as far forward as geometry allows, but other posts recommending getting the weight as far back as possible scared me off. JP are you not concerned with the center of gravity issue? My AutoCad drawings show that I can get the engine about an inch off the front bulkhead and still have the vertical clearence for the boxes, but I have been striving to keep the weight as far back as possible as others have recommended.

JP, I like your comment about the fact that there are alot of ways to get the job done. I am slowly comming to that conclusion.

Once again the help is greatly appreciated!

Ironman · Post by **Ironman** » Feb 13th, '07, 22:25

Vince: They fit nicely ...no up & over needed.. I put in the 330s. 2inches from the front bulkhead.. Tried changing the belt before bolting up. Took a full 2 minutes...
The port mixing elbow is close but the boxes close .I used a 1/8 fiberglass bend Ill try & attach pics.
Wayne

Ironman · Post by **Ironman** » Feb 13th, '07, 23:39

I also used 1/8 bend hi temp rubber...
Hey Capt Pat did you fix my botched pic attempt? or did it magically appear after I logged off?not too sure of my posting attemts
Wayne.

CaptPatrick · Post by **CaptPatrick** » Feb 14th, '07, 06:51

Yup...

bob lico · Post by **bob lico** » Feb 14th, '07, 10:39

i have cummins 330 and i went over the top with stainless.i really did not explain myself on a earlier post on surge tubes. the reasons for going over the top inconjuction with a centex 6"muffler is the elimination of the surge tubes and most inportant to put the exhaust in the outside stringer making room for a huge fish box.
i also used auto cad and placed the harmonic balancer 6" from the bulkhead wall. the gear mounts are 1/2" from the fuel tank,thus i shifted the engine weight as far back as possible.i still have the option of plus or minus ballast by way of the fish box on port and starboard of the cockpit.the sealed boxes can be filled with sea water with the press of a button(TO MAKE SLUSH FROM ICE)or remove water thru meacerrator out thru hole. right now the boat is perfect balance at 38 knots without water ballast in 2to 3' seas.

In Memory Walter K · Post by **In Memory Walter K** » Feb 14th, '07, 10:48

Bob- Sounds like you've thought of everything! Congratulations. Took a while but sounds and looks like it's a gem. Walter

bob lico · Post by **bob lico** » Feb 14th, '07, 11:22

very inportant i should have noted i used a slotted adapter on the flange that mounts to the tubocharger,thus i "rolled"or tilted the over the top exhaust foward so it would fit in the oem engine hatch the starboard is also rolled foward.i used 70degree ss 6" fitting at the bottom and connected both side with high temp. silicon.this presents two advantages ;eliminates any vibration from engine movement and in a catatrophic raw water loss you prevent the melting of a fiberglass fitting.i know a few on this board would argue the point but i feel the higher melting point of the hi temp silicon will give you a few minutes to realize you loss water and shut down the engine before filling the boat with exhaust water.

Ironman · Post by **Ironman** » Feb 14th, '07, 11:24

Vince; listen to Bob Lico, He was very key in helping me with my template.. & other things.
It was so easy..( I,m sorry Bob, but I questioned a few things for no reason.) Great help also from these faithful..
BTW I wont be having a port side fishhold.
Wayne

JP Dalik · Post by **JP Dalik** » Feb 14th, '07, 11:28

Bob.
You had another advantage in your install. It looked like the outside stringers were "lower" than normal. Is that were you got the extra height to run over the top with stock engine boxes?

Vince Luciani · Post by **Vince Luciani** » Feb 14th, '07, 11:58

Thankyou everyone for the info. I'm following the discussion pretty well. Bob, if one keeps the shaft angle as is is now, the further you move the engine back, the lower it is mounted. I guess that is what JP is questioning, whether you had to cut down the outboard stringer. I am curious to hear Bob's reply to JP's question.

I'm starting to realize that I need to decide on a strategy for the engine installation. I either have to keep them forward and try to route the exhaust under the deck ahead of the fuel tank. Or, I have to move the engines back (get center of gravity back) and cross over the top.

I was leaning towards going over the top to gain some elevation between the waterline and the invert of the turbo outlet. Cummins wants a minimum of 12 inches and by my drawings I would be right at 12 inches without a loop overtop in the exhaust. Plus going over the top gives me more buffer to avoid water surge to the turbo. That over the top exhaust work is all custom and must be pretty pricey $$$.

Thanks again guys!

bob lico · Post by **bob lico** » Feb 14th, '07, 12:09

actually the rear of the engine box sit on top of the cockpit floor and the floor is slightly higher.i made up for that loss of inside gunnel height by filling in the area along the gunnel than i put 11/8" teak covering board over the entire gunnel eliminating that taper lip that goes from fore to aft you know jp like the big guys (merrit/rybo/davis etc)a completly flat service no vents or any other line cutters.3 rod holders on each side at 90,45,and 30 degrees.i also have a belly band around around the entire inside edge of the cockpit laying on top of the outside stringer this seals the cockpit floor from the bilge area like a self bailing floor on a center console.i don`t have your fishing experiance but i have put water over the trasom backing down on a 486lb bluefin.WOW 4" of water on the cockpit floor i don`t have to tell you it don`t take much more to sent that water into the cabin!!!!noy a pretty sight.

bob lico · Post by **bob lico** » Feb 14th, '07, 12:24

sorry jp i throught you were reffering to the stringer after the rear bulkhead.in the engine compartment outside stringer the rear edge is cut down and capped with a u shaped piece of titanium 1/2' thick that goes from foward bulkhead to rear bulkhead than tie across (from one stringer to the other)all welded one piece tieing the foward bulkhead to the rear bulkhead thru bolted in a zig zag pattern.

JP Dalik · Post by **JP Dalik** » Feb 14th, '07, 13:42

Yeah Bob,
Thats what I thought I saw when the shots were up. Must have given you alot more room, considering every inch gained is priceless in these things.
Regarding the cockpit set up it sounds like we used similar system we to all the available decking out to the hull sides(no formica panels)and incorporated a full 2-1/2" gutter around the deck.
We've gone with rolled covering boards and they're looking sweet!!!! Full roll down 4" all the way around the corners and transom killbox. To make it a little nicer we got rid of the hausers on top and rounded the back corners to make a nice transition for the teak coming as it comes off the killbox. The hausers will go out the back now.
We glassed a 4" pvc tube up the starboard side and into the engine room for gaff storage.
The underside of the gunnels have been finished off along with the interior hull sides by epoxying finished fiberglass skins to the surface. Now the whole cockpit is cleanable with a mit.
The teak cockpit deck is nearly finished then we just need to make the kill boxes for the deck. Been a busy winter.

John Jackson · Post by **John Jackson** » Feb 14th, '07, 16:36

Don't be afraid to modify the engine boxes. With mine, we made them about two inches wider and then made a return to the bulk head on a Sportfish model to fit 270Bs. I will try and get pictures. The exhaust on the port engine goes underneath, and we had to notch out the engine box in addition to making it wider. It was a tight fit, but it worked. If you can put in engines, modifying the engine boxes is child's play!

JP, you should put some pictures up, your boat is comming out fantastic!

JP Dalik · Post by **JP Dalik** » Feb 14th, '07, 17:18

Not putting any pics up yet, she's got lots of holes and faring goin on.
The guy that should be puttin pics up is you.

The Hound is lookin good...........

I'm thinkin about gettin some cots for when the wife kicks me out for workin on the boat.

You want in.

Brewster Minton · Post by **Brewster Minton** » Feb 14th, '07, 17:35

With the guys on this site if your getting cots for guy whoes wives kicked them out for working on the boat too much your going to need a lot.

bertram31.com

Engine Installation Questions?

Engine Installation Questions?

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