Willard 730 - Moving engine crossbeams?

[clloyd]

Anyone have experience removing or more specifically moving the position of the aluminum engine crossbeams in a mid 90's era Willard 730 Diesel - Cummins 6BT, Konrad?

Boat is not here so no pics.

The guys doing outboard conversions have definitely removed them to make space for fuel tanks.

It looks like they are bedded down and then bolts come from the stringers through the cross and tightened with Nylock nuts.

I don't see access to the back of the bolt.

Maybe they are driven into threaded inserts?

Could they be backed out with a stud driver?

Thanks for any insight.

[RyanPratt]

Moving it would not be recommended if you are going to keep engine. Shaft length transmission?

Could help if I had more information. Why do you want to move. What is your ultimate goal?

[RyanPratt]

The bolts back out they are threaded into stringers. Sledgehammer or heat gun will work. Some times they slide out of the bedding sometimes they don't without a little help. I could not get mine out without trimming deck also. You could move bed but not much more room fwd as the bow starts to get shallower to aromas ate the rise in the bow.

[clloyd]

Thx. I am putting together options for a repower from the 6BT to something in the 300hp range with more top rpm capability.

The easiest would be to stick with Cummins but I'm trying understand if another option is viable as well. Cummins seems to have the widest base, so any movement would likely be pushing the forward crossbeam aft a touch.

If this becomes more serious, I'll be sure to post progress.

I welcome any opinions.

Current options on table are

Cummins 370B mechanical. @3150 rpm top end. Easiest to install. Drop into existing mounts. Reuse all guages etc. Need to move sea strainer. Need larger exhaust size and outlet. Larger raw water hose.

Cummins QSB 330 or 380 - @2950-3150 rpm. Drop into existing mounts. Some guage changes. 24v/12v system is tricky to accomodate. New controls, transmission actuator or new transmission with electronic control. Exhaust size change, move strainer.

Volvo D6 330 - 3500 top rpm. Similar to QSB in install complexity, electronic engine, new controls, transmission actuator, guages etc. Forward engine mounts would need to move back. Exhaust size may not need to change (Unsure).

Yanmar 315hp 6lpa-ste or similar. 3800 rpm top. Engine mounts would need to move. Exhaust size change, move strainer, similar to mechanical B. Know boats with this engine and they have a good top end speed. 40-45kts

I favor Cummins. I know the engine well now. I like the community and ease of parts, working on it etc. The drawback is lower top RPM, more crushing low end torque. I still think you could imagine a 32kt fast cruise and a 40kt top end. Top torque lines up with the Konrad 520 specs.

[RyanPratt]

Todd on this forum claims to hit the speeds you want with the current power and just juicing up the current engine pulling around an extra 100hp i believe. I have a friend who has done two yanmar conversions if you go that way i can see about putting you two together. I love the ease of the cumins but not the sound. I love the quiet of the yanmar but not cost.

[clloyd]

Thx ryan. 6bt is not worth trying to juice up in its current config. It uses the cav rotary injection pump. Best you can do is 250 adding jwac aftercooler and technically it should have different pistons even for that. Its a good engine though.

Anyway im going down the route of a cummins qsb.

Maybe i end up with enough bits to redo another williard.

These things become quite the project if you let them.

[RyanPratt]

Yes they do!

I have never done a Diesel so i have no experience. Please post what you are doing would love to follow your progress.

Best of Luck!

[Bigtalljv]

My mounts came out without much trouble. Some light tapping with the 8lbs sledge. I did have a hole to fix in the deck and I was able to see on the backside of my stringers there was a large metal backing plate that had the nuts welded to it. It was glued to the outside of the stringer. If you did manage to move the mount you will need to cut an access hole somewhere to get a backing plate in there. They put all that in before they put the cap on.

Jason

[clloyd]

Thx Jason, this is great information for other owners.

I've decided to repower with a Cummins QSB 330hp. QSB's are supposedly much quieter, less smoky than the mechanical ones.

Selling my 6bt.

Ill start a new thread and show the repower as it progresses. Will be doing a bunch of prep work first this winter with the original engine out.