45 HP chrysler long shaft conversion?

[kapuse]

I was wondering if i can take out the mid section of my 45 chrysler to shorten the length, it looks like theres a 5 inch section thats secured with four bolts on the lower exhaust housing, and four bolts connecting the top of the lower unit that if removed will bolt right back up to eachother, was this done for just this reason, are there any parts i will need, and how difficult a project is this to complete?

 

[Frank Acampora]

Re: 45 HP chrysler long shaft conversion?

The 5 inch center section has a 5 inch piece of brass tubing that slips over the short water tube. All you need is a short drive shaft and you don't need to disassemble the lower unit. The shaft is splined to the pinion gear and slips right out after you remove the water pump screws. My experience was that because they were never loosened, the top bolts were corroded into the aluminum, almost welded. So, removing the 5 inch center section will be the most difficult part of the task.

 

[kapuse]

Re: 45 HP chrysler long shaft conversion?

Thanks for the quick response Frank, as usual your a huge help

 

[kapuse]

Re: 45 HP chrysler long shaft conversion?

Oh the reason i ask this question is because the distance between where the mounting bracket sits on the transom and the antivent plate is 23 inches, where my transom on the boat is only 15 inches, should i go ahead with this procedure to make up for some of that difference or am i wasting my time because 5 inches isnt going to make a big difference in the drag created?

 

[Frank Acampora]

Re: 45 HP chrysler long shaft conversion?

Those older Chryslers were slightly long so 23 for a 20 inch transom would have been normal. It will definitely be way too deep on a 15 inch transom if you do not shorten it.

You may want to build up the transom 5 inches--it won't be any more difficult than shortening the engine. BUT, then you will have more engine choices to mount on it in the future.

If you search in the general boating forum or search keword transom you will probably find a couple of replies with decent photos of simple and safe ways to raise the transom.

 

[kapuse]

Re: 45 HP chrysler long shaft conversion?

considering i need to replace the wood in the transom due to rot and oldness, i think the heightening option would make more sense plus like you said i have more options in the future, if i didnt shorten the motor would it make sense to bring the transom up 8 inches to make the plate line up directly with bottom of the boat or do i want a some space between the two?

 

[Frank Acampora]

Re: 45 HP chrysler long shaft conversion?

Conventional wisdom has the cavitation plate lining up even with the bottom of the vee or flat of the hull as the starting point. You can try raising it 1/4 inch at a time. Many times, 1 inch higher will increase performance while not causing ventilation/cavitation in the turns.

If you want to experiment this way, do not drill the holes in the bottom of the clamps until you find the correct height. It will be safe for the short testing periods without the lower bolts

 

[Turn4fun]

Re: 45 HP chrysler long shaft conversion?

If you do decide to take the extension off, I'll swap you a short drive shaft for your extension. I've been wanting to convert my short shaft to a long for a while.

 

[kapuse]

Re: 45 HP chrysler long shaft conversion?

turn, you can email me with some contact info and details

Kapuse@aim.com