engine replacement in 78 nautique
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=1339
Printed Date: November-22-2024 at 3:33pm
Topic: engine replacement in 78 nautique
Posted By: doogs
Subject: engine replacement in 78 nautique
Date Posted: March-16-2005 at 12:38am
I have recently purchased a 78 nautique only to find out the engine is stuffed. The problem is I am located in Australia. The current engine is a PCM 351 and BW velvet drive.
I have gathered that these engines rotate opposite to a standard car engine and that is where my dillema lies. I cannot seem to locate a direct replacement so is it possible to swap it for a different motor such as a 351 Cleveland? These are pretty common motors here so they are pretty cheap which is important. Will the gearbox be ok running in reverse? i understand i will need to replace the prop, is there anything else other than the usual things? or am i better off trying to rebuild the existing motor?
Sorry for so many questions im just in a bit of a dilemma and dont want to spend a fortune to get it on the water!!
Thanks in advance!
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Replies:
Posted By: AWhite70
Date Posted: March-16-2005 at 1:09pm
As for switching to a LH rotation engine I've heard you can turn the pump around in the transmission and you'll be ok.
As for switching engine types (i.e. 351W to 351C) I think it could get pretty expensive since you won't be able to reuse any of your old parts (i.e. exhaust manifolds, engine mounts, front drive components, etc.)
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Posted By: doogs
Date Posted: March-16-2005 at 9:18pm
so by switching the pump around does that mean the prop still spins the right way? or am i on the totally wrong track? were these engines bought out in anything else? at least the same block?
So far it looks like rebuilding the original motor im just a bit worried after reading other posts about getting seals and the crank reground the right way! what are the other concerns if i was to get it rebuilt?
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Posted By: Siveck
Date Posted: March-16-2005 at 10:14pm
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Don't forget the little reverse rotation front cover and rear main seals. Those supposedly care which way the crank spins. I'm currently replacing the cam in my '75 Nautique after I sheared the teeth off of the cam gear. Let us know if you figure out which way the crank bolt turns for removal.
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Posted By: reidp
Date Posted: March-17-2005 at 12:38am
Doogs,
Rebuilding the existing is by far your easiest and cheapest way to go. Just make sure you order the correct seals for that reverse engine and your crank will be fine as you just need to have it turned, and not worry about the rotation issue if keeping it the same. So, UNLESS WOODY OR SOMEONE AT CORRECT CRAFT SUGGESTS CHANGING THE ROTATION, DO NOT. They didn't make them that way to make it difficult on us down the road. The cost of the new prop alone is greater than the increased cost of rebuilding it rev. rotation as opposed to standard/automotive rotation. If there are parts you can't get over there, just let us know. Unfortunately, the Cleveland engines really didn't make it on the marine scene here. Good luck.
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ReidP
/diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang
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Posted By: doogs
Date Posted: March-17-2005 at 1:40am
thanks reidp so the only real specialty part is the seals? everything else should be right? I wonder if seals could be bought over here otherwise would skidim be the best option?
Will keep you posted as to what happens
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Posted By: Stan C
Date Posted: March-17-2005 at 3:05am
Doogs
reidp is correct, rebuilding the existing reverse rotation engine is the cheapest and most rewarding option. The seals should be available direct from PCM also.
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Stan C
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Posted By: Tim D
Date Posted: March-17-2005 at 4:16pm
If your crank has a one piece seal, get the marine, because the lines are directional on the seal, if it is a two piece it doesn't matter, (use auto about $14)cause the crank has the directional lines which pull the oil back.
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Tim D
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Posted By: workky
Date Posted: March-17-2005 at 8:22pm
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make sure you get a reverse rotation camshaft as well,and also the distributer gear is reverse rotation also.
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Posted By: doogs
Date Posted: March-18-2005 at 10:45pm
thanks Tim D for that info fingers crosed its two piece. Workky the original motor is still all there it still has all the parts you mentioned so they shouldnt be a problem!
Just on replacing the complete motor again if i have to? if i replace the motor and only utilize the raw water pump and the gearbox from the old motor and just switch the oil pump on the gearbox around is there anything else i would need to do other than whats involved in a normal engine swap? Would the exhaust manifolds and risers fit on a conventional windsor?
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Posted By: reidp
Date Posted: March-19-2005 at 1:32am
So you're still considering an automotive rotation? Well, a Windsor's a Windsor in that your original engine is as typical as they get, but only as far as a base engine design is concerned, so your manifolds will swap just fine. But not knowing where your proposed engine is coming from, your starter must match the engine rotation as it's not bi-directional. The marine distributor/engine is set up for mechanical advance and not vacuum like the autos. To use your existing dist you must have the cam-drive gear changed for std. rotation. Some one else chime in to talk Doogs out of this.... And did anyone mention that it's highly probably that the boat will list to starboard when cruising down the outback rivers and lakes?
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ReidP
/diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang
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Posted By: Guests
Date Posted: March-19-2005 at 9:51am
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I concur...keep the rotation LH.
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Posted By: doogs
Date Posted: April-03-2005 at 9:50am
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ok some good and bad news the block was stuffed but the guy who is rebuilding it found another block. i did notice that the oil seal on the water pump side was one piece and had grooves cut into it does this mean that i need specific reverse rotation seals?
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