5.0 to 5.7 Rapido rebuilt engine swap

Ridemywideglide

Petty Officer 2nd Class
Joined
Jan 13, 2009
Messages
166
Re: 5.0 to 5.7 Rapido rebuilt engine swap

I'm new to the boat world, so I may be talking out my butt here..
If it's the same pump as car application, you can get one cheap at any parts store, it's just an SBC. If it's not, and the pump is marine specific, it will cost more. I don't see a reason why that pump won't pump water. I'd run it if it were me. Worst case is you'll see it leak (because you'll be monitoring your new engine closely for a while!!!) and then replace it. It's easy to get to in the boat.
I don't see anything to cause alarm.
 

fyrfightr

Petty Officer 3rd Class
Joined
Aug 13, 2007
Messages
93
Re: 5.0 to 5.7 Rapido rebuilt engine swap

I'm new to the boat world, so I may be talking out my butt here..
If it's the same pump as car application, you can get one cheap at any parts store, it's just an SBC. If it's not, and the pump is marine specific, it will cost more. I don't see a reason why that pump won't pump water. I'd run it if it were me. Worst case is you'll see it leak (because you'll be monitoring your new engine closely for a while!!!) and then replace it. It's easy to get to in the boat.
I don't see anything to cause alarm.

Marine water pumps use differant materials for the impeller and shaft seal than automotive. Marine are designed to handle salt water running through it, Autos are designed for antifreeze.
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
Re: 5.0 to 5.7 Rapido rebuilt engine swap

Let me make sure I am understanding you completely. When I am ready to install the intake I shouldn't use the plastic end pieces at all? Just the bead of RTV and the gaskets?

That is correct. DO NOT use any end pieces that might have come with your gasket set.
 

wil7483

Petty Officer 1st Class
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Jan 19, 2007
Messages
377
Re: 5.0 to 5.7 Rapido rebuilt engine swap

Which gaskets are you wanting to hold on? You throw away the end pieces and run the silicone up far enough to come into contact with the main intake gaskets...
Here's a good page to show you how

Great link, thanks. I was refering to the actual intake gaskets. Do I put them in place with a small amount of silicone or just lay them on the heads dry? Then run the bead of silicone around the ends and a 1/4" up the heads.
 

jy118lfd

Chief Petty Officer
Joined
Jun 18, 2004
Messages
497
Re: 5.0 to 5.7 Rapido rebuilt engine swap

Let me make sure I am understanding you completely. When I am ready to install the intake I shouldn't use the plastic end pieces at all? Just the bead of RTV and the gaskets? Also, in the gasket set is some metal restrictors for the intake. What are they for and where do they go?

As was already said do not use the plastic ends. Just a healthy bead of silicone. Make sure the block and intake is clean and dry, you want to glue them together so to speak. Make sure you get the silicone in the corner of the head and block joint. It depends on what kind of gaskets you have if you need sealent. The plastic gaskets used on most vortec motors no sealent. If they are paper with the raised blue beads around the intake ports I use aviation gasket sealent on the heads to hold the gaskets in place. You will not need any on the top of the gaskets.


Make sure you get everything ready for the install and clean and dry the block, heads, and intake even if it is new. With the new intake Wash it with hot soapy water inside and out try and get a stiff brush in the runners to make sure there is nothing inside it that could screw up you new motor. Sand has a nice way of sticking to new cast iron and your motor will not like to eat sand. Next put the aviation gasket sealent on the heads, around all the inake ports and coolant passages. Then put a nice bead of silicone on the block and bring it up the heads a little bit (just so there is some sealent under the intake gaskets in the corners. Place the gaskets on the heads being carful to line them up. Then put a little silicone on the top of the gaskets in the corners where the gaskets meet the block (where you just put the silicone) so now you have silicone under and above the gaskets. This will prevent oil seepage in the corners of the intake. Set the intake on the block and heads by going as straight down as you can. Start all the bolts and torque to spec starting from the inside out in a circle. Torque it in multiple steps. IE snug it up by hand first then torque it to 75% of the value then 100%. You will now have a leak free seal that will last the life of the motor.
 

jy118lfd

Chief Petty Officer
Joined
Jun 18, 2004
Messages
497
Re: 5.0 to 5.7 Rapido rebuilt engine swap

Refering to you changing the main bolts to the studs from the old motor. I personally do not like changing bolts to studs on the main bearings without checking clearences. Different torque values tend to change the "roundness" of the main bearing bores.

It has been done and problably will not effect your motor in any way but when I was building race motors a few years back we would align hone any block that was changed to studs from bolts. Some were way out and others were near perfect. I dont know if the windage tray is neccasary on a boat motor as it will not see more than 5000 rpm. You can call the motor builder and ask him his opinion. You may have a problem if you have a warranty claim and you changed the main bolts.
 

jy118lfd

Chief Petty Officer
Joined
Jun 18, 2004
Messages
497
Re: 5.0 to 5.7 Rapido rebuilt engine swap

One more thing I almost forgot and many a motor has met its demise cause of this.


Check your oil pan to pickup clearance!!!!!! You need a 1/4 inch of clearance or you may end up starving your motor for oil. I also would not put any pickup on a sbc without brazing it so it cannot come out. This requires disasembling the pump and having a compentant tech braze the pickup. You do not want to heat it more than you have to. I then would use some 220 grit sandpaper and a piece of glass and surface the inside of the pump, use a little soapy water and just lightly run the pump base over the paper set on the glass. You don't need any pressure. You just want to see even, fine scratches. Then clean and dry the pump. Lube it with some 30wt oil and reassemble it. It sounds harder than it is. Only about 5 minutes of work and it give you piece of mind.
 

sschefer

Rear Admiral
Joined
Nov 13, 2008
Messages
4,530
Re: 5.0 to 5.7 Rapido rebuilt engine swap

Just my 2 cents, but looking at your thermostat opening and your water ports I would scrap it. You're putting in a brand new engine, why risk it if it leaks. Those areas look pretty rough and you should be able to find that intake even used off a fresh water boat pretty cheap. Good luck, hope you have a better season this year.
Agree, probably a stress crack just below the port.

While your at it change the vibration damper, no point in finding out that the rubber is shot after the fact. Get one that's degreed or put a degree tape on it. Helps get the timing and advance exactly where you want it when you want it without a bunch of fancy equipment.
 

wil7483

Petty Officer 1st Class
Joined
Jan 19, 2007
Messages
377
Re: 5.0 to 5.7 Rapido rebuilt engine swap

Not a lot of work on the engine itself today. I spent what free time I had away from work cleaning up the water pump (although I already ordered a new one, can save this as a spare I guess) and the fuel pump. I installed new gaskets in the fuel pump and removed all the grime and built up gunk on/in it. Then I went ahead and installed it on the engine. I will wipe it down in lacquer thinner later to remove any oils and then repaint it black.

DSCF00075.jpg
 

wil7483

Petty Officer 1st Class
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Jan 19, 2007
Messages
377
Re: 5.0 to 5.7 Rapido rebuilt engine swap

............While your at it change the vibration damper, no point in finding out that the rubber is shot after the fact. Get one that's degreed or put a degree tape on it. Helps get the timing and advance exactly where you want it when you want it without a bunch of fancy equipment.

Help me out on this one.....what would be wrong with the harmonic balancer that was on the old engine?
 

wil7483

Petty Officer 1st Class
Joined
Jan 19, 2007
Messages
377
Re: 5.0 to 5.7 Rapido rebuilt engine swap

Ok, I did some reading and research and see what you meant about the "bad rubber". So in your honest opinion do you really think I need to change it out? I saw nothing that would make me suspect that it is bad. Anyway to test it?
 

Ridemywideglide

Petty Officer 2nd Class
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Jan 13, 2009
Messages
166
Re: 5.0 to 5.7 Rapido rebuilt engine swap

Marine water pumps use differant materials for the impeller and shaft seal than automotive. Marine are designed to handle salt water running through it, Autos are designed for antifreeze.

Well now I know... :D

I still haven't seen anything that would discourage me from running the old pump. Save the new one for 3-4 years down the road.
 

Ridemywideglide

Petty Officer 2nd Class
Joined
Jan 13, 2009
Messages
166
Re: 5.0 to 5.7 Rapido rebuilt engine swap

Ok, I did some reading and research and see what you meant about the "bad rubber". So in your honest opinion do you really think I need to change it out? I saw nothing that would make me suspect that it is bad. Anyway to test it?

If you see cracks or tears in the rubber, it's time to go. As long as it looks solid, then it's ok.
 

wil7483

Petty Officer 1st Class
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Jan 19, 2007
Messages
377
Re: 5.0 to 5.7 Rapido rebuilt engine swap

If you see cracks or tears in the rubber, it's time to go. As long as it looks solid, then it's ok.

Call me stupid but isn't this thing metal? Where do I look to see the tears or cracks?

DSCF0039.jpg
 

Ridemywideglide

Petty Officer 2nd Class
Joined
Jan 13, 2009
Messages
166
Re: 5.0 to 5.7 Rapido rebuilt engine swap

STUPID

:D

No man I'm just messin with ya...

The inner hub where the 3 bolts go, is mated to the outer via a rubber "ring" to allow it to cancel harmonic vibrations.
Looking at what you have, I can't see the usual rubber area that most car dampners have. Maybe looking at the back would show, but maybe not.
That looks a bit rusty to me... Can run it, will be ok for a while, but I'd order a replacement. Marine environment is much harder on rubber parts than auto.
What's the age of the motor your taking out?

on edit:

I've enjoyed following your progress.. I may be in your shoes someday, and asking all the same questions.. I hope not... But.....
 

nbrock

Recruit
Joined
Feb 22, 2009
Messages
4
Re: 5.0 to 5.7 Rapido rebuilt engine swap

Marine water pumps use differant materials for the impeller and shaft seal than automotive. Marine are designed to handle salt water running through it, Autos are designed for antifreeze.

What if you only run your boat in fresh water..wouldnt that be the same as what a vehicle runs?
 

Ridemywideglide

Petty Officer 2nd Class
Joined
Jan 13, 2009
Messages
166
Re: 5.0 to 5.7 Rapido rebuilt engine swap

What if you only run your boat in fresh water..wouldnt that be the same as what a vehicle runs?

No.. You run anti-freeze of some sort in your car. This not only provides freeze protection, but corrosion protection. Raw water boat pumps have to deal with "non-treated" water. Nothing in there to help stop corrosion.
The anti-freeze in your car also lubricates the pump bearing, helping it last longer.
 
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