5.0 to 5.7 Rapido rebuilt engine swap

[wil7483]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

Standard break in procedure is 2000 rpm for 20 minutes, change oil and filter. After 10 hours re-adjust valves at idle speed by tightening until the cylinder falters then backing off 1/4 turn. Change oil and filter, re-torque head bolts and you should be good to go. At 50 hours or end of season, (which ever comes first), change the oil and filter and run for 5 minutes at idle.

Hey thanks, I'm sure that I have ran it at least 20 minutes if not more so far. Not sure of the rpm however. Tomorrow I should be able to get an idea of the rpm once I start it while it is in the boat. Then I can change the oil. During the 10 hour time span, what rpm's should I or shouldn't I be running it at? I sent Raul an email with these questions but he hasn't gotten back to me yet. I'm about to buy a new hour meter now since it is a new motor. Thanks again for the advise.

 

[wil7483]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

Wowwwwww. I was sitting at my desk just now and out of nowhere I decided to just look at the forecast for tonight. It's supposed to get down to 25 tonight. I ran outside and opened all of the drains on the block and the manifolds and water just poured out. Then I loosened the hoses and more water gushed out. I am so glad I had the forsight to think about that before I woke up in the morning to a cracked block. Whew!!!!

 

[sschefer]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

Wowwwwww. I was sitting at my desk just now and out of nowhere I decided to just look at the forecast for tonight. It's supposed to get down to 25 tonight. I ran outside and opened all of the drains on the block and the manifolds and water just poured out. Then I loosened the hoses and more water gushed out. I am so glad I had the forsight to think about that before I woke up in the morning to a cracked block. Whew!!!!

Wow, that was close...!!!

For the first 10 hours you should not exceed 2500 RPM. This break in will let the bearings take a set and the rings seat. Essentially your just letting everything find a home so to speak. The first 10 hours is where most engines will spin a main or glaze a cylinder if they are over reved.

Your oil pressure gauge and your tach are your best friends right now. A good constant oil pressure is a sign of a healthy engine. On a 350 with a stock high volume pump you should see about 40-45 lbs of oil presure if the engine was built to stock tolerances. After the break in it should be between 38 and 42 lbs. When I watched the video, it stopped quick when you shut it down. That's a very good sign that the engine was built right.

 

[wil7483]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

Wow, that was close...!!!

For the first 10 hours you should not exceed 2500 RPM. This break in will let the bearings take a set and the rings seat. Essentially your just letting everything find a home so to speak. The first 10 hours is where most engines will spin a main or glaze a cylinder if they are over reved.

Your oil pressure gauge and your tach are your best friends right now. A good constant oil pressure is a sign of a healthy engine. On a 350 with a stock high volume pump you should see about 40-45 lbs of oil presure if the engine was built to stock tolerances. After the break in it should be between 38 and 42 lbs. When I watched the video, it stopped quick when you shut it down. That's a very good sign that the engine was built right.

OK, so I got the engine installed in the boat today and aligned. I connected the water supply and started it and it buzzed to life. The oil pressure was in line with what you posted above and it was idling around 950rpm. I think that was too high so I backed off the idle screw on the carb and got it down to about 750-800rpm but it idles rough to me at that speed. In any event, my temperature sending switch is not working so I guess it does matter if it is auto or something. I wish I hadn't thrown the old one away now. The manifolds or the risers never got hot to the touch so I don't think it ever was in trouble of overheating but none-the-less I erred on the side of caution and only ran the engine about 7 minutes once I noticed the temp gauge was not moving up. Does anyone know the part number for the temp sender?

This is the boat reved up to about 2000rpm for a few seconds prior to me noticing that the temperature gauge was broke.

This is a picture of the boat idling normally before I adjusted it down to about 750 - 850rpm.

 

[krisnowicki]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

are you going to run a 1.5 or 1.62 drive and what size prop??

 

[wil7483]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

are you going to run a 1.5 or 1.62 drive and what size prop??

I have a 1.5 that came off of it with a 17p prop. When I get the SEI drive I will get whichever ratio that they recommend for this motor. Most likely still going to be a 1.5 for the V8 engine. This is a 23' 3900lb boat when it's empty with no fuel or people. It has a 90 gallon fuel tank which once is full will add considerable more weight plus my 260 lbs to boot and equipment. I will have to experiment with props and trim settings until I find that sweet spot I guess.

 

[Ridemywideglide]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

I don't know where yours normally ran before, but mine will not move off cold when on the hose. On the lake, it'll go higher, but the hose is colder I guess.. Maybe the lack of rpm's....

Also. 9.5k would be ruining you day...

950rpm, or the 800rpm is much better...

 

[betayv]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

hi there looking very good here is the part # for the temp sender depend of the size that you need this are sierra part # but you can find them on any auto parts store just be sure the temp range is right and is a single wire sender here is 3/8 -18 npt (18-5897 ) 1/2 -14 npt ( 18-5898)

http://ww2.sierramarine.com/sierra/...itle=Temperature Senders&item=18-5898&check1=


http://ww2.sierramarine.com/sierra/...itle=Temperature Senders&item=18-5897&check1=

 

[sschefer]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

750-800 is about right. I'll bet you've got all those plug wires nice and stragiht huh.... Problem is that 5 and 7 fire in close succession so you need to cross the 5 plug wire over the 7 plug wire to stop the induction that will occur with HEI ignition. The induction from 5 firing will cause 7 to fire and burn off the fuel that is just starting to get compressed.

That should cure some of the low speed roughness. The next step is to put a vaccum gauge on it and tweak the carb for max vaccum at idle then back them off 1/4 turn to the rich side.

As for temp, don't worry, the gauge isn't broken, the engine temp is whatever the water temp is comming out of the hose. It will warm a little but not much. I've actually put a gate valve in some boats to restrict the water flow so the engine will warm up. Try turning down the water flow and that should bring the temp up.

 

[wil7483]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

Oh wow, thanks everyone. I will put the drive on tomorrow I guess. The old engine would get up to the 150 - 170 degree range pretty quickly so I just figured the sender is wrong for this engine. Then again the previous engine was broken now wasn't it. I will definitely try to work on getting the roughness out of the idle though.

 

[dan t.]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

well I must disagree on the plug wire bit ,crosseng # 5 and # 7 wires over or under each other is just asking for trouble, keep them separated with wire spreaders. I had a stock car engine detonate so bad it cracked #5 cylnder wall, the cause? #5 and #7 wires crossed over each other. any high performance book will tell you this

 

[Ridemywideglide]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

well I must disagree on the plug wire bit ,crosseng # 5 and # 7 wires over or under each other is just asking for trouble, keep them separated with wire spreaders. I had a stock car engine detonate so bad it cracked #5 cylnder wall, the cause? #5 and #7 wires crossed over each other. any high performance book will tell you this

Your incorrect.. Crossing any 2 wires at 90* angles will stop induction from 1 to the other. Leaving them side by side will cause induction, making, as stated, #5 fire when the parallel #7 fires.
Your engine popped because you had them laying next to each other, if that caused at all..

 

[dan t.]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

hey if you dont believe me look it up, Power Secrets by Smokey Yunik. The Chevrolet Racing Engine by Grumpy Bill Jenkins, How to Hot rod Small Block Chevs by Bill Fisher,Small Block Chev Marine Performance by Dennis Moore, and 1/2 a dozen others if I cared to type them out. these guys know what they are talking about and they all say, DONT CROSS #5 and #7

 

[wil7483]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

Today I vacuumed all the leaves and debris from the boat and gave her a really good bath in and out. I then ran to West Marine and picked up a new gasket set so I could put the sterndrive back on. I ran her on muffs for about 20 minutes to be sure the impeller was still ok and then I changed the lube in the drive. Now that she is really clean I plan on taking her to the dirty lake tomorrow and testing out the new setup and put the old girl through the paces. I will post some pics and videos online when I get back.

 

[FreeBeeTony]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

Hope all is going well.............looking forward to your report/videos!!!

 

[QC]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

Yeah, you should be back by now. We want info and hopefully . . . data!

 

[wil7483]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

Well my maiden voyage with the new engine was good and bad. First the good I guess. I can definitely feel the power of the new engine. Got on plane easily and speed on dash and gps was consistent at about 31 mph at 2400 rpm. I tried not to go over 2500 rpm while out there but every once in awhile it would peak over until I got the trim set at that sweet spot. I rode around for about 2 hours and really enjoyed the boat for the 1st time.

The bad things is I still have an oil leak at that same valve cover so tomorrow when I come back from the range in the morning I will definitely take that manifold aloose and put another gasket on there. I thought I was leaking fluids from the outdrive because I noticed a slick on the water but I soon realized it was oil coming from the bilge pump being flushed overboard so I cut the pumps off to keep from contaminating the water (yes I'm a tree hugger in a sense). Second, I have a loud lifter noise coming from that same side of the engine so while I have the cover off tomorrow I will try to tighten that up as well. Thirdly, I need to either adjust the lower shift cable or replace it. I was having a hard time shifting from neutral to reverse and then back to neutral so docking was a really fun experiance. It is sticking and takes a really stiff jerk of the control handle to get it to seat itself sort of speak. Lastly, like I said earlier in the post I can just tell that the outdrive is not as strong as it should be. I can't explain it but it just was something about the ride that still makes me want to go ahead and order the new SEI drive.

I asked my daughter to take pictures of the boat riding around but due to operator error she wasn't able to get the camera to work.

 

[FreeBeeTony]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

Not bad for the 1st run.........

31MPH @ 2400RPM................is that right?

 

[krisnowicki]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

Not bad for the 1st run.........

31MPH @ 2400RPM................is that right?

at 1.5 ratio
at 21p that is 2% slip
and
at 23 that is 11%

what size and kind of prop are you running?

 

[lmannyr]

Re: 5.0 to 5.7 Rapido rebuilt engine swap

...Thirdly, I need to either adjust the lower shift cable or replace it. I was having a hard time shifting from neutral to reverse and then back to neutral so docking was a really fun experiance. It is sticking and takes a really stiff jerk of the control handle to get it to seat itself sort of speak. Lastly, like I said earlier in the post I can just tell that the outdrive is not as strong as it should be. I can't explain it but it just was something about the ride that still makes me want to go ahead and order the new SEI drive.

Make sure your shift interrupt system is working properly.