Cylinder wall rust / replace block?
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=47770
Printed Date: October-06-2024 at 6:26am
Topic: Cylinder wall rust / replace block?
Posted By: SN85
Subject: Cylinder wall rust / replace block?
Date Posted: July-18-2019 at 10:41pm
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Well, back in 1986 I purchased a one-year old Ski Nautique from Southeast CorrectCraft. The boat had been loaned out to a church camp by the Meloon family and after a season of use offered for sale with a new trailer. Price was great and boat gave my family many years of use, about 16 or so, before I let it go into disrepair just sitting on its trailer covered by a tarp in all sorts of weather and humidity. The last year of use I noticed that the stringers were going bad as I was able to turn one of the lag bolts with little resistance. Fast forward to now, over 30 years since I bought the boat, the fiberglass hull / gelcoat is in great condition as is the interior (previously re-skinned and removed from boat and put into dry storage) but there are now soft spots on the deck (floor) of boat. The trailer is structural sound but all the sheet metal needs to be replaced. Trailer bearings are fine. Obviously, I'm going to have to replace the stringers, below-deck foam, decking and carpet. But I'm wondering about the motor. It's a PCM 351 (about 90% SN were done with Ford engines back then). I just removed all the spark plugs -- seven of the eight plugs looked fine but the eighth plug showed a lot of corrosion. I then inserted a cheapo borescope into each cylinder and found that cylinder walls looked very good, with only a bit of surface rust here and there, on seven cylinders but on the eighth cylinder there appears to be heavy rust. I'm going to pull the heads off the engine to see "in person" what I have, but I suspect that this one cylinder is too far gone and that a honing will not adequately restore it. Assuming I"m right about that eighth cylinder, what are my options? Can I obtain a refurbished short block and simply swap over everything else from my engine to the "new" block? Would this approach require new rings / main bearings / camshaft bearings? I have never re-built an engine but I do own an engine stand and have lots of tools. What other options should I consider if my original engine is not repairable or repairable at a reasonable cost? |
Replies:
Posted By: MrMcD
Date Posted: July-19-2019 at 12:16am
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I will offer this free advice, it does work but some will say it is advice from outerspace. First, fill the bad cylinder with Coca Cola, leave it for about 2 weeks. Coke can eat a nail if you drop one in the bottle. I was told it eats rust pretty quick. Next vacuum out the coke and fill that cylinder with a mix of 50/50 Tranny Fluid and Acetone. Std automatic tranny fluid/ATF mixed 50/50 with acetone has proven to be one of the top rust busters available at any price. Let this sit for a few days, longer is better. As long as you are using the ATF/Acetone mix you might as well fill the other cylinders also. It really does a pretty good job of loosening up rust on the cylinder wall and breaking loose those Cast Iron Piston Rings that will also be stuck to the cylinder walls. Next, you will need to pull the valve covers for this part, pour some of your 50/50 mix over each valve, the valves that were open while it sat will have the same rust issue. You can take a ball pen hammer and tap on the valve stems heads lightly, if they bounce up and down they are free, if they go down but not up you have one stuck. I freed up my 1966 327 that had been parked in a unheated garage in Michigan for 28 years. It took some work but I got it free and it now spins normally. I still plan to rebuild it but now I can tear it down much easier. Mine freed up even though it had some serious rust in one cylinder. The rust takes away some of your cylinder wall and it does not come back so I will have to bore this block to save it. If your block has minor rust it may clean up and run just fine, worth a try, even if one cylinder has a bad spot, one bad spot does not mean the engine is toast it might run just fine. I mixed up a quart of the 50/50 mix and keep it in an old Oil quart container, the plastic type with a good cap on it. I have used this same mix for about 5 years now, the cap keeps the acetone from evaporating. This is the go to mix for breaking loose stuck bolts. Of course replace the acetone mix with Oil once it breaks loose. Hope this helps. Mark ------------- |
Posted By: Gary S
Date Posted: July-19-2019 at 12:41am
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Are you going to replace the stringers? If you are I wouldn’t mess with it until they were done. If you want to use it with the questionable stringers by all means give Marks method a try, My Mustang was stuck when I got it,penetrating oil worked for me at the time. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: SN85
Date Posted: July-19-2019 at 1:19am
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[QUOTE=Gary S] Are you going to replace the stringers? If you are I wouldn’t mess with it until they were done. ./QUOTE] Yes, going to replace stringers, foam, deck, carpet, etc., Intent would be to have boat done by beginning of next summer. So would probably get engine done during this fall / winter. If time allows and I think I can get it done before winter, I may start boat work this fall but probably not until spring of 2020. What's the issue of doing engine before stringer job? Also, my intent is to keep boat on its trailer so that I can do messy work outside garage and move boat back into garage for installation of stringers and other "clean" work. (I've got two cars in garage that I will not expose to fiberglass dust.) Since trailer does not support boat by its keel as is I plan on adding supports to trailer to support boat by keel both fwd and aft. I should be able to fabricate necessary additional supports out of structural metal add-ons to trailer with wood pads bearing weight of keel. |
Posted By: Gary S
Date Posted: July-19-2019 at 10:29am
From a well known car restorer- Our rule is simple: Don’t rebuild the engine until it’s time to put it back in. We’ve seen too many engines rebuilt early in the restoration only to sit and degrade in a dusty corner of the shop. Not only that, but an engine rebuild sucks a lot of money out of the budget. If that money gets spent early, it sometimes means cost-cutting in important areas, like paint and body. You can always paint a used engine, put it back in, and pull it for a rebuild later. Try redoing the budget bodywork because you spent too much too early on your engine. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
SN85 wrote:Posted By: SN85
Date Posted: July-21-2019 at 6:10pm
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Ah, I see. Well, I'm going to try an assess everything (boat and engine) at same time. Money availability will not be an issue but while I'm OK spending more than what boat will be worth when I"m done but only up to a limit (I'm thinking that I'll be OK spending up to about $7k-$8k for boat and trailer repair and engine work / replacement, maybe a little more. Of course, I'm valuing my labor at zero for this project and I think I've got pretty much all the tools I need unless of course I get into buying engine rebuild-related tools (indicators, hones, etc). |
Posted By: KENO
Date Posted: July-21-2019 at 7:19pm
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Did you take the heads off yet to see what you're starting with. Once you know that, it ought to be a lot easier to decide what to do or to get recommendations. Can you turn it with the plugs out or heads off over or is it frozen |
Posted By: MrMcD
Date Posted: July-21-2019 at 9:31pm
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Now that you stated your budget have you looked into a replacement boat? There are 2001 model Nautiques for sale in great condition for $7-8,000 and you could use it this year. Sell yours and recover part of the cost. I like to rebuild things but sometimes replacment makes more sense. I understand if it is sentimental, I have a 66 Corvette that I am bringing back to life after it has sat since 1978. I could have followed my advice above and been money ahead but I enjoy the project. ------------- |
Posted By: SN85
Date Posted: July-21-2019 at 9:37pm
Not yet regarding the heads. Experiencing horrific heat out here right now. I am concerned that if rust is extensive in that one cylinder that putting a wrench to harmonic balancer bolt may cause more damage (also I wonder if valves stuck open whether I could put a piston into a valve?). I'm going to try and get the heads off in a week or so and then I'll be back with some photos/additional information. |
Posted By: MrMcD
Date Posted: July-21-2019 at 9:38pm
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Owner: Rob Rojas Forum Nickname: Location: Hillsboro, MO Phone: (314) 280-0955 Model: 1986 Ski Nautique 2001 Length: 19.5 Engine: Ford PCM 351 HP: 240 Hours: 150 Hull ID: 2001 Price: $8,500 Listed on this forum in boats for sale today, new stringers, engine and interior. As mentioned, this type overhaul costs more than the asking price. Reading the ad it sounds to me like this boat has lots more hours and the 150 hours listed are on the new engine? But it looks nice as is today. ------------- |
Posted By: SN85
Date Posted: July-21-2019 at 9:45pm
I'll keep an eye out on a Nautique but I think that I would only be interested in one after '93, after CC got the wood out? Flatter wake would also be a benefit. Need to do some basic research on this. There is sentimental value associated with this boat, so that is a factor, maybe a big factor. And since the hull itself and gelcoat are still in very good condition it seems like at least a somewhat worthy project. I may be wrong but I think that my wood working skills and substantial tool inventory will allow me to do stringers, foam and decking fairly quickly. I'll need to check into associated material costs for this work but without researching what it cost others, I'm guessing somewhere in the neighborhood of $1,5k or perhaps a bit more? Thanks for the advice. |
Posted By: KENO
Date Posted: July-21-2019 at 11:09pm
I think for the next week or till the heads are off, I'd have all 8 cylinders swimming in whatever your favorite rust busting solution is. It won't hurt anything and can only help |