Many people seem to have some very strong opinions about the Atomic 4 engine. At the risk of sending the board up in flames I am going to fish for opinions.
As I shop for an older sailboat I find that many of these boats still have Atomic 4's installed. Is this a bad thing? Certainly diesel is better. It is also considerably more expensive, particularly if one contemplates removing a functioning A4 in favor of diesel. Many would highlight the safety concerns of gasoline on board but I often find these same individuals installing propane which to my knowledge has destroyed more cruising sailboats and caused more injuries/deaths then gasoline ever did. Using similar efforts applied to propane installations could gasoline be considered "safe enough?"
I recently bought an Atomic 4 overhaul manual and was impressed with the overall simplicity and apparent ease of maintenance. From an economics standpoint, sticking with whatever engines are installed seems the way to go.
I welcome all opinions...
-Britton
Atomic 4 - What do you REALLY think...
-
Tim
- Shipwright Extraordinaire
- Posts: 5708
- Joined: Tue Apr 01, 2003 6:39 pm
- Boat Name: Glissando
- Boat Type: Pearson Triton
- Location: Whitefield, ME
- Contact:
No! Not necessarily. Remember, however, that these engines are typically 30-40 years old, and therefore may have significant maintenance-related issues to deal with before reliable operation can be expected. Many times the electrical ignition system and carburetor can cause inconsistent operation and, sometimes, engine failure, perhaps at an inconvenient time.As I shop for an older sailboat I find that many of these boats still have Atomic 4's installed. Is this a bad thing?
I think any older engine most likely deserves some significant maintenance and upgrading to ensure reliability. Expecting an old engine (and, more importantly, and old, stale fuel system) to run perfectly with no upgrades or maintenance is asking a lot. With what often amounts to minor work, A4s run very nicely--particularly once one gets the hang of their quirks. Clean fuel is king--both for A4s and, especially, diesel.
They are quiet and smooth. In Tritons, however, beware that the jacketed exhaust is much noisier than more modern waterlift exhaust systems. The engine itself is quieter than a new diesel.
There have been plenty of explosions caused by gasoline problems on boats, but in nearly all cases they are the result of neglectful behavior, lack of maintenance, improper fueling techniques, or related issues. They also tend to be powerboats, and often boats of the type that might be purchased by "boaters" who might be, well, less inclined to actually know what they are doing. Gasoline boats don't simply blow up for no reason. I feel this is (pardon the pun) the most overblown argument there is in the old gas vs. diesel wars.Many would highlight the safety concerns of gasoline on board...Using similar efforts applied to propane installations could gasoline be considered "safe enough?"
Now, gasoline fuel systems are no place to skimp, and most likely, the fuel tank, lines, and other components in an older boat (like a Triton) are probably showing their age, or are of less ideal materials, and may need a thorough overhaul. A gasoline system is not the place to say, "well, that hose is looking sort of old, but it'll be OK". This is the sort of maintenance attitude that leads to problems with gas installations--and lots of other systems as well.
Maintenance cannot be ignored, much as many would like to think it can. The entire gasoline system should be frequently inspected to ensure that all hoses, clamps, and other connections are tight and in good order. Some basic prudence during refueling and general operation is required--but this is hardly an issue. Boats are not like other material objects, where lack of maintenance and proper procedure can be overlooked. Boats, and the marine environment, are historically unforgiving of neglect of this nature, so simply pay attention to the details, be conservative in your maintenance schedules, and there should be no problem.
Removing an A4 in good running condition in favor of diesel probably makes little sense in these old boats. That said, repowering with diesel makes sense in plenty of situations, but each is too individual to truly comment on. But in general, there's no need to replace the Atomic Four "just because".
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Forum Founder--No Longer Participating
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bcooke
- Master of the Arcane
- Posts: 2272
- Joined: Sat Oct 04, 2003 10:55 pm
- Boat Name: Jenny
- Boat Type: 1966 Pearson Triton
- Location: Rowley, MA
- Contact:
I posed the question because it seems most people upgrading their boats go the diesel route. I agree that a 30 to 40 year old engine is not to be trusted. I would go a step further -as a mechanic by trade- and say that a five year old motor without good maintenance can bite you. Come to think of it, all motors can and sometimes do fail ... but I digress
Looking at pricing it seems as though replacing an older A4 for a rebuilt motor would naturally be the way to go. I find professionaly rebuilt motors can be had for 4-5K (Do it yourself 2-3K?) and that is without the hassle of creating new engine beds and such. If one were looking to make the best possible boat (a.k.a. Glissando) then certainly diesel is the only way to go. If, however, economics were a strong dictating factor then I can see no reason not to stick with gasoline... but I am still learning. Money saved by keeping the A4 could be used to better purpose elsewhere. I suppose you are right; every situation is unique.
About the noisy exhaust. I thought the Atomic 4 could be fitted with a water lift kit. Is the Triton limited to a jacketed exhaust by design? The exhaust could be one of those "unique situations" you mentioned. I don't care much for engine noises on sailboats. I sail for the sound of wind in the sails and use the motor mostly to cover my lack of sailing skill and those times when there is no more time to idle away and even less wind. If I really had the time I would be tempted to take the route of Jeff Baldwin and go engineless. Think of all that space that could be put to better use.
Now that I think of it, didn't Jeff install an outboard on his Triton? I would have a hard time doing that to a beautiful Triton transom. I guess function can be its own form of beauty.
Thanks Tim, maybe I will bump into you sometime soon ;-)
-Britton
Looking at pricing it seems as though replacing an older A4 for a rebuilt motor would naturally be the way to go. I find professionaly rebuilt motors can be had for 4-5K (Do it yourself 2-3K?) and that is without the hassle of creating new engine beds and such. If one were looking to make the best possible boat (a.k.a. Glissando) then certainly diesel is the only way to go. If, however, economics were a strong dictating factor then I can see no reason not to stick with gasoline... but I am still learning. Money saved by keeping the A4 could be used to better purpose elsewhere. I suppose you are right; every situation is unique.
About the noisy exhaust. I thought the Atomic 4 could be fitted with a water lift kit. Is the Triton limited to a jacketed exhaust by design? The exhaust could be one of those "unique situations" you mentioned. I don't care much for engine noises on sailboats. I sail for the sound of wind in the sails and use the motor mostly to cover my lack of sailing skill and those times when there is no more time to idle away and even less wind. If I really had the time I would be tempted to take the route of Jeff Baldwin and go engineless. Think of all that space that could be put to better use.
Now that I think of it, didn't Jeff install an outboard on his Triton? I would have a hard time doing that to a beautiful Triton transom. I guess function can be its own form of beauty.
Thanks Tim, maybe I will bump into you sometime soon ;-)
-Britton
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dasein668
- Boateg
- Posts: 1637
- Joined: Thu Apr 03, 2003 9:09 am
- Boat Name: Dasein
- Boat Type: Pearson Triton 668
- Location: Portland, Maine
- Contact:
Personally, I would have a hard time shelling out 4-5K for a rebuild?even a "professional" one?unless that rebuild came with an iron-clad warranty/guarantee. By the time you reach 5K, you are getting awfully close to the cost of a new small diesel.
That's not to say that the diesel is better than gas, but that I would feel much more comfortable spending 7K on a brand new engine than 5K on a rebuild...
My personal opinion, of course!
Cheers
That's not to say that the diesel is better than gas, but that I would feel much more comfortable spending 7K on a brand new engine than 5K on a rebuild...
My personal opinion, of course!
Cheers
Nathan
dasein668.com
dasein668.com
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Dave, 397
On the outboard...
I used to have a Ranger 23, and it had the coolest outboard bracket, made to help facilitate quick removal and stowing of the motor so as not to mess up the sailing performance with the motor's weight hanging out there. Simple, too.
Basically you had a stainless pipe welded to a plate to which a plywood pad was bolted. This is the motor end of things, and the motor clamps right onto it like any other mount. As a quick aside, it's a nice plan to add gussets between the plate and pipe if you want to be sure and keep your motor.
The other end of things was basically a SS pipe flange that the pipe slid into/thru the transom. On the R23 the transom was awfully thin so there was a second flange mounted inside the cockpit. The pipe slid thru both of these and secured to the inner one with a bolt or a PTO-type lockpin. Very simple, very clean.
The Triton transom is pretty heavy, and would likely carry it no problem (assuming a fairly small motor...BTW, a British Seagull will push a 10,000 pound sailboat just fine!), but I would probably be moved to glass in a plate of 1/4" bendy-ply to reinforce for good measure. The outer flange would need to be set on a wood adaptor so that the pipe could come out parallel to the WL, and a matching part might be best fitted inside to back up an inner flange just for ease of aligning/mounting. The whole thing could be removed easily and the stern lightened as a result, outboard could stow on chocks in a cockpit locker.
Watertight integrity could also be maintained simply enough by 'glassing over or welding a cap to the end of the inner flange. The resultant little flange visible on the transom...would just lead people to think you had a Sailomat or similar type 1-point-mounting vane gear.
Best,
Dave
I used to have a Ranger 23, and it had the coolest outboard bracket, made to help facilitate quick removal and stowing of the motor so as not to mess up the sailing performance with the motor's weight hanging out there. Simple, too.
Basically you had a stainless pipe welded to a plate to which a plywood pad was bolted. This is the motor end of things, and the motor clamps right onto it like any other mount. As a quick aside, it's a nice plan to add gussets between the plate and pipe if you want to be sure and keep your motor.
The other end of things was basically a SS pipe flange that the pipe slid into/thru the transom. On the R23 the transom was awfully thin so there was a second flange mounted inside the cockpit. The pipe slid thru both of these and secured to the inner one with a bolt or a PTO-type lockpin. Very simple, very clean.
The Triton transom is pretty heavy, and would likely carry it no problem (assuming a fairly small motor...BTW, a British Seagull will push a 10,000 pound sailboat just fine!), but I would probably be moved to glass in a plate of 1/4" bendy-ply to reinforce for good measure. The outer flange would need to be set on a wood adaptor so that the pipe could come out parallel to the WL, and a matching part might be best fitted inside to back up an inner flange just for ease of aligning/mounting. The whole thing could be removed easily and the stern lightened as a result, outboard could stow on chocks in a cockpit locker.
Watertight integrity could also be maintained simply enough by 'glassing over or welding a cap to the end of the inner flange. The resultant little flange visible on the transom...would just lead people to think you had a Sailomat or similar type 1-point-mounting vane gear.
Best,
Dave
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Kaynee30boot
A4
Britton:
If you're a mechanic, you already own the tools to rebuild...which cost me about $500. Rings, bearings and stuff run about $500. Figure another $500 for replacement of major parts, and some costs associated with possible sleeving and magnafluxing parts, and yer talking a "new " engine for about $1500 bucks.
My A4 cost me $2500 to completely rebuild. That includes the new block ($500) and the tools ($500) and a new exhaust manifold (and assorted electrical parts)
I have the straight pipe exhaust. It's loud, but you can't flood the engine dry-cranking. Waterlift exhaust would have you running whisper-quiet, though.
Add to that reuse of the old mounts, and it was a real time/money saver. Moyer's Manual got me, a near total novice, through the entire process...and the engine runs pretty good: ask Timster.
Jeff
If you're a mechanic, you already own the tools to rebuild...which cost me about $500. Rings, bearings and stuff run about $500. Figure another $500 for replacement of major parts, and some costs associated with possible sleeving and magnafluxing parts, and yer talking a "new " engine for about $1500 bucks.
My A4 cost me $2500 to completely rebuild. That includes the new block ($500) and the tools ($500) and a new exhaust manifold (and assorted electrical parts)
I have the straight pipe exhaust. It's loud, but you can't flood the engine dry-cranking. Waterlift exhaust would have you running whisper-quiet, though.
Add to that reuse of the old mounts, and it was a real time/money saver. Moyer's Manual got me, a near total novice, through the entire process...and the engine runs pretty good: ask Timster.
Jeff
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Tim
- Shipwright Extraordinaire
- Posts: 5708
- Joined: Tue Apr 01, 2003 6:39 pm
- Boat Name: Glissando
- Boat Type: Pearson Triton
- Location: Whitefield, ME
- Contact:
Yes...an A4 installation in a Triton can be fitted with a waterlift exhaust, if desired. A4s truly are whisper quiet when equipped this way. Getting the old copper exhaust out is quite a trick, even with the boat completely dismantled inside. It can be cut into pieces, much to the chagrin of Triton aficinados. I would try to save it whole, but it's a challenge!
An engine in good running condition should never need to be cranked so much as to flood a waterlift or the cylinder head. Any engine type that is properly maintained, free of problems, and connected to a strong battery should start immediately. And besides, avoidance of that problem, as it were, is as simple as closing the intake seacock if excessive cranking seems to occur. The impeller can survive this fine, as long as you immediately open the seacock thereafter. Or choose a blue nitrile impeller, which for most sizes are barely more expensive, if at all, and can run up to 15 minutes with no water without damage to the impeller.
There's no question that diesels are noisier. It's the nature of the beast. Good sound insulation is an easy fix. There's a difference between mechanical sounds and dry exhaust notes, though.
Personally, I like the deep rumble/rattle of a diesel, though, so whatever sound they make doesn't bother me. I'd rather be sailing, but when the engine's on, so be it. I now have a diesel pickup too, and have come to really enjoy the sound.
When economics are a factor in the engine decision, I think it only makes sense to plan on using your own labor and skills, and doing the work yourself. It's a great learning experience anyway, and you will cut the cost of a rebuild dramatically. While spending 1-2K on parts to do the work yourself (and at the same time learn your engine intimately, which will serve you very well going forward), I agree with Nathan in that spending 4-5K for a rebuilt A4 is cause for some serious thought versus going new diesel. There are advantages either way--again, depending on each individual situation. One size does not fit all.
Jeff's rebuilt A4 in Kaynee ran beautifully last summer, though it took a fair bit of minor adjusting and fiddling here and there, partly because the whole thing was new, both to the boat and to Jeff as the skipper. The exhaust sounded like something out of Jesse James' shop, but when three of us were in the cockpit and the outlet was submerged, it was quiet.
[aside]Jeff: you in the water yet? If not, when?[/aside]
Tim's engine mantra: it would be nice to have none at all, but given the practical need for one for most people, it only makes sense to have one that is 100% reliable. If you can't count on it (insofar as you should ever truly count on an engine in a sailboat--which you shouldn't), then there's no worth in having it. That's the mantra that led me to the new diesel.
Of course, by the time you read this I expect I will have already told you this in person, so...
An engine in good running condition should never need to be cranked so much as to flood a waterlift or the cylinder head. Any engine type that is properly maintained, free of problems, and connected to a strong battery should start immediately. And besides, avoidance of that problem, as it were, is as simple as closing the intake seacock if excessive cranking seems to occur. The impeller can survive this fine, as long as you immediately open the seacock thereafter. Or choose a blue nitrile impeller, which for most sizes are barely more expensive, if at all, and can run up to 15 minutes with no water without damage to the impeller.
There's no question that diesels are noisier. It's the nature of the beast. Good sound insulation is an easy fix. There's a difference between mechanical sounds and dry exhaust notes, though.
Personally, I like the deep rumble/rattle of a diesel, though, so whatever sound they make doesn't bother me. I'd rather be sailing, but when the engine's on, so be it. I now have a diesel pickup too, and have come to really enjoy the sound.
When economics are a factor in the engine decision, I think it only makes sense to plan on using your own labor and skills, and doing the work yourself. It's a great learning experience anyway, and you will cut the cost of a rebuild dramatically. While spending 1-2K on parts to do the work yourself (and at the same time learn your engine intimately, which will serve you very well going forward), I agree with Nathan in that spending 4-5K for a rebuilt A4 is cause for some serious thought versus going new diesel. There are advantages either way--again, depending on each individual situation. One size does not fit all.
Jeff's rebuilt A4 in Kaynee ran beautifully last summer, though it took a fair bit of minor adjusting and fiddling here and there, partly because the whole thing was new, both to the boat and to Jeff as the skipper. The exhaust sounded like something out of Jesse James' shop, but when three of us were in the cockpit and the outlet was submerged, it was quiet.
[aside]Jeff: you in the water yet? If not, when?[/aside]
Tim's engine mantra: it would be nice to have none at all, but given the practical need for one for most people, it only makes sense to have one that is 100% reliable. If you can't count on it (insofar as you should ever truly count on an engine in a sailboat--which you shouldn't), then there's no worth in having it. That's the mantra that led me to the new diesel.
Of course, by the time you read this I expect I will have already told you this in person, so...
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Forum Founder--No Longer Participating
Forum Founder--No Longer Participating
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Figment
- Damned Because It's All Connected
- Posts: 2847
- Joined: Tue Apr 08, 2003 9:32 am
- Boat Name: Triton
- Boat Type: Grand Banks 42
- Location: L.I. Sound
In addition to agreeing with just about everything written above, I'll add....
If you're a mechanic, then I would think that the A4 would be the clear winner for you. Most mechanically-inclined folks (to say nothing of actual mechanics) find the A4 to be refreshingly simple to maintain/tune/operate, and I think that a person with a mechanic's ear and eye will experience far greater reliability than the average sailor might.
I'm developing the opinion that most A4 reliability problems are quite easily preventable, and that they really only rear their heads when the operator doesn't know which "warning signs" to look/listen for, or when they're simply ignored until they become "actual problems".
From my position as an owner of an A4 with spotty maintenance records, and which hadn't been run in at least 5 years prior to my arrival, I can say that all I've done to it is to replace all "tune-up" ignition components and rebuild the carburator. This is an early-model (1959) motor with none of the freshwater cooling or electronic ignition upgrades that now seem to be standard fare. I had some compression issues at first, but the more I run the motor the better it runs. I've had my head down in the hatch a bit more than I'd like lately, but that is entirely due to my stubborn refusal to retire the original generator for a modern alternator. Mechanically, she's a rock. Starts immediately, runs smooth and strong, and is at least 200% more motor than the Triton needs.
As far as the economics go.... yeah, diesels are better, no doubt, but are they so much better to be worth the additional several thousand dollars? I think that this depends on your application, and on how much money you have to throw around at the moment.
If you have longrange cruising aspirations for the boat, then the greater efficiency and longevity of the diesel may tip the scales. I can also see the benefit of having diesel on board for cooking and heating fuel. For the lifestyle of most recreational boats, however, I remain convinced that the engine simply doesn't get enough use for the efficiency and longevity benefits to bear fruit.
Oh, other economic issue.... I forget which publication I saw this in recently, but someone surveyed a few mechanics and brokers and concluded that, though resale price does increase with a diesel, the typical increase is not enough to recover the cost of conversion.
Yeah, there are very real safety concerns with gasoline on board, but I've never felt that the precautions required are an undue burden to the prudent mariner.
I have a used 2cyl. yanmar sitting on a pallet in my dad's barn in case I ever change my mind, but I don't see that happening anytime soon.
If you're a mechanic, then I would think that the A4 would be the clear winner for you. Most mechanically-inclined folks (to say nothing of actual mechanics) find the A4 to be refreshingly simple to maintain/tune/operate, and I think that a person with a mechanic's ear and eye will experience far greater reliability than the average sailor might.
I'm developing the opinion that most A4 reliability problems are quite easily preventable, and that they really only rear their heads when the operator doesn't know which "warning signs" to look/listen for, or when they're simply ignored until they become "actual problems".
From my position as an owner of an A4 with spotty maintenance records, and which hadn't been run in at least 5 years prior to my arrival, I can say that all I've done to it is to replace all "tune-up" ignition components and rebuild the carburator. This is an early-model (1959) motor with none of the freshwater cooling or electronic ignition upgrades that now seem to be standard fare. I had some compression issues at first, but the more I run the motor the better it runs. I've had my head down in the hatch a bit more than I'd like lately, but that is entirely due to my stubborn refusal to retire the original generator for a modern alternator. Mechanically, she's a rock. Starts immediately, runs smooth and strong, and is at least 200% more motor than the Triton needs.
As far as the economics go.... yeah, diesels are better, no doubt, but are they so much better to be worth the additional several thousand dollars? I think that this depends on your application, and on how much money you have to throw around at the moment.
If you have longrange cruising aspirations for the boat, then the greater efficiency and longevity of the diesel may tip the scales. I can also see the benefit of having diesel on board for cooking and heating fuel. For the lifestyle of most recreational boats, however, I remain convinced that the engine simply doesn't get enough use for the efficiency and longevity benefits to bear fruit.
Oh, other economic issue.... I forget which publication I saw this in recently, but someone surveyed a few mechanics and brokers and concluded that, though resale price does increase with a diesel, the typical increase is not enough to recover the cost of conversion.
Yeah, there are very real safety concerns with gasoline on board, but I've never felt that the precautions required are an undue burden to the prudent mariner.
I have a used 2cyl. yanmar sitting on a pallet in my dad's barn in case I ever change my mind, but I don't see that happening anytime soon.
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BadjerJim
My A4 Rebuild Experience
I'll share my A4 story:
When I got my Cal 2-29 last summer, the A4 engine was missing entirely. Previous owner had run short of funds, thrown an outboard on the back and then skipped town (it's a long story...). Like you, I investigated repowering with a diesel engine... but thanks to this atomic-4 list on sailnet.com, I was talked out of it. I went looking for a used A4 engine.
I found one advertised in a local boat mag for $500. A complete A4, but set up for V-drive (I needed the other setup: direct drive to the prop). The owner of the engine said it was pulled out running, from an owner who decided to repower with diesel (sound familiar?). However, two of the cylinders measured "zero" compression. A "mechanic" had told the owner that he was sure it was from burned valves.
I got this engine back to my shop, and tore it down using the Moyer manual. Now this engine had virtually no rust, and visually was as close to "new" as I've ever seen - even though it was 30 years old! Even the decal showing the model and serial number looked like it had just been applied.
After removing the head, there was no carbon on the pistons or combustion chambers. Yet, on turning the engine over by hand, two of the intake valves were stuck fast.
So I pulled the valves to find a hard "carmelized glop" on all of the valve stems. I took the valves to a buddy with a cylinder head shop, and had them bead-blasted for analysis. His comments? "Jim, these valves are close to perfect. I wouldn't grind them... I'd just put them back in!" He went on to say: "The only time I've seen this on a marine engine was caused by bad gas. If the boat sat a couple years and he tried to start and run it with the old gas... this is what you get. Especially if he tried to add some Marvel Mystery Oil to the bad gas."
To satisfy myself, I did the valve-grinding-compound-spin job on each valve, and found that they all sealed perfectly. Fit of valves stems to guides was as new.
Next, I poured a cap-full of Marvel Mystery Oil onto each of the piston tops, and slowly rotated the engine. It took 24-hours for the oil to leak past the rings. I repeated this three times to soak the rings with the oil.
There was no rust, or salt deposits in the head or the block. This engine may never have seen salt water.
Finally, with the help of this list, I found a local A4 owner who had an old, used, rotted-out A-4 block -- but it had a good direct-drive reversing gear and output flange. He kept all the other parts, but sold me the block for $100. So I swapped this old reversing gear assembly into my newish A4, and installed a new output seal. It wasn't easy... the bolts holding on the reversing gear cover were rusted into a solid mass, and it took an angle-grinder to cut all the bolts off. (Hey! When working on rotted metal that you don't have to re-use, angle-grinders are FUN!)
Put the whole thing back together, and tested the compression: 100psi on all cylinders (+- 2psi). Right on!
The engine's now back in the boat, and runs smooth and quiet. To date, I've got 37 hours on it (per hour meter) with zero problems. With maintenance, I look forward to 20 years of service out of this engine.
Here's a cost breakdown (and you're aware that I did the work myself):
$500 - Used A4
$100 - Rotted block with good reversing gear
$100 - The two Moyer manuals
$150 - Gaskets, seals, and misc from Moyer
$35 - Napa electric fuel pump
$50 - Plugs and wires from Napa
$630 - Indigo Fresh Water Cooling, with thermostat kit
$70 - Pertronix electronic ignition
$75 - Exhaust plumbing and misc stainless screws (hardware store)
---------
$1,710 total
Without the fresh water kit or the electronic ignition, the total cost would have been right at $1,000. (Well, a notch more, if you accurately tracked the cost of beer.)
It doesn't really qualify as a "rebuild" - because all of the hard parts were in perfect shape. But I suspect there are hundreds of used A4 engines sitting around in this condition. Suspected "burned valves" that really only need to be cleaned.
As long as I had no engine in the cave, I replaced the rotted-out gas tank with a new Tempo 18-gallon tank. Was even able to hook it up to the original gas-filler in the cockpit sole. With gas gauge and sender, this was about $200... but it forever solved worries about the fuel system.
So I'm here to tell you: an A4 rebuild/refurbish/repower can be done very inexpensively. Don't give up on the Atomic 4! And from the other messages in this thread, I'm not the only one with a story like this!
Jim Wolcott
Gibson Girl - Cal 2-29
La Conner, WA
When I got my Cal 2-29 last summer, the A4 engine was missing entirely. Previous owner had run short of funds, thrown an outboard on the back and then skipped town (it's a long story...). Like you, I investigated repowering with a diesel engine... but thanks to this atomic-4 list on sailnet.com, I was talked out of it. I went looking for a used A4 engine.
I found one advertised in a local boat mag for $500. A complete A4, but set up for V-drive (I needed the other setup: direct drive to the prop). The owner of the engine said it was pulled out running, from an owner who decided to repower with diesel (sound familiar?). However, two of the cylinders measured "zero" compression. A "mechanic" had told the owner that he was sure it was from burned valves.
I got this engine back to my shop, and tore it down using the Moyer manual. Now this engine had virtually no rust, and visually was as close to "new" as I've ever seen - even though it was 30 years old! Even the decal showing the model and serial number looked like it had just been applied.
After removing the head, there was no carbon on the pistons or combustion chambers. Yet, on turning the engine over by hand, two of the intake valves were stuck fast.
So I pulled the valves to find a hard "carmelized glop" on all of the valve stems. I took the valves to a buddy with a cylinder head shop, and had them bead-blasted for analysis. His comments? "Jim, these valves are close to perfect. I wouldn't grind them... I'd just put them back in!" He went on to say: "The only time I've seen this on a marine engine was caused by bad gas. If the boat sat a couple years and he tried to start and run it with the old gas... this is what you get. Especially if he tried to add some Marvel Mystery Oil to the bad gas."
To satisfy myself, I did the valve-grinding-compound-spin job on each valve, and found that they all sealed perfectly. Fit of valves stems to guides was as new.
Next, I poured a cap-full of Marvel Mystery Oil onto each of the piston tops, and slowly rotated the engine. It took 24-hours for the oil to leak past the rings. I repeated this three times to soak the rings with the oil.
There was no rust, or salt deposits in the head or the block. This engine may never have seen salt water.
Finally, with the help of this list, I found a local A4 owner who had an old, used, rotted-out A-4 block -- but it had a good direct-drive reversing gear and output flange. He kept all the other parts, but sold me the block for $100. So I swapped this old reversing gear assembly into my newish A4, and installed a new output seal. It wasn't easy... the bolts holding on the reversing gear cover were rusted into a solid mass, and it took an angle-grinder to cut all the bolts off. (Hey! When working on rotted metal that you don't have to re-use, angle-grinders are FUN!)
Put the whole thing back together, and tested the compression: 100psi on all cylinders (+- 2psi). Right on!
The engine's now back in the boat, and runs smooth and quiet. To date, I've got 37 hours on it (per hour meter) with zero problems. With maintenance, I look forward to 20 years of service out of this engine.
Here's a cost breakdown (and you're aware that I did the work myself):
$500 - Used A4
$100 - Rotted block with good reversing gear
$100 - The two Moyer manuals
$150 - Gaskets, seals, and misc from Moyer
$35 - Napa electric fuel pump
$50 - Plugs and wires from Napa
$630 - Indigo Fresh Water Cooling, with thermostat kit
$70 - Pertronix electronic ignition
$75 - Exhaust plumbing and misc stainless screws (hardware store)
---------
$1,710 total
Without the fresh water kit or the electronic ignition, the total cost would have been right at $1,000. (Well, a notch more, if you accurately tracked the cost of beer.)
It doesn't really qualify as a "rebuild" - because all of the hard parts were in perfect shape. But I suspect there are hundreds of used A4 engines sitting around in this condition. Suspected "burned valves" that really only need to be cleaned.
As long as I had no engine in the cave, I replaced the rotted-out gas tank with a new Tempo 18-gallon tank. Was even able to hook it up to the original gas-filler in the cockpit sole. With gas gauge and sender, this was about $200... but it forever solved worries about the fuel system.
So I'm here to tell you: an A4 rebuild/refurbish/repower can be done very inexpensively. Don't give up on the Atomic 4! And from the other messages in this thread, I'm not the only one with a story like this!
Jim Wolcott
Gibson Girl - Cal 2-29
La Conner, WA
-
bcooke
- Master of the Arcane
- Posts: 2272
- Joined: Sat Oct 04, 2003 10:55 pm
- Boat Name: Jenny
- Boat Type: 1966 Pearson Triton
- Location: Rowley, MA
- Contact:
Whew! Thanks guys, that was exactly the response I was looking for.
I hadn't realized diesels could be had near the $5k mark. It would be silly to spend the same on any rebuild when a new is available.
Doing the rebuild yourself seems like the best idea. Not too difficult, fairly inexpensive, establishes a positive body of knowledge for the day when the purr turns into a growl.
Before anyone thinks I am eminently qualified however I should add that I work on aircraft and most of my experience is with turbines (hardly ever break) sheetmetal and electrical troubleshooting. Piston engines is a fairly recent venture for me. I do have a fair amount of tools and my friendly, local Snap-Off man has my home phone number on speed dial.
I will remember the outboard mount for when I contemplate the four year minimalist cruise. I am not quite ready to make that leap just yet. As for Seagull motors. They have a fan following but I am not on the list. Incredibly simple, fairly reliable, and the most obnoxious, noisy, polluting beasts I have ever mounted on a boat of mine. I have two Seagulls missing carburetors in the basement if anyone is interested. About ten years ago I had a Banks dory with the transom cut out to allow a motor mounted at the last frame to tilt up into the aft well. I think it was a popular modification in Nova Scotia where the boat came from. It was quite the image - ancient wooden dory requiring vigorous bailings on the half hour, pushed by a Seagull you could hear two miles away. No joke, lunch would be started when they heard me and would be served before I arrived. EVERYONE knew who and where I was with that boat. Kinda cool in a dorky way.
-Britton :-)
I hadn't realized diesels could be had near the $5k mark. It would be silly to spend the same on any rebuild when a new is available.
Doing the rebuild yourself seems like the best idea. Not too difficult, fairly inexpensive, establishes a positive body of knowledge for the day when the purr turns into a growl.
Before anyone thinks I am eminently qualified however I should add that I work on aircraft and most of my experience is with turbines (hardly ever break) sheetmetal and electrical troubleshooting. Piston engines is a fairly recent venture for me. I do have a fair amount of tools and my friendly, local Snap-Off man has my home phone number on speed dial.
I will remember the outboard mount for when I contemplate the four year minimalist cruise. I am not quite ready to make that leap just yet. As for Seagull motors. They have a fan following but I am not on the list. Incredibly simple, fairly reliable, and the most obnoxious, noisy, polluting beasts I have ever mounted on a boat of mine. I have two Seagulls missing carburetors in the basement if anyone is interested. About ten years ago I had a Banks dory with the transom cut out to allow a motor mounted at the last frame to tilt up into the aft well. I think it was a popular modification in Nova Scotia where the boat came from. It was quite the image - ancient wooden dory requiring vigorous bailings on the half hour, pushed by a Seagull you could hear two miles away. No joke, lunch would be started when they heard me and would be served before I arrived. EVERYONE knew who and where I was with that boat. Kinda cool in a dorky way.
-Britton :-)