#1
IP: 24.231.99.102
|
|||
|
|||
Crankcase ventillation
The older blocks have a trap door by the power takeoff, to use for adding oil. The cover is designed not to close exactly over the rectangular opening, but beyond the opening, allowing air into the crankcase preventing changes in pressure.
With older engines there is smoke escaping. The newer blocks have another arrangement. So could I cover better the opening, and prevent the smoke from freely rising? A little square of tin attached to the underside of the trap door would help a lot. Smoke rising from the crankcase could still leave over the flame arrester, or push open the trap door when it could. Last edited by Sony2000; 03-20-2012 at 07:19 AM. |
#2
IP: 68.56.139.11
|
||||
|
||||
Worn engines experience blow by from combustion. This makes pressure in the crankcase that needs to vent. I dont know how much volume of smoke and air will come out, but it will come out one way or another.
I dont think the location of the vent makes much difference. Many guy use a PCV valve to help ventilate the crankcase and remove the smoke. I recall a couple threads on this issue. Dont block off the air escape without opening another route. There is pressure that will be relived one way or another. A rebuilt engine would not have the smoke problem. Aside from getting a rebuild, the pcv valve has worked for many. |
#3
IP: 96.248.13.91
|
||||
|
||||
The Atomic 4 crankcase is not airtight, so there's not a whole lot of possibility of pressure building up to worry about.
The forward end of the crankshaft (behind the flywheel) is not sealed - there is no "oil seal," as there is on a car engine. If you were to tip the engine forward far enough, you would find that the oil in the pan will run freely right out the front of the engine. Feel free to ask me how I know this. So even if you were to seal up that little trap door completely air tight, you would find smoke wafting out that front seal - and out the little crankcase vent on the side valve cover. If you have that much smoke coming out of your crankcase, that suggests worn rings/cylinder walls or perhaps worn valve guides, allowing excessive blow-by. As Neil will argue, applying a PCV valve to an engine in that condition serves only to mask the underlying problem - at a certain point, it means the engine is due for an overhaul. Truly excessive blow-by will dilute and contaminate the engine oil, leading to premature and excessive wear on parts, making the situation worse, in a downward death spiral... Some blow-by on an old engine is not the end of the world - you just need to change the oil regularly and keep an eye on the condition of the oil - and deal with a smoky engine compartment, or add a PCV valve to help reduce the smoke.
__________________
- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#4
IP: 24.152.131.155
|
||||
|
||||
Sony,
Try retarding the timing slightly and see if it helps.
__________________
Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#5
IP: 24.231.99.102
|
|||
|
|||
This is my first Atomic and it arrived in a few pieces. Presently functioning well on it's test bed, I want to redirect the blow by, to the carb for reuse. All summer the engine will receive decarbonization treatments, in an effort to increase compression by 20 psi.
It's good to know the odour of crankcase fumes may exit by the flywheel, but at least I won"t see the trails of white smoke from the TO. I must scrounge up a dwell meter soon. This engine runs with almost any timing setting. |
#6
IP: 99.182.64.233
|
|||
|
|||
A Critical Componant
Sony,
An extremely important piece of equipment in controlling engine blowby is what we refer to as the vent/slash tube. A good view of what it should look like can be seen on the carburator side of the Moyer site picture. Before adding any other vent system equipment, it is always a good idea to get the ignition set at it's factory spec. and to make sure that the V/S tube is installed correctly. Many of us with "high mileage" A4's are able to keep our engine compartments "smoke free" without the addition of other vent aids. Tom |
#7
IP: 96.248.13.91
|
||||
|
||||
Hey Neil, Tom is singin' your song!
__________________
- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#8
IP: 206.125.176.5
|
||||
|
||||
thatch, this weekend I was up at Ajax's boat and we were checking the engine...of course I ran it at WOT at the dock to see how it sounds.
His blow-by is coming out of the oil filler cap & his slash tube was in place I think. I have pointed him to this thread, so he can comment. I also know that he's been fiddling with the engine timing recently, so the 'timing' of this thread is very 'timely' for him as well.
__________________
-Shawn "Holiday" - '89 Alura 35 #109 "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!) |
#9
IP: 99.182.64.233
|
|||
|
|||
Shawn,
I can almost hear Neil groaning from here. One other thing that I neglected to mention in regards to the slash tube's efficiency is the condition of the flame arrestor element. Similar to what happens to a PCV valve, these elements do get dirty over time and need periodic cleaning. Because of their "waffle" construction they may look relatively clean but may actually be quite plugged up inside. Soaking in carb cleaner is the method I use for cleaning mine. Ignition timing is a subject that has created much controversy. Because Universal did such a poor job of giving us "useable" marks to go by, the generally accepted method is to "time it by ear". While this will normally give us the most power output, it will also put the timing several degrees ahead of what the factory spec is. With this advanced timing will most assuredly come increased blowby. Sorry to open up this line of dialog again, but I seriously doubt that it will ever go away. Tom |
#10
IP: 24.152.131.155
|
||||
|
||||
__________________
Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others Last edited by ndutton; 03-20-2012 at 08:06 PM. |
#11
IP: 71.252.27.159
|
||||
|
||||
thatch, your comments are exactly why I am sending Ajax to this thread. He noticed that his distributor was not clamped and he thought the engine timing had slid to be extremely retarded, and it was running bad, and asked me to come visit the boat when convenient (not necessarily in that order, details below.) Before I got there, he figured out the issue and 'power timed' the engine, as is common practice among the A-4 crowd.. When I visited the boat this weekend, it sounded fine to me, but has blow-by coming out the oil fill.
I do also recall that I also soaked my flame arrestor in a 1 gal paint bucket sized can of carb cleaner (Chem-Dip)...generally available from your local auto parts warehouse..that can has been golden for clearing up old A-4 gunk for just about anything that will fit in a 1-gal paint bucket..I am probably having as much stuff settling in the can as is evaporating off the top with the lid open. Me & Ajax & my other buddy Robert (good friend, but owns a dinghy with no motor) that met up this weekend for St. Patrick's Day festivities only had about an hour to screw off on Ajax's boat...so a lot still remains to be discussed as he discloses his findings. He is like me (probably more so) at wanting to understand things and make them right, within reason.
__________________
-Shawn "Holiday" - '89 Alura 35 #109 "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!) Last edited by sastanley; 03-20-2012 at 10:22 PM. |
#12
IP: 108.23.219.10
|
|||
|
|||
Your call
Sony, as per Tom's comments timing and ring -cylinder sealing are common causes of elivated smoke or fumes. Making sure your slash-tube is in good working order will probably help. As far as sealing the opening~no biggie. Confining your fumes to gather and extract is a good thing and the engine can still breath through the front of the crank.
Run a bit of top oil, 2 stroke or MMO in the fuel for a few gallons at least and check the compression again. Probably the single most important thing is to be sure she is in good tune before making unnessarry assumptions. Example, my engine now has better compression than when I got it running after I purchased it and that was 26 years ago. Don't rush these engines show an amazing ability to "heal" with good care. Dave Neptune |
#13
IP: 24.231.99.102
|
|||
|
|||
If members are power tuning the Atomic they maybe overlooking an important element, octane. Adding MMO not only keeps the carbon down, but importantly raises the octane to the 92-94 level. This was the level of regular gasoline, at the time when the engine was developed.
My modest proposal is if you can't use the MMO, throw some diesel fuel in the gasoline to raise the octane, and maintain a burn. Other side effects could be its effect on this ethenol addition to the gas. So far it's kind of a negative. If I wasn't prohibited from self fueling at my yacht club, I would use a higher octane gasoline. |
#14
IP: 72.92.236.118
|
|||
|
|||
I found the same issue with my flame arestor, I tried cleaning it with carb cleaner, it got some of the crusty green stuff out but not enough, so I used a soft wire brush nice and gently going with the grain of the induction fins, worked like a charm, it even shines nice and brassy
|
#15
IP: 167.225.107.17
|
||||
|
||||
Quote:
Sony- Surely you can carry fuel cans down to your boat, depart the marina, and fuel at anchor somewhere calm? How can the marina prohibit you from carrying "extra" fuel for a trip that you may be embarking on? |
#16
IP: 24.231.99.102
|
|||
|
|||
Membership has its priveledges since 1888, and I don't want to rock the boat.
|
#17
IP: 71.118.13.238
|
|||
|
|||
Fuel
Sony, the fuel is much better today and burns much cleaner. The octane rating have also changed since then. In the 60's to run over 10:1 you needed to run the old Chevron Custom Supreme, I think it was rated @ 108. Those same engines run fine on the 91 fuel today.
More octane in such a low compression engine is a waste of money and can cost you torque. I would still avoid "marina gas" whenever possible and if I must buy it I would go to the bussiest one I could find. Can't you carry gas for the dinghy down the dock? That's a suckie rule. Dave Neptune |
#18
IP: 71.181.37.6
|
|||
|
|||
We have the same rule at my YC. They want people to buy their gas
They also won't let you bring cans of gasoline that you fill from their pump out in the launch to your boat. |
#19
IP: 24.152.131.155
|
||||
|
||||
Art,
My marina has the same rule and also owns the fuel dock concession. After dark my friend, after dark.
__________________
Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#20
IP: 128.183.140.38
|
||||
|
||||
Mine is the opposite. No gas dock, and they don't mind jerry jugs.
In fact, the marana owner told me that the DHS wants him to report anyone carrying more than 2 jugs of gas aboard, and gave me an earfull of what he thought about that!. I had a friend setting out from that marina on a trip down the ICW, and he was deathly afraid of running out of gas, so he had six 5-gallon jugs on the deck, three at each set of chainplates!
__________________
@(^.^)@ Ed 1977 Pearson P-323 "Dolce Vita" with rebuilt Atomic-4 |
#21
IP: 96.248.13.91
|
||||
|
||||
My marina has very few rules. Calling it a "yacht club" must be done only with a wink of an eye and tongue firmly planted in cheek.
It's owned by a husband and wife who both have full-time day jobs. It's a mix of working boats, semi-abandoned pleasure craft, a couple truly sweet older, very well-kept pleasure craft, and a handful of fair-to-middlin' sailboats and power boats. I think there is a total of about 40 slips, and it's very secluded, quiet and private. There are no haul-out facilities, no ship's store of any kind, no mechanics or repair facilities, no fuel dock and a minimum of frills or frippery. Just the way I like it! Here's what it looks like when you're standing on the dock at my slip - which is at the farthest-out extreme end of the dock, as far away from shore as you can get, which should also give you an idea of the scale of the place: That badly-listing sailboat was abandoned a couple years ago, and the marina owner purposely shoved it there so it wouldn't sink. It's usually vertical, but that picture was taken a couple weeks ago when we had a couple days of strong winds and an exceptionally low tide. The little building houses the men's and ladies' facilities and a simple kitchen for marina "members" to use. You can also see my incredibly awesome truck over to the right. Anyhow, the owner couldn't care less if I hauled out three 5-gallon jerry cans of gasoline out to my boat, as long as I don't set his dock on fire.
__________________
- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#22
IP: 71.253.202.232
|
||||
|
||||
Quote:
Anyway, that thing smoked like a train, and spark knocked like one of those childs push toys that pops those little balls around.. just found this http://www.afdc.energy.gov/afdc/pdfs/afv_info.pdf Diesel "octane" is bad low. #8-15 It's cetane rating is higher but you have to compare gas at octane and diesel at cetane, and if you convert them, diesel still has low numbers.. Some old industrial engines years,years ago would switch to kero after starting on gas, but some also added water to bump the compression back up..
__________________
Tyring to keep the Bay's Wooden Boat's history from dying off completely. Daniel Last edited by Ball Racing; 03-21-2012 at 05:54 PM. |
#23
IP: 76.122.168.101
|
||||
|
||||
In defense of some of the yacht club rules about things like fueling at the dock, running the barbeque at your slip and such they may have taken the path of least resistance. Some places have gone to those rules to obtain more affordable insurance, or because the local fire-marshal requires it or because of some local or state regulation. In Michigan, many of the state owned marinas prohibit grilling at your slip for that reason.
The yacht club may also be run by nerf-herders, hard to tell : ) |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Water in crankcase | BBH | Overhaul | 4 | 10-11-2011 11:39 AM |
Crankcase corrosion- how bad is bad?? | anglosax | General Maintenance | 3 | 03-16-2011 12:36 PM |
Crankcase ventilation | rickinnj | General Maintenance | 4 | 02-23-2011 09:45 AM |
Excess Crankcase Pressure | David Kippen | General Maintenance | 5 | 02-16-2009 03:06 PM |
Crankcase Vent Pipe | Bob.Griffin | Safety | 2 | 08-19-2007 09:49 PM |