Cabin fumes

[timbremac]

My Atomic 4 is in a Pearson Vanguard. While motoring, the fumes in the cabin are pretty bad. They aren't fuel or exhaust. I have no known leaks. Can any who has had this same problem give a testimonial as to whether the crankcase vent upgrade by Moyer can really solve the problem?

[houckpa]

I had the same problem with my Atomic 4. The bypass upgrade solved the problem right away. I would definitely recommend it.
Brad

[bigWalt]

I'm not familiar with any crankcase vent bypass kit that Moyer offers??? Are you by chance referring to the PCV (Positive Crankcase Ventilation) kit that Tom Stevens @ Indigo Electronics offers?? (http://www.atomic4.com/crankcase.html)

If this is what you are referring to - I have one installed on my A4 and it works great!

[ericson_35]

I agree, the Indigo crankcase ventilator kit is a good adit. I had some obnoxious fumes in my Ericson 35 cabin after running the ol A-4 for a while and the Indigo kit cured that 98%. Good investment in my book and took about an hour or two to install (dependeing on access). All the parts are included: new carbo mounting gasket, carbo spacer, longer copper fuel line, new crank breather appaeratus, hose, and new bolts.

http://www.atomic4.com/

Quality $75.00 item that works!

John M.

[timbremac]

Thanks guys, sounds like a good upgrade. My wife will be happy too.

[Silver Lining]

I purchased this PCV kit from Moyer Marine a few years back and it improved the smell immensley. I does take a little time

[paulchristi]

I installed the indigo kit, and it seems to work, but has a problem...the hose supplied seems to have a very slippery core, which causes the PCV valve to pop out occasionally, making the unit nonfunctional.

I've tried gluing the valve into the hose, no go.

One of these days I'll take the thing off the boat and take it to NAPA and see if there is another type of hose that will hold the PCV valve in place a bit better.

Anyone else run into this problem?

thanks, :)

Paul Christiansen
Cal 2-27 "Wampeter"
Astoria, OR

[Bob Nash]

I found in the last few weeks that fumes/smoke are not the only problems with the breather tube as installed by Universal. I found droplets of oil in the bilge water. After my initial concern about an oil leak, I traced the source back to the air intake of the carburator. About a quarter of a teaspoon was puddled in the intake--and the breather tube was the source. Besides the mess in the bilge, I was concerned about the oil being pumped out by the automatic bilge pump when I'm not around. I plan to add the Indigo PCV kit over the winter.

[ericson_35]

Paul,

have you tried a small hose clamp? I think that's what I have on mine and almost certain it came with the kit, and if not, I added one as I like things attached not just slipped on. Small width hose clamps are out there....seek and you shall find. Cheapest stainless hose clamps in the world I've found are at:

Plumbingsupply.com

They are 1/2 to 2/3 cheaper than any place I ever seen before. Yes, they are all stainless clamps and screws (Ideal clamps). Just purchased a variety of sizes (1" to 4") which came to 48 total hose clamps for $65.00...absolute bargain!

John M.

[duncan59]

Guys, I have been thinking about the PCV valve myself, as my own A4 offers up quite a stink in the cabin, and it occasionally makes me feel somewhat nautious. My girlfriend has also complained. However, I must recommend the website of one salty dog Robert Hess of Vancouver, Canada, whose page "Atomic Four Frequently Asked Questions" claims this:

"Many people will spend a lot of money on cheaply made accessories for their boat and marine engine, but skimp on basic maintenance and regular overhauls. We recommend purchasing a heat exchanger and suggest the Indigo Electronics PCV valve kit is a good short-term fix for an engine that needs a ring job and is smoking up the cabin, but don't recommend an accessory oil filter, an electronic ignition, or an adjustable thermostat bypass valve."

...which makes me think that the rings on my pistons probably need to be evaluated. Or is it just that these are now older engines and will inevitably have some degree of mechanical smell when running?

[marthur]

What I found isn't quite in accord Mr. Hess' opinion.

For starters, the rings on my engine are just fine.

However, the A-4 crankcase vents to a tube that ends just above the carburator flame arrestor. The theory is that the carb will suck in the crankcase vapors, which naturally contain enough oil vapor to make a strong "oily engine" smell when the thing is run.

Unfortunately, the theory doesn't work perfectly I had an engine smell after running the iron wind. Not excessive amounts of oil due to bad rings, just a hot oil smell due to the crankcase being warm.

The PCV valve eliminated the vapors.

[duncan59]

Thanks Marthur, that's good to know.
I think I will look into getting one. Is it much hassle to install?

[marthur]

I installed the Indigo Electronics PCV kit. Installing the PCV valve took slightly longer than advertised, but was an easy afternoon's project.

Good Luck,

Mike

[msauntry]

Either kit will work fine and fix the problem. Direct crancase ventilation like on the A4 used to be on cars as well, but back in the 60's or 70s they did the exact same thing by plumbing that tube into the carb intake, like these kits are designed to do. The slash tube that is originally there doesn't cut it. The fumes are not the best thing for the environment in general and especially not an environment our girlfriends enjoy down below!

[Rich Chandonnait]

I usually change my oil and filter, but the problem is when I insert the tube in the dipstick holder [I] seem to get more air out than oil is there an easier way to do it can I go from my oil filter housing, and pull the oil out that way, recently I have been getting a bad exhaust leak from somewhere around the intake/exhaust manifold and I cant seem to locate it can anyone tell me where to look before I spend 350$ for a new manifold

[SEMIJim]

I usually change my oil and filter, but the problem is when I insert the tube in the dipstick holder [I] seem to get more air out than oil is there an easier way to do it ...Look for Product No. - KTAS_05_90 on this page (http://www.moyermarine.com/cgi-bin/shopper.cgi?search=action&category=KTAS&keywords=all&template=Templates/B000_storebuilder.html). I have mine led out to just behind the companionway steps that come off for engine space access. Works like a champ :).

Suggestion: In the future, Rich, please start a new thread, rather than tacking your question(s) onto an existing thread about a different issue.

Jim

[Kurt]

Rich - sounds like you might have separate issues. As far as the exhaust leak, do you mean visible blow by smoke in the cabin or actual exhaust that would cause elevated carbon monoxide readings on detectors. I had the latter problem lately and it turned out to be a failed exhaust flange gasket. These don't last forever and are easy to replace.

[kwalters]

I have noticed that most of my fumes come out the oil filler cap. In conjunction with the PCV kit should I do anything to the vented cap like maybe switch to a non vented cap? What about doing this without the PCV kit? Would this help force it out the tube running to the spark arrester?
Ken

[kwalters]

Fume problem gone after winter soak in MMO. During layup last December I squirted about a 1/4 cup of MMO in each spark plug hole. This spring, no more cabin fumes when running the engine. Must have had gunked up rings to the point that blow by was taking place.
Ken

[charles@pricefarrington.c]

I recently purchased the indigo PVC kit. Tom there recommends relocating the scavange tube to the carb throat and it looks as though the MMI kit does the same. What is the benefit of relocating the tube? Just curious. Tom indicates it spreads any fuel evenly through the engine.

I'll probably set it up the recommended way but any comments are appreciated.

[Dave Neptune]

Hi guys, here's my two cents. I bought my boat twentyfive years ago and the blow-by was accumilating in the cabin:eek:. I went to the autoparts store and bought a cap that was vented. I ran the vent line from the cap into the blower vent line and all was well ( although not completely fixed )for a long time. I since installed an Indigo PCV kit with "hose clamps" and haven't looked back since. I also left the vent line hooked up.. The PCV kit absolutely eliminated the fumes and also does a lot to keep the inside of the engine cleaner by extracting and reburning the stinky gasses. The cabin now smells of beer and cookies!:rolleyes:

Note~~~A good reason to keep the blower running whenever the engine is!

Dave Neptune:cool:

[rigspelt]

A good reason to keep the blower running whenever the engine is!
Beer and cookies? I guess so ... rum and cookies is OK though, wha'?

[keelcooler]

Indigo list for acceptable PVC valve replacements are:

NAPA-Echlin CRB29229 or Mileage Plus Fuel-MPF39229

Purolator-PV789,Robertshaw-PV191,Fram-FV191
ACDelco-CV789C,Motorcraft-EV-90

Replace every 200 hours.

[Jesse Delanoy]

I, too, have a vented oil cap on my A4. It has a short hose on it, that sits on top of the flame arrestor/air intake on the carb, right next to the short hose coming from the side of the crankcase. I always assumed this was a standard setup, but have since learned that many (most?) A4 oil caps do not have this.

When I replaced my engine with a Moyer rebuilt A4 three years ago, the mechanic commented that the oil cap looked like a "neat" idea - so when he swapped out the old engine and installed the new one, he kept my original vented oil cap for me on the new one.

I've never had a fume or blowby problem in my cabin or engine compartment with either engine. I do, typically, run my bilge blower whenever the engine is running. This is probably of more benefit than the vented oil cap.

[keelstep]

I installed an expandable rubber plug in the oil tube about 20 years ago. With that and the PVC kit I have not had any concerns.
I later rebuilt the motor and continued to use the plug.

I was motivated to do this after testing for carbon monoxide near the tube. I could not get a reading since it was way above the scale used to measure air in working places.

Don

[sailcnc]

I recently installed the kit on my 1979 Atomic 4 in my C&C 30. I installed the spacer plate and the PCV hose. The kit alos came with new fuel fittings and a black rubber fuel hose. I dod not install this as I have a copper hose between my fuel pump and carb. This still fit . Should I have installed the new fittings and hose to increase fuel draw or will the fuel system work still with the larger spacer plate in there?

Thanls

Joe

[dvd]

The PCV Kit (Positive Crankcase Ventilation) creates just what it says. It is sucking the blow by through the intake. I think you need to have a vented oil cap to let the pvc kit do its job. I have the indigo pcv kit and a vented oil cap and no more blow by smell.

dvd

[sailcnc]

My kit did not come with a new oil cap. It vents directly in to the side case where the original hose was and directly in to the carb.

Joe

[domenic]

This is not to say I know what the problem is guys.
When I got Geronimo, she smelled. I could smell mussed, and engine fumes.
I think the dirty mussed smell was was from being shut up, and stuff left to rust, and rot in lockers. About six months after I got her is I found the gas leak around the bottom of my FG fuel tank, which was under the starboard quarter berth.

I aired her out about three times a week. (all hatches open.) Removed all the roted, and rusted stuff. Changed my tank, and relocated it under the cockpit seat at the transom.

I have no smells. The little bulkhead between the cabin, and engine compartment I have had off for several months due to work on the engine.

I run the engine every 2-3 days for 30 minutes. I still have no smells inside the boat.

My oil cap fits tight. No smell from there.

During the summer I took the covers off all the beding, seats, dried and aired them on deck...no smell there. I cleaned the FG liner top to bottom with oxiclean.
My boat smells like a pretty women should.
The only part I can not clean keel under the liner. God only knows what is under there.

[joe_db]

My "new" engine has no blowby at all I can detect in the cabin. I am running the Indigo PCV kit. Keep in mind there is no front seal. If there is sufficient blowby it will be coming out there perhaps and definitely through the oil cap. Running a hose from the oil fill to a blower might do the trick ;)

[Mark S]

The PCV Kit (Positive Crankcase Ventilation) creates just what it says. It is sucking the blow by through the intake. I think you need to have a vented oil cap to let the pvc kit do its job.

Seems to me when the feds required autos to have PCV valves they also banned vented oil caps. I don't think the valve sucks fumes so much as provides a single exit point through a one way valve to the air intake of the carburetor.

Mark

[joe_db]

The A4 is NOT airtight, vented cap or no.
Try putting one with the oil still in it into your wife's Accord and let the front end get lower than the back and you too will be scrubbing oil out of the car :eek::eek:

Seems to me when the feds required autos to have PCV valves they also banned vented oil caps. I don't think the valve sucks fumes so much as provides a single exit point through a one way valve to the air intake of the carburetor.

Mark

[ILikeRust]

joe db has it right - the Atomic 4 is NOT an airtight engine, period.

The fed standards for automotive engines do not apply to our old friend, the A4. So whether or not the feds banned vented oil caps doesn't matter.

First, as has been pointed out above, the front end of the crankcase is not sealed. If you tip the engine forward a few degrees, with a crankcase full of oil, you will find oil dribbling out from behind the flywheel and running all over your shoes. Second, the stock oil cap on the filler tube on the front of the engine (on the newer-style engines) does not make an air-tight seal on the filler tube.

The reason the PCV valve kit works better than the stock arrangement is because it takes advantage of the point of high vacuum within the intake plenum. The spacer plate allows you to take advantage of the Venturi effect right behind the carb. This creates a stronger "suction" effect than just pointing the little stock rubber hose towards the flame arrester. This direct connection causes the crankcase fumes to get sucked through the PCV valve and into the intake plenum and re-breathed, rather than getting pumped out the front of the crankcase, or the oil fill cap, or out the vent tube on the side, where they might or might not actually get sucked back into the carb.

[ILikeRust]

I recently installed the kit on my 1979 Atomic 4 in my C&C 30.

Are you referring to the MMI kit, or the Indigo kit?

I installed the Indigo kit, and it did not come with any new fuel fittings, so I'm curious as to the differences.

[joe_db]

BTW - if you have an old Indigo kit with a horizontal PCV valve it will not work. You need the new fitting with a vertical valve.

[Mark S]

I only meant that the vented cap isn't necessary. Poorly expressed, no doubt.

Mark

[dvd]

I installed the Indigo PCV kit and completely eliminated the blow by smell. I think it is for any engine, new or old.

DVD

[ndutton]

Just One Sailor's Opinion (JOSO, remember?) but I view the PCV kit a stopgap measure, albeit a potentially long term one, to mitigate a specific symptom of internal engine wear.

I do not mean to suggest it should not be used. Who wants a stinky boat? Maybe those diesel guys can get used to it but not us, right? But recognize the presence of blowby is for a reason and the more blowby you have, the more serious the reason.

[Marty Levenson]

Hey All,

I will be installing the Indigo PCV to my recently purchased rebuilt A4 soon.

My old A4 has a short copper pipe coming out of the block just behind the flywheel cover. The Indigo clamps onto that nicely. My new A4 has no such pipe: just a smooth hole. The PCV slips into the block pretty snugly, but can't be clamped in any way. Wondering if I should attach a pipe (how? JB Weld? tap?) or is there a way to glue that hose in so that it is still removable for replacement? Or is a fairly snug pressure fit enough?

Thanks!
Marty

[keelcooler]

Marty, Looks like you have an early model plate. Copper pipe section works best, drill out to match your plate and secure with a long cotter pin.

[Dave Neptune]

Keelcooler, you are lucky that the A-4 is still vented. It is not a good idea to plug or seal the crankcase as explosive gasses can accumilate. I have seen the pans of Hi-performance and duty engines literally blow the pan off of the engine when ventilation was eliminated.
In the case of the A-4 even by plugging the oil fill it is vented to the carb through the side plate vent and any extra fumes will still go out through the open crank on the flywheel end.
The PVC still requires that fresh air be allowed into the engine so it mixes and is extracted by the PCV system.

Just an FYI.

Dave Neptune

[Marty Levenson]

Hey Neptune,

I thought Keel meant for me to insert a copper pipe snugly into the vent hole, pin it with a cotter pin, and hose clamp the PCV valve to the other end of the pipe. Does that seem like a good plan to you? Totally agree with your warning: I would never plug the vent hole.

If the pipe insertion plan is a viable way to go, wondering if I should put a sealant around the pipe....and what type?

Just noticed your handle is "Neptune". Our Tartan 27 is "Poseidon"....(Neptune was the Roman version of the Greek god Poseidon, as you probably know...).

Thanks,
Marty

[Jkeevy]

I installed the indigo system and fixed some gas related leak issues and lo and behold no smells of any kind at least from the engine. :)

[keelcooler]

Marty, That's right you should find a cotter pin hole at 12 o'clock. The early vent hoses were metal flex and attached in this manner.

[Dave Neptune]

Marty, I'm not exactly sure what the pin is for unless to hold in position. I too have the Indigo and I just attached a bit of hose to both ends of the copper elbow one to the block and the other to the valve and clamped them, so far they have held fine. I don't want any vacuum getting by the valve not sucking on the crankcase itself. I think he is referng to the early type and I would fasten it with the pin if you have access or you could clean it well and put together with some JB Weld or even orange RTV.
Yeh it's Neptune and I have gotten a bit of milage and a few dinners from people betting it wasn't really my name.

Jim, my point was that unless you have air coming in you won't displace enough to get the accumilating gasses out and that can be explosive. I have seen pans and valve cover blown clear off an engine. Ever see the straps on a blower motor at a track? I was part af a blown alchohol car crew a few times and once at the old Irwindale raceway the car we were going against had a cranckase explosion and fake straps. Te blower went clear over the stands and landed abot 200 feet away, that was a 8-71 with most of the manifold attached. They were in deep doo doo and were suspended from competition for a while. When it went it scared the ~~~~out of me :eek: for sure. The track officials went nuts, and thanked their lucky stars it didn't land in the stands or on someone in the parking lot, however it did do a number on a cars trunk and rear window.

Dave Neptune :cool:

[Marty Levenson]

Thanks for the clarification. I'll glue the pipe in with JB weld and attach the Indigo as it was in our old A4. Worked great there: cut fumes by 90%.

This rebuilt I bought is quite a hodge podge. Early 60's transmission, late 70's block, new MM head and manifold, and this prehistoric vent (not sure what that plate is called).

Came with the sheet metal flywheel cover, which is a different bolt pattern than our cast iron flywheel on the old A4. Is there a cast iron one that would fit? I'm just not warming up to the sheet metal version: seems flimsy.

Thanks all,
Marty

[keelcooler]

The early valve spring panel cover plates were cast and are preferred because they did not warp and leak. If you look close at Marty’s photo you can see the cotter pin attachment hole.

We should not confuse Dave further and tell him about the oil main going to the plate. That’s right the early models had a valve spring oil shower! You can plug that main pressure line and not blow out your pan or launch your blower into the bridge deck.

The cast iron fly wheel covers will not fit the sheet metal fronts.