A4 hybrid? needs work, need advice

[Guest]

This is an old 1967 A4, seems to be a hybrid of sorts, oil filler is on top of the cover of the reversing gear, but the head has the late model thermostat housing. It's on a 1967 Islander 33 which I purchased two years ago and have slowly been restoring (bottom job summer 2010), replaced starter, alternator, electronic ignition, new gas tank and hose, great compression, actually runs great in idle and for the most part in gear. See album on my profile of eight "before" pictures.

Problems:
Spark plugs #1 and #3 are black and sooty after one run (have to
replace often, using RJ12Cs), exhaust blows white smoke, bilge full of black oil, but compression on all cylinders tests between 105 and 120. Also, engine slowly loses power (starts at 4 kts, drops to 1 after 20 minutes, can't get out of the harbor to go sailing. Oil pressure gauge old mechanical style, not sure it's reliable, no way to check oil level except visibly by removing cover (dipstick was caked over with engine grime, discovered and uncovered after removing engine...looks like a homemade job). Someone had bypassed the "bypass" system, so all intake water was going into the block and there was no thermostat when I finally got the housing off. Interesting. The water jacket was a mess, which I flushed with muriatic acid.

Pulled the engine, got the manifold and head off, about to do the valves, which are very black and sooty, think maybe oil is leaking into the compression chamber somehow, but can't be through pistons, can it? Through the valves, maybe?

Need some advice about the blackened plugs and the leaking oil.

Great to be on board! Have learned so much from looking at all the posts and comments, hope to learn even more as I resurrect this old girl!
Hope to hear from you experts.

Thanks,

BigO

[hanleyclifford]

Interesting engine. Late block, head and gear housing - early distributor and carb. Acc drive could be either. If you have oil in the combustion chambers, it's either rings, valve guides, or both. Make sure you ID each valve and lifter so you can get them back into their original holes. My guess is that you will need a valve job including guides. What is your rebuilding experience?

[Marian Claire]

Welcome to the forum. A few thoughts.
Black plugs: I think if the oil ring is stuck you can get oil into the piston area and foul the plugs. The compression rings are working but are not designed to stop the oil. Try treating #1 and #3 with MMO to get the rings free.
Bilge oil: What appears to be a bilge full of oil may be a bilge full of water with a layer of oil on top. It could have come from a sloppy oil change, or be signs of a leak.
No T-stat etc: Could be a sign of old "fixes" for a over heating problem. How clogged are the cooling ports in the head?
Keep us posted. Dan S/V Marian Claire
Edit; The pics are on BigO's profile.

[edwardc]

... Acc drive could be either. ...

I believe it's an early model accy drive. The early ones have the tapped hole for the distributor hold-down bolt, as shown. On the late models, this hole was tapped into the block housing that the accy drive mounts onto.

[BigO]

Minimal experience

Hello all,

Thanks so much for your responses.

About the oil...since the dipstick was undiscovered until I pulled the engine and dug it out, I was always guessing about how much oil was in there. I would put 1/2 liter (used the thickest oil I could find...SAE 40) each time just to be safe (advice from an experienced boat mechanic). Perhaps I overfilled, which may have caused leaking or overflow. Yes, some of the bilge fluid was water underneath, yet there was still a significant amount of oil, enough to cause the pump to spill oil into the water, very embarrassing. Perhaps the rear oil seal is not working, or tight enough?

About the cooling system...I agree that it could have been an overheating "fix" done before I got the boat. The opening into the water jacket was half covered with a wall of sedimentary buildup, I guess sand and stuff got through over the years. I need to put in a strainer, I suppose, as is recommended in the manual. Anyway, I cleaned it out the best I could with acid and elbow grease, and now it's fairly clean. I'll reinstate the bypass system with a thermostat to see how that works.

I had my machinist build a new water jacket cover...the old one was getting pretty thin with all the rust layers that came off.

About my experience...never done an overhaul, but have had reasonable mechanical experience (rebuilt Frigidaire washer transmissions as a college job) and have dabbled in various jobs on my vehicles over the years, so I'm somewhat comfortable following Bill's overhaul manual through this process, and I'm trying to learn as much as I can reading through it as well as reading through all the forum posts looking for answers.

I pulled the valves yesterday and starting cleaning them with compound. I had to scrape off quite a bit of carbon buildup on a couple of valves, and hopefully can get them reseated with a good seal.

Question...hanleyclifford, you mentioned valve guides...please clarify. I'm not sure what you are referring to (again, still learning the terminology).

Also, when I do the valves, is it necessary to remove the tappets as well? They look good and rotate freely, but I want to do this whole job right the first time, so please advise.

Thanks again, and Merry Christmas to all!
BigO

[BigO]

Valve guides

OK, I looked up and found valve guides...do I remove and replace, or clean and reinstall? Again, thanks so much for your advice.

[Marian Claire]

I know how you feel about the oil. It takes so little to make a sheen on the water. Along with the block cooling passages the head probable needs a good cleaning. All the openings, other that the bolt holes, connect to each other. I have just been cleaning my spare head and a wire and a vinegar bath have helped. My old head was so blocked I had to drill out some of the holes. Pic is of old head. Dan S/V Marian Claire

[BigO]

Head, how to post a pic

Yep, that looks like mine did when I first removed it. Took it to the machine shop to mill and resurface (per Bill's manual instructions).

By the way, how do you post a picture? I figured out how to create the album, but when I click the "insert picture" icon, it asks for a URL, and I just have the pix on my computer...please help...still learning how to use this forum...

Thanks so much!

BigO (John Owen)

[hanleyclifford]

OK, I looked up and found valve guides...do I remove and replace, or clean and reinstall? Again, thanks so much for your advice.

Valve guides are a tight fit in the block casting and must be pressed or driven out with a special tool. They should never be re-installled. But before removing them (or having it done by a machinist) make sure the procedure is necessary by measuring the valve stems with calipers or micrometer. The guides themselves can be measured for excessive ID with a special tool for the purpose or by trying successive drill sizes or reamers. If you are not comfortable with this kind of work I suggest you let your machinist do it. If you decide to do it yourself you will need to buy a driver and reamer from www.Goodson.com. The guides are available from a number of sources including Moyer Marine.

[Marian Claire]

BigO: There are several methods to post pics. I go to the reply page. Click on the attachment icon, the paperclip. That brings up the browse page and from there I can access any pics I have stored in the computer. Remember to re-size them to 640 X 480 +-. I have to do that first so I end up with both the original and the re-sized in the file. Others may have simpler methods. Dan S/V Marian Claire

[BigO]

Thanks for the picture advice. Sounds easy enough. Here goes an attempt...


Homemade compression tool...worked for removal, probably won't for reinstalling.

About the valve guides...I went back and hand-tested each valve, and each has a tiny bit of wiggle inside the guide, all about the same. It makes sense that there should be some, but how much difference should there be between the diameter of the valve stem and valve guide?

Again, thanks so much for your responses! Happy Holidays!

BigO (John Owen)

[BigO]

Valve stem to guide clearance...found it

Found this information in the manual....003" to .004" clearance between stem and guide. I'm guessing that my "wiggle" is more than that, but I'll figure out a way to measure it...probably have my machinist do it for me...have to take the engine there anyway to bore out and replace a broken stud.

[hanleyclifford]

I'm hanging out with that compression tool (welcome to the tinkerer's corner). Seriously, though, the tool is cheap from Moyer Marine. Regarding the valve guides: the tolerance values are listed in your Moyer Service Manual. Two things are involved - the ID of the guide and OD of the valve stem. Sometimes a new valve will bring the value to spec; sometimes a new guide will do the same. Don't rely on the "wiggle check". Since you have the engine apart, get a caliper and check the stem ODs and compare to spec. Remember to keep each valve and tappet in it's original hole.

[jpian0923]

Early accessory drives have the port for the mechanical tach next to the distributor port (like yours does).

Oil in the bilge is likely from over filling the engine. Oil probably leaking from flywheel weep hole which is not visible unless you turn the engine upside down, or remove flywheel cover.

You mentioned power loss...did you mean power loss or speed loss? If it's speed loss, you might need to adjust clutch. It's in the Moyer Manual.

Merry Christmas yall!

[BigO]

Necessity is the mother of invention

About the homemade compression tool...sometimes you gotta improvise.......thanks for the props! I did order the "real" tool and will definitely use that to reinstall the valves. Those retainers will be enough of a pain to get back in there without using that big, bulky thing!

About the power/speed loss...the answer is both. The engine would slowly wind down, and then die. My thoughts are that one or more of the valves was stuck, causing exhaust build-up, maybe? Hopefully the current valve job I'm doing will fix that.

I think the clutch is OK (did not sense any slippage), but I'll check on that, too.

I don't think overheating was the case. Someone had completely bypassed the "bypass" system (see the "before" views album) and there was no thermostat to trap water in the block, so everything was going through the block and out the exhaust. I had recently installed a new temp sensor and gauge, and the heat would barely rise during operation, and would only rise significantly after it was turned off, which makes sense since no more cold water was going through.

Oil over-filling does makes sense since I didn't have (or was not aware of the hidden...see attached pic) dipstick, and was paranoid about low pressure so perhaps I'm in better shape in that regard. The oil pressure gauge was old, and I'm not sure it was giving an accurate reading. I've ordered new oil and water gauges and senders, as well as a thermostat kit to install.

I'll have my machinist measure the ID and OD of the guide and stems so I can make a good decision about that.

Last question, for now. Is it possible to test drive the engine outside of the boat? I've thought about how best to do that, but any ideas would be welcome.

Thanks again for your help!
BigO