Some engine questions from a new Model A'er

[ryanheacox]

Hi all,
I've just recently been getting more involved with the Model A hobby since my grandfather passed away about a year ago and I've got a few quick questions.

First: The engine makes a light but pronounced thunk when cold (I'll attach a youtube link if I can), its been like this for years now and hasn't gotten any worse (even after I logged about 1000MI on it last summer) but we could never decide on what might be causing it.

Second: The radiator likes to bubble over especially when under loads like climbing hills, I also think that I can smell exhaust gas in the radiator neck and it tends to loose water yet doesn't leak any. I think it could be a warped head since the head gasket was replaced about 4 years ago but I'd like to get some opinions before I start tearing stuff apart. After a hard run (like 30-50 miles with plenty of hills), oil also leaks around the head gasket and #4 plug.

Third: This isn't a question so much as some more info. As far as I can tell, the engine still makes good power and it's pretty quiet once warmed up thoroughly. It pulls just about any hill in 3rd at about 35mph and it'll push right up to around 60 on level road. This engine is also completely stock as far as I know, babbitt bearings, stock head, plugs, everything.

If anyone could give me some feedback on this that would be great. It's getting harder and harder to find old school mechanics that know this stuff in my area.

Link to engine noise:https://www.youtube.com/watch?v=jjI6z-qHc5w

Thanks,
-Ryan

[Rowdy]

Ryan, I hate to say it, but likely the thud ins the center main bearing. Hard to tell without hearing it in person. Have you ever checked the clearances and adjusted them. Likely the head gasket is the cause of the bubbles, but could be that the pacling nut on the water pump may need tightened. Rod

[1930artdeco]

When you pull the head off be sure to check that there are no cracks between any of the valves and a water jacket. Especially the exhaust valves as that is where they seem to like to crack. And welcome to the club.

Mike

[ryanheacox]

Thanks for that very quick response. That confirms most of my suspicions. Everyone I've talked to says that it'll go another hundred thousand miles on that knock but I think I'll check the clearances on the mains and the condition of the babbit. Anyone know of anyone that can repour bearings in CT if it were to come to that? The block has also been cracked and patched with lead in the front near the timing cover so I might also start looking around for a spare block.

[Tom Wesenberg]

You sure have a nice looking car, but I didn't hear any bad noise.
I did hear an engine running at full retard, which can overheat the engine and cause loss of coolant. I wouldn't run full retard more than a few seconds. A shop can use a tool to sniff the coolant for exhaust gases.

[ryanheacox]

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Thanks Tom. Like I said, I'm kinda new to this. I might know my way around a Model A better than a typical 18 year old but I still have a novice ear and eye. There is a shop about a minute from us that could both sniff the coolant and resurface the head if need be. Also the timing was a little messed up in the video but has been reset as per Les Andrews instructions.

[Wick]

Ryan retorque the head,it probley hasen't been done in 4 years....this could very well stop the water loss. Pull the plugs and see how there burning. Sometimes when a head is cracked water will leak over night into a open valve port. Hard to first start and when it does it blows All the water out of the exhaust pipe! Makes a black mess on the garage floor. Also you can leave the plugs out over night and in the morning spin her over...if water has leaked from the head gasket,it will blow it out the spark plug hole! I know...I was standing too close when one did this.
Welcome
Wick

[ryanheacox]

Wow, all this advice is fantastic. I'll retorque the head this weekend while I'm home. Also, I know all too well about the black mess on the garage floor... When we got it out about 3 weeks ago, there was black gunk scattered across the floor. It seemed to start easily though, especially for sitting 6 months. I think the starter only cranked over twice and she fired right up. I will also try taking all of the spark plugs out and cranking it over the next morning. I've also been meaning to do a compression test.

[1931 flamingo]

On loosing water when climbing a hill, ck the gasket under the radiator cap.
Out of curiosity what year/model A do you have.
Paul in CT

[ryanheacox]

Paul,
That gasket has been checked and double checked. In fact, a new cap was ordered to see if that would solve the problem, no luck. The only thing that has seemed to help is that rug doctor anti-foam stuff, I read about it awhile back on some Model A site and it seems to help quite a bit. I have (its really my grandmothers but it seems like its mine, I drive it and keep it rolling) a 1930 3-window Fordor, two-tone blue and black, if you live in CT you may have seen it. If you look at my first post, there is a youtube link near the bottom. I will say it drives better and better the more it gets driven, I'd just like to make sure there's nothing seriously wrong since I've already put 150 miles on it this year and plan on putting quite a bit more on it.

[ryanheacox]

Also, on a bit of an unrelated note, the clutch chatters quite badly. I have a new disk, pressure plate, throwout and pilot bearing for it. However, some people I've asked say that this might not fix the problem. And is it easier to pull the rear end or the engine to do the clutch (if the engine needs work this might be a no brainer...)

[BILL WILLIAMSON]

Ryan, Dog here, black crap on the floor does not necessarily mean an abnormal problem, they just do that from condensation in the Kzhaust plumbing.
Buster T.

[robw]

Are you overfilling the radiator? Mine foamed a bit, till I lowered the level to just above the tubes.

[Rusty Homestead Fl]

I'm with Tom. I was taught to start the engine at full retard (spark lever all the way up) let run for a minute or so, and then drop lever to mid way. I know it sounds cool at full retard but the engine may be happier with more advance.

[BILL WILLIAMSON]

Originally Posted by Rusty Homestead Fl

I'm with Tom. I was taught to start the engine at full retard (spark lever all the way up) let run for a minute or so, and then drop lever to mid way. I know it sounds cool at full retard but the engine may be happier with more advance.

Minerva was extremely HAPPY & bright EYED when retarded & goin' VOILLE, VOILLE, VOILLE, VOILLE & warmed up QUICKER. FULL retard IS for starting & idling! HALF advance IS for half road speed & FULL advance IS for balls out flatland!
Bill W.

[Tom Wesenberg]

Originally Posted by ryanheacox

Also, on a bit of an unrelated note, the clutch chatters quite badly. I have a new disk, pressure plate, throwout and pilot bearing for it. However, some people I've asked say that this might not fix the problem. And is it easier to pull the rear end or the engine to do the clutch (if the engine needs work this might be a no brainer...)

My clutch chattered worse than a paint shaker when I first bought my 29 Tudor. A new disc, light sanding of the flywheel, and a good used pressure plate made it as smooth as an automatic. I removed the rear end to do the job, and after unclamping the U bolts and reinstalling them, it also fixed the left leaning problem.

[KGBnut]

I can't say for sure, but that 'thud' could be timing gear. A loose one can give you a sound like a rod knock. I just swapped mine out a few weeks ago and the sound went away.

Wasn't a bad job at all. About two hours of light wrenching, and that was really taking our time.

[ryanheacox]

Bill, thats exactly what I've heard, the quicker you go, the more advance you give it. Tom, thats reassuring about replacing the clutch, thank you. And about the timing gear, that makes sense, he always said he thought the noise came from the front end and I don't think he ever touched the timing gear. Was the noise yours made a light thud when cold? About 4 years ago, the car had a terrible knock and it turned out to be the front generator bearing had seized and the shaft was pitted and rattling around so I can't rule anything out.

[KGBnut]

It was more of a knock than a thud, but it was most noticeable at low idle. As soon as you revved it up, the sound went away.

It can be caused either by a worn (or loose) timing gear, or a problem with the Camshaft Thrust Plunger/Spring. They are in the same place in the engine, so if you open it up, just check 'em both.

[antiquepa]

My car would also throw water when on hills or hard pull, I was told by an old timmer they run cooler with just plane water, which solved my problem..be sure to ad a rust probiter and rember to put anti=freeze back in when the cold weather sets in..!