Engine inspection (with pics)
 

So, I pulled the head to change the gasket and inspect the cylinders. What I found was zero ridge except for cylinder 3 has just the SLIGHTEST hint of a ridge. Could be carbon. Pistons are .100 over, cylinder walls have NO cross hatching at all. So this is after 300 miles using 5 quarts of oil. Plugs should be a lot more fouled if it was burning that much IMO. The wife was following me the other day and said that it is smoking a bit. I'm thinking perhaps pulling the pistons, deglaze the cylinders, new rings and it should be good. Not convinced that all that oil when through the cylinders so must be leaking more than usual somewhere. Thoughts??.
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Re: Engine inspection (with pics)
 

sounds like a good idea
check and clean the valves while your at it

Re: Engine inspection (with pics)
 

Lap your valves while you're there, it's cheap, quick and easy

Re: Engine inspection (with pics)
 

First question, are the spark plugs in order from #1 (L) - #4 (R)?

My initial observation is oil is possibly coming from the valves. The fuel mixture appears to be close based on spark plug tips. The carbon appears to following the suite of the combustion chamber which would indicate to me that it is originating from valve guide area and not piston ring. Typically you see more even spread of carbon around the entire piston top when it is the oil rings that are worn.

To totally diagnose this, it would be better to see the margin of the valves, the seat surface, check concentricity, and valve stem to guide clearance. I would also like to measure the bore with a feeler gauge to see how loose the piston is in the bore, etc.

Re: Engine inspection (with pics)
 

no the plugs are not in order. Another observation, the head mimics the pistons in that the combustion chambers are black/sooty with a little bit of carbon buildup and the flat area is shiny but all had a light coating of oil. Also the carbon was "wet" on the head right above where the buildup is on the pistons.

Re: Engine inspection (with pics)
 

I pulled the valves. The guides were shot. I didn't take any measurements but they were quite sloppy. Without removing a piston, there is quite a bit of play at the top of the pistons side to side when I bring them up to the top. Not sure what to make of than as it seems to me that if the cylinders were wore it would show with a ridge at the top. Unless it was bored wrong or maybe this is normal for these engines, I don't know.

Re: Engine inspection (with pics)
 

Mic the cylinders top and bottom.



Just a guess. I've read that when cylinders are bored over, pistons have to be replaced with correct sized pistons/rings. Perhaps someone did not replaced the pistons.

Re: Engine inspection (with pics)
 

Just off topic slightly I have an engine with all compression reading just under 70 PSI but has heavy blow by at the oil filler so must be worn valve guides. I did not want to fit the extended oil filler gizmo as they aint pretty IMHO . I fitted the much larger model "B" filler and no blow by oil drops/mist and looks good too . I suppose in USA these "B" oil fillers could be difficult to find as not many 4 cylinder 1932 onwards cars were built . They can be found in UK as the "B" engine was built in Dagenham into WW2 . English "B" fillers are one piece construction not two piece as USA but have the same cap .

John in really lovely sunny hot spring weather Suffolk County England .

Re: Engine inspection (with pics)
 

From a cost perspective the most expensive part of a rebuild is rod and main bearings,crankshaft and connecting rods.The cost of sleeving bores is up there too. Alot can be done to improve an engine that has decent rod and main bearings and minimal crankshaft thrust without getting too deep cost wise.In versely,a lot of time an money can be wasted trying to 'save' an engine with worn bearings..Engines need to be looked at as a whole,all processes must be in specification for long life,at .100 over with questionable bores and valves my next move would be a bearing inspection if it passes bearing inspection honing bores is a possibility if the bore measures correctly,lapping valves if the seats aren't too far gone,basically an old fashioned overhaul..

Re: Engine inspection (with pics)
 

I've never heard of someone boring a block and not replacing the pistons but that doesn't mean it didn't happen. Would be odd since pistons for these are so cheap but maybe it was someone that just didn't know??. You may be on to something there.

Re: Engine inspection (with pics)
 

My thoughts exactly. I have already checked the bearings as i had the pan off when I first got it to fix an oil leak and checked/adjusted all the bearings at that time. If the crank/rods/bearings are good the rest can be rebuilt very cheap. For now, I'm going to do the valve guides and see what that does for me. I'm not going to be putting a whole pile of miles on this so putting it back to perfect is not necessary. I just need it serviceable/drivable in reasonable condition. I'll mic the bores and see what I have in that respect. Perhaps, like 30CCPU suggested, it's been bored to .125 but has .100 pistons??. If that turns out to be the case, it's not a big job to change the pistons/rings and deglaze the cylinders. FWIW, I did a compression check when I got it and they were all in the high 50's IIRC. It was definitely using oil through the guides though so I'l fix that first.

Re: Engine inspection (with pics)
 

That is why I suspected & suggested worn guides.

Unless you have a decent selection of metrology, you are not going to be able to tell much regarding bore size and piston clearance.

The other thing you need to determine is just how far do you want to go with this project?

Re: Engine inspection (with pics)
 

I'm not going to get TOO carried away as I doubt that I will put 5000 miles on this car in my lifetime. The car is not anything special. It's what you refer to as a "junk restoration". It's basically stock with many jobber parts and a few mods (second tail light and signals, want to maybe add a voltage regulator, that sort of thing). Basically your run of the mill $10,000 model a. If I can get it to stop useing so much oil and improve the brakes (maybe cast drums and learn to set them up properly), I'm a happy camper.

Re: Engine inspection (with pics)
 

Again am arm chairing here, but could swear I have read or heard when cylinders/rings are wore, some honed the cylinders and installed over sized rings to get by. You never know what farmer fixes have been done on a 90 year old car, by people going through tough times - some of what you refer to as a "Junk Restoration".

Re: Engine inspection (with pics)
 

There isnt anything bad about building the car to meet what you want. Guides are cheap,so are rings and lapping compound. No engine will tolerate a piston .025 smaller than the bore,your 'slugs match your jugs'..dont worry about being able to wiggle the piston some,wall clearance is way better loose than tight.You know what to do...good luck..

Re: Engine inspection (with pics)
 

Whoa, WHOA, ....W H O A!! I never called your car a "junk restoration"!! :eek:


Yes, it is often difficult to find a stopping place, but replacing guides & valves, re-ringing it, and tightening up the lower-end clearances should put you on your way to many happy miles.

Re: Engine inspection (with pics)
 

Might be a while before i can get to putting it back together. Weather cleared and will be going back to work. Unwell report back when It's back together and i have a chance to drive it and check the oil consumption but I think Brent hit the nail on the head with the guides. I still don't get why the plugs are not fouled from that much oil consumption but we will see.

Re: Engine inspection (with pics)
 

I was referring to a comment you made awhile back in a thread about a restored model A that was on eBay IIRC for $50,000. You're familiar with the car and were defending the price from those that thought the seller (the owner had passed away IIRC) was nuts. You had said something to the affect that "this is not your typical junk restoration". You were not referring to my car specifically but my car fits the definition of what you meant. I don't disagree and am not offended. There are "levels" of restoration and I would put mine in the average category. While I can appreciate the pristine cars, restored or unrestored, I want something that I am not afraid to drive so I'm OK with "junk restored". It looks good, drives good and as soon as i get this oil consumption fixed, runs good. It's all good. Like I said, I wasn't offended and understand what you meant. Not a bad description IMO. ;);)

Re: Engine inspection (with pics)
 

Licensed, get modern straight-stem valves and guides, they are made to tighter tolerances and will seal better and last longer. Use guides with the step, that looks like original guides, the spring will hold them in place.

John C, blow by is caused by gases blowing by the rings, not valves.

Re: Engine inspection (with pics)
 

PM sent