Throttle rod /valve cover hole

[Bryant]

It’s probably been talked about before but Iam not finding any old threads to answer my question.
Can you seal up these holes to closer tolerances or are they acting as a PCV?
Iam sure the valves must be getting oil but just looking at it how the oil gets in it amazes me they do.
Has anyone engineered a solution to theses holes?
I picture dirt flowing in,oil coming out and stink bugs taking up residence during the winter months.

[Scott_Conger]

It's a Model T.

It should survive just fine as it is.

[Les Schubert]

Many 27 didn’t have the holes as they can with the vaporizer carb and the throttle rod goes across the top of the engine.

[Bryant]

Many 27 didn’t have the holes as they can with the vaporizer carb and the throttle rod goes across the top of the engine.

So your valve train is completely sealed?

[TXGOAT2]

I believe the holes do serve as crankcase ventilation. They serve to relieve crankcase pressure and will allow some water and fuel vapor to escape. They can admit dirt and bugs. I don't think they'd allow much dirt in while the engine is operating, since there is usually a slight overpressure in the crankcase due to normal ring blowby. Bugs are another matter. On my 26-27 car, the valve cover has no hole, but the block does have. I stuffed a metallic dish scrubber into the gap between # 2 & 3 cylinders to act as a filter and bug excluder. The scrubbing pad (looks like strands of copper) stays put and allows free air flow but keeps wasps and bugs out. It collects a film of oil which acts to trap dust, too.

[TXGOAT2]

As I understand it, some 26-27 engines had the hole in the block for the throttle rod, and some did not. Valve covers are available with and without the hole. My engine carries a 1926 motor number, and it does have the hole in the block.

[Norman Kling]

The throttle control rod goes through that hole and it tends to move up and down and side to side as the throttle is opened or closed, so it is not a good idea to bind it. Very little dirt should go through that hole because it only goes into the valve chamber and a little bit of oil will flow down into the crankcase, but if you change the oil often, it should be OK. If you are getting a lot of blow by, you most likely need some engine work such as new rings or even a rebuilt engine. The only other source of breathing is the oil filler cap and some of that is going to go into the car if it smokes a lot.
Norm

[Bryant]

I believe the holes do serve as crankcasae ventilation. They serve to relieve crankcase pressure and will allow some water and fuel vapor to escape. They can admit dirt and bugs. I don't think they'd allow much dirt in while the engine is operating, since there is usually a slight overpressure in the crankcase due to normal ring blowby. Bugs are another matter. On my 26-27 car, the valve cover has no hole, but the block does have. I stuffed a metallic dish scrubber into the gap between # 2 & 3 cylinders to act as a filter and bug excluder. The scrubbing pad (looks like strands of copper) stays put and allows free air flow but keeps wasps and bugs out. It collects a film of oil which acts to trap dust, too.

that’s what I was thinking. Only thing that made since for oil to get in there good. Thanks for the useful info with the filter media. Pretty simple

[Bryant]

The throttle control rod goes through that hole and it tends to move up and down and side to side as the throttle is opened or closed, so it is not a good idea to bind it. Very little dirt should go through that hole because it only goes into the valve chamber and a little bit of oil will flow down into the crankcase, but if you change the oil often, it should be OK. If you are getting a lot of blow by, you most likely need some engine work such as new rings or even a rebuilt engine. The only other source of breathing is the oil filler cap and some of that is going to go into the car if it smokes a lot.
Norm

thanks I did notice on some valve covers the hole was slot shaped so it could follow the carb linkage. My cover is just a round hole. My engine is a fresh rebuild. I just think about any weak links. Possible simple mods not seen by the eye to protect my investment.

[Les Schubert]

I have encountered 27 blocks that don’t have the throttle rod hole.
The oil filler cap provides plenty of crankcase ventilation!

[Kerry]

Canadian RHD blocks never had a reason to punch the hole in the cast so breathing is not an issue, the filler cap breather is all that is needed.

[Bryant]

Reading the oiling system on the ford fix web site. It states the oil mist is drawn into the valve chamber during the intake stroke thru the valve since there are no valve seats. Interesting. I personally like/think it’s funny that the rod goes thru like it does. But also engineering a seal tight style rod linkage would be neat. Now knowing it’s not really relying on a venting of some sort.

[TXGOAT2]

A good crankcase ventilation system, which many early cars, including the Ford T, lacked, will have both an inlet and outlet for air. The inlet on a good system will have some kind of dust filter, and the best ones, such as those used on the Ford Y Block V8s in the 1950s, will have a filter on both the inlet and outlet. Carmakers began designing proper crankcase ventilation systems in the 1930s, and engine life was much improved as a result. Crankcase ventilation serves to reduce crankcase overpressure from normal blowby AND, just as importantly, it serves to remove water vapor and fuel vapor from the crankcase, preventing oil sludging and dilution. All engines make water vapor during the combustion process, and some of it gets past the rings and collects in the crankcase, where it does great harm. Fuel vapors also collect and tend to dilute the engine oil. A gasoline engine will emit about 3 gallons of water for every gallon of gasoline it burns. Many carmakers, including Ford, touted the advantages of good crankcase ventilation in their sales literature during the 1930s. The better systems took advantage of the blower effect of the rotating crankshaft to assure positive air movement through the engine's interior spaces. Air would be drawn into the inlet, which was typically a filter built into the oil filler cap, then circulated through the engine interior and expelled through a short "road draft" pipe that was arranged to discharge the air and contaminates below the car. This arrangement kept most all of the water vapor and fuel vapor out of the oil and the engine's interior spaces. A Model T engine will benefit from having the valve chamber vented, and would also benefit from having a filter tyupe oil filler cap adapted to it. Besides keeping the oil and engine interior free from harmful vapors and condensation, such an arrangement will tend to reduce crankcase overpressure and thus mitigate oil leakage.

[TRDxB2]

Did RAJO and/or Fonty valve covers have vents or did he rely on the oil filler cap for crankcase ventilation?

[Bryant]

Iam not sure about the over head systems. But if the valves are causing vacuum and drawing the oil mist into the valve chamber. Wouldn’t it actually be processing the crankcase ventilation into the combustion chamber? Maybe even using the oil filter cap as an intake source? Trying to wrap my head around it here

[Kerry]

Seems like some over thinking on this, millions of T engines had the 2 and sealed valve covers with no issues, look at motor cycle or stationary/small engines, no more than one small vent.

[TXGOAT2]

Valve guides in good shape will not allow significant air leakage at the valve stems. The Ford T engine depends on direct splash lubrication from the connecting rod troughs for most engine lubrication, while some parts, including the valve stems, depend on oil mist that is always present in an operating engine for lubrication. Valve stems require some lubrication, but they receive a minimum amount of oil in most engines. They do not move much, and they do not move all the time, and they have light mechanical loading compared to many other engine parts, so a flood of oil is not needed or wanted. Excessive oiling of valve guides/stems causes oil burning problems and carbon deposition. The throttle rod holes have no role in valve lubrication on a T engine, and they don't seem to cause much of a problem under most conditions. Obviously, they can admit dirt, bugs, mud dauber wasps, and mud-laden road splash under some conditions, and if you wash your motor, you're going to get water in it. I chose to add a simple filter to the throttle rod hole in the block on my car, which uses an overhead throttle rod. If I come across a filter-type oil filler cap that is of an appropriate size, I will adapt it to my T engine to enhance ventilation and prevent entry of dust. The ideal set up would be a modern PCV type system with the valve connected to the T valve cover and a filter-type oil filler cap added, which would reduce oil leakage under most driving conditions and provide good crankcase ventilation. I'm not sure just how a T carburetor would react to adding a PCV valve. It might only be necessary to adjust the main jet a little, or it might be more complicated. I would not attempt to add a modern PCV system to a car which uses the throttle rod through the block, since it would draw unfiltered air into the engine through the throttle road holes and metering intake air for the PCV system would be impossible.

[TXGOAT2]

A T engine will last longer if steps are taken to keep dirt and other foreign matter out of the engine. A stock T engine running under normal 1920 road conditions (dirt, sand, mud) might go 10,000 miles or so before needing an engine overhaul. The same engine running under the same conditions, but with an effective air filter and a good filtered crankcase ventilation setup would likely go over 30,000 miles before needing an overhaul. Adding an oil filter and transmission cover screen would add more service life, and if you could figure out a way to add an effective oil filter, that would add more good miles yet.

[Bryant]

Seems like some over thinking on this, millions of T engines had the 2 and sealed valve covers with no issues, look at motor cycle or stationary/small engines, no more than one small vent.

Thanks I like to think. Probably on to something as later years they sealed them up. Mainly just wondering if it would effect oil entry. Ford web sites say the valves draw it in during intake stroke. Not to many engines produced with open holes any more. Probably aids in the high mileage newer engines get. I guess we will see

[Kerry]

I don't believe for a second that a good crankcase ventilation system was a first consideration for the engine but for the comfort of the people in cars as they became more enclosed. Engines not vented to the right spot would stink you out with oil fumes, the vent pipe on engines from the 30''s to the 60's was near the lowest part of an engine to vent the fumes away with air flow when moving. Then the invention of the PCV changed it to a nice sealed system.

[TXGOAT2]

The ventilation systems were added to enhance engine life, along with oil filters, air filters, and other refinements. The modern PCV systems were developed to reduce overall vehicle emissions. They work very well, and have little or no detrimental effect on the engine. Passenger comfort was addressed by other means. The road draft tubes were designed and located to take advantage of the scavenging effect of air rushing past the end of the pipe when the car was in motion with the aim of improving air flow through the engine. I would think that most all closed body Model Ts were heavily perfumed with gasoline fumes and tobacco smoke, just as courthouses used to reek of tobacco smoke and Pine Sol. Model As often as not smelled like gasoline, and Ford pickups from the 1940s thru 1972 usually smelled like gasoline.

[Kerry]

And yet the poor old VW engine with no more than an oil path air cleaner and unvented filler cap, just one breather pipe, was good for 100,000 miles.

[Bryant]

Probably had something to do with the air cleaner
Didn’t Henry say the T was good for 10k? I could be mistaken

[John kuehn]

It’s a Model T not a Rolls Royce. Plus it’s 100 year old technology.

[Bryant]

You are right it is a model T. So to wrap it up it should be fine to close up the holes like they apparently did on the later version. I don’t think that will turn it into a rolls Royce. Thanks all for playing

[TXGOAT2]

If you don't need to run throttle rod through the block, the best course is a valve cover with no hole in it and put a pot scrubber over the hole in the block. I stuffed a copper mesh type pot scrubber between #2 & # 3 cylinders to cover the hole and keep dirt and bugs out, yet let air in and out. That was thousands of miles ago and it has stayed put and done its job. The pot scrubber material is a lot like the stuff they used in factory equipment vented oil filler caps like the ones Ford used in the 1930s and beyond.

[TXGOAT2]

If my T turns into a Rolls Royce, I'll sell it and buy a fleet of Model Ts.

[Bryant]

OCT 2 Acc. 94, Box 169, Ford Archives
The one-piece valve chamber cover without the hole for the throttle rod was adopted on October 2, 1926. Notes in another file discussed the problem of DIRT getting into the engine through the passageway for the throttle rod. Someone in the Norfolk, Virginia, plant made up a device for what was in effect two plates with a tube connecting them. The tube was for the carburetor rod and the two plates sealed either side of the block. Eventually, of course, the opening was sealed.
Copied from the MTFCA encyclopedia section 1926. Looks like my over thinking was period correct

[Scott_Conger]

After you seal up the hole and can no longer run a standard intake, standard exhaust or standard carb setup, and have to change over your steering column, give me a call. I have an old vaporizer that is just dying to be installed. You're on your own, converting your steering column, though.

It is a testimony to their robust design that so many T's have managed to survive the years in spite of the improvements foisted upon them through the decades. Anyone losing sleep over something like this is likely in the wrong hobby.

I used to see these sorts of improvements when I owned an old historic home...when I lived in FL, my neighbors were all too happy to spend $50,000 on aluminum siding and $30,000+ on ugly new windows, just to save $25 a month in cooling costs . When the tour of homes happened each year, the tour leaders often said "this is what an old home should look like". It was a gracious old home...inefficient windows, wood siding and everything that goes with it. And I didn't lose a bit of sleep wondering if the odd insect or dirt managed to get in...I don't own that home anymore, but I do still own my T's, and I don't lose a wink of sleep over them, either.

[Bryant]

sounds like it. I just thought it was interesting that there was a ford archive on it. wish I would have found it earlier

[Bryant]

my original post asked if anyone engineered a solution to the holes. I know some don't mind them open. it's a model T. I get it. according to the archive someone years ago tried to develop something. Iam sure if I followed suit I could do it without changing anything outside of the valve cover/block holes. probably wouldn't even be visible.
I just can't wrap my head around why some choose to just come into a topic discussion and try to lay waste to people. its ok to disagree but please be helpful or just pass by.

[TXGOAT2]

My 10-second, no mod mod works very well.

[Bryant]

My 10-second, no mod mod works very well.

Thanks I definitely like your solution. Simple and effective

[TRDxB2]

my original post asked if anyone engineered a solution to the holes. I know some don't mind them open. it's a model T. I get it. according to the archive someone years ago tried to develop something. Iam sure if I followed suit I could do it without changing anything outside of the valve cover/block holes. probably wouldn't even be visible.
I just can't wrap my head around why some choose to just come into a topic discussion and try to lay waste to people. its ok to disagree but please be helpful or just pass by.

Suppliers sold accessory styled Finned, RAJO and Frontenac valve covers that included a simple eye-bolt & neoprene pad threaded through the valve hole to secure the matting cover on the water inlet side. So: bolt+pad+washers on each side to hold pad in place a lock nut . Pad choices are neoprene or copper scrub pad. Throttle link through copper scrub pad or switch to vaporizer conversion linkage

[BHarper]

One day, when I didn't have bigger fish to fry, these two openings spoke to me.

A couple of smallish pieces of felt sheet were slit and the two pieces were placed together with the slits at ninety degree angles. I used some light duty mechanics wire (easily formed) to "sew" them together around the two slits. This felt sandwich was then inserted through the hole in the block between cylinders two and three. A bit of careful manipulation (fiddling) had the edges of the felt sandwich on the inside and outside of the block. A length of the mechanics wire which protruded from the felt was then threaded through the eye of the cotter pin of the main bearing bolt on the left side of the block and secured to the bolt.
I took a big enough piece of felt and after placing a slit in the needed location, I placed the felt sheet between the valve cover and the valve cover gasket.
Better than nothing.