Pressurizing Rocker Shafts


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By Dobie - 4 Years Ago
I'm considering pressurizing the rocker shafts on  my '55 292. I know there are at least a couple of methods, pinching off the shaft drain tubes appearing to be the easiest. My concern is about possibly starving some other part of the engine for oil. It looks like the output of the passenger side shaft goes to the timing chain. I don't know where the oil from the driver side tube goes, distributor/oil pump drive gear maybe...? I'm pretty sure a few guys here have done this so I'd like to know what method you used and the results before I pull the trigger. TIA for any advice.
By Florida_Phil - 4 Years Ago
Much has been written about this.  You will receive many replies.  I suggest you go to YouTube and check out the numerous videos on this subject.  I have done this a number of different ways myself.  Pinching off the tubes is one way.  You can block off the oil to the tubes in other ways as well.  I have never seen any noticeable adverse effects from these modifications on a street driven car.  Make sure you have enough oil flow to begin with.  In a Y-Block. the oil flows through small holes in the heads that can become easily blocked or restricted by sludge. 

When I built the engine in my TBrd, I handled this issue differently.   On this forum I learned that cutting the cam grove deeper increases oil flow to the heads. The oil grove in my new out of the box Isky cam had an .018" deep grove.  I put the cam in a lathe and cut the grove to .030".  I had so much oil in the top end, I decided to leave the oil tubes open.  Some people have had to restrict the oil flow after cutting the grove, in my case this wasn't necessary.  I have about 3,000 miles on my rebuild so far.  My valve adjustment and top end are as new.
By Ted - 4 Years Ago
Here is an older link related to this subject.
 
http://forums.y-blocksforever.com/FindPost10464.aspx
 
 
And here are some other discussions related to Y-Block oiling.
 
Center cam bearing
Grooving the center cam hole in the block
Oil Flow Diagram
Pressurized rocker shafts
Pressurized rocker shafts more
Pressurized timing chain oiling
Rocker arm overflow tubes Cons
Rocker arm overflow tubes Pros
Rocker arm overflow tube More Pros
Slotting the rocker shafts for improved oiling
Timing chain oil trough
By Florida_Phil - 4 Years Ago
Everything you always wanted to know about Y-Block Rockers, but were afraid to ask...   Rolleyes
By 2721955meteor - 4 Years Ago
first move is be sure the inside of the rocker shaft is clean, on higher milage the spill tubes plug up at opposite end of spill tubes..,those rockers and shaft suffer.
the tip from this form had some good info such as tap the end rocker stand, take a Allen screw grind a tapper this blocks the spill tube  drain and positions the assembly for easy inst.  my current ride has a 292 with the largend grove in cam and fullpresure to rockers, I installed early 289 umbrella seals on valve s
,I tried the umbrella 1/8 in. when running engine withe covers offsets of oil and all push rods spin which helps take oil into valley. the drain tubes on exhaust Sidadequate to handle  all the oil drain some to chain aria and dust drive. mine is in its 4th year, no issues and no increase ionic consumption. plus have not had to adjust the valves 3years. the rate of pushrods rotate says all is well  with cam and lifters

By Tim Quinn - 4 Years Ago
Leave it stock.
By Tedster - 4 Years Ago
I found this on the FTE forum in a similar discussion:

Lets start with the FE. The FE also feeds the rocker shaft from the cam bearings but it uses 2 cam bearings (2 and 4) instead of just one cam bearing, The FE oiling system for the rockers/shaft also has a severe dog leg in it (both heads). But the big difference is it is pressurized.

Beyond that pressure is a function of flow. Input more flow than can be output and you build pressure.

Now where the issue arose with the Y block was 2 fold, the oils available in the era and the lack of a pressurized rocker shaft. We all know where the hottest part of an engine block is during operation, the cylinder head, this is also a factor in the Y blocks pugging up the rocker shaft oiling circuit.

As we all know the oils from back in the day had a much lower vapour point and in turn coking point temp wise than modern oils. And we all know how to raise the vapour point of a liquid, increase the pressure it is under.

The fact that the Y block had an unpressurized rocker shaft helped contribute to the coking and sludge build-up in the feed to the rocker shaft and within the rocker shaft itself. If the oil feeding the rocker shaft and the rocker shaft was/is pressurized the propensity for coking and sludge build-up in the oil passages and the rocker shaft will be greatly reduced. So pressurizing the rocker shaft will have an effect on the propensity of coking and sludge build-up.

The FE was built concurrently with the Y Blocks so both got used with the same oils in the era, yet it never suffered the same rocker wear issues of the Y block nor had near the issues of coking and sludge build-up in the rocker shafts, some of this was due to better oiling but a big part of it was due to the system being fully pressurized.

The Y Block stuck around till 1984 in South America and when they moved to the Phase 2 heads in the mid-late 60's (SBF style intake and exhaust port layout) the rocker shafts were fully pressurized and the overflow tube done away with.


Makes good sense to me. One thing I don't understand. Let's say someone simply pinches off the overflow tubes. Now the rocker shafts are pressurized, assuming that rocker shaft and rocker bore clearances are within clearance spec.

The oil that "leaks" past and through the rocker arms ultimately will travel along the head channel should and exit down through the very same drain holes anyway? I'm missing something surely, but that's not news.
By Ted - 4 Years Ago
Here are some more thoughts on the subject.
 
A major difference between the FE engines and the Ford Y is that the FE engines had hydraulic lifters while the Y had solids.  I am excluding the 406 and 427 Fords from this discussion.  With hydraulic lifters, the rockers are loaded against the shaft at all times which means there is no period of relaxation of the rocker to the shaft.  In this instance a pressurized rocker shaft will force oil in those locations that normally would not get it.  The Ford Y on the other hand does have that period of relaxation of the rockers to the shafts and simply relies on gravity to feed oil to the bottom of the shafts.  The overflow tubes do allow the shafts to stay full of oil thus eliminating air pockets while at the same time allows the flow of oil through the shafts to be increased thus carrying away the excess heat generated there.  Another plus to the overflow tubes is the right side of engine tube providing additional oil to the timing chain set that it would not receiver otherwise.  The oil trough on the early engines worked in tandem with the oil flow tubes to insure that the oil did indeed get on the chain.
 
As already mentioned, the root of the Ford Y top end oiling problems was with the use paraffin based oils of the time.  The Y was designed originally for the modern multi-weight oils that were introduced at the same time as the Y but not all owners saw fit to use those oils from the onset.  I do still see Ford Y engines with 300K miles with the overflow tubes still intact and these engines are still providng oil to the rockers.  These high mileage engines all run a good quality oil which is routinely changed.
 
A big fail point on engines being rebuilt now is with the softer than stock cam bearings that are being used.  The cam bearings end up wearing much quicker to the point that the groove in the center journal of the camshaft journal is pushed into the bearing thus either restricting the oil flow to the top or shutting it off completely.  Part of this accelerated wear comes from using valve spring pressures that are now much higher than stock.  Common fixes for this are using a center camshaft bearing that has a groove machined on the back side of it, cutting the groove in the center camshaft journal deeper, or machining a groove in the center cam bearing hole in the block that allows the three holes there to be connected thus eliminating the need for the groove in the camshaft.  A recent cam bearing for the Y from Engine Tech (made in South America) is made from a harder material and has thus far helped considerably in stopping the aforementioned problems associated with the softer cam bearing material.
  
For stock engines, I use the overflow tubes.  For performance applications where the valve spring pressures are increased, I will convert the shafts to a pressurized system.  All the Harland Sharp roller rocker arm assemblies I prepare are set up for pressurized oiling as these use bronze bushings within the rockers which are prone to galling if they starve for oil.
By 2721955meteor - 4 Years Ago
I would say that the cast rockers on hardened shafts are more likely to gall than bras . the people I deal with are not trying to make big power from the y blocks. the cost per hp in the old girls is to high.
 I strive to get best power posable,threw comen cents cost. the load on camshafts and galing  of rockers  and shafts  makes no cents. the oil draining threw the return holes is more than adequate to lube  tieing chain etc,as well lots of oil returns via push rods spinning. I do agree that modern oils work well as far as cloging rocker shafts, but do not come close to full pressure to all rockers and the spill that lubes the valve train.  I see no reason to increase spring pressure in valve train as if you are driving the vehicle on the street,these engines work best 5000 and under, and dollar pr hp best spent on good carbs and electronic ignition along with good exhaust, and hear in the coast of bc heat riser and elect. choke is a must.  I am sure to get bad press for my opinion but we Canadians know we are looked at as less wise than our us friends. but the population  of y Blocks and  high cost of parts made us creative
By Tedster - 4 Years Ago
2721955meteor (11/19/2020)I am sure to get bad press for my opinion but we Canadians know we are looked at as less wise than our US friends.




Well there's obviously some serious issues with certain skill sets amongst your peoples, for example, Bacon Recognition ... LOL /jk
By Dobie - 4 Years Ago
Tedster (11/19/2020)
2721955meteor (11/19/2020)I am sure to get bad press for my opinion but we Canadians know we are looked at as less wise than our US friends.




Well there's obviously some serious issues with certain skill sets amongst your peoples, for example, Bacon Recognition ... LOL /jk


Yeah, what up with that?  I don't think we look at you as less wise, just, ummm, different. I might add that if it weren't for Canadian bacon there would be no Egg McMuffins...😉

By 55blacktie - 4 Years Ago
All things being considered, I was hoping our northern neighbors were better off. It's hard to imagine otherwise. 
By FORD DEARBORN - 4 Years Ago
From a Y-block point of view, remember, Canada had the foresight to keep the flat-head one more hear.
By Dobie - 4 Years Ago
FORD DEARBORN (11/19/2020)
From a Y-block point of view, remember, Canada had the foresight to keep the flat-head one more hear.


Or Ford had some leftover flatties they had to do something with. Just sayin'...
By Tedster - 4 Years Ago
Dobie (11/19/2020)
Tedster (11/19/2020)
2721955meteor (11/19/2020)I am sure to get bad press for my opinion but we Canadians know we are looked at as less wise than our US friends.




Well there's obviously some serious issues with certain skill sets amongst your peoples, for example, Bacon Recognition ... LOL /jk


Yeah, what up with that?  I don't think we look at you as less wise, just, ummm, different. I might add that if it weren't for Canadian bacon there would be no Egg McMuffins...😉





They get a pass on their "Bacon" because of their hallowed status as Strategic Maple Syrup Repository.
By 55blacktie - 4 Years Ago
Engine Tech CC508 cam bearings are available from Rock Auto. I bought mine on ebay, thinking I was getting a good deal, but Rock Auto's price, including USPS shipping, is about $15 cheaper.
By Rusty_S85 - 4 Years Ago
Ted (11/19/2020)
Here are some more thoughts on the subject.
 
A major difference between the FE engines and the Ford Y is that the FE engines had hydraulic lifters while the Y had solids.  I am excluding the 406 and 427 Fords from this discussion.  With hydraulic lifters, the rockers are loaded against the shaft at all times which means there is no period of relaxation of the rocker to the shaft.  In this instance a pressurized rocker shaft will force oil in those locations that normally would not get it.  The Ford Y on the other hand does have that period of relaxation of the rockers to the shafts and simply relies on gravity to feed oil to the bottom of the shafts.  The overflow tubes do allow the shafts to stay full of oil thus eliminating air pockets while at the same time allows the flow of oil through the shafts to be increased thus carrying away the excess heat generated there.  Another plus to the overflow tubes is the right side of engine tube providing additional oil to the timing chain set that it would not receiver otherwise.  The oil trough on the early engines worked in tandem with the oil flow tubes to insure that the oil did indeed get on the chain.
 
As already mentioned, the root of the Ford Y top end oiling problems was with the use paraffin based oils of the time.  The Y was designed originally for the modern multi-weight oils that were introduced at the same time as the Y but not all owners saw fit to use those oils from the onset.  I do still see Ford Y engines with 300K miles with the overflow tubes still intact and these engines are still providng oil to the rockers.  These high mileage engines all run a good quality oil which is routinely changed.
 
A big fail point on engines being rebuilt now is with the softer than stock cam bearings that are being used.  The cam bearings end up wearing much quicker to the point that the groove in the center journal of the camshaft journal is pushed into the bearing thus either restricting the oil flow to the top or shutting it off completely.  Part of this accelerated wear comes from using valve spring pressures that are now much higher than stock.  Common fixes for this are using a center camshaft bearing that has a groove machined on the back side of it, cutting the groove in the center camshaft journal deeper, or machining a groove in the center cam bearing hole in the block that allows the three holes there to be connected thus eliminating the need for the groove in the camshaft.  A recent cam bearing for the Y from Engine Tech (made in South America) is made from a harder material and has thus far helped considerably in stopping the aforementioned problems associated with the softer cam bearing material.
  
For stock engines, I use the overflow tubes.  For performance applications where the valve spring pressures are increased, I will convert the shafts to a pressurized system.  All the Harland Sharp roller rocker arm assemblies I prepare are set up for pressurized oiling as these use bronze bushings within the rockers which are prone to galling if they starve for oil.


Thats kinda like my '56 the 292 is still running without a rebuild, sat some 30 years before I got it running again.  Still uses the overflow tubes and on last check had oil flow at the rockers when I ran the engine with the covers off to get to temp before making my valve lash adjustment.  I been meaning to double check mine though as well as check the valve lash as some of them when I did a simple check did seem to be a little tighter than I set them initially years ago.  But I have been running VR1 oil in mine since I got the engine running again.  First 20w50, now 10w30 as its easier to source locally now than it was when I was first needing the oil.  Before sitting the car was running multi weight oil I know as in the back of the car on the floor was two cases of Exxon 10w30 oil cans from the late 70s early 80s.
By Tedster - 4 Years Ago
I have been meaning to double check mine though as well as check the valve lash as some of them when I did a simple check did seem to be a little tighter than I set them initially years ago.

Rusty I know you know this, but some reading this might not, valve lash clearance tends to get tighter over time, not looser as it might be supposed. The old adage "A tappy valve is a happy valve" has some basis in truth as far as that goes. The valve doesn't spend very much time on the seat, but this is the primary method of cooling, a too-tight valve lash can lead to valve burning or other problems. I really find the whole valve train stuff kind of interesting.
By paul2748 - 4 Years Ago
There is a thing called valve reversion where the valve sinks into the head lessening the clearance, probably because of the seats.  I had this happen on a long trip (east to west coast) in my TBird.  Had a valve job done and all was ok.

Tedster (11/29/2020)
Rusty I know you know this, but some reading this might not, valve lash clearance tends to get tighter over time, not looser as it might be supposed. The old adage "A tappy valve is a happy valve" has some basis in truth as far as that goes. The valve doesn't spend very much time on the seat, but this is the primary method of cooling, a too-tight valve lash can lead to valve burning or other problems. I really find the whole valve train stuff kind of interesting.


By KULTULZ - 4 Years Ago
There is a thing called valve reversion ...


Valve recession ... Wink
By 2721955meteor - 4 Years Ago
valve recession is posable  but highly  unlikely with a y blocks. cam  and lifter wear as well as rocker and shaft wear,rven with some oil at spill tubes, indicates some oil is getting to some rockers and some valve train.. tho with todays oils from rebuild to high miles and heavy valve springs some seat and valve recession is posable
By Tedster - 4 Years Ago
It's been my understanding valve recession was usually or at least often associated as a result of the use of unleaded gasoline, esp. with high speed highway use and/or heavy load operation. In addition to providing anti-knock properties to gasoline the addition of tetraethyl lead compounds to motor gasoline provided some protection to valve seats at high temperatures.

I'm a little hazy on which engines were particularly prone to this problem, Ford (and others) used stellite seats or good steel on some engines (from the 50s thru 60s) some engines didn't need them? But some engines were notorious for sunken valves, designed for leaded gasoline and operated into the unleaded era.

Are Y-Block heads known for soft steel in the valve seats? Leaded-gasoline wasn't the only choice back then either, seems to me Amoco gasoline was specifically sold as an unleaded choice long before TEL was banned for automotive use.
By paul2748 - 4 Years Ago
I had valve recession in the 312 in my Bird (mileage unknown).  All seemed ok when I started out on a coast to coast trip.  By the time I got to Oregon, the car was not  idling good.  Worked the carb a little bit and it didn't help.  At speed it ran fine.  When I got back I started looking into things and found the valve gap was  off  (tight).  Redid the valves and it idled ok.  This was the first time I'd heard of valve recession.  Over the next winter got the correct heads for the car (it had later heads) and had a valve job done (hardened seats installed).  Next cross country trip everything was fine (except for the oil leak)
By Tedster - 4 Years Ago
Paul, that's "interesting", although probably not so interesting at the time.

This is getting a little off the beam from the original topic, but it is lubrication related, sort of right? Was this something evident you could see, or maybe with a straightedge? - I don't know, but wouldn't the valve stems be variable height across the head, maybe higher on some or several cylinders?( probably exhaust)

I stressed a bit about this because I did a few cross country trips before ever pulling the valve covers. When replacing the rockers/shaft/pushrods, valve guide seals & valve springs etc, the valve stem heights were all perfectly equal, but the valve spring installed height was out of spec and required various shims to get them to the correct installed height. I'd suggested hardened valve seats to the feller who "rebuilt" the engine, but I don't know if that happened. I doubt it.
By Florida_Phil - 4 Years Ago
In reference to hardened valve seats.  I have owned at least a dozen classic cars in my lifetime.  I love working on older engines. With few exceptions, I built a new engine for each car I owned.  The question of whether to install hardened valve seats has come up numerous times.  The logic is always that gas without lead will beat out the seats.  Some heads were beat up so bad by the time I got to them I had no choice. Others, like my current engine were pristine. 

I once owned a "G" code 406 Galaxie and a couple of 427 powered cars. Back then I bought boxes of lead additive to keep them running.  Today, I use Florida high test pump unleaded in my classic cars.   I hold the compression to about 9 to one. I time my engines correctly and they don't knock.   Since they started adding alcohol to the gas, I have not experience any damage from unleaded gas in any of my engines.  My current machinist agrees. He advised me not to install new seats in my Y-Block heads.  Keep in mind that I only drive my cars on nice days and to cruises.  If I was to build an engine to make a cross country trip, I would install new seats.  If nothing else, it would make me feel better.
By 2721955meteor - 4 Years Ago
new seats in eczG heads is a big risk as there is. very little cast left to hold them in place.in propane and natural gas engines you need stelight valves and seats.
I have herd from a number of machine shops that the alcahaul additives  that are in our gas helps.a easier solution is small amount  of engine oil in the gas at every fill, like 2 ounces.
  the so-called hardened seats in small block fords is heat the heads and quench them, looks good but rather question the hardness
By Lord Gaga - 4 Years Ago
I agree with FL-PHIL. Hard seats not necessary on lightly loaded, low speed engines.
Except I've started using Stabil 360 lately and I've always added some type of top end lubricant to the gas every so often out of habit.
By Rusty_S85 - 4 Years Ago
Lord Gaga (12/6/2020)
I agree with FL-PHIL. Hard seats not necessary on lightly loaded, low speed engines.
Except I've started using Stabil 360 lately and I've always added some type of top end lubricant to the gas every so often out of habit.

Thats all I use on my engines, that stuff works good.  My 56 would normally get 3 weeks before the humidity here would result in separation of ethanol and fuel in the tank.  I started using the Stabil 360 and I can go a good 7 or 8 months without separation but the gas does get weak.

I also toss a bottle of Redline lead subsitute as well as my engine is original from '56 and I do plan on a complete rebuild with harden seats but my grandfather drove this car hard though foot always on the floor and it still running but lead gas was as far as i could tell was still avaliable in the early 1980s at some stations so maybe that is what saved this engine.
By 55blacktie - 4 Years Ago
I think it's wise to go with hardened exhaust valve seats while the engine is being rebuilt. I know that "G" heads can crack between seats, but I have no direct knowledge of that occurring while installing hardened seats. I suppose it has much to do with the condition of the heads and who is doing the work. Having to baby it while driving can be stressful and takes the fun out of the experience. If in doubt, ask the man who knows. His name is Ted.
By Cliff - 4 Years Ago
I've seen seats come loose and beat the piston, cylinder and head. 
By DryLakesRacer - 4 Years Ago
I’ve been using an additive for the 10 years I’ve had this Y. Brite Star at the beginning and Sta-Bil Marine now. 1-oz in every tank.
To me it’s a personal choice😊 do it if you want and if you think it’s a waste don’t.
Here in SoCal we can drive all year round and I do every weekend.
I don’t add a lead additive but put in some 112 Sonoco every so often because I have it.