Valve replacement - 26-27 block

[fireheadman]

Couldn't locate anything using the forum search for my concerns...
Was looking for some pictures (and guidance) of other's T's showing valves properly seated and without head installed.

On the last start up, I noticed coolant bubbling out from the rear head and knew I needed to replace the head gasket.
Today I got the head removed, spent an hour drilling/tapping a broken head bolt then cleaned up the pistons/valve deck and head.

Noticed the valves on the front and rear are really pitted/worn compared to the others.
Also noticed the cylinder walls have some bad pits, so might evenually need to have the block sleeved.

Wanted to get some inputs from the forum on what to do with that valves.
(Keep in mind, I am not trying to get crazy on performance).

• How do you know when you need to replace valves?
• Do most of you replace with standard "T" valves?
• What dictates (to what degree of play/wobble/looseness) the need to use an oversized 15 or 30 over valve stem?
• Is there a budget friendly way to do this type of job without needing to pull the block and visit a machine shop?
• If yes to last question....Can valves / springs / lifters just be replaced with a cleanup/brushing to the block?

This is my first Model T, so learning as I go with this... trying not to mix my past knowledge with V-8s here.
So far I have done a basic cleanup of the block and head (scraped the gunk + wire brushed) then chased and cleaned up all the head bolt holes.
Inserted the new head bolts and taped up the coolant holes/jackets to keep anything from getting in.

Would love to know what you guys think....
Really not wanting to pull the block.

[Ed Baudoux]

The engine in your pictures would definitely benefit from a complete overhaul. Dark spots, especially at tje top of the cylinder bores, indicate a lot of wear. The valves appear to be the original two piece style. Please understand that this engine doesn't exhibit the typical ridge at the top of the cylinder that other engines show, since the rings are designed to travel to the top of the bore.

[TXGOAT2]

The cylinder in the first picture appears to have severe pitting, perhaps from sitting with water in it for a long period of time. That cylinder cannot function as it should in that condition. Most of the valves look OK, by what little you can tell by looking. The ratty looking exhaust valves are pretty well shot. Replacing all the valves and springs, and grinding each new valve to its seat, is do-able, assuming no seats are cracked or ground too deep into the block. How well did the engine run? I'd be more concerned about the pitted cylinder than the valves. Hot gases blowing past the rings will continue to erode the pitted cylinder wall and may lead to broken rings or a scored piston, besides lost power, rough running, excessive oil leaks, and oil burning. Assuming no cracks in critical areas, it may be that the cylinders could be bored to a standard oversize, or the worst one may need sleeved and the rest bored. Is the engine the correct year for the vehicle? If not, obtaining another engine and overhauling it might be an economical route to a reliable, good-running engine.

[ModelTWoods]

I agree with Ed on all issues. #1 The bottom side of each valve is not shown, however the two holes in the top of each valve shown, appear to indicate original two piece valves. Two piece valves are known to 'loose their head' from the stem: not good. If they are original two piece valves they should be replaced. #2 Are the present valves, standard stem. Mic them to find out. If they are standard, do they 'wobble in the guide? If they do, you probably need to go to .015 o.s. stem valves. Valves should not bind and should drop easy into their seat without 'wobble'. As for cylinder bores, if I'm seeing an actual picture, each cylinder may not 'clean up' without sleeving. I have a 27 block that wasn't pitted, but had been a stationary motor and had over .080 wear and I had no choice but to sleeve. If you have the proper valve seat cutter, you might could true up the seats and install new valves, however if the engine requires oversize stem valves, reaming the block for oversize stems is best done out of the car in a machine shop when the cylinders are being taken care of. I know you don't want to pull the motor for a tear down, but attempting to solve your problems with short cuts is just putting a "Bandaid" on your motor.

[fireheadman]

all of this helps.... much appreciated and thank you!

Here is a link to the last time she was running (summer 2025).... and she sounded great. I even ran her in my chapter show this past summer.
Prior to that, she sat in a Ford Dealership showroom for 7 years. Before that happened, she ran in parades yearly in the 70s and 80s and sat through the 90s. I've gone through a lot of repairs and replacements this past year, so reached most of my "planned" cost to get her running. And to also answer, yes.... when she sat idle, the oil was never changed, I had the luxury of changing 30 yr old oil. Oh, numbers do not match. This is a depot hack (1911 mostly w/26 engine/trans) might see some variant years in between on some parts. It's been in the family since the early '70s so there is sentimental value present. I inherited it form my Grandfather.

Walk around Running and Cleaned up
https://www.youtube.com/shorts/L_cDpnoV_Fw


...finding this condition today made my stomach knot up!! I know there is the easy way and the right way.
I am currently looking for a replacement block, believe i have a 1926 block/trans. Just unsure how successful this search will be.

Option 1)
At best, I'm toying with the idea of finishing the clean up, slapping a head gasket on her and seeing how long she will run for. (I know this would be very risky). - quickest route to running again

Option 2)
Should I be lucky enough to source a good block, I could build that up in time and hope that my son gains an interest when it gets older to swap it in.
- slowest and most costly option, but cleanest and longest lasting

Option 3)
Remove the intake/exhaust manifold + valve cover plate, inspect the stems/fitment, springs, lifters (are they called that on this engine?) and make a more educated decision... replace parts as needed with some light grinding on valve seats (where needed). As for piston rings, I could risk this as it is not a high HP or high compression engine. -little more time spent offline, little more money on extra gaskets

Option 4)
no replacement engine found, pull block and overhaul it (sleeve and/or bore cyclinders), possible chevy valves I have heard about. -equally as expensive as option 2. Honestly either of these options scare me the most because I know there will be thing lurking in the dark to be replaced too!

[Humblej]

Ben,
You are getting excellent advice from some model T folks ranging from very knowledgeable to expert and none of them is suggesting replacing the block. Read their advice and take it to heart. Not only will your engine need a complete overhaul, the transmission and rear axle probably do too. The original valves indicate the true condition of your engine and insight to the mechanical condition of the entire vehicle. Regardless of how pretty and shiny the paint is and how nice the engine sounds, it is mechanically unrestored and in need of serious attention to be a safe and reliable driver.

[Dan Hatch]

Before you do anything clean up the block around the valves. Look for cracks. 26/27 blocks like to crack, special around the exhaust valves. Crack from valve to cly and valve to outside of block.
Looks to me that one cly needs a sleeve, maybe the others will too?
You need to Mag the block to find cracks. I have seen them that you can’t see cracks till you mag them.
Good luck
PS check here special for cracks.

[TXGOAT2]

Since your current engine is very well worn, and not original to the vehicle, locating a '26-'27 block assembly in better condition, or rebuilt, is probably a good option. The engine you have shows evidence of being very well worn, and you can expect that the crankshaft and all other internal parts are well-worn. The block itself will need one sleeve, and likely more. It looks as though at least two exhaust valves have been run a lot of hours while leaking. The block may well have cracked seats. Beyond that, the transmission probably needs work, too. It looks as if that engine has already been patched up a number of times.

[Scott_Conger]

Now, aren't you glad you pulled that head?

Sadly, it is very common for these things to leak coolant at the rear of the engine...they often stop weeping once hot and running. My dad had such a "T"...engine rebuilt, began weeping after 5 years and he went on to drive the car for another 25 years. THE HORROR!

I'll offer a different perspective: go with Option 1. You say it would be very risky...what's the risk?? Before you knew that the engine needed extensive work, you said it ran fine, or at least well enough, despite being a mess inside - and I'll wager to say that you had ZERO concerns with it then, right?

Should the valves be replaced? Yes
Cylinder sleeved? Yes
Any one of a million other things along with a total rebuild? Yes

It doesn't sound like you're emotionally or financially prepared at this stage to do any of that, and that's exactly why I am suggestion OPTION 1. I think that's the best option for you right now

The only other work I would suggest RIGHT NOW is to review all the bolt holes in the block...there are likely some really marginal threads in at least a few holes which may well strip out during the head gasket replacement. So, rather than spoil a perfectly good gasket, do the hole repairs NOW

Give the new gasket a generous dose of commercial spray gasket sealer and go for it. Finally do not fall for any advice to tighten to 50 ft/lb or you'll tear out threads. Tight, with a standard 3/8 socket wrench or similar length box wrench is about all you want. No torque chart in the world is going to account for 100 year old rusty threads in cast iron, so just assemble it the way it was done originally.

Even if the engine self-destructs in the near future, you're left to do a rebuild - and that's exactly the point you're at right now, so why not try to enjoy the thing for a bit while you and your family regroup and make plans for the future - either with this engine or rebuild another engine at your leisure and cash flow for use in the future.

I'll bet Grandpa would approve

[TXGOAT2]

" This is a depot hack ("1911 mostly w/26 engine/.......... ")
It looks like you have a very nice vehicle with a worn-out late T engine and transmission. Finding a good 1911 engine/transmission would probably be a challenge, but finding a good or properly rebuilt 26-27 engine transmission would be easier and less expensive. It would also offer the option of a starter and generator. If the present engine ran well enough, and you don't drive the vehicle a lot, I'd put the head back on it and run it, as-is, while looking for a replacement engine/transmission. There are several reputable rebuilders who can assist you with that. Installing a good engine/transmission will allow for a once -and-done replacement, with minimum chances for vehicle damage and a string of ongoing disappointments with a series of halfway repairs, and you will have a dependable vehicle that runs as good as it looks.

[speedytinc]

This is the typical "Opened a can of worms" situation. You see the damage & a major rebuild is needed. Ignorance was bliss.
On the Bright side, The valves are not razor sharp & the seats are not deep cut. That tells me this is a relatively low mileage motor.
The Babbitt may be usable.
If I were to go with option 1, since the head is off & she ran well, I would grind/lap the valves & check valve lash. Important to get the valves seating. You may need to replace the rusty exhaust valves.
Enjoy what you have as you prep for major motor work or motor replacement.

[Jack Putnam, in Ohio]

Scot Conger is spot on. Follow his advice for now. When the time comes for a rebuild take the block to a competent automotive machinist to do the work needed for a sound rebuild.

[fireheadman]

Now, aren't you glad you pulled that head?
and I'll wager to say that you had ZERO concerns with it then, right?

It doesn't sound like you're emotionally or financially prepared at this stage to do any of that, and that's exactly why I am suggestion OPTION 1. I think that's the best option for you right now

The only other work I would suggest RIGHT NOW is to review all the bolt holes in the block...there are likely some really marginal threads in at least a few holes which may well strip out during the head gasket replacement. So, rather than spoil a perfectly good gasket, do the hole repairs NOW

Give the new gasket a generous dose of commercial spray gasket sealer and go for it. Finally do not fall for any advice to tighten to 50 ft/lb or you'll tear out threads.

I'll bet Grandpa would approve

I actually did have some concerns at the start of the process which mostly subsided once I heard her run after 30 years (replaced all of the ignition, fuel, exhaust/intake component). The first oil change in 30 yrs had me worried (chocolate milkshake), but then next 2 oil changes proved to be much better, same for the radiator flush job (used Irontite + seal) and removed a couple handfuls of rust chunks.

Yes, I have mostly hit my budget to get her on the road, but I might be able to fudge that number to a degree if needed (but not by thousands more). Copper spray will definitely be used generously, I used that on my supercharged v-8 w/copper gaskets religiously!! As for the head bolts, those are in excellent shape (aside from the 1 that I had to drill/retap.... however being this is a low compression - 20HP engine (maybe less with mile high elevation and years of wear/tear), I totally agree with you that "snug with a wrench" should be adequate to prevent stripping anything.

As for "Grandpa would approve"... you sound like you know him somehow?! LOL. Yeah, he was known for rigging up several things, most of which I have had the pleasure of undoing on this vehicle.

She isn't expected to be driven a lot so there should be some time on the side to source a new block.
The only concern I would have with Option 1 is a valve blowing up, ring exploding and losing the head... but that can be replaced too I suppose.

This is the typical "Opened a can of worms" situation. You see the damage & a major rebuild is needed. Ignorance was bliss.
On the Bright side, The valves are not razor sharp & the seats are not deep cut. That tells me this is a relatively low mileage motor.
The Babbitt may be usable.
If I were to go with option 1, since the head is off & she ran well, I would grind/lap the valves & check valve lash. Important to get the valves seating. You may need to replace the rusty exhaust valves.
Enjoy what you have as you prep for major motor work or motor replacement.

I did sleep on this and several other thoughts since yesterday...
There are maybe 5-6 start cycles on the current copper exhaust/intake gaskets, so I bet I can knock the soot/carbon off those and reuse them with no issues. I will take those off plus the cover plate and inspect the valves. The retarded mistake I realized is when I was scraping the carbon off around the valves, For no reason at all, I turned a couple of the valves (spun them). I realize that was bad to do as I just disturbed the seating of them as will as possibly the alignment of them. So might as well look at cleaning them a little more and inspect for wear internally best I can.

My grandfather did swap this engine/trans in back in the 70's to have a starter and I just upgraded the generator.
I also just finished upgrading the bands to kevlar, so ya I could look at this as I have pretty much everything outside of the engine updated/upgraded so having a overhauled block would be about the last thing I need to do. The magneto is working fine also.

Guess this vehicle needs to be re-evaluated as a heirloom that will be passed down. If I continue going down this path it will by far surpass the value 3 times over!


And again, love the added insights, comments, recommendations... helps keep me motivated!
Thanks guys!

[speedytinc]

You do no harm turning the valves. You will need to do this to lap the seats. Valves seat 360 degrees uniformly.
You might want to lift, by cam, the valves to confirm they are 1 or 2 piece. Look @ the base where the head & stem join.
They may not be 2 piece. The intakes look more like 1 piece valves.

[Scott_Conger]

Even if it "blows up", heads for that engine are relatively cheap and abundant, thus my lack of concern to just button things up.

One word of warning, you MUST replace the intake/exhaust gaskets if they were disturbed. Not doing that risks creation of an intake leak which will test your sanity trying to diagnose. Buy the best gaskets you can afford - copper clad 3-in-1 with glands or better yet the individual crush rings and glands. If you do so, you'll never know how good this advice was and that's the point.

Have fun.

[fireheadman]

I use the copper 3n1, so can get another set easily.

[Allan]

Option one for me, with a couple of tips. The copper 3-in-1 gaskets will only fit well if your exhaust manifold is straight. The individual copper crush rings Scott mentions may be the better option.
Check that the block and head are faces are flat. Often they are somewhat eroded on the outer edges of the water galleries, especially if they have been leaking at that point. You can improve the seal at this point by cutting a brass shim to take up some of this erosion. Cut to shape and insert between the copper covers and the crush material between them. It is a shade tree fix which can work well until either or both the block and head are faced
Hope this helps.
Allan from down under.

[fireheadman]

3n1 gaskets on ther right now are leak free, so will just get another set. I have a brand new exhaust manifold on her, so I know it also is straight.
you (Allan) already set me straight on that issue last year. As for the coolant passages/galleys, I have a tad bit of roughness on the edges, believe it to be corrosion that I might be able to take off with a wire wheel and do a little block sanding (if needed). I'll keep that brass shim trick in my back pocket for just in case. Thanks for that!

not sure I will have any time this weekend.... supposed to be going to a home/garden show, then a gun show.
but man is the weather been soo perfect for doing these kinds of chores! 71 degrees in feb in denver!!

[Allan]

Cleaning up/sanding the pitted ares can only increase the problem of the block and head surface not being perfectly flat. It would mean making the brass shim of a mite thicker material to compensate for what you remove. Still do-able. You might fit the head dry without the gasket ans see what a feeler gauge may tell you. It is still a patch-up to get you on the road until the job can be done perfectly.

Allan from down

[fireheadman]

its not so much as corrosion I am referring to, it is more of the old gasket that needs to be cleaned off the block...think a wire wheel will do the trick and then generous amount of copper spray.

[Scott_Conger]

A wire wheel will cause grain pull-out and erode sharp edges, no matter how careful you are and will further exacerbate any rolloff you're already suffering from that caused the original leak.

A straight edge razorblade and perhaps a hand held scotchbrite pad for localized spot contamination is all you want to use

[fireheadman]

Perfect. Thanks for that info, will give that a shot

[Dan Hatch]

Just hit it with a little MBRT, like the old timers did back in the day.

[Jerry VanOoteghem]

Just hit it with a little MBRT, like the old timers did back in the day.

[Steve Hughes]

I would go with option 1 for now. Look for a decent running engine that you can just drop in. Should be able to find one for a lot less money than doing a rebuild. Since the engine doesn’t match the rest of the car there is no reason you need to get a’26 or’27 engine. Anything ‘19 or newer with starter and generator should work great for you.

[Mark Gregush]

Didn't see this on a read through, 26/27 blocks are known to crack in the valve chamber area. Valve stem bosses up into the ports. This is another place to check for cracks.
Ya on the can o worms! My 25 had a very loud clunk in the drive plate area but ran good cast iron pistons and all but needed a complete rebuild. The pins in the push plate did a number on the holes in the drive plate, really wallowed them out.

[fireheadman]

Got into the valve plate yesterday evening to check things out..... very glad I did.

• I noticed was the failing/deteriorating cork gasket. There was small pieces all over the place, so would have been a matter of time before that clogged up an oil port and starved the lower end.
• Then noticed was a valve seat that is falling off a retainer pin, unsure how long it has been like that!?
• I also see the valves are the original 2-piece and I do have adjustable lifters. The valve stems have some wear on them so I should get those replaced.

Forgot to check to see if there is any significant play in the guides, so will check on that.

Here is a video going through each valve... (Wish we could post embedded youtube videos on here).
https://youtube.com/shorts/5CDrdT4PBrg?feature=share

Showing the 2-piece and bad spring retainer

Close up the the end valves (the worst condition ones)

[Dan Hatch]

Here is some information on your spring retainer.
https://www.mtfca.com/discus/messages/5 ... 1450555390

[fireheadman]

I read that a few days ago... staying away from the retainer with a slot.
I will compress the spring and insert the pin, the retainers I am looking at are solid without the slot

This

Screenshot 2026-02-16 at 1.09.09 PM.png (223.14 KiB) Viewed 447 times

VS this

Screenshot 2026-02-16 at 1.09.25 PM.png (172.63 KiB) Viewed 447 times

[speedytinc]

I read that a few days ago... staying away from the retainer with a slot.
I will compress the spring and insert the pin, the retainers I am looking at are solid without the slot

This
Screenshot 2026-02-16 at 1.09.09 PM.png

VS this
Screenshot 2026-02-16 at 1.09.25 PM.png

You don't understand, the slot is the worn thru part of the retainer. Thus: failure.
You are looking for evidence the pin is wearing thru your retainers.
As warned, original retainers were tougher/thicker than past thin replacements..

[Dan Hatch]

You missed the point. They NEVER made a retainer with a slot. The pin wears a slot in the retainer cause the reproduction retainer aren’t worth a s!!!. Pin is harder than the retainer.
Go to a modern valve from a 390. That is all I install in customer engines.

[fireheadman]

well why didn't ya say in the first place guys? lol.
thanks for clarifying. I imagine I will find that same issue on the one that is crooked.

[Mike Silbert]

And watch out for worn pins also.
They do wear, especially if someone replaced them with nails years ago.

If I am deep enough to replace valves I use modern angled keeper type for reliability.
I make up a set from various parts and sources.
Mike

[fireheadman]

Here's what I am looking at for this:
I will look a little more of the thicker or modern retainers as some of you have mentioned, otherwise I'll go with these...

Also from what I am reading, since I am not oversizing the valves (this time around), I can simply use a bottle brush and some carb spray to clean up the guides. No need for a reamer unless it ends up being clogged up with corrosion a bottle brush can't remove.

Let me know your throughts on all this.

[Scott_Conger]

You are now committing to a full valve job, which includes cutting new valve seats. Cutting new seats means fixturing a cutter to the old worn valve guides and cutting a 3 angle seat.

A set of Neway cutters and tools will set you back around $300-350. Don't just go to eBay and buy a set...call Neway and tell them what you're working on and they will build you a set specifically for a Model T. Plenty of folks will suggest you grab a drill and some old crummy valve grinding stones and whale away on the valve seats. If you do, that will give the engine builder just something more to charge you to repair when that inevitable day comes.

If you chose to just pop in some new valves without reworking the seats, do not be surprised if the car runs worse than it did before you started this work because the odds favor that outcome.

If I were you, I would forget about any new parts at all...ask the Forum for a couple (as needed) original valve retainers and matching original pins, all the while keeping the original valves at this point. If you want to drive the car twice a year to take the grandkids for ice cream, the repro parts are fine. If you want to drive the car any more than that, then you want original parts here.

The above advice is predicated on the fact that I believe you said the car ran pretty well before all of this - and now you know the engine pretty much needs a full rebuild. Just putzing around on this thing at this point will spend maybe up to $750 in parts and cutters and you will still have an engine that is in need of a total rebuild...I would save that $750 for that day when it comes.

FWIW - your engine already has adjustable lifters, so the cam was out and lifters were replaced at one point, and valve keepers were replaced with repro parts at one time, as well. They weren't worried about those valves and neither should you. It's the first time I've ever advised keeping original valves, but with the condition that one cylinder is in and the general condition of things you have very little to lose in keeping them. Save your $$, drive the car easily, rebuild when you're ready. Anything else is simply spending money with little return on the investment.

Finally, it looks as though the valve seats have never been reworked, or if done, were barely kissed. This at least bodes well for the block in that the valves are not sunk down in like many tired engines are.

[fireheadman]

That's exactly what I like to hear!!

I'm blind going down this path, so thank you for guiding me.

I was watching a video on youtube of a father/daughter rebuilding the valves. He applied a gritty paste to the valves and had her turn them back and forth several times. I'm guessing this was grinding down the irregular highs/lows to reseat them. Does that sound correct and is this more in line with your thoughts?

I'm definitely not going to be blasting this on the roads at all, ice cream runs a couple times a year is about it.
I could start with retainers/keepers and pins for sure..

[Scott_Conger]

Ideally, grinding is to just kiss a new round valve to a new round seat and bring the angles into perfect contact. Some folks don't understand this and simply transfer one faulty un-round part to another...not good. Plus, you have cast iron valve heads on at least some valves and they will be essentially the same hardness as the block and imperfect in their geometry so everything will cut everything...not good either.

Still other people insist on doing a "kiss job" on newly cut Neway seats...wrongwrongwrong! A 3 angle seat with a Neway cutter leaves a 1 degree difference between the valve and seat and upon starting the engine, the valve peens a perfect seat into the block...no lapping necessary.

Finally, lapping a seat with a valve even if done to perfection, ends up creating too wide of a seat in the block...now the area is increased and thus the seating pressure from the spring goes way down as the area goes up. This will allow carbon flakes to keep the valve open some and cause overheating havoc on both seat and valve. A properly narrow seat has high seat pressure and the valve will more likely pulverize or chop up the carbon flake and the valve will seal. That is the reason for "3 angle seat". To properly put the seat in the middle of the valve, once the seat angle is made, a different angle is used to cut away the top of the seat and the bottom of the seat, leaving a narrow ring of sealing area right in the middle.

All these simple jobs come with surprisingly unusual or complex reasons for being done a particular way.

Today, there are a lot of "T"s because of the sheer volume made. In the future there will be plenty of "T"s because we take thoughtful care of them.

Good luck

[fireheadman]

3-angle seat.... found a diagram of this vs a conical seat (single angle)

[TXGOAT2]

Another issue with lapping valves against their seats is the possibility of creating a slight groove in the portion of the valve face that contacts the seat. When the engine is started, the valves heat up and expand, which moves the grooved portion of the valve face out of register with the seat contact they were lapped to.