Erosion of Headgasket Surface

Discuss all things Model T related.
Forum rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules

Topic author
George Hand
Posts: 305
Joined: Sun Jan 06, 2019 12:02 pm
First Name: George
Last Name: Hand
* REQUIRED* Type and Year of Model Ts owned: 1912 open express, 1920 touring, 1926 tudor-lisenced and insured, 1921tt project 1922 fendered chassis, 192x tt dootle bug 192xengine w/winch projects
Location: Preble NY
MTFCA Number: 28114
MTFCI Number: 21834

Erosion of Headgasket Surface

Post by George Hand » Mon Jul 27, 2020 6:25 pm

I soon will be sending out a block for cylinder boring and fitting of .030 oversize Aluminum pistons, the head gasket surface of the block is eroded at the front and rear coolant ports. what would be a safe material removal for cleaning up the deck, I am guessing .025-.030 or more may need to be milled away. The cylinder head will most likely need a skim cut on it's surface also. I figure the head bolts will need a shaving an equal amount of the total material removed from both castings. I do not want any interference with the pistons which are not high compression pieces.


Roz
Posts: 79
Joined: Fri Feb 15, 2019 7:53 pm
First Name: Dennis
Last Name: P
* REQUIRED* Type and Year of Model Ts owned: 1925 Coupe, 1925 TT, 1927 Speedster, 1931 Model A
Location: Humboldt TN
MTFCA Number: 31449
MTFCI Number: 24373
Board Member Since: 2012

Re: Erosion of Headgasket Surface

Post by Roz » Mon Jul 27, 2020 7:26 pm

Most shops only take off a few thousandths when they deck a block. Just enough to make it flat. I usually have them leave witness marks to show that a minimum was removed. I have had to have the area you are concerned about spray welded to build it up before the decking operation. I don’t like to cut the block down any more than necessary. 0.010” is a lot.


Jerry VanOoteghem
Posts: 2953
Joined: Sun Jan 06, 2019 4:06 pm
First Name: Jerry
Last Name: Van
Location: S.E. Michigan
MTFCA Number: 24868

Re: Erosion of Headgasket Surface

Post by Jerry VanOoteghem » Mon Jul 27, 2020 7:28 pm

Not saying it's a good idea for your car, but my dad claimed to have had 1/16" taken off the block in his/my '25 Touring. No problems.

For deep pitting at the outer edge of the block, (not next to the bore), you might consider filling with hi-temp JB Weld, or even babbitt.


2nighthawks
Posts: 406
Joined: Sun Jul 21, 2019 2:53 am
First Name: Harold
Last Name: Schwendeman
* REQUIRED* Type and Year of Model Ts owned: '23 Roadster Pickup, '26 Touring, '27 Depot Hack, '23 Roadster
Location: Seattle
MTFCA Number: 0
Board Member Since: 2005

Re: Erosion of Headgasket Surface

Post by 2nighthawks » Mon Jul 27, 2020 8:14 pm

Jerry - I've been led to believe that you can take off more than that,....maybe as much as 0.080", but the trouble is, it's hard to determine if the head (or block) has ever been "shaved", "planed", or "milled" for any reason prior in it's nearly 100 year old life, right?


Allan
Posts: 5205
Joined: Sun Jan 06, 2019 7:21 pm
First Name: Allan
Last Name: Bennett
* REQUIRED* Type and Year of Model Ts owned: 1912 van, 1917 shooting brake, 1929 roadster buckboard, 1924 tourer, 1925 barn find buckboard, 1925 D &F wide body roadster, 1927LHD Tudor sedan.
Location: Gawler, Australia

Re: Erosion of Headgasket Surface

Post by Allan » Mon Jul 27, 2020 8:51 pm

I have a reserve 1915 block in my shelves. It was badly eroded around the back water passage. I had a professional bronze the low area so that when the block is faced, the minimum can be removed and the bronzing cleaned up at the same time. I don't know for sure, but I think this bronze was added without any concerns for the bearings, not that that mattered with this spare, as they will be repoured anyway.

Allan from down under.


Kerry
Posts: 1297
Joined: Mon Jan 07, 2019 2:42 pm
First Name: Frank
Last Name: van Ekeren
* REQUIRED* Type and Year of Model Ts owned: 1916 touring, 1916 pick-up, 1924 coupe, 1926 touring, 1927 touring
Location: Rosedale Vic Australia

Re: Erosion of Headgasket Surface

Post by Kerry » Mon Jul 27, 2020 8:55 pm

Hand brake any idea that any more than a light decking would be a good idea for a T block

T blocks have no wear lip in the bore for a reason, the top ring comes up flush with the deck on cast pistons and only a small fraction off TDC on aluminium ones.

Depending on make of piston, always check;

This photo shows the piston on the left that popped the ring out at TDC
000_0617.JPG
.

User avatar

GrandpaFord
Posts: 146
Joined: Sun Jan 06, 2019 2:46 pm
First Name: Neil
Last Name: Kaminar
* REQUIRED* Type and Year of Model Ts owned: 1915 Touring
Location: Mebane, North Carolina
MTFCI Number: 22425

Re: Erosion of Headgasket Surface

Post by GrandpaFord » Mon Jul 27, 2020 9:16 pm

I would be a little scared of brazing as the heat could crack the cast iron, but I suspect that someone who knows what they are doing could braze it.

You can determine how much has been taken off before by running the piston up to the top of the stroke and noting where it lands. You will have to temporally install a crank, one rod, and a piston. If you have a ridge in the cylinder that would tell you too. You could also measure a good block, deck to center of crank bearings, and compare that to your block. A rod mounted in place of the crank could be used for the measurement.

There are several metal filled epoxies available. One use for milling machine beds is Lab Metal, available on Amazon. The slow cure JB Weld is another. The surface has to be absolutely clean before adding any filler. Strong soap and water then bead blasting.

I guess it depend on what you are going to do with the engine. Are you planning on driving across the US or just down to the local ice cream shop?

User avatar

Duey_C
Posts: 1518
Joined: Sun Jan 06, 2019 12:28 pm
First Name: Duane
Last Name: Cooley
* REQUIRED* Type and Year of Model Ts owned: 18 Runabout, 24 Runabout for 20yrs, 25 TT, late Center Door project, open express pickup
Location: central MN
MTFCA Number: 32488
Board Member Since: 2015

Re: Erosion of Headgasket Surface

Post by Duey_C » Wed Jul 29, 2020 2:06 am

Thank you Kerry for bringing this question up.
I was wishing to ask along the same lines and wondered why no-one... Ya know, "peanut gallery syndrome"...
Decking the block: Don't we need to be mindful of the top ring as it comes right up to the top?
Since I lost my mind mind, I feel more liberated

User avatar

Rosenfelder
Posts: 77
Joined: Sun Apr 14, 2019 8:47 am
First Name: John
Last Name: Rosenfelder
* REQUIRED* Type and Year of Model Ts owned: 1927 Model T touring
Location: Southern New Hampshire
MTFCA Number: 49923

Re: Erosion of Headgasket Surface

Post by Rosenfelder » Wed Jul 29, 2020 2:26 pm

The 'professionally rebuilt' engine (original) block in my '27 has brazed filler at the front and back water passages on the block. (Don't know who did it) It has seems to have held up fine.

User avatar

GrandpaFord
Posts: 146
Joined: Sun Jan 06, 2019 2:46 pm
First Name: Neil
Last Name: Kaminar
* REQUIRED* Type and Year of Model Ts owned: 1915 Touring
Location: Mebane, North Carolina
MTFCI Number: 22425

Re: Erosion of Headgasket Surface

Post by GrandpaFord » Wed Jul 29, 2020 2:54 pm

I don't know if this works with brazing but when welding on cast iron using a nickle rod (stick welding) we used to hammer the weld to put it in compression. Because the weld was hot and cooled it was in tension which would lead to another crack along the weld, so hammering it changed it from being in tension to being in compression which took the tension away from the cast iron, which was the cause of the new crack.


Allan
Posts: 5205
Joined: Sun Jan 06, 2019 7:21 pm
First Name: Allan
Last Name: Bennett
* REQUIRED* Type and Year of Model Ts owned: 1912 van, 1917 shooting brake, 1929 roadster buckboard, 1924 tourer, 1925 barn find buckboard, 1925 D &F wide body roadster, 1927LHD Tudor sedan.
Location: Gawler, Australia

Re: Erosion of Headgasket Surface

Post by Allan » Wed Jul 29, 2020 8:17 pm

Neil, the welder who arc welded my concrete mixer frame used nickel rods, and on every pass he hammered the weld as it cooled. Then another pass and the same. The weld ended up filling a void 1/2" deep and just as wide. It has held up now for some 40 years.

I have never done the same with bronze, or seen it done, but it does need to cool in its own time rather than being quenched.

Allan from down under.


Jerry VanOoteghem
Posts: 2953
Joined: Sun Jan 06, 2019 4:06 pm
First Name: Jerry
Last Name: Van
Location: S.E. Michigan
MTFCA Number: 24868

Re: Erosion of Headgasket Surface

Post by Jerry VanOoteghem » Wed Jul 29, 2020 9:00 pm

Any kind of filler that can withstand 212F and almost zero pressure should work fine. No need for very heat intensive welding/brazing.


Topic author
George Hand
Posts: 305
Joined: Sun Jan 06, 2019 12:02 pm
First Name: George
Last Name: Hand
* REQUIRED* Type and Year of Model Ts owned: 1912 open express, 1920 touring, 1926 tudor-lisenced and insured, 1921tt project 1922 fendered chassis, 192x tt dootle bug 192xengine w/winch projects
Location: Preble NY
MTFCA Number: 28114
MTFCI Number: 21834

Re: Erosion of Headgasket Surface

Post by George Hand » Wed Jul 29, 2020 9:14 pm

Kerry, In your photo the piston on the left looks to me like a Model A piston, I am unsure of the compression distance difference between the
A & T piston I know the wrist pin is larger in diameter on the A. The piston on the right looks more like the ones I have. Thanks for your reply. George


Kerry
Posts: 1297
Joined: Mon Jan 07, 2019 2:42 pm
First Name: Frank
Last Name: van Ekeren
* REQUIRED* Type and Year of Model Ts owned: 1916 touring, 1916 pick-up, 1924 coupe, 1926 touring, 1927 touring
Location: Rosedale Vic Australia

Re: Erosion of Headgasket Surface

Post by Kerry » Wed Jul 29, 2020 10:06 pm

George.
Don't know the origin of the pistons but are T STD bore size and wrist pin size.
The engine was recon many years ago and left in storage, brought to me to check out to be used. What a mess it was :o never would have ran the way it was.
000_0583.JPG
000_0586.JPG


Topic author
George Hand
Posts: 305
Joined: Sun Jan 06, 2019 12:02 pm
First Name: George
Last Name: Hand
* REQUIRED* Type and Year of Model Ts owned: 1912 open express, 1920 touring, 1926 tudor-lisenced and insured, 1921tt project 1922 fendered chassis, 192x tt dootle bug 192xengine w/winch projects
Location: Preble NY
MTFCA Number: 28114
MTFCI Number: 21834

Re: Erosion of Headgasket Surface

Post by George Hand » Thu Jul 30, 2020 8:16 am

My block is out being bored for the new pistons, have put deck resurfacing on hold for now will check top ring exposure with crank, rod & piston in place when I bring home. Thanks for the responses. George

Post Reply Previous topicNext topic