Trying to diagnose the problem of low power

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Model T Ford Forum: Forum 2016: Trying to diagnose the problem of low power
Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Sunday, November 27, 2016 - 05:34 pm:

My '10 engine runs fairly smooth and on four cylinders, but it never seems to have as much power as I think it should have. Yesterday I was priming it with the key off before a drive to the store. I noticed that one cylinder did not feel like it has as much compression as the other three. So today I did a cold cranking pressure test.

With all the plugs out and the carburetor wide open I pulled it through with the gage inserted in one cylinder at a time. Each cylinder received five compression strokes, which means the engine was pulled through 10 revolutions per cylinder. It's a lot of hand cranking.

Results were what I expected:
#1 50 PSI
#2 18 PSI
#3 35 PSI
#4 50 PSI

One of the benefits of an open valve engine is that you can see all the valves open and close. All of them appear to be opening about the same amount, and all have clearance when the valve is closed and the cam is on base circle. So I am thinking it may have some burned or carbon caked valves.

Time to pull the head.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Sunday, November 27, 2016 - 06:04 pm:

Good luck and keep us posted! :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kevin Matthiesen on Sunday, November 27, 2016 - 06:43 pm:

Royce, I noticed that the compression is down between #2 and #3 cylinders. Maybe it is just the head gasket leaking between those two cylinders. That would be a easy fix, good luck.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Sunday, November 27, 2016 - 07:00 pm:

That would be great if it was that simple! Will know tomorrow.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Charlie B actually in Toms River N.J. on Sunday, November 27, 2016 - 07:06 pm:

Wet test wasn't done. Eliminates the rings.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Sunday, November 27, 2016 - 07:11 pm:

Good point Charlie. I will try a squirt of oil in each cylinder and do the cranking pressure test again before removing the head.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Eviston on Sunday, November 27, 2016 - 08:28 pm:

My wager, a very small sum, is head gasket. Gordon Kirwan, a friend I dearly miss, had this happen to his '10 every few years. He had several theories why it did this. And, I, myself, would not have the testicular fortitude to mess around with the headboard for fear of pulling the threads out of the block.That would be my luck. I know Royce will have no trouble.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Charlie B actually in Toms River N.J. on Sunday, November 27, 2016 - 09:23 pm:

Just to make sure the rings aren't involved. Extra step I know but worth it.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gary Tillstrom 30 miles N of Memphis TN on Sunday, November 27, 2016 - 09:30 pm:

Royce, look on eBay for an endoscope. They are cheap. I bought a wifi unit that records images in HD. It has saved me a lot of time. These have a mirror on them and will give you a great view of both valve and seat. If you have an android phone they are about $10. Mine talks to my android tablet and iPhone and was about $60. I recently did an annual and showed the guy the cylinder issue he was having with documented photos before pulling his cylinder. It's about as handy as a sharp pocket knife.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Monday, November 28, 2016 - 12:54 pm:

Ggary,

In this case an endoscope, whatever it sees, will simply tell me to pull the head so I can fix the problem. Which is what I am doing.

I did try a compression test with oil in the cylinders. There was no change in the numbers.

First I drained the coolant. Then removed the bolts from the water outlet. Next I loosened the head bolts. Some came loose with a load CRACK and others felt like the bolt was going to snap, so I hit those with some heat from the propane torch.



With all the bolts out, I hit the head a couple times with the rubber faced dead blow hammer to free it from the gasket. With the head out of the way we can see the gasket looks fine.



And the head looks OK too. Lots of carbon on both the head and the pistons. The cylinder walls are like mirrors.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Monday, November 28, 2016 - 01:06 pm:

Next thing to do is remove the intake and exhaust to allow better access to the valve springs so we can get the valves out.

The exhaust manifold nut resisted the efforts to loosen it. So out came the MAP gas torch again. The nut came right off after it was dull red.



With the manifolds out of the way I can compress the valve springs. Then tap the valve with a hammer to break it free from the valve retainer.



Then the pin can be removed with your fingers.



Looking at the intake valves of the weak cylinders we can see caked carbon on the valve seats that is keeping the valve from making a good seal. This will be easy to fix.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Monday, November 28, 2016 - 01:10 pm:

Correction, the problem valves are #2 intake and #3 exhaust. Anyways lots of carbon needs to be scraped from the head, pistons, and valves.

The valves will all get lapped on every cylinder. Then I check valve clearance gap and grind stems if necessary before installing the valve pins and springs and keepers again.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Eviston on Monday, November 28, 2016 - 01:16 pm:

Good deal. Are those the original valves seats? No matter what I do, I can't get rid of the s on valve. Damnedest thing, and I am too stubborn to start over.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Monday, November 28, 2016 - 01:24 pm:

The exhaust valves have all been replaced previously. The intakes are original, and the valves all sit proud of the head even thogh they have been ground a few times. There are no seat inserts. The engine has aluminum pistons, we will see if the bore size is stamped on top. Otherwise I will be measuring the bore size. In any case it appears to be a relatively low mileage engine.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Tomaso - Longbranch,WA on Monday, November 28, 2016 - 01:40 pm:

As always, great tutorial Royce.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Monday, November 28, 2016 - 01:50 pm:

Great pics, do I see a few original two-piece valves? Will you be re-using them?

Maybe my eyes are calibrated for more modern V8s, but those exhaust valves look pretty dark. You might be able to adjust the carb a little leaner once everything is buttoned back up.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Monday, November 28, 2016 - 02:00 pm:

Mark when I got the car it had been sitting for years. It had a set of 1911 - ish Heinze coils that were barely capable of lighting the fire, and a Kingston L2 carburetor with the float set too high. It ought to run great with a set of freshly lapped valves. I don't have any other valves here or I would be changing them. It will have to get by with the original intake valves for a while longer, other projects are priority and this car does not get driven much for now.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem - SE Michigan on Monday, November 28, 2016 - 03:11 pm:

Royce,

I hear what you say about not driving it much, but wow, I wouldn't trust the life of an open valve block to those two piece valves. You can have new valves on your doorstep in 24 hours I would assume.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Monday, November 28, 2016 - 04:22 pm:

Jerry,

I decided the same thing after thinking more about it. Plus, the old valves are not any good. I'll elaborate........

I finished pulling the rest of the valve keeper pins. Then I put all the valves, springs, pins and retainers in the handy organizer and set them on the work bench while the engine gets cleaned up.



You need all the valve springs completely out of the way in order that you can check valve clearance easily. Any time you do a valve job or lap the valves you are removing material from the valve and the valve seat. This decreases clearance. So the last task in this job before reassembly will be checking valve clearance and then grinding the valve stems to achieve the proper clearance.



To clean off the carbon on top of the pistons and in the combustion chamber on the block I start with this 90 degree air motor fitted with a plastic stripping disc. It makes quick work of the carbon without removing any metal.



I put the #1 and #4 pistons at TDC and clean those up.



Then vacuum up all the carbon dust, wipe everything off with a lacquer thinner soaked rag, and do the other two the same way.



With the piston tops clean I can read the .040 stamped on top of each one.



The combustion chambers on the cylinder head get scraped by hand and vacuumed before using power tools. You've seen those old photos where the guy in a Ford dealership shop is covered in black and has a black face? This is how to relive that history.



Another 90 degree air motor, this time with a cup shaped wire wheel.



The valves are next. I started with cylinder #1 and the valves looked OK. When I cleaned the carbon off the #2 exhaust valve I could see that several valves had been cut too thin in the past. When a too - thin exhaust valve gets red hot it curls back from the valve seat. This one had actually cracked on both sides too. I just got off the phone with Chaffins. New valves are on the way. To be continued.....


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Monday, November 28, 2016 - 04:39 pm:

Things are moving right along, thanks for taking and posting pictures along the way!

Yep, no "margin" left on those valves, glad to hear you're replacing them.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Willis Jenkins on Monday, November 28, 2016 - 07:50 pm:

I always thought that "air motor", was called an angle die grinder?

Willis


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Eviston on Monday, November 28, 2016 - 09:27 pm:

And, I believe those are Firestone Polonium plugs. I have run hell out of those with great success.Amazing. I believe I still have a new box of 10,long reach pipe.These I'll keep.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Charlie B actually in Toms River N.J. on Tuesday, November 29, 2016 - 07:44 am:

There's a post this morning about valves and they seem to think that the valves with the 2 holes in the top aren't always 2 piece valves. Thought I'd ask here if it's true or not since they don't seem to know.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Tuesday, November 29, 2016 - 09:57 am:

True, there are replacement T valves that have the two holes that are not two piece. Also, Model A exhaust valves are one piece stellite valves, they have the two holes and make dandy replacements for Model T valves if you have the machine shop skills necessary to do the modifications.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Charlie B actually in Toms River N.J. on Tuesday, November 29, 2016 - 10:15 am:

Some thing learned.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tim on Tuesday, November 29, 2016 - 12:05 pm:

Could be the photo itself but I see no seat for the valves in the block. You'll need to cut them in then lap in the new valves.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Tuesday, November 29, 2016 - 12:15 pm:

Tim,

Incorrect. The block is in excellent shape. There is no reason to install repair valve seat inserts.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les VonNordheim on Wednesday, November 30, 2016 - 08:02 pm:

Royce,
How do the valve springs compare to new springs? Weak springs can allow carbon to build up on the seats allowing the valve to not fully seat. Also, is the camshaft a regrind? Speaking from personal experience....The first camshaft in my rebuilt 13 engine was a early design 270 drivers camshaft that performed very poorly on hills. I understand that Glen corrected the design sometime after I bought the camshaft. I chased my tail trying to figure out what was wrong with my car when any "Sick" T would blow off my doors on a hill.
That along with other bad experiences dealing with regrind camshafts.....I will walk the plank for a new camshaft when ever possible or be happy with a good used original stock camshaft.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Trent Boggess on Wednesday, November 30, 2016 - 09:56 pm:

Hi Royce,

I am also enjoying your pictures and commentary as you replace the valves in your '10. I have had the privilege to know an original May of 1910 car that belongs to a very good friend of mine. I have ridden and driven that car and was thoroughly impressed with the power of it. When I read that your '10 wasn't performing well, my first suspect was the valve train.

Depending on when your car was built in 1910, none of the valves you found in the engine may have been original to the car. Looking at the Record of Change cards for T-424 Exhaust and Inlet Valve, Model Ts built up through July 1910 used one-piece valves made from drop forgings. These look a lot like two-piece valves, but on careful examination the head and the stem are both one piece. Model NRS cars used a similar one piece drop forging valve, except the stem is 3/8 inch in diameter.

At the beginning of August 1910 the Ford engineers revised the design of the valves and introduced the two-piece valve design. Another important date is March 19, 1919. That was when the Ford engineers specified that the name "Ford" should be sunk into the head casting as Jerry Vanooteghem described earlier in this thread. But prior to that date, Ford two-piece valves were unmarked.

The next important date was December 20, 1926. This is when Ford introduced the one-piece steel valve. These one-piece valves were not put into all Model T chassis, but were only used in engines for Model TT trucks. There were two types of Model T engines being produced simultaneously in 1927. T-532 designated the engine used in passÚnger car and regular T chassis production, while TT-532 indicated engines intended for use in Model TT trucks. The TT-532 engines differed from the T-532 engines only in the use of the one-piece steel valves. The one-piece Ford steel valves do have the name "Ford" in script on the underside of the head.

Finally, on August 3, 1928 the engineers removed the two holes from the top of the valve head. So, there are some one-piece Stella Ford valves out there that do not have the two holes in their heads for attaching a valve grinding tool.

Respectfully submitted,

Trent Boggess


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Wednesday, November 30, 2016 - 10:10 pm:

Trent,

Much appreciated. My car left Highland Park in October 1910 so it seems like the intakes could be original two piece style. The exhaust valves match the description for replacement valves from the late 1929's.


The car was "restored" around 1957. I use that term loosely.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Thursday, December 01, 2016 - 09:42 am:

Les,

Sorry I forgot to answer your questions. I am going to check the valve springs on my Moroso valve spring scale. They all seem as stiff as needed. I don't think they are originals, they have a uniform black coating that looks too good to be 106 years old. I don't know anything about the camshaft. I am going to measure lift on all 8 to see if it is in good shape or not before reassembling. It would be easy to change cams right now. If I install a cam it would be a new 250 from Stipe.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Thursday, December 01, 2016 - 05:00 pm:

The new stainless valves came this morning from Chaffins. They are excellent.

I used one of the valves to check camshaft wear on every cylinder. This involves setting the lifter on base circle of the cam, setting the dial indicator to zero, and checking the clearance between the lifter and the valve. The sum of the two measurements is the gross lift of that cam lobe.



I made a chart of the lobe lifts and clearances. As you can see the camshaft wear is minimal. The last lobe was .248". The most worn lobe is the intake on #2 cylinder with a gross lift of .247". The least worn is #1 exhaust with .255". I can accept a variation of .009".


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Thursday, December 01, 2016 - 05:07 pm:

I started by doing a very light cut of each seat with a 45* cutter with a 5/16" pilot shaft. This makes each seat uniform, I did about one turn on each seat. The cutter is very sharp, you can easily remove too much material if you are not careful. The objective is to have a narrow contact pattern on each valve, about 1/32" or so.



After the 45 degree cutter I use the 60 degree cutter again very lightly. It cleans up each port below the 45 degree cut.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Thursday, December 01, 2016 - 05:19 pm:

All of the valves have .005" or more clearance so they can be lapped with a little dab of Clover compound.



I used a suction cup lapping tool on all but the #4 exhaust.



That valve is right below the firewall. So it had to be drilled to accept an original Ford lapping tool.



You only need to spin each valve backwards and forwards about 10 seconds each. You will know when the valve is making 360 degree contact when it becomes tough to spin. You are just trying to make a perfect seal about 1/32" wide on the valve.

After wiping the Clover off you can see the pattern.




Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Thursday, December 01, 2016 - 05:25 pm:

The last thing to do is cutting the valve stems for correct clearance. I set all the valves at .015" grinding the stems on my Van Doren valve grinder's stem holder after carefully dressing the stone. I took this photo showing approximately how it is done using one of the old scrap valves; I can't demonstrate how the valve is rotated as you grind it while holding the camera.

In any case each stem is carefully ground and repeatedly checked using a .015" feeler gage with the cam on its base circle. The easy way to do this is to place each cylinder at TDC on the compression stroke, then grind both valves on that cylinder.

After all this each valve was cleaned with Berrymans B12 spray, each port was blown out with compressed air after wiping it with lacquer thinner. It is all ready for assembly tomorrow morning and I can't wait to see how it runs.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Thursday, December 01, 2016 - 05:30 pm:

You're zipping right along! Thanks for the pictures.

I may have missed it, did you order standard diameter, or oversize stem valves?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Thursday, December 01, 2016 - 06:26 pm:

I used standard size stems.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Harold Schwendeman - Sumner,WA on Thursday, December 01, 2016 - 07:34 pm:

Royce - Another GREAT "step by step" tutorial! Thanks for taking the time to photograph the whole process.

Just wondering about the tops of the lifters, or tappets (Ford Model T Manual calls them "pushrods"). Sometimes the top surface of the tappets wear to the point of becoming concave,....were yours still flat? Such wear makes it more difficult to set the valve lash accurately. Mine were quite noticeably "dished" out, obviously from many miles, and years, of hammering by the ends of the valve stems. I did not remove the tappets to grind the ends flat again, but probably should have. In fact, if I had gone to the work of removing the worn tappets, I probably would have installed a new set of adjustable tappets, but again, did not do so. Just wondering if you had such a situation,......harold


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Thursday, December 01, 2016 - 08:02 pm:

Harold,

I did not take any photos of the tops of the lifters but they looked to have virtually no wear. The cam has wear of .009" on one lobe, if I replace the cam in the future I will also install new non adjustable lifters. I suspect the engine will run very well after this and not need attention until the rods need adjustment. Since the pan on my 10, like all 1910's, has no inspection door, that will be time for a general overhaul.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Wayne Sheldon, Grass Valley, CA on Thursday, December 01, 2016 - 08:13 pm:

Yes, thank you for such a nice tutorial. Such things should help many newcomers. It appears you do things much how I do.
I had to chuckle when I saw your "Clover" tin! It looks almost exactly like the one I still use. It was my father's before, and bought new when I was very little. I also have an older single side Clover tin that had belonged to my grandfather, but it is empty.
Again, thank you.
Good luck with your test drive!
Drive carefully, and enjoy, W2


Top of pagePrevious messageNext messageBottom of page Link to this message  By Sean Butler Huntington Beach, CA on Thursday, December 01, 2016 - 08:28 pm:

Excellent, well photographed and documented thread. Thanks for sharing, Royce!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chuck Martel in Temperance MI on Thursday, December 01, 2016 - 10:21 pm:

Thanks Royce for the Great Tutorial.

I will be doing a similar operation to freshen up one of my engines soon, so this could not have come at a better time.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les VonNordheim on Thursday, December 01, 2016 - 11:58 pm:

Great Tutorial and pictures. Look forward to hearing how well it performs. Amazed on how narrow the valve seats still are. As a final check, I like to spray a little Wd40 around each valve/seat, pushing the valve down tight with one finger and blow air in the intake/exhaust ports looking for leaking air bubbles around the seat.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Friday, December 02, 2016 - 05:12 pm:

A lot of routine stuff today.

I started by wiping down the head gasket surfaces on both the engine and the head with lacquer thinner.


Then hung the head gasket by a nail and sprayed both sides with Permatex Copper Coat.



The water outlet gasket was cleaned up with a sanding disc and coated with contact cement, as was the water outlet. After they dried the gasket was stuck to the water outlet.



RTV was then applied to the surface that mates with the cylinder head.



The head was installed. I put some C5A anti seize compound on the head bolt threads. Several of the head bolts were rusted to the point they were likely to snap off, so I replaced those with some good ones from my spare bolt collection. The exhaust manifold was installed with a pair of half clamps.



Then the intake manifold was installed.



Everything was hooked up and the coolant poured in. I checked the oil and the gas. Pulled up four times on the crank with the key off. I fired it up and adjusted the mixture, which was way richer than it needed to be at first. I suspect the burned valves were acting like a vacuum leak.

After everything was adjusted, the car runs great. Going on a drive now.

https://youtu.be/u9JZNjv3fK0


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Friday, December 02, 2016 - 05:32 pm:

Well done, I love it when a plan comes together! :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob on Upper Texas Gulf Coast on Friday, December 02, 2016 - 06:48 pm:

Royce - What do you use the petcock valve on the intake manifold for?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Friday, December 02, 2016 - 07:38 pm:

Bob,

It plugs the hole in the intake.


Top of pagePrevious messageNext messageBottom of page Link to this message  By George n LakeOzark,Missourah on Friday, December 02, 2016 - 10:52 pm:

Royce, good show. Would you please share with us how you mounted your camera and how it was so steady ??


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Noonan - Norton, MA. on Friday, December 02, 2016 - 11:12 pm:

Great job Royce, sounds great! What kind of shape were your lifters in as far as cupping, and what did you end up using for final valve/lifter specs?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Friday, December 02, 2016 - 11:18 pm:

George,

I held the camera in my hand for all but the video.


John,

I set the clearance at .015" for all valves / lifters.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gary Blake, Kansas City on Saturday, December 03, 2016 - 03:33 pm:

Ah nice, Lawther drive around White Rock lake. A perfect road for a T.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Sam Mendenhall on Wednesday, December 21, 2016 - 12:40 pm:

Royce, great thread. I have one question. Why do you not use RTV on water outlet side, is the contact cement you use just regular contact? Thanks again for a very informative tutorial.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Wednesday, December 21, 2016 - 12:45 pm:

Great thread Royce, please keep us updated when you start phase 2 of this project.

For the others, what is phase 2? You'll just have to stay in suspense until Royce decides to tell you! :-O


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Wednesday, December 21, 2016 - 12:56 pm:

Sam,

I want the gaskets to be glued permanently to the outlet and inlet. That way if I take the radiator out the RTV turns loose and the gaskets are reusable by just rubbing the RTV off with my thumb.


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