Riddle of the day

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Model T Ford Forum: Forum 2009: Riddle of the day
Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert G. Hester Jr. on Thursday, December 03, 2009 - 03:42 am:

When your car refuses to move in low or reverse and the problem is a bad head gasket, what kind of car is it? I'm guessing that most of you know the answer to that. My 27 touring, after sitting for a few days, started right up but didn't want to move. Shut her down after about five minutes and started checking, found water and oil pudding. Drained the sump and the radiator right away. Tried to torque the head bolts and none of them moved at all. I removed the cylinder head, fearing the worst. I found no cracks but the gasket was leaking near number three. It appears that the head was never pulled down properly due to the head bolts bottoming out on the junk in the holes. I've checked the block and head with a good straight-edge and found nothing to indicate anything needs to be milled. This engine is equipped with aluminum pistons and a Simmons high compression head and is just about the sweetest running T model that I've been associated with. I guess my reason for posting here is two-fold. First, to say make sure those bolts holes are clean. Second, to ask what you guys think about installing the head with studs that have fine threads at the top? And if so, what kind of torque should I use? I'll appreciate your comments. Bob


Top of pagePrevious messageNext messageBottom of page Link to this message  By Richard Gould on Thursday, December 03, 2009 - 03:49 am:

I don't believe you can get the head to fit over studs at the rear of the block due to the firewall. I am not a big fan of studs anyway since they all have to be perfectly lined up to work. Heck, I have had problems fitting an early driveshaft spool to the rear end because the six studs didn't line up. I can't imagine trying to fit a head over 15 studs.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert G. Hester Jr. on Thursday, December 03, 2009 - 04:23 am:

Thanks for your response, Richard. I had figured that if I used studs I'd set the head and gasket in place, line everything up with a few of the original bolts, then install the studs by jamming two thin nuts together at the very top and using this to snug them to the bottom of the holes, not very tight. Since the studs will be longer than the bolts I still could have a problem at the very back, haven't got it all psyched out yet. Bob


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Thursday, December 03, 2009 - 09:03 am:

I use studs on the Fronty head. Model A studs should work on a flathead. An acorn nut or jam nuts will seat the stud. If there is a clearance problem, you can install studs in the head first, holding them clear of the block with tape.

I torque the studs to 45 lbs, dry. It used to blow a head gasket every couple of years until I went to studs a few years back. Haven't changed one since.

rdr


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert G. Hester Jr. on Thursday, December 03, 2009 - 10:56 am:

Thank you, Ricks. I think you've helped me decide to go with studs. Excellent suggestion about setting the studs in the back of the head and securing with tape. Might even use clothes pins. Happy T'ing. Bob


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert G. Hester Jr. on Thursday, December 03, 2009 - 10:59 am:

Thank you, Ricks. I think you've helped me decide to go with studs. Excellent suggestion about setting the studs in the back of the head and securing with tape. Might even use clothes pins. Happy T'ing. Bob


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jeff Humble on Thursday, December 03, 2009 - 11:26 am:

Robert,
What you and Ralph are suggesting will work easy enough installing a head, but it will be a pistol to take the head off again. You will have to remove all of the studs to get the head off, that means double nut each stud and hope you can get them out or a stud remover which is destructive to the studs. The 26-27 firewall overhanging the head just makes studs impracticle. If the rear most stud becomes frozen to the block you will have to remove the engine or body to get the head off. Best solution is to clean out all the head bolt holes with a drill bit and chase the threads wtih a standard 7/16-14 tap followed by a 7/16-14 bottom tap, and blow out with air. Always test the hole depth with the head bolts to confirm the bolts are not too long or too short. Never lube or apply anti-sieze, always torque dry in the typical patern to 30, then 35, then 40, etc., not to exceede 55 ft lbs torque.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert G. Hester Jr. on Thursday, December 03, 2009 - 11:59 am:

Good point, Jeff. I'll for sure have all the threads cleaned out with a tap and probably use a little anti-sieze on the bottom of the studs and also won't seat them tightly. I think I'll chance it. Sorry for the double post above, don't know how that happened. Bob


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chuck Richardson on Thursday, December 03, 2009 - 12:17 pm:

Regarding Jeff Humble's message: "Never lube or apply anti-sieze..."

Why no anti-sieze?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush on Thursday, December 03, 2009 - 12:22 pm:

Because anti-sieze will act like a lubricant and give a false reading when torquing head down.


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Stauffacher on Thursday, December 03, 2009 - 12:30 pm:

I opted for studs when installing the RAJO since my other high-performance engines all use studs. I've had to remove the head a couple of times due to poorly made gaskets. Each time I never had a problem removing the studs via jam nuts which I really did not have to do as I had the firewall modified so that I lift the RAJO straight up. When putting the head back on, I install a couple of studs as pilots and the set the gasket and head in place.
my centerdoor


Top of pagePrevious messageNext messageBottom of page Link to this message  By Richard Gould on Thursday, December 03, 2009 - 02:36 pm:

I stand corrected. I assumed you would remove the head over the studs rather than remove the studs when taking off the head. That causes me to question why use studs? I thought the value of using studs was that you were not disturbing the threads in the block as you do when removing and installing bolts. If you're removing studs just like bolts, I am curious why you are using studs?


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Stroud on Thursday, December 03, 2009 - 05:33 pm:

Richard, there are two reasons. First, you can screw the studs all the way to the bottom of the holes to take advantage of all of the threads in the block. Second, and probably more important, the threads in the block will hold much more pressure with a straight pull than with a twisting pull that you get when tightening the bolts. Kind of like trying to pull a hose off of a hose barb, much easier to get the barb out while twisting than trying to pull it straight out. Dave


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Stroud on Thursday, December 03, 2009 - 05:33 pm:

Richard, there are two reasons. First, you can screw the studs all the way to the bottom of the holes to take advantage of all of the threads in the block. Second, and probably more important, the threads in the block will hold much more pressure with a straight pull than with a twisting pull that you get when tightening the bolts. Kind of like trying to pull a hose off of a hose barb, much easier to get the barb out while twisting than trying to pull it straight out. Dave


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert G. Hester Jr. on Thursday, December 03, 2009 - 06:40 pm:

Also Richard, fine threads at the top of the stud provide less of an inclined plane than the coarse threads so that an equal amount of torque gives more downward pressure. This plus the fact that you can use all the thread in the block was gonna be my reason for using studs. This afternoon I searched the Tampa area for studs and didn't find any. I took one out of an old A model engine and it was about 1/2 inch shorter than I'd have wanted, could have worked in a pinch, maybe. So for now I'm going back with the bolts. I augered out the holes in the block with a drill bit and ran a bottom tap down'em. They were harboring a lot of crap. I also have a set of new bolts. I think it'll be okay. If I have trouble in the future I'll just make a set of studs. Thanks to all who responded. Bob


Top of pagePrevious messageNext messageBottom of page Link to this message  By William Dizer on Thursday, December 03, 2009 - 09:32 pm:

Somewhere, sometime in the past, I was told that you didn't gain any more strength with more threads after you had exceded the diameter of the bolt-ie: if you are using a 3/8" bolt after you have it threaded in 3/8", you don't get more strength by screwing it in any more. Has anyone any ideas on the subject?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Thursday, December 03, 2009 - 10:24 pm:

I would not use studs. The Model A uses studs and it is a bear to remove the head, compared to the Model T. The two back bolts must be put in the head before you install it. you can't lift the head high enough to remove without either pulling the engine or lifting the body. The 2 nut method might work if you are in the habit of removing the head often. Usually, though, we leave it on for years at a time.

This is what should be done. First clean out all the dirt from the bolt holes in the block. You might need to use something like an awl to loosen it up and then blow out with compressed air. Next place your head on without the gasket and be sure all the bolts go down all the way to the head before they bottom out. If you are using an aluminum head, use the washers when doing this step. If any are too long grind to shorten and then measure and grind all the bolts to the length so that they will be interchangeable. Be sure everything is clean and all surfaces flat. Place the head with the gasket and torque to 55 ft lbs. Some people use aluminum paint on the gasket before installing it. Warm up the engine to normal temperature and if you use a steel head, re torque to 55 ft lbs while hot. If you have an aluminum head re torque to 55 ft lbs after it cools off.

The usual reasons the head gasket blows are either the surface is not flat, the bolts bottom out giving a false torque, or not properly torquing the bolts.


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Stroud on Thursday, December 03, 2009 - 10:46 pm:

William, I think it would make a lot of difference what material you were threading the bolt into. Dave


Top of pagePrevious messageNext messageBottom of page Link to this message  By Aaron Griffey on Friday, December 04, 2009 - 12:46 am:

When you use studs you get fine thread at the top where the nuts go on.
If you torque to 35 Foot Lbs. on a fine thread stud you will get the same gasket crush as 50 lbs. on a course thread torque stting.
You mutiply the course thread setting by 70% (.70) to get the same crush in fine.
That is if your favorite number was 50 for the coarse than multiply 50 by .70 and get 35.
If you torque fine thread nuts down to 50 lbs. you get the same gasket crush as 70 lbs. with coarse threaded bolts.
So put some anti-sieze on the studs and screw them down till they bottom out.
Then torque the nuts down to 40 and you'll have plenty of crush on the head gasket.
Aluminum heads should not be torqued more than 45 with coarse bolts, about 40 with fine.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth Harbuck - Shreveport, LA on Friday, December 04, 2009 - 06:41 am:

Dry vs "Lubed" threads:

I cannot, for the life of me, assemble anything antique (valuable) without using anti-seize lubricant on most fasteners. I do this so that some guy many moons in the future can remove them without damage. Corrosion protection is why I do it.

So I compensate somewhat I guess by only torquing to the bottom of the specification if one is available. I haven't had a problem by doing it this way.

Seth


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Weir on Friday, December 04, 2009 - 07:31 am:

After stripping the threads in three locations in the block @ 15-18 Ft Lbs. the first time I tried to install the head, I installed Heli-coils in all locations.

This is the same engine that when I first fired it the "extreme compression" blew a hole in the head, and water was coming from every where. The corrosion was so severe that just pushing with my finger, would crumble the combustion chamber.

I wonder what the Texas water would do to our insides.

Sincerely

Jim Weir


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Friday, December 04, 2009 - 08:41 am:

Arlington VA

Loctite fills the gaps between threads, so no corrosion can enter. Blue Loctite doesn't have to be heated to break loose, IIRC. It assures the bolt/stud won't back out.

If your car is in the way of your engine, you could always use bolts in the last couple of holes, if you don't trust Loctite. But I'd use Loctite on them, too.

rdr


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert G. Hester Jr. on Friday, December 04, 2009 - 09:08 am:

The trouble with Loctite on head bolts is that you have to retorque them a couple of times after the initial installation. The Loctite will have already "kicked" by then, I think. Bob


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth Harbuck - Shreveport, LA on Friday, December 04, 2009 - 09:21 am:

Yes Ralph, I use Loctite too, but only where it makes sense. Like on the studs that screw into the cylinder assemblies and hold the intake manifold on the Wills. They aren't going to be removed and any retorquing is at the other end.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Deichmann on Friday, December 04, 2009 - 09:43 am:

@William Dizer: You are right it is only the upper threads that do all the strength - the rest is a free ride. And the rule of thumb is like suggested by David Strout - the upper diameter length of the thread is all that matters.
The explanation is, that the bolt/stud are stretched to the threads ot the upper part of the hole bear the pull while the lower holds none or minimum.
I have a story from real life that supports this, but I think it is a little OT to bring it here.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Friday, December 04, 2009 - 10:02 am:

Arlington, VA

Which begs the question, Robert, why do head bolts have to be re-torqued? It's not done on modern engines.

Using a stud into the block, it doesn't get torqued anyhow, just threaded down to the bottom of the hole, and it's all pull - no torquing. The stud in block not moving again until removal is a good thing. All the torquing is done on the SAE threads at the top.

I'm kind of surprised Model A studs are too short for the T (high head?). At any rate, the right length should be available from any good auto parts store or McMaster.com . The two long Mdl A studs near the water outlet are just the right length for the Fronty.

rdr


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth Harbuck - Shreveport, LA on Friday, December 04, 2009 - 10:18 am:

Head bolts have to be retorqued because either: 1. the gasket compresses (relaxes) and/or, 2. the head bolts are not stressed enough to become "springs".

In the case of the model T with a copper sandwich head gasket, "and" applies.

Retorquing is probably not required if the modern "asbestos look-alike" head gasket is used.

Seth


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bill Dodd on Friday, December 04, 2009 - 11:24 am:

As Seth said, the gaskets compress and the bolts are not torqued to approach "yield". On many modern engines the headbolts MUST be replaced if removed as they can only be stressed 1 time without loosing their elasticity.
My Ford A needs 3-4 head torquings when changing gaskets and the exhaust manifold gasket needs the same proceedure if I don't want to do a yearly gasket replacement. And yes my A has studs and I do never-seize the end in the block.
I also have to re-torque the manifold on my T to keep it from leaking. I have NEVER had the head off my T

Bill


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bill Dodd on Friday, December 04, 2009 - 11:26 am:

As Seth said, the gaskets compress and the bolts are not torqued to approach "yield". On many modern engines the headbolts MUST be replaced if removed as they can only be stressed 1 time without loosing their elasticity.
My Ford A needs 3-4 head torquings when changing gaskets and the exhaust manifold gasket needs the same proceedure if I don't want to do a yearly gasket replacement. And yes my A has studs and I do never-seize the end in the block.
I also have to re-torque the manifold on my T to keep it from leaking. I have NEVER had the head off my T

Bill


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Friday, December 04, 2009 - 11:52 am:

The problem with studs is not just getting the rear two in place, but the entire head must be placed directly over the studs to install and pulled up to the top of the studs to remove. Cannot do that with the firewall over the engine.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gary Tillstrom on Friday, December 04, 2009 - 12:06 pm:

Seth

When assembling stuff that you are concerned with being able to get apart later, apply zinc chromate primer to the bolts and assemble wet.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth Harbuck - Shreveport, LA on Friday, December 04, 2009 - 12:16 pm:

Thanks Gary.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert G. Hester Jr. on Saturday, December 05, 2009 - 03:08 am:

To update, I got the head back on my 27 touring today, using new bolts from Lang's. I decided to try it with the bolts because it was going to take a few days to get the studs and I didn't wsnt to wait. Besides, some of you guys made a pretty good case against studs. I made sure everything was clean and flat and I think it'll be okay. The bolts turned out to be almost too long and I wound up using washers with them. The cylinder head is a Simmons Super Power and might not be exactly the same height as a stock head. I ran the engine for forty minutes and drained the oil. Still quite a bit of water in it. Probably take two more changes to get rid of all of it. Didn't drive the car because it rained all afternoon. This car has in addition to the Simmons head, aluminum pistons .040" oversize. It appears to have a stock cam, somewhat worn, as the four valves that I checked with an indicator are only opening .200 to .204". Rear axle is 3:1 ratio and has a Starr Planator two-speed auxillary. If we can keep the oil and water away from each other I think this going make a good touring machine. Anyway, gentlemen, thanks very much for all your helpful suggestions and hints. Made the job a lot easier. Bob


Top of pagePrevious messageNext messageBottom of page Link to this message  By Billy Rose on Saturday, December 05, 2009 - 11:03 am:

Are you sure that the bolts that appear to have bottomed out did not break into the block water jacket? Just a thought. Cleaning out the holes with a bottoming tap and using a shorter bolt should give enough squeeze to compress the gasket and solve the proble.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Aaron Griffey on Saturday, December 05, 2009 - 02:25 pm:

When using bolts: Put the gasket and the head on.
Make a cheap hardware store bolt an eighth of an incg longer than your head bolts and run it into each hole untill the bolt head touches the cylinder head. That will insure that you have room at the bottom to tighten the head down with the headbolts.
If you remove the threads from your test bolt you can check the depth quicker by just dropping the test bolt in and checking that the head touches down.
If you are using an aluminum head you need flat washers. So first run the bolts down without the washers to test for bottoming out.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jeff Humble on Saturday, December 05, 2009 - 05:11 pm:

Robert,
If yu are going to use washers I would recommend hardend steel washers made for head bolts, available at many auto parts stores. The OD is smaller than a standard washer so they do not look out of place. The thicker hardended material will keep the bolts from buggering up your head.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert G. Hester Jr. on Saturday, December 05, 2009 - 09:23 pm:

Thanks, Jeff. I did use the thicker, smaller o. d. washers normally used with grade 8 bolts. Also, I don't like the sloppy fit that washers always seem to have so I used 3/8" washers and drilled 'em out to be a close fit on the 7/16" bolts. I drove the car today and then retorqued the head. The bolts all took up another 5 to 10 ft/lbs. After the initial refill I've changed to oil twice and still getting water out of there. The bands (Kevlar) are a little chattery but at least they're pulling okay. I think it'll get better. The brake band seems to be doing fine. Ever onward. Bob


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