How to fix a blown head gasket...??

[markctr3]

A quick refresher...

Once I got my new TR3 engine back in the car, I had to remove the head to replace the casting plug (freeze plug is actually a misnomer) on the back of the head that was leaking. The engine hadn't been started and I was told that I might be okay using the old gasket (I know it's not the best way to do it, but I did it anyway). I cleaned the gasket with acetone and re-sprayed it with copper sealer and re-torqued in a three step process -- 30, 60, 90. The manual called for 100 to 105, but ARP, via a phone call, said 90. After a couple of hours, I noticed coolant leaking from the head bolt on the intake/exhaust side between #1 and #2.

Since that time, I've have had two conversations with British mechanics that have been building TR3 engines since the mid 50s -- one on the East coast and one on the West coast -- I will not give their names to protect the innocent.

As I've said in the past, I get completely different answers/opinions from everyone I talk to. Here's what they had to say about the issue...

One said to use the copper/asbestos gasket and do a one step torque right to 105 ft. lbs., and don't use the steel-shim gasket because "you'll have more problems than you have right now." The other said to torque the copper gasket in a three step process to 102 ft. lbs., but said that the steel-shim gasket is your best bet, because it will NEVER leak. He also said that this is not uncommon -- not that you WANT it to happen -- but sometimes it does. He also suggested to try Barsleak (not sure of the spelling, but you all know what it is). That should/could stop the leak, then you could drain the coolant and put in new after the leak is stopped.

On a completely different matter, I asked about the "D" grind cam I purchased from TSI. Since this is a regrind and TSI does not harden the cam after it is ground, I asked if that was okay. One said that the cam should be surface hardened, or it will quickly wear, and the other said that the cam will surface harden during break-in.

So, these are both respected mechanics that have been doing this for 40+ years...who do you believe? Are they both right? CAN they both be right? As I've said in the past, I'm NOT a mechanic, I'm a graphic artist that has a fair amount of mechanical ability to attempt a project like this. I'm not afraid to ask questions (actually, I love to ask questions and learn about things of interest), but it is VERY frustrating to get conflicting advice.

Is anyone else in this boat? What would you do?

 

[Paul Johnson]

These perplexing situations come up not because one fellow is right and the other wrong, but because they are both describing what works for them. In effect, it means both methods will work, but the key is a feel in the wrist that comes over the years. Either way might work or fail for you, so I'd suggest you pick the one most comfortable. Just to add a little fog, I always used (because that was how I was taught) whichever gasket the parts guy handed me, never used any sealer, and always torqued according to the manual. It always worked for me, and so I'd never consider doing it any other way, but would not suggest it is the only way. Have fun. Make sure everything is clean, gaskets are new, and enjoy the reaults.

 

[markctr3]

Sage advice Paul. I think that when you ask too many questions, you're going to get too many opinions. I guess I know the right answer (I believe that Ann Rand once said, "Advice is what you ask when you know the answer.") I may try the Barsleak as a stop-gap measure, but when I install the Webers, harmonic balancer and move the fan to a "puller" -- since I have to remove most of the stuff anyway -- I'll install a new head gasket (copper sandwich) and do a 3-step torque to 102 ft. lbs.

I guess I do like to hear from other owners who have "been there, done that". So, please let me know what you think.

Thanks.

 

[Alan_Myers]

Hi Mark,

Paul is right, there are probably eight ways to do any particular job and often it can come down to what works for you.

In part, you have to look at any advice based upon the particular mechanic's perspective. Some mechanics build a car to get it out the door and back on the street as quickly and inexpensively as possible. Others use tricks learned over the years in an effort to build a stronger, more durable engine that will last for many years of normal driving. Still others are building race engines that maximize balance, precision and strength to get the engine to survive higher than usual rpms and hard driving, but plan to tear it down and rebuild it annually or every few thousand miles.

I even take with a grain of salt advice from people I respect and know have tons of experience with these particular engines, such as Kas Kastner in his books or Ken Gillanders at British Frame and Engine. Both are/were building race engines and drivetrains that might not see all that many miles between major servicing. So, Kas' advice on a clutch may not be totally applicable to a street car where we expect 50,000 or more miles out of it. Ken's suggestion to use this, that or the other engine part perhaps should come with a similar disclaimer. He builds to race, too.

Another example, Kastner's original tuning manuals don't take into account unleaded gasoliine, which is now an important consideration particularly when it comes to valve, valve guide and valve seat materials, ignition timing and engine compression ratio. So, good and helpful as they are, those older manuals need to be consulted with some care.

On the other hand, racing, and in particular endurance racing such as Sebring and LeMans, is a good proving ground and can give us *some* helpful insights.

Moving on, head gasket sealer might not be necessary, if the top of the block and the head have been dressed and are both in very nice condition. However, it's a good precaution if there is any doubt. Head gasket sprays are fine, but an old Ford commercial truck mechanic showed me that plain old silver, gold or copper rattle-can spray paint works very well, too. These paints have a high enough metallic content to do the job in a pinch! There are many 30 year old, very high mileage truck engines motoring around Oregon with this "cheap, quick & easy" sealing done.

The shim steel gasket was originally offered by Triumph to detune the 83mm bore engine. It was to be used in conjunction with the copper sandwich gasket to reduce compression for cars being used in countries/areas where gasoline was poor or unreliable grade. Engine tuners also noted it was a lot thinner than the copper sandwich gasket (steel is .020") and used alone gives a nice increase of compression. This is also useful since it was a factory spec part and would allow a race car to remain in "Production" classification, where it might be more competitive, and not bump it into a modified class. Plus, it's more easily adapted to different cylinder bores (which were allowed up to 1.2mm oversize by SCCA rules of the day).

So, the shim steel head gasket can be used alone (without the copper sandwich) to increase compression, but since it has little or no compressability might need a truer head and block than the original gasket did. But, once sealed a shim steel gasket should be stronger against blowout.

I think Bars Stopleak can be a good option, at least temporarily. In fact, it's factory specified for regular use on some all-aluminum and aluminum/cast iron combination engines. GM/Cadillac, for example, used to specify it or a very similar product (this was a few years ago, don't know if they still do). I've been using it in a friend's Pontiac that's always been a nightmare to keep the cooling system sealed. There is a known and documented overheating problem on this particular engine and car. Her's had the head warp and a lot of very expensive work was needed in the not-too-distant past! Through a combination of uprated water pump, summer thermostat, improved electric fan controls, and careful servicing we've got the cooling system working very reliably. However, it still will gradually weep a little coolant into the crankcase if Bars isn't used, too.

A cam *will* self-harden during first start-up after a regrind (the grinding removes the thin layer of hardening it had acquired when the engine was running previously).

However, that also results in some immediate wear and the extra step of having it hardened is simply a good practice. Hardening is even more important if heavier rate valve springs are used, due to the extra pressure on the lobes of the cam. (BTW, valve spring rates should be checked, too... some are too soft and won't seal the valves as well, some are too hard and will accelerate cam/follower wear... and a set should also match pretty well, ideally.)

And, during a regrind, often a cam needs some areas welded up to repair chips in the edges of lobes, or flaked out of the face of the lobe, etc. The added material might not have exactly the same hardness as the original metal. Overall hardening might help protect against chipping on the edges and faces of the lobes.

The cam is simply a potential problem area. IMHO, why risk it and not just have it hardened? It's a little extra expense and hassle to be as secure as possible to minimize wear and tear, to built a good durable engine.

I think it's also important to use new cam followers. And on flat-faced cams/followers like those used in TRs, sometimes it's a good idea to "dress" the edges of followers with a grinder or file to slightly radius the sharp edge. Cam followers (tappets, lifters, whatever) are also often phosphated or otherwise hardened to match the cam, for the same reasons.

The actual material of the follower is critical to cam life, too. After a lot of experimentation, several vendors are recommending smaller diameter Ford GT40 followers be used, requiring a sleeve that's inserted into the block. This is more expensive, but these have proven a good match to a hardened TR cam and trustworthy under heavy use. Stock type followers are the next best choice, but only if they are the right hardness (they should be checked... I don't have the Rockwell number handy right now.) There were bad batches around a few years ago... some too hard, some too soft, or just inconsistent sets. There are methods of lightening stock followers a little, for improved engine performance, if desired.

A couple other closely related, top-end considerations:

If the head has been milled and/or the thinner shim steel gasket is used to increase comression, pushrods need to be adjusted for length accordingly. IMHO, the best way to do this is with an adjustable pushrod designed to take the measurement. Each individual pushrod can be precisely cut to length for each follower/rocker, but more typically done is a slightly less accurate method where all are cut to an averaged length, if there isn't much difference when measured. Tubular pushrods with the press fit ends are probably the strongest and certainly the easiest to cut to a custom length. I know Ted Schumacher offers that service, since that's who you got your cam from.

Also, valve springs need to be checked for possible binding. In other words, when the cam is at full lift, do the spring coils come in contact with each other? If ther do, something is bound to break! The D cam shouldn't give any problem, by itself, but there is some variation in the wire used to make the springs themselves.

I get very nervous when I hear about people using roller rockers with 1.55:1 or 1.60:1 ratio. Stock was 1.44:1 I believe, and "standard" rollers are 1.5:1, both of which are most likely safe. However, increased ratios increase the possibility of valve spring binding *and* mess around with the careful, proven profile of the cam.

Speaking of roller rockers, many ride on needle bearings. These tend to wear the shaft pretty quickly, due to the lashing back and forth or reversal of motion with each stroke. The "latest and greatest" design roller rockers go back to using a solid bushing, instead. If needle bearings roller rockers are used, the shaft should be hardened.

Roller rockers are another area where the experts disagree... Overall I've formed the opinion that a set of good quality rollers - correct ratio - can help an engine run quieter and reduce strain on the valve train a bit, but will give little if any real performance increase. OTOH, I've heard reports that some of the most commonly found rollers are not necessarily great quality and might break.

Finally, the rocker shaft itself is another area of possible concern, if using the original type of supports and shaft. The rear end of the shaft overhangs the supporting pedestal *and* has a hole drilled in it for the keeper screw. This is where the shaft sometimes breaks. Again, upgraded shafts can be used, or better still there are improved methods of supporting them with special pedestals. (I don't think these can be used in conjunction with roller rockers, not sure.) This extra support might not be all that necessary with a street engine used for normal driving. But, even then, a new shaft should be usually used, IMHO.

All in all, there are many ways to rebuild a motor, top and bottom. The basic ways might get the car back on the road quickly and with minimal cost, but possibly with some compromise of strength and durability. A little more careful attention using stock or similar parts and a few proven refinements and installation methods can produce a smoother running and longer-lived engine. And, there are plenty of choices to upgrade for durability, weight reduction and modified performance, with exponentially higher and higher costs involved at each level of improvement.

But, hey, these are just my opinions /ubbthreads/images/graemlins/wink.gif

 

[markctr3]

Alan,

Could you move down here for a couple of weeks till I get the bugs sorted out?

Thanks for taking the time to reply. I will try the Bars until I replace the head gasket (copper, not the steel shim) sometime next week. I did have the head milled in order to get the compression ratio up to 10:1. I will have to get in touch with Bill at Xtreme Cylinder Heads to find out how much was taken off. I replaced the rocker shaft with the "performance" shaft from Moss, as well as the rocker arms, bushings and adjusters. In addition, I used Isky springs & retainers, oversize stainless steel valves and the "lightweight" lifters from Moss (I'm putting somebody's kid through college!). I did not know about using shorter push rods however. Any suggestions as to deciding the proper length? Do you simply shorten the pushrods the same amount the head was milled?

Yes, having the cam hardened would have been a great idea if I wasn't told it was unnecessary. It does sound like the valves are getting noiser, but maybe that's just my paranoid imagination. /ubbthreads/images/graemlins/shocked.gif

I'm going to do a compression check and check the valve lash before I install the new gasket. That may shed a lot of light on the situation. This has really been a learning experience, and I hope it doesn't cost me a lot of money/seat time to figure it all out.

Thanks again for your help!

 

[Alan_Myers]

[ QUOTE ]
Alan,

Could you move down here for a couple of weeks till I get the bugs sorted out?

[/ QUOTE ]

A free Florida vacation? Sounds good to me!

[ QUOTE ]
I did have the head milled in order to get the compression ratio up to 10:1. I will have to get in touch with Bill at Xtreme Cylinder Heads to find out how much was taken off.

[/ QUOTE ]

The person who worked on the head should be able to tell you exactly how much material was removed, since you were trimming to get to a very specific CR. They should also have checked the deck height of the pistons and the volume of the squish area in the head, while taking into account the compressed thickness of the head gasket being used, to determine each cylinder's combustion area volume, calculate CR accurately and equalize the cylinders.

You can also measure the thickness of the cyl. head the next time you have it off, to get some idea how much was removed. TR heads were usually 3.330" thick originally. Just subtract whatever it measures now to get a pretty good idea how much was removed.

[ QUOTE ]
I replaced the rocker shaft with the "performance" shaft from Moss, as well as the rocker arms, bushings and adjusters. In addition, I used Isky springs & retainers, oversize stainless steel valves and the "lightweight" lifters from Moss (I'm putting somebody's kid through college!).

[/ QUOTE ]

Sounds good. We're each helping someone put their kid through med school, I think.

[ QUOTE ]
I did not know about using shorter push rods however. Any suggestions as to deciding the proper length? Do you simply shorten the pushrods the same amount the head was milled?

[/ QUOTE ]

Best way to determine pushrod length would be to have it measured with an adjustable dummy pushrod. Perhaps the guy who did the head work has one in the right size range and can check it for you. This is best because it also takes into account the amount the head gasket has compressed. The goal is to have the rocker sitting level or balanced in the middle of it's range, a neutral point if you will, when the cam follower and pushrod are exactly halfway through their up-stroke. (There are some variations on this used by some racers.) This will give the least amount of sideways push against the valves and pushrods, or looking at it the other way, the most direct transfer of pressure and thus the least wear and tear on the valve train.

Alternatively, once you have an accurate idea how much was milled, talk to Ted Schumacher and see what he recommends. No, I don't think it's exactly the amount milled off the head, but the right side of my brain isn't capable of doing geometry today for some reason! I think I need to take a break and go to Starbucks for some inspiration. Anyway, Ted can probably get pretty close to the correct length, just based upon his experience. Still, there's no substitute for measuring for the correct length.

[ QUOTE ]
Yes, having the cam hardened would have been a great idea if I wasn't told it was unnecessary. It does sound like the valves are getting noiser, but maybe that's just my paranoid imagination. /ubbthreads/images/graemlins/shocked.gif

[/ QUOTE ]

The valves probably are getting noisier. For one thing, there probably was some initial wear on the cam, at first start up, so it would be a good idea to re-adjust valve lash. Also, with a D cam you are probably running a larger gap, which will be noisier. I'm guessing it's .012" hot or so, but Ted can tell you. Higher lift cams need a little more clearance than stock cams. Finally, with the head having been milled and original/longer pushrods still being used, that will add to tappets noise. This will increase over time, as the extra sideways thrust on the valve train wears faster.

I'd suggest retorqing the cyl. head nuts to factory specs, though, before measuring and adjusting to the valve lash.

[ QUOTE ]
I'm going to do a compression check and check the valve lash before I install the new gasket. That may shed a lot of light on the situation. This has really been a learning experience...


[/ QUOTE ]

A compression check would be a good idea, but will be of limited value until after the pushrods are corrected. The valve timing will be off with too long pushrods, and that will in turn effect CR to some degree, I think.

A CR check might tell you if a cyl. is leaking, or if that seepage is just from the coolant jacket out alongside one of the cyl. head studs.

There is a lot of stuff to think about and remember when doing one of these rebuilds, even though the TR motor is a relatively easy one to work and learn on. If we were doing it every day, it would all become second nature I'm sure. But, speaking for myself, I only get into these jobs once every 5 or 10 years so I am writing up a detailed, step-by-step procedure - based upon all the good advice I can find -before I even start to tear down my motor. I've also gathered most of the necessary spares already, so that I don't have to wait on backordered items or rush a machine shop job.

Cheers!

 

[Adrio]

[ QUOTE ]
I had to remove the head to replace the casting plug (freeze plug is actually a misnomer) on the back of the head that was leaking.

[/ QUOTE ]

I have a pin hole in that plug which I 'repaired' by putting a small screw with a rubber washer in there. Needless to say I am not happy with the idea as a 'permanent' solution. On the TR4 with the battery out there is a fair bit of space behind the head. My question to you is how hard is it to replace that plug and how is it done. I am trying to figure out if I can do it with the head on the engine and the engine in the car.

 

[markctr3]

Adrio,

To replace mine, I simply hammered a screwdriver into the plug (the first time I didn't get it in far enough and broke off the tip of the screwdriver) and pried it out. Very simple. Then I cleaned out the hole -- there's a ridge inside the hole that doesn't allow it to go into the head. Finding a new one was a bit of an issue. The "traditional" auto parts stores didn't stock the one I needed. I went to a machine shop (the one that took three tries to install the cam bearings) and they normally stock it, but were out of stock, but they got one the next day. On the TR3 head, it is a 1 3/4" disk -- not a plug. The disk is simply a concave circle; it doesn't have sides like a traditional freeze plug. I put some black Permatex around the edges, inserted it in the hole with the bulge facing out, and whacked it a few times in the center with a rather large ballpeen (not sure of the spelling) hammer to expand the outer edges into the head a bit, and that was that. It hasn't leaked a drop and the whole job -- if you have the disk with you, takes about 12 minutes.

 

[Geo Hahn]

[ QUOTE ]
...On the TR4 with the battery out there is a fair bit of space behind the head. My question to you is how hard is it to replace that plug and how is it done. I am trying to figure out if I can do it with the head on the engine and the engine in the car.

[/ QUOTE ]

As noted, the plug gets hammered flat to seal it and secure it. I doubt there is enough room to swing a hammer in there (in Fla for a few weeks with no TR to look at or drive). They do sell a rubber freeze plug that inserts like a stopper and has a bolt thru the middle that engages a metal plate on the inside. When the bolt is tightened the plug expands and is quite secure.

I did this on my TR3A with the engine & head in situ and it was fine for more than 20 years. Finally 'did it right' when I had the head off for other work.

 

[Alan_Myers]

Re: Freeze plug... How to fix a blown head gasket

Hi again,

"Ballpeen" works for me...

That's the usual way to install one.

In his TR4/4A competition prep manual, Kas Kastner recommends scrubbing around that plug with a wire brush to get down to bare metal and rough it up a little, then sealing over the plug with heavy duty epoxy. He's suggesting this to add some extra security. It would be a major Exxon-Valdez type oil spill if that plug ever popped out!

There are a number of good pointers like this in the comp prep manuals.

Another is to safety wire the bolts holding the generator (or alternator) bracket, because they go the whole way through the wall into the oil galleys and if one of them loosens and drops out will cause major problems in a hurry, too. He suggests the same for the bolts holding the cam bearings in place, for the same reasons.

All these would need to be removed temporarily and have the heads drilled for safety wire, of course. I suppose an alternative or additional level of security would be some Locktite on each bolt, provided the threads and bolts are clean and oil-free.

/ubbthreads/images/graemlins/cheers.gif

 

[markctr3]

(in Fla for a few weeks with no TR to look at or drive).

If you're anywhere near West Palm, look me up and we'll go for a cruise down A1A!

 

[Adrio]

Mark,

Thanks for the reply. Gives me the answer I need to attempt the job. I have been putting it off because I did not want to take a driving car and turn it into a head removal project for something that did not leak. But now given your description of the process (I have the disk, as I ordered it a year ago) I have no fear it will be OK. Provided I can swing the hammer, and I will not be able to see that until the car comes out of winter storage (it was 20 below this morning on my walk to work....BRRRR!)

 

[markctr3]

I know how you feel Adrio, it was 20 below here too.

20 below 98...a nice balmy 78 degrees.

 

[trfourtune]

Re: Freeze plug... How to fix a blown head gasket

head torque. first, arp sells a special lubricant for their studs. that is why they suggest a lower torque value than specs. if you don't use the lube, then stay with standard torque using 10/30 engine oil. NEVER torque any head to full specs directly. always do in increments of the proper sequence. this is even more important since you shaved the head (the metal is thinner). the metal head bends against the gasket if you tighten one stud completely before the next and can dammage the head permanently.the tr3/4 head has a weak spot that is mentioned in kastners book, vizards book, and others. they "stake" or reinforce the head at certain spots becuase it is thin and can't hold the pressure,the material deflects and leaks. you also need to be sure that the liners project .004" above the deck on all four holes (see the range and ensure they are all the same). the sandwich copper clad head gasket is NOT reusable. a solid copper head gasket is but needs to be annealed before reused (to the correct temperature). bars leak is bad! it puts a coating on the surfaces inside your engine that need to transmitt heat. it reduces the cooling efficiency of your engine, and the tr3/4 engine is notorious for running hot.
rob

 

[trfourtune]

Re: Freeze plug... How to fix a blown head gasket

camshaft hardening, all reground triumph cams need to be hardened period! all cam company regrinders specializing in triumph cams state this. the racing specialists in uk recommend nitriding not just parkerizing! followers also fall in this category. "work hardening a camshaft" ???? I don't think so tim! it may work harden (or not-remember this is cast iron)once the profile has been beaten and worn off. lifter hardness has been stated to be too low in testing, below rockwell C 50(from some suppliers). i don't think you can go too hard (as long as they don't break). there are ceramic lifters out there with proof that the lifter AND the cam survive without a scratch, when without the ceramic lifters- the lifters and cam were destroyed in seconds (in some cases). schubeck can make these to order, but bring a wheelbarrow full of money (guaranteed never in three lifetimes to wear out).
the vw guys go to LN engineering. some stock car racing classes ban them because of the cost and advantage.
all reputable cam companies state that you can ruin a new cam in the first 5 minutes of running without a good cam lube on the cam. even a special steel billet cam!
rob