Moss Motors, Ltd

SWEET!  Blew my first MG head gasket :D

Seriously though, what kind should I put back on there?  I want to use one of the copper ones so I don't have to do it again.  Opinions?  I am running a weber and a header, if that makes any difference.  Also thinking of taking the head to a machine shop and having it milled a bit, and having them check out the rest of the valves, etc.

Opinions, ideas?

 

Thanks! 

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1979 MGB, Pageant Blue.
-Weber Conversion w/ header
-Back-Dated to points ignition, Lucas 45D Dizzy, Lucas Sport coil

As far as taking off a head it don't get much easier.Definately get the head resurfaced minimum. Let the machine shop make further recommendation as to valves,guides,etc. It's a good idea to do the upgraded unleaded gas components( valves,guides and seats). I've had good luck with Payen gaskets and not sure if you need the copper.That's up  to you.You should clean the head studs and lighly oil to insure good torque results.Uneven torque from dirty threads will put you back in the same boat soon.

Took the head off, went to the machine shop, and had it magnafluxed.  There's a crack (GEE WHO KNEW, LOL).  So we're having it sent out for an estimate to see how much welding will cost.

I'm also checking out some remanufactured and new heads, just to gauge prices and stuff.

Did end up with the payen gasket, so thanks much! 

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1979 MGB, Pageant Blue.
-Weber Conversion w/ header
-Back-Dated to points ignition, Lucas 45D Dizzy, Lucas Sport coil

rlich8,

What you have here is your basic GOTCHA, many of our cars have a number of these incorporated as original design features!!

I dont know if welding cast-iron has become easier/more effective of late but it was never reckoned to be a permanent fix. MotorBill made a very cogent case, for me anyway, re going  straight for an alloy head rather than throwing good money after doing up the old head. Maybe he will comment here?

Sympathies!!        steve

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To a man equipped with only a hammer, most problems look like nails

rich8,

Where is this head cracked? I was somewhat suspicious when you posted about a head gasket failure. These are quite unusual in the MGB engine. Cylinder head cracking, however, is not all that unusual. If the crack is anywhere at all in the combustion chamber I'd say to replace the head either with an inspected good used and rebuilt one or with one of the alloy ones. We've installed a number of these with great success.

The most common place for the MGB head to crack in the chamber is between valve seats. If this is the case, DOUBLE FORGET IT!! It's new head time. Let me know.

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Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon

I'm waiting for a call back from my machine shop regarding where the head is cracked and what the estimate is on fixing it. I as well was weary of welding a cracked head, however, this guy has been in the area in business for 35 years. He says he has done MG heads before and that they have held up quite well.  He says he does some work for nascar as well.  If I can repair this head for a reasonable price, I might do it. I just am not keen on spending over $1,000 on a head for my car. I'm also a stickler for original equipment, too. If I do replace the head with something "new" I think I'd like to do a crack free reconditioned head. I think I can get one of those for about $600 give or take $50.

This is the place that is to do the weld on my head: http://www.windycityeng.com/ 

There's also another few things I'm taking into consideration:
 
-Another thing, the valves. I do NOT need a valve job. They're all good. So essentialy I'm just paying for a weld and a quick mill of a few thousands off. If the weld job ends up being a decent price, it's a reasonable consideration to me. I am willing to take a $200-300 risk rather than shelling out the money for a new head. 

-I also have to partially listen to my father. He was in this business 25 years ago and buying pallets of heads from England for $75-150 a piece.  Those days are long over now obviously! So it's also a bit of sticker price shock, basically.  I think he would be disappointed if I just went off and spent  that much on a new head without fully doing my homework on the matter.  Money is tight right now, too.
 
-Lastly, the second we examined the gasket thoroughly, we found were it failed. The gasket failed in between cylinder 1 and 2 from the water jacket into the second cylinder. It was a steel layered gasket and one of the layers was completely blown out.  Maybe the gasket blew because of a cracked head? Is that possible?
 
So let's see what the machine shop says and take it from there. Thanks for your help guys!  When I get a quote on a weld, I will post back up here, and we can take it from there.  I'm not saying yes or no to anything yet---I just want to fully consider both options.  Thanks motorbill and everyone else, you are a great help to me!

 

P.S. If the head is cracked between valve seats I think the answer is obvious.

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1979 MGB, Pageant Blue.
-Weber Conversion w/ header
-Back-Dated to points ignition, Lucas 45D Dizzy, Lucas Sport coil

Sorry for so much posting but,

Motorbill---can you explain why I should not weld if it is in between the valve seats?  I do believe you, however, I just want to be able to talk intelligently about the matter.  Also, maybe some general minuses about welding.  Thanks! 

 

Edit: 5/28 

Head is cracked in FOUR yes FOUR places (including near the valve seats and in between the valve seats).  Shop wants $350.  FORGET IT.  Time to find a new head.  I think I'm going to go with a replacement recondition cast iron head.  I can get one for about $600.  Any objections?

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1979 MGB, Pageant Blue.
-Weber Conversion w/ header
-Back-Dated to points ignition, Lucas 45D Dizzy, Lucas Sport coil

rich8,

Smart move. Make sure to look the "new" one over REAL GOOD. A reconditioned head with a crack gets you nowhere. You could have it pressure tested for integrity. I'm not sure what this might cost in your area. Can you get a guarantee?

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Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon

Motorbill,

I am, in the end, glad you guys suggested a new head.  Maybe it was wishful thinking on my part to save a few bucks on trying to weld up my old head, but I am very excited to have a nice new cylinder head.  This one I got is VERY sweet.

I got a phenomenal deal on it, and it was magnafluxed and pressure tested---no irregularities at all!  New everything.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=290320099512&viewitem=#ht_500wt_1332

 

I did purchase a brand new Payen gasket.  I must say that thing is also very, very nice.  Compared to my old one this is spades better, I can tell by looking at it.  Should I install it dry?

Lastly, is there any run-in procedure for these heads?  Is there anything I can do to avoid having a cracked head in the future?

 

Thanks again guys! 

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1979 MGB, Pageant Blue.
-Weber Conversion w/ header
-Back-Dated to points ignition, Lucas 45D Dizzy, Lucas Sport coil

rich,

Good going. The Payen gasket is the way to go. As far as coating it goes, it isn't truly needed, but we often spray on a very light coat of plain old silver spray paint. This settles into any irregularities or pits in the metal surfaces and gives you better all around contact. The key word here is "light".

The cylinder head needs no actual run-in procedure, but it's always smart to run one up to normal temperature and shut it off. Then let it cool COMPLETELY and retorque the head nuts, which along with the washers should be in excellent or new condition. Don't use any suspicious looking nuts or cupped out washers. If the washers are bad, go to a local hardware supplier and ask for hardened ones. Anyhow, after retorquing the head, readjust the valves and you're ready to play.

A word on retorquing. Don't simply go over the nuts in the described sequence with the torque wrench preset to the correct value. This will not gain you anything as the "starting torque" is always greater than the "dynamic torque" which you are seeking to establish. So, starting with the first fastener in the tightening sequence, LOOSEN it just slightly and tighten it with the torque wrench (which I trust you DID NOT use to loosen it!) to the correct value. Go thriough the sequence this way on both initial installation and retorque. On initial torquing, I usually go through three steps to get to correct torque. Say the final torque is to be 60 pounds. I'd go through once at 25, once at 45, and then final at 60.

Finally, what kind of torque wrench are you going to employ? The old pointer-on-a-scale jobs weren't too bad in their day, but are inadequate to say the least now. They can be off by as much as 25% from brand new. Quality control, anyone? Use a click stop type at the least, and one that is fairly fresh, well cared for, or brand new. These too can go out of calibration in time. Torque should be attained WHILE MOVING THE WRENCH, or dynamically. In other words, the "click" should happen not at the very end of the swing, nor when you start, but WHILE swinging the wrench. This is very important to attaining correct actual clamping force evenly over the entire structure. If you find that you make a swing that doesn't include the "click", you may very well find that the instant you try the next swing, it does indeed click. Don't fall for this. This is that "starting torque" effect. Back off just slightly and have another go at it. You'll get the hang of this, I'm sure. And when you do you'll be doing something correctly that most nonprofessionals do wrong, and many pros as well. To set up properly for this operation, get two sets of the correct size. One setup on the torque wrench, and the other on a breaker bar (tommy bar in Jolly Ole). This will make the whole business go much smoother and quicker. Enjoy.

And yes, there is one thing you can do to avoid having a cracked head in the future. Wear a helmet!

Bill W.

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Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon

In this being my profession for over 30 years I always follow manufacturers reccomendations.Most would say use no sealant.Always have both mating services perfectly clean and dry.After cleaning up the surfaces I will use either brakeclean or lacquer thinner to remove all oil film then install gasket. An old timer taught me to use wheel bearing grease and coat the whole gasket lightly rubbing it between your hands. He said he did it everytime. I used that practice on every headgasket I ever did for years and never had a problem. I usually refrained from using Hi tack or copper coat or any of the others.The only time I had a problem is if I didn't send the head out for resurfacing.Without any sealer the head should seal perfect with a dry gasket,perfect mating surfaces, and proper torque.You will also need to adjust the valves properly. 

Sure enough Ken,

 I've been building MG engines for forty years, and I never USED to use any coating, but:

I got my plain old silver paint light coat advice from a five time SCCA champ who builds MG engines by the scads. I've been doing this for some time and it has worked great. I do not waste money on, nor do I believe in, copper coat. I wouldn't use grease on a bet.

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Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon

Motorbill---

 

Your help was instrumental in my project! Can't thank you enough.

 

Unfortunately, I'm afraid we have a bigger problem at hand here.  Got the car up and running again just a few moments ago, but unfortunately the head gasket has blown yet again.  I am seeing oil inside the valve cover and there is a smokey exhaust.  Oil pressure however, is good, and the car is not overheating.  I was wishfully thinking that maybe the engine was just burning off all the water that was in the system from the previous blow, however, there's just simply too much water and it isn't stopping.  I only ran the car for about 8 or 10 minutes before it blew.  The car didn't overheat, but somehow the gasket still managed to blow I believe.

My father was working with me all morning on it, and he said the only things he can think of is that the head was somehow not as described on the eBay ad (that it is a bad head advertised as a good one and we simply got swindled), or, that we have a cracked block.  He has been a british car guy since he was 17 (and he is now 52!) and ran a shop for 15 years.  He said in all of his days he has never experienced something like this before.

How frustrating.  I just want my car to run well again!

Thanks in advance again. 

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1979 MGB, Pageant Blue.
-Weber Conversion w/ header
-Back-Dated to points ignition, Lucas 45D Dizzy, Lucas Sport coil

rich8,

Did you check the deck of the block for straightness or erossion? especially at the "scene of the crime". I bet you did. This is a tough one. Check to see if this block has been resleeved on a cylinder. Sometimes this is really hard to detect if it was done by a competent machinist.

Just a hunch, but maybe the edge of a sleeve is leaking by. Or, as you already suspect, may indeed have a crack in the block. Let us know what you find.

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Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon

I did in fact.  I cleaned it up very well with a razor and I tripple checked it before I gave it my (novices) blessing!  I  was not able to check for a sleeve, however, I am now thinking the prospect of a cracked block is just very low.  Have you ever seen one before?

 

Anyways, this is another perspective offered---what do you think? This is from the gentleman I purchased the new head from.

"Sounds like you have a decent head gasket and I know the head surface is absolutly flat. I think you have an air lock preventing the coolant to completly fill. This has happened to me many times with the MGB's. The best way to cure this problem is to use the late model thermostat housing (one with the pipe plug on top). Insert a transmision filler funnel and keep adding water while the engine is running. Expect some burping as the voids fill." 

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1979 MGB, Pageant Blue.
-Weber Conversion w/ header
-Back-Dated to points ignition, Lucas 45D Dizzy, Lucas Sport coil