NA6C-Guy

iTrader: (1)

Im new here, have been browsing for several months. Figured i would show you guys how not to do a head gasket install. Just spend the last 2 months or so working on my engine preparing it for boost. Ported the head (cleaned up the ports mostly) and worked on the combustion chambers a bit. FM flywheel and an ACT clutch to prepare for the BEGi that will be coming soon. The block was left alone since my compression was still good (185-190) except for the center 2 cylinders with a blown head gasket. Anyway, I finally got it all back together and got to drive it for about 10-20 miles, maybe a half hour of driving, then I noticed burning coolant smell *gulp*. Pulled the head today and what do I find?




THANKS MAZDA! A free staple, just what I wanted! It was sandwiched between 2 of the gasket layers where I didnt see it. It was at the very rear edge of the gasket, so it held the rear of the head up slightly, not letting the intake side of the cylinders seal. Ended up with puddles of coolant and oil mix on top of all 4 pistons.



Can see the rings around the cylinders, one side of them looking somewhat untouched.



Now my clean ports and combustion chambers have a nice oily sut coating them



Had already cleaned the outer 2, but you can see some of the remaining oil and coolant.



My head now has a battle scar. I guess iron is more dense than aluminum



Finish picture of the severed head. Got it back on this afternoon but ran out of daylight and its kind of cold outside. Got the timing belt back on anyway, just have to plug up some more connectors and do some other little stuff and it will hopefully be good to go.

Just thought I would share this little story with you guys. Amazing to me that a staple that probably only cost $0.001 ended up costing me over $100 and a weekend of extra work. So play it safe and triple check your gasket. I thought mine was fine and never thought about it until it failed to seal.

Braineack

iTrader: (62)

what cost you an extra $100?

NA6C-Guy

iTrader: (1)

Head gasket and oil. It may not have been needed as the only real damage was the staple area and the slightly uneven sealing around the cylinders, but I wasnt about to take any chances.

Bryce

iTrader: (24)

His time = money

elesjuan

iTrader: (11)

ah, don't let the oil inside your nice ports get ya down.. The shitty EGR would've done that in notime flat anyway.

Sucks about the staple, I'll check my head gaskets from now on... :(

NA6C-Guy

iTrader: (1)

Yeah, probably so. Just sucks to see my several days of porting go to **** in a few minutes. As long as the damn thing runs tomarrow I will be happy.

944obscene

Damn. Sounds like you need to give someone a call about that.

patsmx5

iTrader: (16)

Porting cleaning.

Sucks that happened though. Some boxes that gaskets are boxed in are stapled shut. So perhaps that's the source.

NA6C-Guy

iTrader: (1)

****!!!

WHY GOD! Im losing hope now. Got it all back together... STILL a head gasket leak. Coolant and/or oil in the cylinders and a slight leak outside around the seam. Either I got screwed and the shop didnt machine my head very well, or somehow my block is warped. Thats all it could be. Im getting more broke as the build goes on, and more depressed/mad about it. A few weeks of prime convertable weather is here and I have no Miata.

So here comes another $85 head gasket, more oil and coolant and another 2 weeks of tinkering between work and sleep.

Braineack

iTrader: (62)

Sucks.

Start buying $20 Topline HGs.

patsmx5

iTrader: (16)

Dam that sucks dude. Get a feeler gauge and a straight edge and check the damn deck and head yourself. Not hard to do. Was this engine ever overheated? I'm assuming you have a Haynes manual or a copy of the Mazda manual and are following the instructions when doing the HG swap? Have you ever done one before? What are you torquing the head bolts too? Is your torque wrench accurate? How many times have these head bolts been used? Do they take the correct torque?

kenzo42

iTrader: (6)

I always heard copper spray worked well w/ sealing headgaskets.

NA6C-Guy

iTrader: (1)

Topline gaskets worth a crap? I might do that. $85 a pop OEM is killing me. This will be #3 in under a month. Im not made of money.

Yeah, I had planned to use a "straight edge" and feeler gauges, though Im not sure how true the edge is. I did an eye check with the straight edge on the block last time, and I saw no visible gaps, so its got to be within .020 or so. Im thinking its the head though. Its possible the shop I brought it to screwed me. Didnt seem like a very formal transaction, and I never really saw any of the work. But $30 got me a machined head. Wether or not its perfectly flat is another thing.

As far as I know, it was never over heated. Last owner took very good care of it and kept a bible size stack of papers on the car from previous oil changes and other things he had done. Since Ive had it, it has never been run even somewhat hot, so I dont think the block is warped. I have done head work before, not alot, but maybe 3 or 4 other (Honda's), so I have a general feel for whats going on. I like to think Im a good mechanic, but this little thing is getting me down and making me think maybe Im not so good...

Ive used my Haynes and online guides/Miata.net and here for some help during this rebuild. As far as I know my wrench is accurate. Its a Craftsman click type, range of ~20-140lbs, 1/2'' drive with a 1/2-3/8 adaptor, and a 6'' 3/8 extension and a 12 point 12mm thick wall socket. So surely that is good enough for close to accurate torque readings. Im sure the extension and adaptor cause a slight loss from flex, but I accounted for that by moving the final torque to about 64lbs vs what the Haynes calls for (56-60 I think it was). I did it in 3 steps, 25lbs, 45lbs and final 64lbs. Starting with center intake side bolt using the Haynes recommended pattern, clockwise spiral. Head bolts as far as I know are original, with no previous head work at 115k miles. I have removed and tightened them 3 times myself so far, so not excesive as I see it. Both block and head were cleaned using clean rags and acetone. So I cant see that there is anything Im doing wrong.

Maybe 3rd time will be a charm. As soon as I get paid again I will be attempting the 3rd time, but until then I will go over everything in a very ---- way to be sure nothing was overlooked. Ive done plenty of engine swaps and quite a few rebuilds (several rotary engines, and probably 3 or 4 piston engines, all 4 cylinders) so I know my way around an engine well enough, and know whats going on. Never taken any of my cars to a shop for work, always have done it myself, and if I didnt know how I would teach myself. This is becoming a pain in the *** I wasnt expecting. I was thinking I would bolt the head back on the first time and fire it right up and drive away into the sunset... guess not. Thanks for the help so far. You guys look after me and make sure Im not missing anything or screwing anything up too badly.

PS, the reason I took it apart in the first place, other than for the clutch and flywheel, was a slight leak between cylinders 2 and 3. 1 and 4 had a compression of about 190, 2 and 3 were about 155-160. So before it didnt really have this kind of major problem, and the only work I had done that would affect this would be the head machine work. I did hit the block deck with a brass wire wheel at low rpm on my drill, but I seriously doubt that little bit would cuase all 4 cylijnders to leak coolant like it does. I also noticed a slight loss of fluid externaly between the head and block on the exhaust side today. Can see a little shine of fluid around the seam. Other than that, I did some minor combustion chamber work (deshrouding the valves ever so slightly), but I probably only cut maybe 1/32'' at most into the chamber walls, not far enough to get into the sealing area of the gasket, so I doubt that has any play in this.

PSS, if any of you mods want to move this to a better section, that would be cool. I was only going to post the pictures at first, but it seems to have become a build thread.

Braineack

iTrader: (62)

I'm using a $29 Topline head gasket. I blew one within 20 miles because the head wasn't torqued down good. My Craftsman Click-type torque wrench isn't worth a crap.

patsmx5

iTrader: (16)

I seen no deshrouding on that head. Where did you remove metal? Put the head gasket on the head's surface, center it perfectly, and take several pics, one of each combustion chamber with the gasket around it, etc.

Did you chase the threads and oil the head bolts before torquing them?

Might take your torque wrench to a tool shop and let them test it to see if it's off. Or use a known good wrench next time. Still would be better to verify yours is correct.

And the deck has to be flat within 1-2 thousands. Mine was .001" out in the center when measured from corner to corner. Less any other way you check it. Take the head to a machine shop and watch them put a straight edge on it and measure it.

When the shop checked mine, they had to unlock a room to get the straight edge out of. He put on gloves such that the temperature of his hands would not cause the tool to expand from heat transfer, and removed the straight edge from its case. FWIW, straight edge was a piece of ~3/8" by 3" flat bar about 4' long that had been ground dead damn flat. He checked the head with light behind the straight edge and used a set of feeler gauges to check it.

Stuff like this lets you know the shop is legitament. Had he picked up the straight edge and dropped it on the table before he went to measure my head, I would have grabbed the head and left. But they were very professional and did a through job.

Here's the kicker. You now say you had a blown HG before the original disassembly but you never checked the head and deck for warpage? Never ASSume ****.

NA6C-Guy

iTrader: (1)

What kind of wrench do you recommend? Dial indicator type? I figured the Craftsman would at least get it into the correct range. This last time it was NEVER sealed. As soon as it started up it was already smoking and stumbling. Just guessing though, having turned so many wrenches I would say the Craftsman is at least getting it in the right ballapark, at least within 10lbs. Maybe I will borrow a dial type from one of my car working naeighbors, I know one of those old timers have one somewhere.

Where can a Topline gasket be purchased? Online Im guessing?

Thanks again.

Arkmage

iTrader: (3)

I've been running a Topline ( or similar ebay gasket) for 35K miles, 10K of that boosted. No problems yet.

patsmx5

iTrader: (16)

I've got a feeling the wrench isn't your problem. Answer all the other questions in my post.

FWIW, dial type is the most accurate. If you're using a click type, when doing the final torque you want to go slow and don't stop turning till it clicks. If you tighten it some and stop, the start again and it immediately "clicks", that's cause the torque required to start turning the bolt is higher than the torque to turn it after it's spinning. That's because static coefficient of friction is always greater than kinetic coefficient.

NA6C-Guy

iTrader: (1)

Like Ive said, I mostly just cleaned up stuff, so the "deshrouding" was more just smoothing up and blending. The valves have that little "shelf" around the side that is against the cc walls. I removed it and smoothed it out. With gasket on the block I have about 1/8-1/4'' of visible material inside the gasket, about the same on the head, maybe a tiny bit less.

Block has to be THAT flat? How do all of these people get away with never having to machine the block deck? Surely it warps just that much from temp changes. I ASSumed it was a head gasket leak. I cant figure where else I would lose compression between 2 and 3, along with a very slow oil and coolant loss. With that kind of tolerance, maybe I should suck it up and pull the block again and bring it to a shop to check for flatness. Do you think they would ever be able to do any kind of machine work with internals in place? I hadnt planned on touching the bottom end since its only at 115k miles and compression is still good.

Reason I didnt really check the deck is I ASSumed it being iron, and it never being over heated to my knowledge, it wouldnt be hurt. Didnt think a slow compression loss and oil/coolant would hurt anything. Visible inspection shows no flaws in the block deck surface.

I did check compression earlier with a static (I guess maybe thats what it is called, its not a leak down tester) gauge set, and after 5 rotations with the starter, all 4 were between 180 and 190. Of course without a leak down that doesnt mean much, but this was using the same gauge set before that only read 155-160ish on 2 and 3, so it seems they have improved.

Shame on me I guess for not checking the deck the first time. I cant afford to not this time though. I just really dread having to redo all of that crap again. Pulling the head isnt a big job, but having to pull the entire engine again I dont look forward to.

patsmx5

iTrader: (16)

It's easier to carry the straight edge to the car and put it on the deck then to carry the engine to the straight edge... Find someone that has one or go to a machine shop and tell them to make you one out of a piece of steel flatstock.

When I checked my block it was dead flat. Your right that iron blocks usually don't warp, it's the head. But that doesn't mean it isn't possible. At this point I question either the head work done around where the HG seals or the shop that decked the head, or the improper torquing of the head to th engine.

Why I'm repeating my self, I have no idea...

DID YOU chase the threads and oil the head bolts before torquing them?