Head Gasket repair

[bil1024]

So thinking I have a leaky head gasket. White smoke at times, bubbling in overflow tank and a wet plug. So I see a few sealants on the market, Bar has you drain the coolant , flush and add sealant etc.. Or just replace the head gaskets ? Thanks fellas

[GoDadGo]

Sorry, but the only viable solution is to replace the head gaskets.
Please be sure to check the block and heads to make sure they aren't warped.
Good Luck & you'll be an even better wrench swinger in the end, but it is a bit of a pain in the neck.

NOTE: If you dig through my most recent thread then you'll know that I feel for you.

http://thefactoryfiveforum.com/showt...mp-That-s-Okay!

Good Luck From The Dart Side!

[NAZ]

Your symptoms are the same as you would expect to see from coolant in the combustion chamber and a head gasket is a strong suspect but not the only possible cause.

The mechanic in a bottle fixes are mostly snake oil. Pull those heads and get to work. A head gasket can be changed with the engine in the car. And you won't know if the gasket is leaking unless you pull the heads and see solid evidence of a leak. Also, I suggest you do not reuse the head bolts -- go back with new or you are risking another failure.

[CDXXVII]

Replace the head gasket.

I am in the process of changing a head gasket in my nearly new Ford Racing Z427. Kind of a pain doing it with the engine inside a finished painted roadster. Best I can say is to take your time. Don’t loose your temper. Clean everything as you go.

[CraigS]

Do you just get the white smoke from one side pipe. Maybe you only need one gasket. OTOH, Once the intake is off might as well do both.

[karlos]

I am in the process of changing a head gasket in my nearly new Ford Racing Z427. Kind of a pain doing it with the engine inside a finished painted roadster. Best I can say is to take your time. Don’t loose your temper. Clean everything as you go.

Not to jack this thread, but interested in what happened as I've got the same engine. You running boost or something?

[RickP]

So thinking I have a leaky head gasket. White smoke at times, bubbling in overflow tank and a wet plug. So I see a few sealants on the market, Bar has you drain the coolant , flush and add sealant etc.. Or just replace the head gaskets ? Thanks fellas

Your singing my song. Exactly what I am in the process of doing. Pull those heads and see what's doing underneath. If your head gasket is blown, you need to investigate as to the "why did this happen". It will most likely happen again if the root cause is not rectified.


In my case, white smoke was present at the passenger side pipe. I won't get into the overheating event that caused this, that's for another day. Didn't make much sense to me at the time as all obvious signs would leave me to believe something was going on internally. i.e. Brand new AFR heads, bolts torqued to spec and I know how the gaskets were installed correctly since I put them on myself. After careful inspection, the gasket on the passenger head "walked" enough to allow coolant into the #3 plug hole. This prompted me to dump the oil and discovered coolant in the pan. Just great!

So, replacing the head gaskets is probably the answer but it begs the question of how it happened. Once you go through this, you won't want to do it again... I couldn't determine any immediate cause for the gasket to walk. Eventually I worked my way to the water pump. This part is a Weiand 8215P (reverse rotation) mechanical pump. Ummm, so I thought. The pump has no part # on it but I had been pretty darn thorough in my investigation up to this point. I cracked the pump open and discovered the pump was actually a standard rotation pump. It was boxed incorrectly and I blindly bolted it on when I assembled the engine. Not too happy with Holley at the moment nor myself.

If your head gasket or gaskets are blown, there is a reason why. Installing head gaskets without determining why they blew is no better than using mechanic in a bottle IMHO as you could be and most likely are band aiding an underlying problem.

[bil1024]

Not to jack this thread, but interested in what happened as I've got the same engine. You running boost or something?

Not sure yet, driver side smoked most, but after a few runs, smoke never appeared again ? But other symptoms persisted. Started tear-down and will post updates, thanks for all the advice guys

[CDXXVII]

Not to jack this thread, but interested in what happened as I've got the same engine. You running boost or something?

E-Street throttle body, no boost. I had some strange cooling issues early on. Seemed similar to trapped air or a hot spot somewhere. Ford Racing ended up having it shipping back to Michigan to the local race shop. Interesting that they do not have their own facility but then again, Ford does not build these engines anyways. Long Story. Holbrook Racing tested the block and could not find anything wrong. They performed some high tech, high pressure test and had a very small concern on one of the head gaskets so they changed both of them out. 2100 miles later and my drivers side gasket failed. No coolant into the engine but it leaked out of the engine below the headers. I am slowly taking everything apart. Intake and exhaust manifolds are off so the head or heads are next. Not sure if I want to do both. My advice is to use a local resource for your engines. Ford Racing had a "good warranty" but you will never use it unless you are super fast at building your roadster. My warranty was up before I had 250 miles on it. Heck, I have 2100 miles on the roadster but I think the engine has over 7500 travel miles on it given all the shipping it's been involved in.

[karlos]

Sorry to hear of the difficulties. Frustrating I'm sure. Sounds like you might suspect trapped air, and if that's the root cause then the gizmo linked below might be worth looking into prior to your next coolant fill. Draws the air out before the coolant goes in.

https://www.uview.com/index.cfm?dsp=...productid=5120


Best of luck getting it straightened out.

[CDXXVII]

Yup! already purchased the Airlift vacuum tool, the cooling system pressure testing system, the lisle funnel, the block tester, multiple radiator caps, a borescope. Pretty close to opening up a shop. Ford Racing just does not want to believe the symptoms. I even sent them video of the symptoms. If I get another failure I am taking the engine to a professional for a complete tear down. If they find the flaw then it's time to raise a little hell.

Sorry to hear of the difficulties. Frustrating I'm sure. Sounds like you might suspect trapped air, and if that's the root cause then the gizmo linked below might be worth looking into prior to your next coolant fill. Draws the air out before the coolant goes in.

https://www.uview.com/index.cfm?dsp=...productid=5120


Best of luck getting it straightened out.

[first time builder]

I purchased a NEW crate engine from GM for my Vette about 12 yrs ago and noticed something in the water pump passages in the block? I called Scoggin Dickey Chevy where the engine came from and they told me its GM "headache pills" It a stop leak that all GM engine are equipped with even factory engines have it. I went on line and GM even sells them as a part. Its not to fix a blown headgasket but to seal any minor imperfection .

[karlos]

At the risk of mentioning something you already know, thought I'd throw this out. The Ford intakes are different (and not necessarily better) than the other manufacturers in that tightening the intake manifold bolts produces a force that tends to lift the heads off the block. Notice how the bolts in the Chevy intake (left side) go in at an angle as compared to the straight-up-and-down Ford bolts on the right side.





To compound this, the Ford intakes typically use a thick cork gasket at the front and back of the lifter valley. When I fit checked my manifold without any gaskets there wasn't much of a gap where the cork gaskets were supposed to be installed. Even with the intake gaskets in place, the gap only measured 0.06" or so. The cork gasket was probably close to 1/4" thick. That's a lot of compression that needs to occur before any preload finds its way into the intake gaskets themselves. In cases like this it might be better to use RTV instead so that you can achieve enough preload to seal the intake gaskets without having to overtorque the manifold bolts.

You probably already did this, but if not maybe one more thing to look at when you reassemble.

[CraigS]

Karlos has sound info there. Maybe 2 yrs ago someone on one of the forums was going crazy until he found that he actually had a slight interference intake to block. So instead of .06" clearance the block was holding the intake off the heads and he kept losing coolant when the intake gasket died at the coolant passages. Good thing to check!

[Big Blocker]

Just FWIW, FORD hasn't "recommended" the cork gaskets since the late 60's . . . true, they supply them with all intake gaskets kits but that's because they will fulfill a need in a seriously mismatched intake to head scenario. 99.9% of FORDS intakes are within spec and won't need the cork. That being said, everyone uses some type of RTV to "create" a bead of gasket sealer for both front and back block surfaces.
One other VERY IMPORTANT thing to remember here, there is a specific pattern to follow when tightening down a SBF intake manifold and should be accompanied with corner studs for guidance so the manifold does NOT "walk" left or right. Also, the lower head bolts need sealer to prevent cooling jacket leaks up the bolt.

Doc

[CDXXVII]

Just FWIW, FORD hasn't "recommended" the cork gaskets since the late 60's . . . true, they supply them with all intake gaskets kits but that's because they will fulfill a need in a seriously mismatched intake to head scenario. 99.9% of FORDS intakes are within spec and won't need the cork. That being said, everyone uses some type of RTV to "create" a bead of gasket sealer for both front and back block surfaces.
One other VERY IMPORTANT thing to remember here, there is a specific pattern to follow when tightening down a SBF intake manifold and should be accompanied with corner studs for guidance so the manifold does NOT "walk" left or right. Also, the lower head bolts need sealer to prevent cooling jacket leaks up the bolt.

Doc

Hey Doc

I am right in the middle of replacing a head gasket on my Z427 engine. I noticed you mentioned corner guide studs for the manifold. I know that the heads have alignment dowel pins in the lower corners but I was not aware of any guide pins for the manifold. I found the torque sequence and specs. for both the heads and the manifold. I also just found some good instructions on adjusting roller rockers. Any other tips/tricks would be great. Everything is off that needs to come off including the rockers. Head comes off next. Hopefully mid week. I have all parts on order to finish the job.

[Boydster]

CDXXVII, what he means is to use studs at the corners instead of bolts. That way the manifold may be lowered straight down without wiggling or moving side to side. This prevents moving the intake gaskets and ultimately, mis-alignments.

[NAZ]

CDXXVII, if you're looking for tips heres one that might save you having to repeat this job. Use new head bolts -- throw the used ones in the trash. Run a tap through all the threaded holes and clean the threads good so you get an accurate torque reading when reassembling.

The job is dirty and hard on your back but really not that complicated. I've done lots of R&R head jobs in the vehicle and the real trick is cleaning everything so you have good mating surfaces.

[Joee]

CDXXVII, what he means is to use studs at the corners instead of bolts. That way the manifold may be lowered straight down without wiggling or moving side to side. This prevents moving the intake gaskets and ultimately, mis-alignments.

You make them out of longer bolts. Cut heads off of them then make slots across top so you can use a flat screw driver to get them out. Dont put them in tight just enough so they dont wiggle. I have needed to use the screw driver on 1 or 2 if they get pinched by the intake.

[CDXXVII]

Thanks for the clarification. I do use temporary studs I made a long time ago with screw driver slots cut in them. I have the same for the heads.

With regards to the head bolts. I spoke to ARP and to Ford Racing and they state that I do not need to replace the bolts unless there are obvious signs of damage.
I believe some manufacturers use torque to yield bolts that need to be replaced every time but there is no need to toss $130 worth of ARP hardware every time.

CDXXVII, if you're looking for tips heres one that might save you having to repeat this job. Use new head bolts -- throw the used ones in the trash. Run a tap through all the threaded holes and clean the threads good so you get an accurate torque reading when reassembling.

The job is dirty and hard on your back but really not that complicated. I've done lots of R&R head jobs in the vehicle and the real trick is cleaning everything so you have good mating surfaces.

[NAZ]

I hear you on the cost aspect -- these fasteners are not cheap. However, did ARP and Ford Racing also tell you that the torque / tension relationship will change? So when you torque down those fasteners at the original specified torque value you will be getting less pre-load (clamping load) on those heads. It's good you checked with the fastener manufacturers and with Ford. Just realize that reusing these head bolts at the same torque value will result in less clamp load and possibly less resistance to high cycle fatigue, especially when used with aluminum heads. And you can't just set your torque wrench to some arbitrary higher value as unless you have access to a Skidmore gauge to measure clamp load you're just guessing.

If these are ARP fasteners I suggest you go back to them and ask if they have a suggested torque value for used fasteners and remember dry vs lubed torque values are different so have them specify which they are giving you. There have been many tests on reusing fasteners and the torque / tension relationship and if you Google it I'm sure you will find charts showing the diminished pre-load upon reuse. I have no dog in the fight -- I'm just passing along info to help you make an informed decision. I've a great deal of experience with fasteners and seen lots of failures. Only you can decide how to spend your money.

Good luck.

[Big Blocker]

WOW, sometimes I just can't back to a thread fast enough . . . Boydster beat my current typing speed - Ha!

Yes, corner bolts with the heads cut off and slotted are exactly what I was referring to in my last post. And I'll repeat the statement about using the correct tightening sequence / pattern. Just remove the "stud" when you get to that bolt in the sequence. Also remember to go over the pattern a few times after you reach initial torque - I've had to repeat it 3 or 4 times in the past to finally get it to torque.

Doc

[bil1024]

Update} pulled head so no damage, but I am wondering if these were the correct gaskets ?


IMG_1545.JPG

[GoDadGo]

Though I'm not familiar with SBF engines; however, I am familiar with the steel shim style gaskets and am not a big fan of them.
What I've been happy with is the Fel-Pro Perma-Torque Composite gaskets, but you will lose a little compression over the steel shim type since they tend to be thicker.
Also, did you check your heads an block with a good straight edge to make sure that nothing is warped?