Blown SOHC head gasket *PICS*

[BobWiersema]

Used Bolts

Why dont you ask the guy that welded up the head for you. I dont know that I would reuse it. There is a big warning about that in my manual. It would suck out loud to have a rod come loose after all this. I looked at the ford parts direct site and didnt see any but it may be worth a call. 801-292-4433 http://www.buyfordpartsonline.com

 

[ranger7ltr]

Is the welded area going to affect the compression in that cylinder?

Obviously they didn't add weld to the rest of the head in the same area but I would be concerned about the volume differences between the welded cylinder and the rest...

And did the shop mention any concern that the heat generated might cause issues with the cam supports or the valve stem seals??? The last aluminum head I had welded to repair some voids had to be remachined to provide clearances for the cams and bearing surfaces..

And it is my understanding that torque to yield bolts are stretched when they are torqued then turned an addidtional 80- 90 degrees whether they are heat cycled or not...

 

[ranger7ltr]

1 source for SOHC rod bolts...

I searched the net and can not find a single source for connecting rod bolts for the 4.0 SOHC. Maybe I will just bolt it together and hope for the best.....

Check this link to Morana Motorsports...http://www.moranav6racing.com/category.html?CategoryID=32

I would also call ARP to see if they have an application that is not in the catalog...Their order and tech support # is 800.826.3045 or 805.339.2200, fax: 805.650.0742

Their email addy which I have found somewhat useful is: info@arpfasteners.com

They are in California and open I think around 730a PST...

 

[BobWiersema]

And it is my understanding that torque to yield bolts are stretched when they are torqued then turned an addidtional 80- 90 degrees whether they are heat cycled or not...

Yes, I believe he is correct. You should probably read this before considering reusing any TTY bolts. http://www.robbos.com.au/myweb/Tech_Bolts.htm

 

[bluestream1]

Yes, I believe he is correct. You should probably read this before considering reusing any TTY bolts. http://www.robbos.com.au/myweb/Tech_Bolts.htm

Good info, I always wondered about why stretch bolt were used. Too bad they are so expensive..

 

[CDW6212R]

I would also avoid reusing those. I always thought that part of their purpose was to make you buy more. The real problem with tightening them more than once is that they do not tighten the same way each time. They stretch, and the next time the same procedure will make them stretch to a greater length than the first time. So the tightening procedure is what cannot be used again, not necessarily the bolt. The bolt is not unusable, but it is not known how to tighten it to the length it was the first time. Buy new bolts.

 

[shelbygt]

I am going to be a rebel...lol
I'm running out of money 1200.00 so far and Ford will only sell the rod bolts and nuts in a set of 12. It has been apart for over a month now and I am waaay past being over working on it.

All, the guys at the machine shop (who do work for all the local major dealerships) agreed that unless the motor suffered a catastrophic failure or had any significant damage, they always reuse the rod bolts whether or not they are torque to yield. He actually had a re-manufactured 4.0 SOHC rod in the box for a customer and showed me that it came with used bolts.

If a shop was torquing a head bolt (he explained) and lost track of the sequence for some reason, They don't remove them and throw them away. That is basically where I am at. The machine guy said that the people from Ford who set the procedures for these bolts and state they must be thrown away... do not build used motors day in and out and they do these all day long and have no issues. I would not reuse the head bolts that have been on a motor and heated and cooled.
Here is a quote from the link Bob posted:

"Conventional head bolts simply just did not wear out. Torque to yield head bolts however, by the very nature of their design, do wear out and should NEVER be reused."
This to me would mean from age and use, not just from torquing them.

I may be taking a slight risk with the rod bolt, but I keep my fingers crossed. After talking to the guys at the shop, I feel safe about reusing the rod bolts and nearly new brand head bolts.

And to add to the fun, the oil pick up tube bolts nearly broke when I torqued them (not torque to yield). They are only 118 in lb and yet the one bolt kept spinning at 100 in lb and finally when I removed it, it is deformed and needs to be replaced. Why this happened is beyond me. Now I get to hunt for these bolts tomorrow.

I am wondering if this will ever end!

 

[shelbygt]

Keep in mind I shared all the same concerns and expressed to him that all the instructions and manuals said emphatically to replace the bolts... just as everyone here has also said. So I do appreciate the advice!

But after taking with him for an hour or so (whom I have known for over 23 years and has done all motor work for me, my friends and family) so I trust what he is telling me. If he thought that it was "iffy" he said he would tell me to replace them.

 

[BobWiersema]

Bolts

After searching all over the web and back yesterday looking for those rod bolts for you, I agree. Nobody is replacing them, period. The only place that had a set for $140. sells them for use in a high performance 4.0L SOHC motor. Your talking about an complete lower end stroker kit. A $3,500 performance package. Thats what they sell the replacement bolts for. So they got a little stretched, if they dont break when you install them, they probably will never break. Were not talking about a motor that is ever going to see 10K rpm here. I dont think Ive pushed mine much past 6K for a long time. Its just old and I worry about it so why push it. Personally, if the motor guy says its cool I wouldnt think twice about it. There must be some dam good reason you can get the head bolts just about anywhere but those rod bolts are almost impossible to find. As far as reusing those head bolts, I think you will get away with it. Same theory, if they dont break when you install them they probably wont.

Good luck and keep us up to date.
Bob

Also why is the word en ti re changing to endonut? What does that have to do with pizza? April 1st is over.

 

[shelbygt]

Thanks Bob! Yeah the rod is back in, no problems all felt good when torquing. The machine guy said the same thing, if it feels like it is loosening up, it is about to break. If it feels like it is staying tight, you are good to go. Worse case on the head bolts is if the bolt breaks, or feels weak .... I have to buy new bolts.

I got burned by the April 1st thing here...it's been a long time since I fell for it! LOL

 

[BobWiersema]

Do you have a gauge type breaker bar. I was just thinking, use that to watch the torque while you add the 90° past torque. If you go past that sweet spot on the bolt you should see the torque go down and you know your screwed before it breaks. You follow what Im thinking?

 

[shelbygt]

I know exactly what you are saying. The problem is when using the dial gauge, I had to use the breaker bar with it as it takes ALOT of force to rotate the bolt once the original torque is reached. You go 90 degree past torque, then another 90, so it gets REAL hard to turn, it might break a bar type torque wrench.

 

[BobWiersema]

The one I have looks like this.

I can remember what the top of the scale is on it, but its at least 200 ft LBs.
I cant imagine breaking the thing. If you cant use yours, youll have to just go by feel. If it takes that much force, you'll know if its failing.

 

[shelbygt]

I have the same type of wrench. I can't convey the amount of force you need to get that extra 90 degrees, the 1/2 inch Craftsman breaker bar was bending...lol

I am sitting here thinking about the head bolts and the chance that they could possible break or loosen up when tightening them and now I am worrying if this happens, I am going to have to buy yet another new head gasket. I think I might just bite it and get another set of bolts. The chance is small, but I can't imagine the regret if I have to buy a 3rd sets of $80 in head gaskets.

I worry I won't be able to find these stupid little oil pump pick up tube bolts. They are odd looking bolts and most likely a 10.00 each, Ford only, special order part.

 

[BobWiersema]

Ya, you havent been having the best of luck. Its your call. But if your not getting that warm and fuzzy feeling about it, you should go ahead and replace them for your own peace of mine. As far as the oil pump bolts go, why dont you pm vroomzoomboom and see if he is going to use anything from that SOHC. He might send you the bolts if that engine is scrap.

 

[BogusSVO]

Dude.... sorry about your luck with your heads....
I am new, your thread, this thread was linked at another fourm I am a member of...
http://forums.tccoa.com/showthread.php?t=128359

but I have some info you may want to read over before you bolt your hads down...

I have been a machinist since 1992, and from looking at the pics you have posted I have some issues with the machin work and welding done to your heads.....

first off. the heads should have been pressuer checked... that pin hole and the crack would have been found.
(the links will take you to a local fourm board I am on)
http://www.driven2modify.com/showthread.php?t=20892

this should have happened also after the welding of the head to make sure the weld got the whole leak

the seat(s) should have been removed and the full crack ground out, then welded back up and new seats installed...
simulair to this.....
http://www.driven2modify.com/showthread.php?t=20813

also with the welding being done on top of the seat as in your posted pic, the heat can and will distort the seat, causing valve sealing issues.

it looks like the surface was done on a belt surfacer.. I do not like this style of surfacing equipment, this is explained and shown why, it is not an accurate machine to use. alost of shops use it beacuse its quick, easy and cheap.
http://www.driven2modify.com/showthread.php?t=22985

your head(s) should have been done like this....
http://www.driven2modify.com/showthread.php?t=20850

I have not read thu this whole thread, but just some posts in it.

 

[BobWiersema]

Dont Engineer it to Death

The type of work your talking about might exceed the cost of a re-manufactured head. I have seen them for around $260. Fully rebuilt, pressure and vacuum tested. If this was a high performance vehicle I would say you are correct, but its not. Its a 12 year old truck with a V6. This is also not a complete engine rebuild, its a repair job. If I was doing a complete rebuild on it, I would replace the head, but hes not. The beauty of the SOHC 4L engine is its fairly forgiving. I drove mine for over 30K with the worst chain noise you have ever heard. It sounded like a rock grinder, but it kept running. So I guess what Im saying is, why engineer it to death. Just get it running. If he puts it back together and the compression is bad in #5 then thats that. But I think its worth a try. And I would be willing to bet it will work.

Bob

 

[BogusSVO]

Bob, I can understand what your saying about the cost factor, but right is right and wrong is wrong.

the shop that did the welding should have done a before and after pressure test in the cost of the repair

there is a big diffrence between some wore chains and guides.. and a bad casting in the head.

now since were in the relm of "what if" the op bolts it all back together, and the head springs another hole in another cylinder? Due to the fact, that the head went thu core shift when it was cast, and there are other thin spots in the head casting. If that head would have come into my shop I would hav had he OP replace it with a RE-man or a JY head, depending on his budget

I dont know, but I do hope the OP will be using a composite gasket, a belt surface head stands a marginal chance of holding a MLS gasket seal for any amount of time.

Your right, fixing the OP's head may have come close ot exceeded the cost of a reman head. But I bet he is close to $260 into the head and still "Iffy" at best

Do not get me wrong, I hopr the OP's project comes off with out an hitch and it runs well for years to come.

 

[BobWiersema]

Well, its Daves truck so its his call. I still think it will be fine.
By the way, do you know these guys in Florida? Odessa*Cylinderhead

 

[BogusSVO]

No I do not know them, I am in the panhandle they are central. I havent even heard of them.

true it is his truck, so its his call to make.