See what I mean? One slip and they jump all over you around here!
Disaster - head IS cracked...
- Thread starter IdahoDoug
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
IdahoDoug said:
Well, sorry to say, here is one or two or three votes for saying it can be "easily" repaired but not necessarily "reliably" repaired. I have had a similar headache on one of our classic Mercedes coupes with aluminum heads (I know I know, someone's thinking, "WTF, a Maaarrrcedes head, what's so similar about that???" --- Well, its an all aluminum head with overhead cams on an old iron block). I had an overheating problem. I removed the head and saw the HG was messed up. I did check for flatness but not for pressure. Replaced the HG, no overheating, however, lots of loss of coolant. Took the head off, took it to the top shop in the area where they were able to show cracks in the head around the valves using the dye trick. They welded it and tested it to reveal more cracks. Then they welded it again and found that the cracks were so deep they had to send the head to an out of area shop with some super powerful super penetrating welder to "get to the bottom of the cracks". So, after three trials with the welding, and then machining for flatness cause the welding caused warpage, the head is supposedly good to go now. Still there is no peace of mind at all and I totally baby the vehicle. Still to this day, if I could find a "NOS" - New Old Stock head, I'd get it.
That leads me to ask the simple question of how much a NEW replacement head from Dan the man would cost???
Still Doug, to repeat what I wrote earlier, you are handling all this remarkably well. I hope it works out well.
Doug:
My gut says go new. Get a price here to compare to Dan's.
http://www.cylinderhead.com/toyota-pricelist.htm
My gut says go new. Get a price here to compare to Dan's.
http://www.cylinderhead.com/toyota-pricelist.htm
- Thread starter
- #44
OK. Big day. Got to it at 8 sharp, and the head was on my bench at 1:45. Took me another half hour to pull the sensors, get all the head bolt washers out, and clean enough oil out of it to make it presentable.
Got to the race shop at 3 and the owner came out to personally take care of me and check it over. Turns out a straight 6 is somewhat of a novelty these days, so half the staff wandered over. They primarily do V8's naturally due to the shop's racing slant. Because this is N. Idaho, he invited me back to help them find the crack and stuff. I had drawn next to it with a marker.
First, he tried to fit it into his block washer - looks like an overgrown dishwasher. The head was too long, so they literally fabricated a wire rod rack to hold it at an angle on the turntable that spins the component while it gets blasted with hot soap. Then they pulled it out and dried it with pressurized air.
After that we went to a table where he sprayed a powerful cleaner on the crack area. Then a red penetrant dye. Wiped that up, then sprayed it with some kind of curing agent that makes the dye more visible. The crack went from the large plug over to the head bolt hole - just skimming into it and stopping before going out the other side. He looked over the head and said it looked fine. We fitted the exhaust camshaft and it turned easily with fingers and he pronounced it straight as an arrow. Then he got his straight edge rod and confirmed it - expertly checking from several angles.
Then he pulled the large plug out and confirmed that the crack goes all the way through as he suspected. Remember, the head is a rectangular cross section aluminum box, and this is on the top - away from the combustion chambers. Generally, a crack occurs on the combustion chambers normally between the valves where there's less material.
He said the head is in fine shape and though he could weld it, he prefers to use a pinning method. Welding can cause a lot of problems on aluminum heads, he explained and cited several. Apparently, aluminum cannot handle welding well and it could end up weaker around the weld. More importantly he was worried it could warp a perfectly straight head.
Here's how he recommended fixing this crack - about 2 inches long. He will drill a hole at the beginning of the crack, tap it and insert an aluminum plug that is seated with a ceramic based sealant. Then he will drill and repeat slightly overlapping each plug so that literally he is drilling away a bit of the previous plug each time. They end up making up a solid mass of aluminum again where once there was cracked aluminum. I'd never heard of it, but he explained that in his opinion this was the most solid and permanent way to do it.
He's going to charge me $150 for the repair, and since he also has the proper machine to remove these tricky valve springs (need a press with a magnet thing to pull out the retainers) I also asked him to install the new valve stem seals that came in CDan's head gasket kit. He's also going to caliper all my head bolts for nothing though I have all new ones on hand (these are $160 for all 14 and I'd really like to avoid using them). By doing this, he'll be able to identify any head bolts that are not fit for reuse - there's a specification in the FSM that Robbie sent me.
He's such a super guy and he's been building race engines since 1966 in California before wising up and coming up here to 'kinda retire' 10 years ago and ended up opening another shop. He even lent me a 36" straight edge to recheck the block though he's pretty much positive the cast iron block is going to be flat.
So, I'm out another $250 plus another head gasket ($100) but I consider this a blessing as I was pretty much thinking this was going to be a grand or more to deal with. I'm content the head is in experienced hands, and that the fix will be permanent and bulletproof.
Overall, not bad, eh? He thinks the crack may have been there from a previous owner overheating it or freezing it and that my heavy towing simply exposed the weakness finally. He felt that there was no way I could have caused the crack unless I literally "had an eighth inch thick piece of debris on the head and bolted it down." So I feel good.
Here's the good part for us 80 guys. He was audibly impressed with the head's construction, design and workmanship and felt that it was one of the better setups he had ever seen. In no uncertain terms, he praised things here and there as he looked it over, recalling only a BMW head exhibiting similar design levels.
Sorry this took so long to post. I spent so much time at this shop watching that I lost track of time and arrived home in my oily coveralls just as our dinner guests arrived. Whoops. So, we just got the dishes cleaned up from that and I'm feeling much better about this whole thing.
DougM
Got to the race shop at 3 and the owner came out to personally take care of me and check it over. Turns out a straight 6 is somewhat of a novelty these days, so half the staff wandered over. They primarily do V8's naturally due to the shop's racing slant. Because this is N. Idaho, he invited me back to help them find the crack and stuff. I had drawn next to it with a marker.
First, he tried to fit it into his block washer - looks like an overgrown dishwasher. The head was too long, so they literally fabricated a wire rod rack to hold it at an angle on the turntable that spins the component while it gets blasted with hot soap. Then they pulled it out and dried it with pressurized air.
After that we went to a table where he sprayed a powerful cleaner on the crack area. Then a red penetrant dye. Wiped that up, then sprayed it with some kind of curing agent that makes the dye more visible. The crack went from the large plug over to the head bolt hole - just skimming into it and stopping before going out the other side. He looked over the head and said it looked fine. We fitted the exhaust camshaft and it turned easily with fingers and he pronounced it straight as an arrow. Then he got his straight edge rod and confirmed it - expertly checking from several angles.
Then he pulled the large plug out and confirmed that the crack goes all the way through as he suspected. Remember, the head is a rectangular cross section aluminum box, and this is on the top - away from the combustion chambers. Generally, a crack occurs on the combustion chambers normally between the valves where there's less material.
He said the head is in fine shape and though he could weld it, he prefers to use a pinning method. Welding can cause a lot of problems on aluminum heads, he explained and cited several. Apparently, aluminum cannot handle welding well and it could end up weaker around the weld. More importantly he was worried it could warp a perfectly straight head.
Here's how he recommended fixing this crack - about 2 inches long. He will drill a hole at the beginning of the crack, tap it and insert an aluminum plug that is seated with a ceramic based sealant. Then he will drill and repeat slightly overlapping each plug so that literally he is drilling away a bit of the previous plug each time. They end up making up a solid mass of aluminum again where once there was cracked aluminum. I'd never heard of it, but he explained that in his opinion this was the most solid and permanent way to do it.
He's going to charge me $150 for the repair, and since he also has the proper machine to remove these tricky valve springs (need a press with a magnet thing to pull out the retainers) I also asked him to install the new valve stem seals that came in CDan's head gasket kit. He's also going to caliper all my head bolts for nothing though I have all new ones on hand (these are $160 for all 14 and I'd really like to avoid using them). By doing this, he'll be able to identify any head bolts that are not fit for reuse - there's a specification in the FSM that Robbie sent me.
He's such a super guy and he's been building race engines since 1966 in California before wising up and coming up here to 'kinda retire' 10 years ago and ended up opening another shop. He even lent me a 36" straight edge to recheck the block though he's pretty much positive the cast iron block is going to be flat.
So, I'm out another $250 plus another head gasket ($100) but I consider this a blessing as I was pretty much thinking this was going to be a grand or more to deal with. I'm content the head is in experienced hands, and that the fix will be permanent and bulletproof.
Overall, not bad, eh? He thinks the crack may have been there from a previous owner overheating it or freezing it and that my heavy towing simply exposed the weakness finally. He felt that there was no way I could have caused the crack unless I literally "had an eighth inch thick piece of debris on the head and bolted it down." So I feel good.
Here's the good part for us 80 guys. He was audibly impressed with the head's construction, design and workmanship and felt that it was one of the better setups he had ever seen. In no uncertain terms, he praised things here and there as he looked it over, recalling only a BMW head exhibiting similar design levels.
Sorry this took so long to post. I spent so much time at this shop watching that I lost track of time and arrived home in my oily coveralls just as our dinner guests arrived. Whoops. So, we just got the dishes cleaned up from that and I'm feeling much better about this whole thing.
DougM
Doug,
I don't want to rain on your parade but I did some research for you myself today and pursued the same angle. I was told the head repair was possible but even the best repair may last only 5000 miles and 15000 at best. I'd hate to see you have to do this again 4 months or a year from now. These heads are prone to crack in the best conditions let alone a cracked head issue. Thats why there is nothing used available. Just a thought. If you have the dough I'd drop the coin on a new head and be done or else you may be back with the same story a few months from now.
I don't want to rain on your parade but I did some research for you myself today and pursued the same angle. I was told the head repair was possible but even the best repair may last only 5000 miles and 15000 at best. I'd hate to see you have to do this again 4 months or a year from now. These heads are prone to crack in the best conditions let alone a cracked head issue. Thats why there is nothing used available. Just a thought. If you have the dough I'd drop the coin on a new head and be done or else you may be back with the same story a few months from now.
Doug,
It sounds like you found a good guy. The repair technique he recommends is often used both in cast iron and aluminum if the surrounding structure will support it, and with good success. I wouldn't presume to second guess a man on the scene. I'm sure that you asked about a warranty.
While it is nearly always best to obtain new parts in any repair the money has got to factor into a decision to buy them or not. I think that I remember seeing you indicate a plan to sell this truck soon? Or was it the other one? If it was this one and the price of a new cylinder head is near what I can imagine it to be you will lose that money at the sale of the vehicle.
I've never met a bimettalic engine that I felt I could completely trust. Is the 100's V8 all aluminum, does anyone know?
It sounds like you found a good guy. The repair technique he recommends is often used both in cast iron and aluminum if the surrounding structure will support it, and with good success. I wouldn't presume to second guess a man on the scene. I'm sure that you asked about a warranty.
While it is nearly always best to obtain new parts in any repair the money has got to factor into a decision to buy them or not. I think that I remember seeing you indicate a plan to sell this truck soon? Or was it the other one? If it was this one and the price of a new cylinder head is near what I can imagine it to be you will lose that money at the sale of the vehicle.
I've never met a bimettalic engine that I felt I could completely trust. Is the 100's V8 all aluminum, does anyone know?
Good morning, Doug!
Best wishes on all this work and filming and dialoguing you've been sharing with the forum.
While you've got half the engine out of the truck anyway, spill with any other PM or mods you're going to throw into the fray! IIRC, the silicone PHH helped leak away a significant portion of coolant in the late summer. Did you already get to that? Also, I think I remember reading you weren't gonna play with the injectors at this time. Anything else easily reachable that you'd just as well get your fingerprints onto at this time?
Again, good luck, and thanks for your "taking one for the team!"
Best wishes on all this work and filming and dialoguing you've been sharing with the forum.
While you've got half the engine out of the truck anyway, spill with any other PM or mods you're going to throw into the fray! IIRC, the silicone PHH helped leak away a significant portion of coolant in the late summer. Did you already get to that? Also, I think I remember reading you weren't gonna play with the injectors at this time. Anything else easily reachable that you'd just as well get your fingerprints onto at this time?
Again, good luck, and thanks for your "taking one for the team!"
excellent news there Doug. So how long before you get the head back?
post pics!
e
e
Dang, I've been so preoccupied tearing apart my questionable BMW purchase, I missed this whole thread. Awesome that it'll be fixed without selling the kids to pay for it. It would be sooooo cool if we lived closer (although I'd keep the garage locked ). I'm keeping my eye out for a Toyota diesel forklift to raid for an engine, only gas ones found so far. Now we really wish we'd saved my totalled 40th, eh? We're both elbow deep in our cars once again (you're more like up to your eyebrows). This is the first time I've had an extra car during the process, it's amazing how much more pleasant the whole operation is!
). I'm keeping my eye out for a Toyota diesel forklift to raid for an engine, only gas ones found so far. Now we really wish we'd saved my totalled 40th, eh? We're both elbow deep in our cars once again (you're more like up to your eyebrows). This is the first time I've had an extra car during the process, it's amazing how much more pleasant the whole operation is!
Last edited:
I have heard of that type of repair before and have seen it on iron blocks. At the time it was refered to as "metal stitching".
v-8 is cast iron block, alum heads.
This head is the first such head that the IH8 list has seen with cracks. While you may be talkiing about cracks in the cumbustion chamber , this crack is on top of the head. totally different areas or a different head all together dj forest. I am sure this guy feels confident his fix will last more than 10-15k miles, other wise it would not be worth doing. This type of crack repair done right will last as long as the head lasts. Not different then drilling and taping several plugs in a row to meld the metal into one.
Doug You have run into a gem of a Master machinest, these guys do amazing stuff if given the chance. Most places would just trash your head and tell you to buy a new one. Any how good luck, next week we should hear the sound of victory. robbie
This head is the first such head that the IH8 list has seen with cracks. While you may be talkiing about cracks in the cumbustion chamber , this crack is on top of the head. totally different areas or a different head all together dj forest. I am sure this guy feels confident his fix will last more than 10-15k miles, other wise it would not be worth doing. This type of crack repair done right will last as long as the head lasts. Not different then drilling and taping several plugs in a row to meld the metal into one.
Doug You have run into a gem of a Master machinest, these guys do amazing stuff if given the chance. Most places would just trash your head and tell you to buy a new one. Any how good luck, next week we should hear the sound of victory. robbie
Does anyone else think it's strange for a head to overheat enough to crack in this area but still remain flat?
When Doug first posted about the crack I immediately figured it was a casting problem from when manufactured.
Definately a first from what I've read over the years.
When Doug first posted about the crack I immediately figured it was a casting problem from when manufactured.
Definately a first from what I've read over the years.
landtank said:
I don't find it strange and suspect the PO may have overheated, possibly due to a clogged rad and dumped cold water in the hot engine. Something like that would easily crack a completely flat head. As I recall, Doug suspected a clogged radiator and replaced it during his initial baselining of the '97.
I agree with Robbie's observation that Doug has found an excellent machinist, experienced with working on engine heads and with aluminum heads in racing engines. I would be 100% confident in this guy's work and the risk vs return ratio makes the decision much easier.
I will still offer my good luck wishes just in case.
-B-
- Thread starter
- #56
This type of meticulous repair is expected to last the life of the head - not a temporary affair at all. Welding cast aluminum often creates widespread stress to the area as the expansion and contraction from the repair itself creates changes in the mass and tension of the piece. A physical repair like this avoids that and essentially amounts to laboriously replacing the crack with solid aluminum that's not under any pressure.
Once the new aluminum is in place, he'll remachine the hole for the plug, and also the head bolt mounting face since obviously they will have threaded plugs across their surfaces. The head looked to be around 3/4 inch thick at the plugs - no wonder it's so dang heavy. BTW, there's so much room in the engine bay that if you follow my DVD recommendation to remove the hood it's easily lifted off the block by one person and handed to another standing at the front bumper. If there were a place to set it down in the engine bay (could set one up by laying boards across a corner) it could be done by one person.
I have never heard of this head cracking before, so I don't know where DJ's info comes from??
IMO, this engine has been heat stressed before based on the following items:
I bought it with a nonstock radiator
This radiator had a repair in it
The large aluminum cooling pipe to the upper rad hose is pitted badly
I made it all good with new OEM rad (brass/copper 93/94 version), flush, hoses etc but also promptly began heavy towing with it. And I contributed my share of abuse when the coolant got low this summer and alerted me to the whole "where's this coolant going" saga. So, a pre existing crack finally showed itself or began passing enough water to get my attention. Interestingly, I have an oil sample taken before this all began and I will be sending it to Blackstone to shed light on that. If it shows I had coolant in the oil in smaller amounts before the dam burst then it will confirm this. If the sample is clean then it happened on my watch. Will be interesting, no?
What's impressive is that this engine runs so incredibly well, burns zero oil, tested with excellent compression and hasn't been opened up before. Clearly, they'll take some abuse and keep on ticking. I still cannot get over how massive that block is. Seeing it stripped bare really brings that home - it's gigantic.
Truck, I've done several things while the head came off including new fuel injector seals, thorough throttle body cleaning, new O rings on water pipes, gaskets, replaced the tiny water line under the intake manifold, etc. For grins, I may index the spark plugs since I'll be able to see them in the head before putting it back on. Also, I'm installing a block heater I got from Cdan as I can basically stand there with my knees against the block at the moment. The 93 has one and it's kinda nice to use once in a while. Oh, and I found a very trick insulating sleeve from NAPA I'll be installing on the engine wire bundle where it passes the EGR pipe. Good for 1200 degrees, etc. All this will be on the DVD. I wasn't going to use the valve seals as they weren't leaking, but since it's going to be at a shop anyhow and they are the only rubber part in a head that's been heat stressed I felt it worth the money to have them put in. I'd feel like moron if they started leaking a year from now and the truck smoked a bit or started burning oil. This way, I should be good for another 200,000 miles of Miller abuse.
I'll be using the shop's tool to check the engine block tomorrow (Sunday) just for reassurance. Hopefully no surprises there. Oh, almost forgot. I mentioned the tiny mark from the edge of the head gasket and he gave me a product name "Gasket Cinch" that is excellent at permanently filling this. He felt it was not enough of a mar to worry about but I confessed my anal tendancies and he laughed and told me how to use it.
DougM
Once the new aluminum is in place, he'll remachine the hole for the plug, and also the head bolt mounting face since obviously they will have threaded plugs across their surfaces. The head looked to be around 3/4 inch thick at the plugs - no wonder it's so dang heavy. BTW, there's so much room in the engine bay that if you follow my DVD recommendation to remove the hood it's easily lifted off the block by one person and handed to another standing at the front bumper. If there were a place to set it down in the engine bay (could set one up by laying boards across a corner) it could be done by one person.
I have never heard of this head cracking before, so I don't know where DJ's info comes from??
IMO, this engine has been heat stressed before based on the following items:
I bought it with a nonstock radiator
This radiator had a repair in it
The large aluminum cooling pipe to the upper rad hose is pitted badly
I made it all good with new OEM rad (brass/copper 93/94 version), flush, hoses etc but also promptly began heavy towing with it. And I contributed my share of abuse when the coolant got low this summer and alerted me to the whole "where's this coolant going" saga. So, a pre existing crack finally showed itself or began passing enough water to get my attention. Interestingly, I have an oil sample taken before this all began and I will be sending it to Blackstone to shed light on that. If it shows I had coolant in the oil in smaller amounts before the dam burst then it will confirm this. If the sample is clean then it happened on my watch. Will be interesting, no?
What's impressive is that this engine runs so incredibly well, burns zero oil, tested with excellent compression and hasn't been opened up before. Clearly, they'll take some abuse and keep on ticking. I still cannot get over how massive that block is. Seeing it stripped bare really brings that home - it's gigantic.
Truck, I've done several things while the head came off including new fuel injector seals, thorough throttle body cleaning, new O rings on water pipes, gaskets, replaced the tiny water line under the intake manifold, etc. For grins, I may index the spark plugs since I'll be able to see them in the head before putting it back on. Also, I'm installing a block heater I got from Cdan as I can basically stand there with my knees against the block at the moment. The 93 has one and it's kinda nice to use once in a while. Oh, and I found a very trick insulating sleeve from NAPA I'll be installing on the engine wire bundle where it passes the EGR pipe. Good for 1200 degrees, etc. All this will be on the DVD. I wasn't going to use the valve seals as they weren't leaking, but since it's going to be at a shop anyhow and they are the only rubber part in a head that's been heat stressed I felt it worth the money to have them put in. I'd feel like moron if they started leaking a year from now and the truck smoked a bit or started burning oil. This way, I should be good for another 200,000 miles of Miller abuse.
I'll be using the shop's tool to check the engine block tomorrow (Sunday) just for reassurance. Hopefully no surprises there. Oh, almost forgot. I mentioned the tiny mark from the edge of the head gasket and he gave me a product name "Gasket Cinch" that is excellent at permanently filling this. He felt it was not enough of a mar to worry about but I confessed my anal tendancies and he laughed and told me how to use it.
DougM
IMO we are seeing the results of hot coolant in back of the head... the same conditions that continue to take out all those head gaskets. It's the last place to be cooled, the EGR cooler is behind #6, the EGR passage along the #6 runner, even the impeller on the water pump is a weak stamped design. They all + up to problems.
THe guy I consulted builds the some of the best race engines for guys all over the country. I passed the current info to him and all he could muster was a good luck. He is a 30 year builder with a nation wide reputation. Like I said I'm not trying to cause you grief but to save you some. I guess I will follow and say Good Luck and if I can help at all I will be more than happy to.
Forrest
Forrest
IdahoDoug said:
Doug - great news!
Please post the name of this race shop - someone who lives close to you might need a good engine shop one day
John
IdahoDoug said:
Is it the same as this stuff that Dan recommended to you when you were chasing down a suspected leak about a month ago?
-B-