#251
IP: 66.183.216.116
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retapped stud failed
On the weekend I carefully drilled and tapped a new hole for my one problem stud. Did it with the head on, using the Moyer kit, re-drilled the 3/8 hole with a 3/8 bit and tapped with brand new 7/16 coarse tap (and then bottoming tap) and the proper oil. Drilled out the head to 7/16. The replacement stud went in and out perfectly several times on the dry fit. Put on some JB weld and started threading in the stud. Started okay, then got tight too soon, but then got easy again....and then never seemed to seat properly. Prayed the JB weld might hold it, left it 48 hours, but on torquing today can't get past 25 - 28 lbs.
1. Am I right in guessing that good ain't enough? (stud is 2nd hole back from the corner, on the manifold side). 2. Why might it have stripped? Can the density of JB cause a problem? 3. Am I right that my next step is head off and install a repair bushing? What size do I want? Do sizes refer to the hole you drill or the diameter of the stud that goes in? Any other option? Frustrating!!! Boat is almost ready for the engine. Thanks for any advice!
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Marty 1967 Tartan 27 Bowen Island, BC |
#252
IP: 97.164.65.153
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It is possible that when drilling the head you went too far and damaged the new threads. Seems best now to pull the head and have a look-see.
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#253
IP: 66.183.216.116
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forensic evidence
Thanks, Hanley....I suspect you are right...didn't think of that. The stud unscrewed pretty easy. See photo for how threads look compared to a new same size stud.
Would it be worth a try re-tapping now? Thanks.
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Marty 1967 Tartan 27 Bowen Island, BC |
#254
IP: 97.11.207.158
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If you used that stop collar as indicated then you should not have damaged the threads that way. But if the 7/16" threads will not hold I don't think you have any option but to pull the head.
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#255
IP: 66.183.216.116
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threads + water pump
Maybe that stud got stripped on the way in, so the threads in the hole didn't have anything to grab? I was thinking that re-tapping might be more like a chaser....cleaning JB Weld out of the threads? Is there any harm in trying?
Not afraid of the work of removing the head, but worried that other studs might not like being loosened and tightened an extra time...asking for more trouble. Any thoughts on my water pump (seven posts back)? Thank you yet again.
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Marty 1967 Tartan 27 Bowen Island, BC |
#256
IP: 97.11.207.158
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At this point the most important thing to consider is the condition of the threads in the block. You have already opened the hole up to 7/16" and the stud will not hold. There is no harm in chasing the threads with the 7/16" tap but I don't think the prospects are good in light of what you have already posted. You may now be looking at a situation where the traditional helicoil is the only alternative which means pulling the head. Don't worry about that small water pump leak until the thread issue is resolved.
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#257
IP: 108.4.61.32
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You think some people are anal retentive about their Atomic 4 engines? You should see some of the guys over on the Miata forum!
There's a guy who posted a whole big long story about taking his engine apart, including going so far as to disassemble his HLAs (which most people don't do) to get the gunk cleaned out of them - complete with pics and digital calipers and explanations and everything. The big difference between the Miata and the Atomic 4 (besides the obvious) is that there TONS of aftermarket kits and mods out there for the Miata from several vendors - lots to make them bump out a little more h.p., or a boat load more h.p. There are bolt-on turbochargers and bolt-on superchargers. You can take the stock 1.6L (early) or 1.8L (later) engines that originally were factory stock at about 110 hp and get 200 or more hp out of them. And then there are the guys who swap out the little 16V 4-banger for a Ford 302 - or even a Ford factory crate motor - or - the ultimate - a Flyin' Miata crate motor, which can be tuned to pump out over 400 hp! In a car that weighs only about 2200 lbs. And yet it supposedly stays remarkably streetable. Anyhow, to avoid further thread drift... The procedure for the ATF flush is basically two oil changes in a row, but the first one is a bit different. The procedure is to first drain as much of the old oil out as possible and remove the old filter. Then put a cheap oil filter on the engine and pour in 1 qt of 50W oil and 3 quarts of ATF. Then let it just run at idle for about an hour or two. Then drain it all out as much as possible and remove the cheap filter. At this point, some people reported that while the drain plug is off, they would run about a gallon of kerosene through the engine to flush it out good, but I don't know - I didn't do that. Then, once you've got it good and drained, you put your good oil filter on the engine and fill with your favorite oil. TO BE CLEAR: I am not saying anyone should do this with their Atomic 4 - it is a procedure suggested for old Mazda Miata engines to deal with crudded-up oil passages in the HLAs. It's relatively well-known on the Miata forum and lots of people (including me) have done it and report very good restuls. I'm just theorizing it might maybe could possibly maybe help in the A4 with something like stuck rings. I also suppose it might could help slow/lazy/sticking valves, too - even though we have solid lifters, if the valve guides or lifters get sticky, this should de-gummify the works and help things move more smoothly. I don't need to do it on my engine, so I'm not volunteering my engine to be the test subject, but it's an interesting idear to consider for an engine that might could benefit from it... maybe?
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- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#258
IP: 66.183.216.116
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re-tap?
Unfortunately I gotta plan ahead: short short sailing season here. Not that a dripping water pump would stop me going sailing, but if I have to order more parts for the stud problem I'll want to order anything for the water pump at the same time. The shipping costs are killers...the more at once the better.
I'll likely give re-tapping/chasing a try on Friday...off to work in Vancouver for a couple days...and hopefully sneak in a little time working on the wiring. If re-tapping fails - and I do agree it is a long shot - off with her head! Thanks again.
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Marty 1967 Tartan 27 Bowen Island, BC |
#259
IP: 128.183.140.38
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Quote:
If you do have to pull the head and put in an insert, be sure to use a "repair bushing" threaded insert instead of a helicoil. Helicoils have a tendency to leak, and this hole goes all the way through into the water jacket. I know this one from experience with my first A4. The repair bushings, like the one MMI sells (OBLK_09_114), are solid-walled, whereas helicoils are not.
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@(^.^)@ Ed 1977 Pearson P-323 "Dolce Vita" with rebuilt Atomic-4 |
#260
IP: 66.183.216.116
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head off
Decided to take the head off to try re-tapping that stripped stud. Just wanted to have a good look. "Chased" the 7/16" hole with a tap, and now the stud screws in pretty well, but with two problems: it is a little wobbly (though straight) and doesn't seat (I can screw it down several turns below the block face).
Two questions: 1. With the head off, I am thinking I might get away with screwing in the stud to the proper depth, even though it doesn't seat. Is that a no-no? 2. I have read and heard many opinions on sealants. Ken and a bunch of local mechanics state that I should use Red Loctite. The retapping kit, and Don's pdf say to use JB Weld. Many on the forum prefer #2 Permatex. I am leaning toward Loctite, might be strongest, but wonder if JB Weld will hold the "wobble" and seal better. Please advise!
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Marty 1967 Tartan 27 Bowen Island, BC |
#261
IP: 66.183.216.116
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testing torque without the head
I'm wondering if there is a way to test a stud's holding power without putting the head back on. Put a short piece of pipe over it with a nut and washer on top, and torque it down....?
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Marty 1967 Tartan 27 Bowen Island, BC |
#262
IP: 108.4.61.32
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Just my 2c - I do not claim to be an ex-spurt on the potential pros and cons of using one of those miracle goops over another, but if it were me and I were doing it, I feel that I would go with J-B Weld. I would get everything very good and clean with solvent to be sure all surfaces are completely free from grease or oil first.
I J-B Welded in my exhaust manifold studs - it's amazing stuff.
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- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#263
IP: 66.183.216.116
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locktite vs JB
Thanks, Rust. Still pondering. My impression is that locktite is stronger, but maybe not as good at filling gaps as JB Weld?
Had a crazy inspiration. After gluing: as the stud is on the edge (exhaust manifold side), I could drill a pin hole (perpendicular to the stud) from the outside of the block, through the stud, and back into the block and pound in a steel pin (1/16"?) to keep the stud from turning. Not going there, but just thinking....
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Marty 1967 Tartan 27 Bowen Island, BC |
#264
IP: 108.4.61.32
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Quote:
Quote:
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- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#265
IP: 66.183.216.116
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a new problem!
Seriously cleaned the holes with acetone and taps. JB Welded the re-tapped stud and reinstalled all the leaking studs (Perm #2) today. Fingers crossed: cold torque it tomorrow.
Noticed some water stain around a water jacket side plate hole and tried to tighten it up...stripped! As were three others. Puzzled how something just goes from "hand tight" to stripped by itself....can the heat change do that? As soon as I turned the bolt I could feel it was gone. Can I drill and tap these? The metal all looks good. I see on the forum people usually use the Moyer two hole repair kit. I understand that if the wall were in bad shape that would solve the problem, but is it advisable to drill and tap instead if the metal is solid? Drill 1/4" and tap to 5/16'"? Coarse or fine? Amazed at the parade of problems! Thanks!
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Marty 1967 Tartan 27 Bowen Island, BC |
#266
IP: 151.200.29.202
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JB weld studs into the block!
Marty, I have two of my eight side plate holes oversized. Last year, I went to studs and ditched the bolts. I JB welded my studs in place. The P.O. had already torn up the 2nd from bottom left hole with the alternator support, and it was a 3/8" bolt. There was enough corrosion that I had to do the same to the bottom left hole...so I have six 5/16" studs and two 3/8" studs.
So, when I pulled all the bolts, I cleaned up the threads with a thread chaser, and then JB welded studs (two 3/8" & six 5/ 16") into all eight holes. If they are sloppy, there can be an issue with aligning the studs to fit in the side plate holes, so be careful. With a little bit of work, I got mine to hold. I am using brass nuts & washers...kinda as sacrificial I figure...they are pretty cheap to replace. This spring, I am planning to replace the forward stbd drain hole (a little forward of the side plate, near the starter) with a zinc, similar to what Moyer Marine is doing with their blocks these days. That might keep the brass nuts from degrading. The other option is to buy the stud repair kit that Moyer sells for the sideplate. That is my next course of action if/when these start seeping.
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-Shawn "Holiday" - '89 Alura 35 #109 "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!) Last edited by sastanley; 05-06-2012 at 12:45 AM. |
#267
IP: 66.183.216.116
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Good plan
Many thanks - I will get eight 5/16" x 1" studs tomorrow. I can use the four "good" holes with screws to align the JB Welded studs, then after those are set I'll switch around and do the other four.
I know there is an ongoing issue with the dissimilar metals, but as I am now fresh water cooled I think it will be manageable. I plan to use SS studs with brass washers and SS nuts. On our old A4, even with RWC, the SS bolts showed no sign of a problem after 12 years...they unscrewed easily. Will use Aviation Permatex again on the gasket, washers and studs' threads. Good to have a plan - thanks, Sastanley!
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Marty 1967 Tartan 27 Bowen Island, BC |
#268
IP: 66.183.216.116
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trouble uploading photos
Yesterday and today I was unable to upload photos. As a test I tried to upload photos previously uploaded....no luck. Is there a forum problem, or just me doing something wrong...?
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Marty 1967 Tartan 27 Bowen Island, BC |
#269
IP: 75.241.42.6
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I'm not trying to discourage you here, but if you are not confident the your head studs can stand a backing off and removal of the head to make a proper repair to the damage head stud hole where is your confidence level on retorqing the head studs once the engine is totally assembled and run? This would not be the time for a failure that could be addressed now, on the bench with everything nice and clean and dry.
I wouldn't make any type of a fixture to Test the strength of a glued in head stud, you risk pulling up a section of the block around the stud and the head gasket will never seal. That's one of the reasons there is a sequence to tightening head bolts. You have a very nice looking engine that appears to have a lot of time and money invested in, it should last a very long time when completed, PS Marty You are not using the right size drill bit for the size tap you are using, that may be part of your problem with the new threads working for you Last edited by Carl-T705; 05-06-2012 at 08:46 PM. |
#270
IP: 151.200.29.202
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Marty, I had the same issue uploading pics..Hopefully a temporary glitch that Admin Bill fixed up.
FYI - I could not find SS studs the correct size/length, so I made my own. If I recall, I bought 3" bolts and chopped them in half with a Dremel tool, then chopped the heads off and filed the rough edges until I could get nuts on them easily. My thread chasing set helped with the burrs, although a die set would do the same. P.S. Carl has a good point. Pull the head and fix the head stud issue while it is on the bench. -Shawn
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-Shawn "Holiday" - '89 Alura 35 #109 "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!) |
#271
IP: 209.121.225.218
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head torqued (cold)
Hey Carl,
I appreciate your comments. I rely on the forum for a reality check, so don't worry about being discouraging. I agree that testing the torque on a single stud wouldn't have been wise...was just wondering if that was an option. Hadn't thought about the undue localized stress that would create! I am not used to JB Weld so, yes, do have a hard time trusting it. However, the kit came with it, and Don and others endorse it, so I went with it. I think you might be confused about the drill bit size because of the picture. The kit came with a 7/16 repair stud. The hole in the block was drilled to 3/8" and then was tapped to 7/16. The larger, 7/16, drill bit pictured, was to enlarge the head to accommodate the bigger stud. My error was probably cross threading the stud when I installed it with JB Weld. To be clear, I have since removed the head, re-tapped to 7/16 and re-JB welded a new repair stud in. Put the head back on right away (reused the gaskets as they looked good) and torqued all studs "hand tight"and left it alone for 48 hours to fully set. This AM I torqued all - in sequence - to 30 lbs. The manual says 30 is adequate, and advisable if there are stud problems. All held fine so far. Will re-torque all two more times at temperature, as per the manual. Glad you think she's looking good: yes, a lot of time..and a lot of learning. Before this I thought that taking the head off was major surgery, but now it is routine. -Marty
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Marty 1967 Tartan 27 Bowen Island, BC |
#272
IP: 209.121.225.218
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water jacket
Hey Shawn,
Same here: bought eight 1.5" hex blots to cut down....couldn't find studs on a Sunday. Yes: took the head off to re-do the head studs (see previous post)...and will again if I need to go to a repair bushing. For sure want everything good before she goes back in the boat. Thanks!
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Marty 1967 Tartan 27 Bowen Island, BC |
#273
IP: 75.214.235.164
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Marty, To tap a a 3/8 thread, the drill size is not 1/4. I can't remember what the bit size is off the top of my head. Glad you got the stud repaired.
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#274
IP: 108.4.61.32
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Quote:
Mix it WELL. You want to completely eliminate any black streaks until the whole mass equally consistently dark grey. And then mix it a little more just for good measure. Don't try it when it's too cold - either the JB Weld itself or the ambient temperature. Shouldn't be an issue right now, but if it's cold, it takes forever to cure - if it even will cure right at all. The other tip I mentioned above - make sure the surfaces of whatever you're JB Welding together are spotless and have been well-cleaned with solvent to remove any oil or grease and are well dried of the solvent as well. Let it cure fully 24 hours and it's almost like steel or concrete.
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- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#275
IP: 66.183.216.116
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JB Weld
Thanks for that, Rust. Yes: done a fair bit of epoxy work in my day. OD'd after re-coring the foredeck a couple years ago! Appreciate the check list. As above, the trouble stud is in, the head on, and torqued (cold) to 30 lbs. Will do the two hot torques this weekend.
JB Weld is my new best friend...hope it lasts!
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Marty 1967 Tartan 27 Bowen Island, BC |
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