Spent $6k on this build at a very well known racing shop Bored, stroked, cam, EDGY head, etc. One head bolt hole had a Timesert installed during the rebuild (.040" over). Shop assembled engine; I was too busy to do it myself, which I have often done without issues. Test run- ran great, smooth, no steam in exhaust, etc., BUT Coolant leaking behind timing chest, dripping at lower pulley. A bitch to diagnose. Tore it down, found RTV on new, hidden core plug (Permatex recommends No.2 (non-hardening), also coolant leaks from several of the new arp brand head studs. Removed front end tin, installed brass core plug, reassembled. One head bolt hole had a Timesert installed during the rebuild (.040" over). Pulled head, removed all the hold down studs, cleaned holes and studs completely w/ 100% iso alcohol, blew them bone dry, reinstalled the studs with Permatex No. 2 on the threads. Noted that the Timesert was a little proud of the deck at that time. Reinstalled head, began torque sequence w/ arp hardened washers and their nuts. As I was going from 50 to 60 ft.-lbs, one nut turned very easily- yep, the one at the Timesert. Stopped, pulled the head off. Found this. Crack from bolt hole to large coolant passage. Suggestions?
That's sad. Maybe a good place to start would be a trip back to the shop that built the engine to open a conversation about the problem. Lynn
Start with the shop; but likely re-do the thread insert, and ensure it's locked in place. Can probably vee out the crack on coolant side and seal with J-B or other compound.
I'd remove the insert and examine the crack from both sides. Hopefully it doesn't extend too deep. Then replace the insert with another with a alot of red loctite or similar. Not to lock it, but to seal the crack from the bolt side. Or, let the builder do it! That timesert looks to be poorly installed anyway, maybe the install process is what caused the crack wedging as it was driven down.
Flathead Fords have the common problem of bolt hole to water passage crack. Doesn’t cause a problem with those. But yeah, insert should be addressed.
I had a similar problem as a 1/2” stud moved when installing a OHV cylinder head on a 6 cylinder. I rented a mag base drill to assure a straight hole and installed a 7/16” timesert. It was on the end. It’s just torqued a little lower. Never a failure in the 5 years it’s been in. 13-1 compression.
That insert is more than a LITTLE proud!!! That could have been the straw that broke the camel's back!
Totally agree. It looks like what we call "part number" cracks in flathead Fords. Whoever put that insert in should have their tools taken away from them. I don't think it's fatal, but I would check everything else they did. Twice.
Not familiar with that brand name but it looks to me like either the threads in the block were not drilled and threaded correctly or that bolt was overtightened and pulled out. It can be fixed but you need to have a competent shop do it. The crack down into the water should only need to be peened shut.
Tomorrow, be nice, be polite and ask them for guidance on how to resolve this. If you get any blowback, send this picture to the shop and ask if they are going to warranty the shit work.
The arp studs are 7/16"-14 In fairness. the insert was only proud enough to catch a fingernail, perhaps .010'. Now it's .060" proud. I will check how thick the block deck is at that location.
Its possible the engine builder installed the insert because of the crack in the block. My engine builder did that on a few of my "factory cracks", on my ford Flathead. He felt that the bolt or stud would be less likely to spread the cracks in the block wider being in an insert. He used inserts that were similar but different than TimeSerts. I use TimeSerts all the time and have never had one pull the threads out of what it was installed in, iron or aluminum. Its not likely that the threads stripped on the insert. It appears that the insert is pulling up out of the threads in the block. which cracked and pushed up the upper flange of the insert. Looks like the hole was pinned in one place, in one of the photos, whats with that? Bill
There is zero "edge distance" between the insert and the adjacent hole. Not a good situation. Any time-sert of keen-sert I have used over a 10-32 usually has locking keys that bite into the material or have a slot to drive them in. Some require an installation tool. The insert should thread in very easily, by hand. This looks like it was a fight since it is quite proud of the surface. The finale of the sham-job was the use of RTV, someone had no idea of what they were doing. Going forward with the correct insert, I would anchor the insert with something like stud-set or at least the red Loctite. Then install a stud permanently.
Timeserts are top hat shaped, that looks to me like it has not been properly threaded into the block, it’s then pulled out and the lip of the hat has caught on hole in the head and fractured. When it comes out I’d imagine that you’ll have either a very short portion of engagement in the block or the hole is oval. As others have said be nice and see what they say.
In answer to the question about the block I don’t think the crack itself is too much of an issue. It’s not going to the bore. There’s plenty of engines that use “wet” studs and you’re not going to be running high coolant pressure, is it even a pressurised system? The wall thickness is also more than you think as you’re looking at the lip of the top hat.
I contacted the machinist and he lent me the installation kit. Also contacted a tech rep from the insert manufacturer, Full Torque. I have removed the insert and and am exploring the possibilitry of installing another one.
What thread is on the outside of the insert? Measure it carefully with a pitch gauge. That doesn't look like a Time-sert to me. Looks like a threaded insert that has a standard outside thread. Time serts use the same thread as a heli coil, STI. This insert seems to be of the type that, for example, had a 7/16 thread inside and 5/8 or 9/16 outside. Time serts are flat on the top, this is crowned and as has been said is proud. I could be wrong but I would check it carefully.
That is a Full Torque insert. From a company that has a great reputation, so I'd put the failure on the installer's technique. Clearly it pulled out after once being flush with the block, as you can tell by the lock pin being ground flush. That brand has a unique thread pitch and shape. Most no them for their crack repair products, locknstitch.
Shouldn’t that be the rebuilders problem? But I get where you’re coming from, do it yourself and do it right.
I have never seen that line before, looks like it should work. Amazingly enough that the lock pin held up but the insert was proud of the surface.
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