Head Studs... 14mm

[TORQUE THIS]

Anyone on the boards put in the 14mm head studs?? Did you do it yourself or have someone else do it?



How bad is it to yank the motor??

 

[JB @ C and L Machine]

how much boost are ya gonna be pushing?... The Van Haisley 12mm are good to 80psi. I would give Van a call and talk to him about your needs. I talked to him for a half hour If I was going to re-drill and tap for 14mm I would do it on our Radial Arm Drill press to insure that everything was true. JB

 

[offshoreracr]

Originally posted by TORQUE THIS

Anyone on the boards put in the 14mm head studs?? Did you do it yourself or have someone else do it?



Enterprise Engine just recieved a guide plate which allows them to do the job with the engine in the truck. Fred

 

[Jim Fulmer]

Piers bought the plate to do it in shop, not machine shop as the cost is like 500 bones!



Jim

 

[JB @ C and L Machine]

$500 bones to just re-drill and tap 26 holes? I probally could do it for appox. $300

 

[Jim Fulmer]

$300. 00 would be fine for me, I hope to have these at some time.



Jim

 

[JRodgers]

I just finished installing 14mm studs on an engine. The job is not too hard to do, but it is definitely easier to do out of frame rather than in frame. If you are going to pull the engine to install the studs, I would go ahead and install the 14mm main studs as well, just since it is out.



The 14mm head studs are definitely beafier than the 12mm studs. Tapping the holes in the block was not too difficult to do, but I did have to run the tap in the holes a couple of times to clear chips out of the bottom of the hole. I also used both a bottoming tap and a plug tap to get the threads to form correctly all the way to the bottom of the hole. I got an indexing fixture from BHJ to do the tapping, It consisted of a plate with drill bushings in the proper locations to help align the drill and the tap to keep them vertical. The indexing fixture, locating dowels, new larger dowel rings and counterbore for installing them, along with the taps, drills and reamer, etc. all cost in the neighborhood of $1400 to do the job. Not cheap, but makes it easy to do it right, and am planning on doing more than one engine.



Once the block was re-threaded and the studs installed. The head stud holes in the head were reamed out to 9/16: to clear the new studs properly. Not a big deal to do. I also counterbored the dowel ring holes in the head so it would slip over the new larger dowel rings. I had to modify the head gasket at the dowel ring holes a little by opening up the holes that fit over teh dowel ring. Otherwise, the gasket dropped right down over the new studs and into position. The firerings installed just as they do with the 12mm studs.



So far everything has gone well and I will set the head back on, torque it all down tomorrow, and get the engine back in the truck.

 

[Vaughn MacKenzie]

Just curious about something, how deep into the block are the head studs threaded?

 

[JRodgers]

Studs are threaded to the same depth as the factory 12mm headbolt holes.

 

[csevers]

Are the studs bottomed? or Lock Tigthted? Are the chances of pulling the threads out of the block any greater with studs or bolts? given more torque is apllied



Thanks

Craig

 

[F8LDOSE]

What the head get torqued to with the 14mm studs?

 

[JRodgers]

As long as proper thread engagement is achieved with the larger studs, there is not threat of pulling them out of the block. By proper engagement, I mean at least 60% thread engagement, which is a measure of how well the threads fit together, not how much is in the hole. In other words, how "loose" to the threads feel when you thread the parts together.



With a larger diameter threaded fastener, you have more surface area engaged between the two parts that are threaded together than you would for a smaller fasterner, so you gain a strength and holding advantage over a smaller fastener.



The 14mm studs are torqued to 150 ft-pds according to haisley specs.

 

[F8LDOSE]

Ok, so your putting in a bigger stud, torqueing it to 150ftlb. Stock 12 bolt is what 90ftlb + 90degrees, @ 120ftlbs. So nobody is worried about twisting the cylinders by doing this???? Studs pull more than bolts..... ???? Fine thread pulls more than course thread..... ???? Somebodys gotta run into problems here i'd think? I have a torque plate, my block is being bored . 020 over using the 14 mm studs and torqued to 150ftlbs. After the cylinders are finished hones and perfectly round, the torque plate removed, and the cylinders will probably be . 005 out of round, until the head is torqued again to 150ftlbs then the cylinders will be perfectly round. Do you guys all want to run with oval bores?

 

[F8LDOSE]

Ok, so your putting in a bigger stud, torqueing it to 150ftlb. Stock 12 bolt is what 90ftlb + 90degrees, @ 120ftlbs. So nobody is worried about twisting the cylinders by doing this???? Studs pull more than bolts..... ???? Fine thread pulls more than course thread..... ???? Somebodys gotta run into problems here i'd think? I have a torque plate, my block is being bored . 020 over using the 14 mm studs and torqued to 150ftlbs. After the cylinders are finished honed and perfectly round, the torque plate removed, and the cylinders will probably be . 005 out of round, until the head is torqued again to 150ftlbs then the cylinders will be perfectly round. Do you guys all want to run with oval bores?

 

[83 crew cab]

oval bores here did not know anybody with a torque plate George

 

[F8LDOSE]

Hi George, I'm Jason, nice to meet ya. Mine will be done by next week, it's two tools in one... . A torque plate and a 14mm stud guide. If your engines not together yet, could you please torque your head down, then measure your cylinders from underneath.

 

[83 crew cab]

thanks for the offer Jason eng is together but I will remeber it next time may take you up on the 14mm stud thought George