My Block Ruined? (Head studs gone bad)

[Ichiban4]

After trying to clean out my block multiple times to get the studs in evenly and many failed attempts I get them pretty close so I figured it should be ok

I get the head on and begin torquing the nuts done, 20lbs went fine, then on 40 lbs I started on the center one and it started getting tight and then all the sudden started free spinning. I turned it a couple more times to see if anything happened and nothing, so I put and allen head in and took the stud out.

This metal shaving was twirled all in the threads.. :(

http://i18.photobucket.com/albums/b124/motegineon/photo_zps8d5505c1.jpg (http://s18.photobucket.com/user/motegineon/media/photo_zps8d5505c1.jpg.html)

Now I tried putting the stud back in and it seems to thread in fine but I don't know what to do. Any experience? I paid a lot to have this block refinished it's going to really suck if the stud holes are toast or should I rethread it back in and try again?

arp btw

[jr_ss]

Helicoil or another thread repair kit and you should be good to go.

[sil14zenki]

def do not thread back in... look up "time inserts". i've used them on head bolts and flywheel to crank bolts and they've held up just fine. make sure the threads are still good on the arp studs

[Sileighty_85]

Yikes man how hard did you thread it in there, should only be until they bottom out.

Having a Machine shop install a Helicoil would be your safest best bet.

[Matej]

ARP hardware seems to destroy SR's.

[Ichiban4]

Are the pulsar arp studs the same length? They are 12mm so I could just drill mine out and retap them for 12mm.

I feel more comfortable tapping to 12mm and not using those little insert things :/

[jorge1190]

I had this happen to me a few months ago.

DO NOT HELICOIL. Either buy a thread-sert kit for a B series honda and use the spacer provided for a B16 or take it to a machine shop to do it.

I make over 400 WHP BTW. My friend had this happen on his car also, he did the same thing and he made 875 WHP.

[tiggertsi]

def do not thread back in... look up "time inserts". i've used them on head bolts and flywheel to crank bolts and they've held up just fine. make sure the threads are still good on the arp studs

i'll second this advice!

[Rich260z]

That happened to on of the SR blocks I had. I brought it to Mazworx for them to check if it could be retapped. They said that the most solid way to do it would be to drill it out for the GTR head studs (12mm or 1/2) head studs, and they wouldn't do any work unless that was what I was going to do.

Just some food for thought. I found another good spare block for $50 less than an hour away from me.

[Ichiban4]

Yea I am leaning towards just having a shop tap them out to 12mm, if you go to 12.7 I think the head gasket needs to be modified.

So the rb26 gtr bolts are the correct length? I was gona go pulsar but i think they are only 155mm where as SR are 165-167. I suppose I will call arp tomorrow and see

[S14DB]

def do not thread back in... look up "time inserts". i've used them on head bolts and flywheel to crank bolts and they've held up just fine. make sure the threads are still good on the arp studs
TIME-SERT, Keensert, Keysert, Acme Threaded Inserts are all better than Heli-Coil's.

[Drift_FX]

This^^^^ or go to 1/2" headstuds and never worry about headlift again....

[Ichiban4]

Just an update 4 of the 10 were stripped and I hadn't even tried torquing the others down yet so I am avoiding a repair kit and just decided to go with the mazworx 1/2" studs. They are pricey but at least I will have the peace of mind I don't have a band-aid covered block and head lift shouldnt be an issue. My machine shop said 100$ to drill the head and block or about 200$ to tap them all too, I can at least tap them myself if not do the drilling as well so after everything I will still be coming out around the same price as the Time -Sert kit.

[zurud]

if 4 out of 10 is stripped, your block is probably toast.. The block is soft and weak now from overheating. Better off get another block.

[mxexux]

I will jump on the Time-sert wagon. Same thing happened to me while replacing a head gasket on a rover V8. I decided to repair the threads with time-serts myself. The truck has been running for over a year and 3K+ miles on it including a long distance trip through 100+ degree weather. :bigok:

[Black240Ct]

We had this happen and the machine shop drilled and tapped The block for a larger bolt. Drilled and tapped the bolt for the stud and decked the block. Been working for two years or so

[codyace]

dolts intalling (insert any brand here) hardware seems to destroy SR's.

Fixed for you. It's not 100% arp's fault. Most people either don't have the proper bottoming taps, or don't even clean out the threads and just slam them home. I've had so many engines with ARP's I can't even keep track, and I can't even tell you one that was stripped.


With that said, for the cost, there are better designed studs for those not cleaning everything up 100%.






Just an update 4 of the 10 were stripped and I hadn't even tried torquing the others down yet so I am avoiding a repair kit and just decided to go with the mazworx 1/2" studs. They are pricey but at least I will have the peace of mind I don't have a band-aid covered block and head lift shouldnt be an issue. My machine shop said 100$ to drill the head and block or about 200$ to tap them all too, I can at least tap them myself if not do the drilling as well so after everything I will still be coming out around the same price as the Time -Sert kit.


Just let the machine shop do everything for you. That way you know it's straight, and know it's done properly. Not saying you're not capable, but you can't have them willly nilly or crooked in there in the least. If it was my moped engine or a lawn tractor, I'd try it...but nothing I care about.

[Def]

You can make a drill bushing and a fixture to hold it, but at that point I'd pay the $100 to have them drill it. $200 to tap it seems excessive, so I'd probably do that myself. I'd think drilling/reaming it square would be by far the hardest part.

[Ichiban4]

Just for those who haven't seen here is a comparison of the ARP Sr20 studs vs the Mazworx 1/2"

http://i18.photobucket.com/albums/b124/motegineon/photo_zps0682e14d.jpg (http://s18.photobucket.com/user/motegineon/media/photo_zps0682e14d.jpg.html)

[om3ga]

Do the 1/2" and never look back.

[slw240sx]

I would have the machine shop do this work. they are likely going to put it on to a machine and have the drilling and tapping done straighter then you can do by hand or with a drill press. Most regular shops do not even have a setup big enough. They are probably saying 200 to drill and tap. Thats not a bad deal to have it done right.

[Def]

Larger headstuds can sometimes cause uneven head sealing due to the clamping force changing drastically as things heat up. That's why so many head studs are torque to yield - putting the stud/bolt in its plastic range with a thinner head stud gives you more room to play with on things expanding and still maintaining things in its elastic range at a given clamp load.

Lots of times I see the 1/2" head studs torqued to such a low number because that's what the head can take, but that means the studs are stretched so little that you either REALLY ramp up the clamp load as things grow, which then causes things to relax due to the high clamp pressures on the head (i.e. the head gives way).


In almost all things with engineering, you can't just say "more is always better." At some point you cause other problems, and fastener design is not as simple as the layman might think it is.

[Ichiban4]

I am having a shop do all the work. For anyone in the future they are charging me $250 to drill and tap. They said they have done 1/2" in a couple Sr's before so I felt comfortable with them.

As far as the sizing and engineering aspect I know nothing about so I can't say much other than this kit was designed for the SR by Mazworx and ARP to withstand extreme boost on their high HP cars so I have complete confidence that it is a reliable choice for my car. Torque spec on these from Mazworx is 95ft. lbs so it is very similar to what the SR head usually gets. Also with about double the threads available in the block after tapping that alone will help with a lot of issues.

I will update again when it goes together hopefully this weekend.

[Ichiban4]

Just an update/insight for future readers who may do the same.

Labor cost $250 to drill/tap/and fit the headgasket. I used a Apexi HG and the only 2 holes that needed to be drill larger were the 2 for the new larger dowels.

Torque spec on these is 65/85/95 although I went 20/40/60/80/90/95.

Few pics for comparison of size.

http://i18.photobucket.com/albums/b124/motegineon/photo2_zps0e6ec434.jpg (http://s18.photobucket.com/user/motegineon/media/photo2_zps0e6ec434.jpg.html)

http://i18.photobucket.com/albums/b124/motegineon/photo4_zpsf6e07183.jpg (http://s18.photobucket.com/user/motegineon/media/photo4_zpsf6e07183.jpg.html)

[aga]

a good read, useful stuff. thanks.

[Def]

I am having a shop do all the work. For anyone in the future they are charging me $250 to drill and tap. They said they have done 1/2" in a couple Sr's before so I felt comfortable with them.

As far as the sizing and engineering aspect I know nothing about so I can't say much other than this kit was designed for the SR by Mazworx and ARP to withstand extreme boost on their high HP cars so I have complete confidence that it is a reliable choice for my car. Torque spec on these from Mazworx is 95ft. lbs so it is very similar to what the SR head usually gets. Also with about double the threads available in the block after tapping that alone will help with a lot of issues.

I will update again when it goes together hopefully this weekend.

95 ft-lbs on a coarser threaded fastener actually gives you LESS clamping force. Same torque on a fine thread fastener gives higher clamping loads due to the mechanical advantage of the finer thread.

Surprised the torque spec is that low honestly...

[codyace]

Def, are you saying you'd think the ARP should be higher than the 85 ft lbs? For conversations sake I'd love to know the differences, as It just doesn't feel 'right' going beyond that....even on the torque wrench it feels bad.

[S14DB]

Def, are you saying you'd think the ARP should be higher than the 85 ft lbs? For conversations sake I'd love to know the differences, as It just doesn't feel 'right' going beyond that....even on the torque wrench it feels bad.
Put some head studs in a Turbo Diesel. 85ft/lb is the initial tq...

[240ss]

Put some head studs in a Turbo Diesel. 85ft/lb is the initial tq...

and your point? this isnt a diesel. You're talking major differences in cylinder pressures.

[Matej]

Egads, just discovered a stripped thread. :(
Can I trust those Time-Sert things?
http://irony.cc/media/image/original/endoftheworld.jpg

Time to buy a new engine.