Stipped head bolt thread in block.

[clubagreenie]

How can I mass email every owner of a Rover V8 and say;

PLEASE USE STUDS.

[malrv1]

Went to do the 180degree tighten, then this happens. All the rest are fin and tight. What options do i have..? Its the middle long bolt.

Are you sure you should not be just tightening to the specified torque??

Early V8s did not have stretch bolts and were just torqued. Not degreed

[clubagreenie]

And at the it's 20Nm, 90 & 90. Not straight to 180.

[MickMc]

Your best off removing the head and taping over all bores and water jackets etc so only the stripped thread is exposed to prevent any swarf entring other areas when you drill into the block to facilitate the heli coil. I wouldn't be placing a larger bolt in there as the torque specification will differ and your head wont be torqued evenly, besides it is the equivalent amount of work to drill and tap the block to suit a helicoil to retain the original 7/16 bolt as it is to drill and tap for a larger bolt. If the block is showing signs of age there is no guarantee that another bolt wont strip even though you have placed the correct load on all others at present to check their integrity. Sometimes blocks just like to check our patients.

[TriPolar]

Well, i just bought a helicoil kit. $120 and has the taps and drills for 1/4 - 1/2UNC with 25 coils each. After that, i ordered the ARP 124-4003 kit for $200. Ill be running a tap through the other bolts before putting the studs in.

Getting to the point where i wish i didnt buy this car..

[DiscoClax]

By the pic it looks like maybe a 3.9 D1 engine?

Note that ARP kit was designed for the Buick 215 (and then cross-referenced to the Rover 3.5) and works well on it and the earlier blocks. The later blocks (serpentine, etc) have deeper threads in the block and the studs don't use all of this engagement. Plus the 'top end' has excess thread sticking out from memory which, although not a job-stopper, does create new and interesting ways of barking knuckles when doing spark plug changes.

Refer also - WARNING: ARP stud kit 124-4003 on Rover V8!!! - Tools and Fabrication - LR4x4 - The Land Rover Forum

I had an engine builder mate in the US rummage through the ARP catalogue and he pulled together a unique set and then parted off the pilots on them so I had close to 1.5" of thread engagement, instead of around 3/4" with the kit above. Plus the threads only extend past the nuts by a few mm once installed. Unfortunately I don't have the p/n's he used - I should get that for future reference. Refer pic for an example of before and after trimming, and typical protrusion.

Having said that, if the block is OK and the threads are in good nick I reckon the Buick 215 kit will do the job if caution is exercised. Remember to back off on the applied torque a bit as the finer thread and hardened steel-on-steel interface means you'll get a LOT more clamp at the same torque than coarse thread into alloy. I did mine to 70ft.lbs (three stages). Can't do torque then angle for obvious reasons...

Plus, don't forget to re-torque after 500miles or so - old school

[101RRS]

You are correct that the 124-4003 kit is for the old Buick engine but ARP do a Rover specific kit for 10 bolt Rover engines - 157-4301.

So why not use the correct studs?

Garry

[DiscoClax]

Bugger

They didn't exist when I did my engine 18 months ago...

Great that they do a proper kit now

[101RRS]

They didn't exist when I did my engine 18 months ago...

Yes they did .

[clubagreenie]

I used the original kit in a 4.6 and there's no issue with engagement. There's no leader on the threads, only a socket head and there's sufficient but certainly not knuckle removing thread excess.

The ARP recommended torque with their assy lube is 80lb, 85lb with oil. Done in 40, 60, 80/85lb stages. I couldn't recommend under-tensioning, nor do ARP recommend re-tensioning. TTY bolts and their associated issues are part of the root cause of head gasket failure that these suffer. I have batch tested both toyota (40 sets) and rover (25 sets) of TTY bolts and they both varied in final actual tension. Immediate readings varied both high and low compared to original non TTY bolts and 24 hours later had changed again, all tensions had relaxed by min 3lb. To eliminate gaskets as a source of variance was done with composite, tin and without gaskets and reading variance was common to all.

Similar testing with sets of ARP studs, pre-measured and measured between torquing (per ARP recommendations) had no variance at 24 and 48 hours regardless of gasket type. There were no instances of studs pulling.

Finally, why would you try to angle tension on tension set studs or re-torque modern gaskets with no re-torque requirements (also the cost of new rocker gaskets for serpertines makes it a crazy prospect)