Dilivar Disappointment Inside - shopping parts list?

[Lapkritis]

Found this yesterday on my 2.7L after it knocked the plug wire off in 2nd gear:



I've done a few engine assemblies/disassemblies/engine conversions etc in my watercooled VW life but I'm new to these cars and engines. By new I mean I'm within the first week of ownership...so this is my baptism by fire if you will. The engine has already been through the major overhaul including case split, full work-up within the last 50k miles and the pedigree was communicated as RS pistons/heads with dilivar studs. I'm ready to jump into this job tonight and to see it through to completion. I have a plethora of tools and a well lit modern garage to clutter up with engine removal.

My question to you, the seasoned head stud replacers, are the basic requirements to complete the job. I have these parts in my cart here and I'm staring cross eyed at my credit card:

1) 1974-77 Complete engine gasket kit: 10-0904-106-M17
2) Supertec Headstud kit: SPTC-HSK-1
3) 90MM Piston ring set, quantity 6: 911-103-939-00-M42
4) Piston Ring Compressor Set (TOL-KD850)... narrow enough to install piston through bottom of the jug so no rod removal required.

Am I missing anything else? The engine job is fresh enough in the car (chain tensionsers, alternator done 500 miles back for example) that the majority of the fasteners are fresh. I would prefer to limit time waiting for parts to come by mail if possible.

Thanks for the click and responses.

[Packet82]

Someone else posted this list when my engine broke a stud:

Head studs X 12 $144
crankcase gasket Kit $57.75
Cylinder Head Gasket Kit $215
Cylinder to case gasket (.25mm) $36
574 Locktite case sealant $22.75
chain ramp brown $6.5
chain ramp black X5 $32.5
solid oil tube lines X 6 $53
Piston ring set $142.5

You may not need new oil return tubes or chain ramps since the engine was done 50k ago, but I'd replace them while I'm in there. They're cheap enough and you might as well.

[Lapkritis]

Originally Posted by Packet82

Someone else posted this list when my engine broke a stud:

Head studs X 12 $144
crankcase gasket Kit $57.75
Cylinder Head Gasket Kit $215
Cylinder to case gasket (.25mm) $36
574 Locktite case sealant $22.75
chain ramp brown $6.5
chain ramp black X5 $32.5
solid oil tube lines X 6 $53
Piston ring set $142.5

You may not need new oil return tubes or chain ramps since the engine was done 50k ago, but I'd replace them while I'm in there. They're cheap enough and you might as well.

Thanks for the post and suggestions.
I believe the list you provided matches mine with the exception of the tubes and chain ramps. The chains/tensioners were just done about 800 miles ago (I forgot about the miles I drove since purchase). The tubes were replaced during the last overhaul and look perfect from the bottom. I will proceed cautiously with my dis-assembly in order to determine if any of these basicaly new parts need replacement. I will hold my parts order until I determine the extent of repairs as I understand the magnesium case is prone to studs pulling out requiring more extensive repair.

[Henry Schmidt]

Supertec head studs.
Anything else is just silly...............

[Lapkritis]

After reading through the search results I was hoping you would weigh in here Henry. I do plan Supertec when the time comes to place the order. As stated originally - I'm not new to engine work but I am new to Porsche/air cooled.

This may seem like a silly question... what engines came with nikasil coating? Is there any coating on a 74 or should I be okay to ball hone this when the new rings go in?

Thanks again for the input,

[jpnovak]

You mention a 2.7. First thing to do is pull the valve cover and see if the stud is broken or has pulled from the mag case. I doubt it has unscrewed itself.

If the stud is broken (yes a possibility with dilivar) then you can replace studs. However, the epoxy coating on those studs looks like it is in decent shape and one does not usually expect dilivar on the top row unless they have all been replaced. It is common to use dilivar on all 24 studs with a mag case due to expansion rates of the two metals.

If the stud is intact, it is possible that it has pulled the threads from the Magnesium case. If this is what has happened then you will need to tear it completely down to machine inserts and possibly linebore.

What is the history on the engine? You mention it is new to you, do you have records?

[Lapkritis]

I do have records that I left at a relatives home last week after I picked the car up. I should have them in my mitts again this weekend. The engine work is thoroughly documented in the records including photos of the work... by my measure of opinion it was properly done. The statement of purpose for the previous overhaul was for replacing the valve guides as well as performance enhancements of fitting the Porsche Mail Order 40mm Webers, RS Pistons, Heads, turbo valve covers, remote oil cooler, centrifugal advance distributor and etc.

I will remove the valve cover over the lunch hour (at home office) to gain access to the stud and report back.

[Packet82]

Originally Posted by Lapkritis

Thanks for the post and suggestions.
I believe the list you provided matches mine with the exception of the tubes and chain ramps. The chains/tensioners were just done about 800 miles ago (I forgot about the miles I drove since purchase). The tubes were replaced during the last overhaul and look perfect from the bottom. I will proceed cautiously with my dis-assembly in order to determine if any of these basicaly new parts need replacement. I will hold my parts order until I determine the extent of repairs as I understand the magnesium case is prone to studs pulling out requiring more extensive repair.

In that case, you're probably fine with the ramps and return tubes unless one breaks on disassembly.

Have you been able to get the offending stud out of the engine? You should be able to see if it pulled or broke at that point. If it pulled, your costs are obviously going to go up significantly. Line bores are pretty much standard on a 2.7 when you open the case.

[Flat6pac]

On a 2.7 in the picture, thats a loose dilivar so the inserts have probably been done but someone failed to loctite the stud.
Bruce

[Lapkritis]

I was holding my breath while fishing this out as I had pushed it back down the hole to get the plug wire back on. I guess I got lucky.



I have a good picture to upload from my slr later tonight of this stud. You can see in the cell phone picture above what I'm going to point out in the SLR picture that shows it much more clearly. The body of the stud has striations in the same manner as the cardboard core of a roll of paper towels or tp...to me this is an obvious indicator of a tooling flaw during the manufacturing process as they roll out the stock. These striations are the same angle as the break. The tool must have had a bur that was imprinted on the body of the stud top to bottom circling around about 1cm at about 30 degrees... definitely a sign of piss-poor quality control.

[Henry Schmidt]

Keep in mind when ordering a gasket set that the Victor Reinz gasket sets are far inferior to the products offers by Wrightwood Racing.
The quality of the Victor Reinz have been deteriorating over the last few years to a point where we won't use any of their products.

[Packet82]

Originally Posted by Lapkritis

I have a good picture to upload from my slr later tonight of this stud. You can see in the cell phone picture above what I'm going to point out in the SLR picture that shows it much more clearly. The body of the stud has striations in the same manner as the cardboard core of a roll of paper towels or tp...to me this is an obvious indicator of a tooling flaw during the manufacturing process as they roll out the stock. These striations are the same angle as the break. The tool must have had a bur that was imprinted on the body of the stud top to bottom circling around about 1cm at about 30 degrees... definitely a sign of piss-poor quality control.

Yup, a stress riser will do that. They'll all break eventually.

Good news though. When you get the engine apart, be sure to check all the studs for signs of them pulling out of the case. There's never any guarantee that they weren't in the process of pulling when the stud broke.

[JFairman]

It seems you could save some money and use a generic piston ring compressor you probably already have like you would use to install pistons from the top of a water cooled engine block.

With the 911 cylinder on a bench install the piston from the top with one of those and push it down to the bottom so the piston skirt and wristpin hole is sticking out. Then slide it on the studs part way and install the wristpin and rod into the piston.

I havn't tried it but it seems that would work starting with #3 and #6 cylinders first on each side. Install the wristpin circlip closest to the flywheel end of the motor before installing the pistons or it may be difficult to get at them on the other cylinders after 3 and 6 are installed in place.

[James Brown]

the absolute cheapest way to go is just replacing that broken stud, $25.50 parts from our host, free labor. the other end has no fixed price. looks like enough of the stud is left to get a grip on it with just removing the intake. Should you just do that? up to you. I would replace all studs and have piece of mind. If you do one at a time, no need to remove cylinders as the engine was just rebuilt. r&r engine is required. Great looking car BTW

[Lapkritis]

Thanks James - I'm in for replacing all studs as a one-timer r&r to get them all out with the belief that it will save sanity, time and probably cash in the long run. I will probably purchase rings from the host but I think I may steer from the Victor Reinz gasket kits. The valve cover gaskets in the images of the kit appear to be fiber which isn't acceptable.

[chris_seven]

Looking at the failure it looks as if the angle of the brittle fracture is about 58 degrees to the tensile axis of the stud.

Coincidentally this is about the correct angle for the Critical Resolved Shear Stress of a Face Centred Cubic material - (Austenitic steels such as Dilavar).

That's not to say that a surface defect didn't initiate the failure but the crack would then be likely to propogate at this angle.

When Dilavar studs fail with a flat fracture perpendicular the the tensile axis of the stud the failure is likely to be caused by a different mechanism.

[Packet82]

Originally Posted by Lapkritis

Thanks James - I'm in for replacing all studs as a one-timer r&r to get them all out with the belief that it will save sanity, time and probably cash in the long run. I will probably purchase rings from the host but I think I may steer from the Victor Reinz gasket kits. The valve cover gaskets in the images of the kit appear to be fiber which isn't acceptable.

Go with the Wrightwood gaskets. I got mine from Henry at Supertec along with his sealant kit. Aside from a minor issue of getting the wrong head gaskets in the set, it worked great.

And hey, misery loves company. Here was mine:

[Lapkritis]

The similarities are uncanny... if this were occuring on a modern car there would be a class action suit.

[Lapkritis]

Started tearing down... figure I'll post the pics as I go here. Any help identifying the mods/parts here would be appreciated as I acknowledge my newb status.

Pics from this afternoon... plan is to drop engine on an evening after work this week, order parts for delivery before Friday and and to attack for re-assembly 1 week from today. Fairly aggressive timeline so probably more like 3 weeks to restart realistically.

Pic of the stud from cyl5


SSI Exchangers removed, needing a clean up from the oil leaker above


Wiring for carb swap


View from the bottom after an hour or so of cleaning/wiping


Exhaust ports measure about 34-35mm


Turbo valve covers?


The SSI exchangers weren't described in the sale. Seller stated simply "This car has everything that Bruce Anderson describes in his book for modifications"...

[Packet82]

Originally Posted by Lapkritis

The similarities are uncanny... if this were occuring on a modern car there would be a class action suit.

Funny enough, the stud that broke on mine was also on cylinder 5. 82 SC though, not a 2.7.