1600 sp head stud fiasco

[energyturtle]

Hello. I am/was helping a friend with a top end build on a 1600 SP, B5 engine code long block. I got the heads machined with new valves and guides, honed cylinders, installed new rings, put it all back together. I was in the process of head torque sequence on the first pass at 11FT LBS and the #3 head stud would not hold torque. I took that side back off down to short block to investigate. Here are my findings,






The pics are of the various head studs on the problem cylinder to show signs of machine work, particularly case savers being installed, along with the hole left by the problem child head stud. I also included pics of the comparison between stock head stud (smaller), and the studs installed on the long block in question (bigger). Before I spoke with Colin, I tried to install a Heli-Coil with no luck. What to do, what to do . I am beginning to hate type 1 engines. I started on type 4's and will stay with them. These type 1's are really testing my patience.

Scottie

[asiab3]

Bummer.

Pictures 1 and 2 show the stud that VW later recessed deeper into the block. I don't know for certain what their reasoning was, but I bet it was along these lines.

Picture 4 looks like the head stud is bent. Is that true? Better get a straight stud for that location.

Picture 5 shows the two different size studs VW used throughout the years, (8mm and 10mm.) From the factory, the 8mm studs were paired with "case savers" threaded inserts in each hole. I'm not sure what year the change happened, but I think it was in '71 with the dual relief cases. They may have recessed the "problem" top left stud at that time too. Brazilian VW replacement blocks only come with 8mm studs, savers, and recessed #3 stud. The heads are set to 18'/lbs for 8mm studs, and 23'/lbs for 10mm studs; the 8mm studs allow more stretching to cope with thermal expansion, which also helps avoid the issue you're having. Competent machine shops can instal savers in all your stud holes, but it requires splitting and cleaning the case. At that point it becomes a slippery slope of new bearings and crank polishing………
I just realized you've gone through most of this with your T4 builds, but I'll leave that info there for the readership…

The amount of time I've spent contemplating a 1700 T4 in place of my 1600 build is scary.
Robbie

[energyturtle]

I really don't want to split this case. Are there any other options Robbie. This is my first type 1.

Scottie

[asiab3]

Someone more knowledgeable than me would have to chime in. I don't have any experience doing those repairs on the fly; I would be nervous about getting swarf in the crank case.

I also think using a combination of 8mm and 10mm studs is a bad idea, due to their different thermal expansion properties. Do you know the Hasta Alaska thread on TS? He has a pulled stud right now and there were a few pages of suggestions geared to getting him back on the road with minimal effort; that sounds like what you're up against. Sorry I can't find it on my phone right now.

[energyturtle]

No worries. I'm familiar with the thread. I'm gonna just split both cases and choose the best and have case savers installed with new studs at the machine shop.

[wcfvw69]

You can buy a long stud at the hardware store. One side has machine threads and the other has course threads to thread into wood. I can't tell buy your picture if the stud pulled the case saver or not?

I had just built a F case bug engine and had it all back together. When I did my final torque on the small studs by the oil pump that hold the case together, one of the studs pulled out! I had checked all the other studs by re-torquing each stud before disassembling it to make sure I didn't need case saves. I didn't however torque those small studs and I got bit. I went to the hardware store and bought the stud I described above. The course threads "bit" into the case nicely with red lock tight. I was able to retorque the new stud to spec and have had no issues with it in 7 years. The next time the engine is torn down for an overhaul, I'll remove it and install case savers.

[Boxcar]

I was happily coerced to have to remove my head studs in order so that I could get my cases decked.
(T4)
Mildy apprehensive, I sallied forth. Did some.mild heating. No issues though. Those longtime mechanical interferences/cooperations relinquished their bonds.and.mutual grasps. Some more reluctantly than others. I forget which held on longer but is it safe to say the engineering was complete by the time of that design?
On T1's is that not so often called for? That is the machining operation known as decking to bring both all sides into parallelism..
Anyhow love the type4. How robust.

[energyturtle]

Thanks all. I'm gonna split it and see what I'm working with from the inside out. If all the saddles are cool, I might timesert case saver everything:) I'll have pics soon. In all their nasty glory.

Scottie

[Amskeptic]

Thanks all. I'm gonna split it and see what I'm working with from the inside out. If all the saddles are cool, I might timesert case saver everything:) I'll have pics soon. In all their nasty glory.

Scottie

Man . . . I was waiting for someone to make a bad call here.

There is no dorking around with head studs. What works around an oil pump or case perimeter DOES NOT WORK around head studs which take a terrible pounding.

Case savers are actual inserts (like the difference between timeserts and helicoils) and they must be installed in a properly hygienic and careful fashion. As Robbie stated, there is no mix-n-matching of head studs. Don't even bother with the 10mm studs. Get a full set of 8mm studs + case savers, and go for the deep stud installation on the #3 stud. This design change was to get rid of a known cracking issue.

Scottie, you ARE going to RESPECT the Type 1 engine as the grandpa of the Type 4 engine. Please remember, that the Type 1 engine, developed in the early 1930's ya pup, continued all the way until the very end, right alongside the Type 4 which was developed in the late 60s.
Fricken gargantuan life span for a brilliant design.
Magnesium is amazing stuff, but it is less forgiving than aluminum. Treat it with care.
Colin

[energyturtle]

I ordered the 8mm with case savers. I am dropping them off with the case at the machine shop Monday. Then reassembly. I do respect the type 1 engine. I started on type 4's and will stay there. I love them. I am not a fan of pulling heads to change pushrod tube seals. I do not like the exhaust ports being on the side, and I do not like magnesium or 40hp, and I absolutely do not like pulled head studs, obviously. Respect my roots absolutely. Respect innovation. Hell yeah. Late model type 4's. Love affair. I was born in 1979, so I feel they are family.

Scottie

[Amskeptic]

I ordered the 8mm with case savers. I am dropping them off with the case at the machine shop Monday. Then reassembly. I do respect the type 1 engine. I started on type 4's and will stay there. I love them. I am not a fan of pulling heads to change pushrod tube seals. I do not like the exhaust ports being on the side, and I do not like magnesium or 40hp, and I absolutely do not like pulled head studs, obviously. Respect my roots absolutely. Respect innovation. Hell yeah. Late model type 4's. Love affair. I was born in 1979, so I feel they are family.

Scottie

Type 1 heads ended up breathing better than the Type 4 heads.

My pushrod seals were installed correctly in Oct 2011 in Dallas, 40,000 miles later they are still not leaking unlike your Type 4 heads so ha HAA, but really folks, the Type 1 pushrod seals will not leak when you follow the directions in the Bentley.
ColinStillAFanOfThe1700/1800 T4

[ruckman101]

I'll defend the Type 1 heads, too. Never have my pushrod seals been a big issue.

There is an entire gestalt to running a 40 hp engine that cannot be equivocated. As there is to running a 67 hp engine. Type 4's have their gestalts. The key to the joy is to have those engines running flawlessly.


neal

[Amskeptic]

I'll defend the Type 1 heads, too. Never have my pushrod seals been a big issue.

There is an entire gestalt to running a 40 hp engine that cannot be equivocated. As there is to running a 67 hp engine. Type 4's have their gestalts. The key to the joy is to have those engines running flawlessly.


neal

For the record . . .
The old
25 1100
36 1200
36modified
40 1200 4mainbearings
50 1300
53 1500
57 1600
engine nomenclatures were in SAE gross, so in fact, their net readings were unbelievably punk.
SAE gross horsepower was used in advertising until the end of 1972.

1600
57 singleport,
60 dualport
post-1972 net horsepower for same engines
44 singleport,
48 dualport

1700
Advertised SAE gross (only in 1972)
74
all subsequent engines net
66 until
2000
67
which would be under the old SAE gross
78

When I yack at people about mellow Chloe, I use the net figure of 44.
"40 horse" description is specific to that famous understressed 1200.
Colin