Catastrophic Failure in a rebuilt 1971 Super Beetle 1600?

[Spowers]

Only about 500 miles on a 1971 rebuilt 1600cc. While driving at a steady 50mph the engine suddenly shuts off and I easily coast to a safe spot on the side of the road. Maybe overheating since it is July? After waiting about 45 minutes I crank the engine but something doesn't sound right. Low compression?

I pop off the valve covers to have a look and as my friend is cranking the engine, the cylinders seem to move freely but there is no intake/exhaust valve movement on either side.

Did the cam shaft disengage from the crank shaft? If so, how is that possible since they are directly geared to each other? Did the cam just break between the gear teeth and the lobes?

Has anyone heard of this happening?? Any advice would be much appreciated. Thanks![/b]

[Bobs67vwagen]

If none of the valves are moving when you rotate the engine it would seem that the camshaft gear is either stripped or broken. That would be my guess. Good luck-Bob

[67rustavenger]

Never heard of this happening but, I guess anything is possible.

Pistons moving and camshaft not moving may indicate a broken crankshaft.
It happens. I don't recall seeing a crank broken on the cam gear end. The ones I have seen usually break near the #2 main bearing.

OP, grab the crankshaft pulley and see it it turns rather freely, like it's not connected to anything inside the engine.
_________________
I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!

There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo!
2003 Astrovan? GFYS again, Xevin!

[Alstrup]

Lemme guess. Empi cam gear. Its stripped. Seen that more times than I care to remember.
_________________
https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[mikedjames]

Maybe somebody left out the Woodruff key on the camshaft drive gear on the crank and it took a bit of heat to let go and start spinning.
_________________
Ancient vehicles and vessels

1974 VW T2 : Devon Eurovette camper with 1641 DP T1 engine, Progressive carb, full flow oil cooler, EDIS crank timed ignition.
Engine 1: 40k miles (rocker shaft clip fell off), Engine 2: 30k miles (rebuild, dropped valve). Engine 3: a JK Preservation Parts "new" engine, aluminium case: 26k miles: new top end.
Gearbox rebuild 2021 by Bears.

1979 Westerly GK24 24 foot racer/cruiser yacht Forethought of Gosport.
1973 wooden Pacer sailing dinghy

[busdaddy]

I'm betting the oil has a silvery sheen.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[Cusser]

[Spowers]

It was rebuilt in a shop but the 12 month warranty is expired. I guess I'll tear it down to see what happened. This will be my first time into the crank case of a VW. First time for everything...Wish me luck...Thanks for the feedback...

[DerrickfromNC1]

Back in the late 70s or early 80s I had to go help a friend tow his bug back home that had suddenly quit running for no apparent reason. Similar to the op…no valve train movement while cranking engine over. When we opened the case we found the camshaft broken in 2 places. Cam was an AP2 which was produced by Resolit of Brazil back in the 70s.

[Brian_e]

I had a core engine that broke the cam right behind the flange for the gear.

Brian
_________________
So more or less the lazier and stupider you want to be, the nicer quality parts you need to buy.
-Modok


www.type-emotorsports.com

Type E Engine Parts and Supplies
https://type-emotorsports.com/collections/engine-parts

[raygreenwood]

I am betting the cam broke. I have had a cam gear on type 4 strip the teeth off from a nut that came loose from the oil pump.

No matter what strips all the teeth off, it will not be a silent stoppage when it happens.

Ray

[BFB]

[Bobs67vwagen]

Spowers good luck on the teardown, tough break but you may be able to salvage some parts of your engine. If you do not already have a copy, I suggest you get How to rebuild your Volkswagen engine by Tom Wilson. It will help you with the proper sequence with the disassembly to try to salvage what you can. Good luck-Bob

[mcmscott]

[Cusser]

If it does turn out to be camshaft-related, I just want to throw in that I have stock VW camshafts and gear in both my 1835cc and 1600cc rebuilt engines. 1835cc was built by me in 1986, and the 1600cc in 2017.
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[NJ John]

Broken cam bolts? Please report what you find.
_________________
1973 standard, yellow, lowered, 3” narrowed front, 1600 blo-thru turbo w/single dell 15.4@86, so far
11.41 et buggy. Long gone
Let’s go O’s! Let’s go O’s!
https://www.youtube.com/@AirSpooledGarage