Pizza

I am getting my car ready for a TS supercharger. One of my priorities was to check my timing belt before adding a lot of horsepower. FeedNFrenzy (Brent) came over with his Kempf tool to help me check it. We found that the belt was too tight. We loosened the belt. We also noticed that the belt is riding on the front edge of the cam sprockets and very close to the front edge lip of the water pump pulley. Is this normal or could the belt being too tight all that time and mileage have made it walk to the front of the cam sprockets and WP pulley?Once the car runs a while will the belt settle out to the center? Is there something else I should check? Other than that the belt looks to be in great condition. According to the PO's records the timing belt, water pump, idler and tensioner were changed on 10-08-2001, about 16800 miles ago and retensioned 1500 miles later. I have some great pictures but I'm unable to upload them. Some help with that would be appreciated.

Thanks

ErnestSw

You should check all pulleys, cam gears, the tensioner and the water pump before you go any further. ASSUME the over tensioning has caused uneven wear resulting in mis-tracking of your belt.

Normy

See my current thread for more pictures. Mine rides about 3/16 of an inch from the front edge of the pulley, and moves back and forth about 2 mm as the engine turns over. I suspect that if it is at the front edge, then something might not be right. Does your belt cover have any marks indicating contact?

[I'm showing you mine...you gotta show me yours!]

N!

Rick Carter

Charles,
This is the first post of a thread I started.
Rick

Bent valves with links to pics

--------------------------------------------------------------------------------

This is my delay to tuning with the SMT-6. This is all I have to say about it now. I won't answer any questions until I have more info. I've posted this for educational purposes.
Rick
85 32v modified

Below is Louie Ott's reply.
Thanks for the pics. That is a real shame. Sorry it happened. I've often
wondered about the serviceability of that feeble little bushing. One
thing that I have observed is that the T belt doesn't need tensioning
after the first 2k miles or so. Not to say it shouldn't be checked. If
it does need to be tightened, something else is wrong that made it
loose. It could be the water pump bearing or as this shows, the
tensioner arm. The belt doesn't stretch after initial wearing in.

Louie


Here are some pictures of the bushing in the tensioner arm that failed causing all the damage. The pictures arent the best, basically the bushing cracked and ovaled out which alloud the tensioner to rock in relation to the rest of the pulleys pushing the timing belt forward into the tensioner bracket (thats what the shiny silver grooves in the arm are, the belt cut them in)

http://www.lasotaracing.com/carter/broke/ten1.jpg
http://www.lasotaracing.com/carter/broke/ten2.jpg
http://www.lasotaracing.com/carter/broke/ten3.jpg
http://www.lasotaracing.com/carter/broke/ten4.jpg
http://www.lasotaracing.com/carter/broke/ten5.jpg

Here are pictures of what it looked like with the belt still on it, you can see how the pulley is cocked at an angle to the crank pulley...

http://www.lasotaracing.com/carter/broke/al1.jpg
http://www.lasotaracing.com/carter/broke/al2.jpg
http://www.lasotaracing.com/carter/broke/al3.jpg
http://www.lasotaracing.com/carter/broke/al4.jpg
http://www.lasotaracing.com/carter/broke/al5.jpg


And this is the end result

http://www.lasotaracing.com/carter/broke/result1.jpg
http://www.lasotaracing.com/carter/broke/result2.jpg
http://www.lasotaracing.com/carter/broke/result3.jpg

The driver side head has all the exhaust valves bent severely, the passenger side isn't as bad, but they still need all new exhaust valves and guides...

bunch of Porsche valvetrain parts... http://www.lasotaracing.com/carter/broke/parts.jpg

Thanks!
Rob LaSota

Bill Ball

This thread gives me the *******.

mark kibort

ouch!!!!!

i still cant believe i lucked out when the holbert car skipped 3 teeth at the world challenge race.
thats 14 to 21 + degrees off! (or 7 to 14 crank degrees) i bet it was only 2 teeth

Sorry to hear about the mess! hope you get it together and running soon.

Mk

Pizza

Pictures

Jim_H

Pizza,

I have seen the belt run close to the edge before but not as close as on your pass side. On the ds it looks like the belt has moved to the outside a bit, revealing the shiney wear area on the teeth. Also there seems to be the start of a wear pattern on the back of the belt.

ErnestSw

I would suspect a bent tensioner roller bolt or worn tensioner roller bearings.

FeedNfrenZ

Nice pictures, very clear, Santa must have brought you a new camera! BUT!!!!!!!!!! we can see all the dirt on your engine now! Try "WET ONES"!

Normy

Just remember that when the Holbert car skips a few too many teeth....Normy's always ready to buy her and race her!

N!

heinrich

Pizza you need to replace the water pump as a result of that forward strain from the belt. Check worn crank timing gear and replace the tensioner big roller bolt.

Normy, ditto.

Pizza

I'm not looking forward to changing the water pump. On the PO's reciept I see were the mechanic stripped the threads and had to drill and tap the holes for the water pump. Oh Boy!!!!

rixter

Charles,
see my thread from earlier this year regarding a similar situation I ran into on my S4
https://rennlist.com/forums/928-forum/209106-tb-wp-dilemma-updated.html

heinrich

Rixter how about pics of where the belt runs now for comparison?