CTTC / B2K scavenge pump tensioner and pulley rebuild

Discussion of Corvette based Callaway Cars including: 1987-1991 RPO B2K Callaway Twin Turbo Corvettes (C4); Callaway SuperNatural Corvettes (CL-1/CR-1); Callaway C12; Supercharged Corvettes; Callaway C16; 6th Generation Callaway Corvettes (SC560, SC580, SC606, SC616, SC620, SC652); 7th Generation Callaway Corvettes (SC627/SC757); NEW Callaway C8 Corvettes - and more!
Post Reply
sjandras
4-PSI
4-PSI
Posts: 39
Joined: Mon May 17, 2021 10:01 pm

CTTC / B2K scavenge pump tensioner and pulley rebuild

Post by sjandras »

Onto the next project on 1988 #064. When running the car after my previous turbo/intake project, I noticed that there was a squeak from the scavenge pump area with the new Callaway Goodyear belt I had just put on. Looking closer, there are a couple issues: the tensioner damper is crumbled out, and more importantly, the custom Calllaway pulleys (water pump and scavenge pump) are both worn through the anodize finish and severely grooved. The scavenge pump pulley was down to only 0.075" thick on the running surface after clean up on a lathe!

I pulled the tensioner apart today and have a new one on order that I will tear apart and piece this one back together with new guts. Thanks to boostedmaxpsi for pictures in his post, so I knew what to expect. To get it apart, the easiest way is to open the vice jaws up and rest the spring side of the tensioner (the GM part, not the Callaway part) on the jaws, then drive the sleeve out with a socket and hammer. It's obvious once you see the small parts of the casting that stick out a bit.

For the pulleys, I talked to Wayne at Callaway and they luckily have a few of the scavenge pump pulleys in stock, I have one coming. The water pump pulley is NLA... I had mine turned down on a lathe to clean it up and remove the groove, it's now being re-hard anodized. The obvious symptom of this is a shiny silver back side of the belt. Keep an eye out for this and fix it quick! When you look at cars on Bringatrailer, quite a few of them show the "aluminized" belt look. The pulleys wear away very quickly once you're through the hard anodize. I can only assume this happened by running a non-Callaway belt that must have slipped under load.

As always, a few pictures below.
Attachments
20240719_144902.jpg
20240719_144826.jpg
*89x2*
VIP COG Brother
VIP COG Brother
Posts: 695
Joined: Tue Oct 21, 2008 9:58 pm

Re: CTTC / B2K scavenge pump tensioner and pulley rebuild

Post by *89x2* »

Thank you for posting this, and please keep us updated. :thumbs
Post Reply