77vettejeff

One of my belts jumped off the pulley and bound things up to the point where my water pump broke and crank pulley was bent.
I'm looking for a new, affordable pulley kit. A reduction kit would be nice if I could gain some power. Any suggestions?

gordie1465

2 things pulleys out of alignment or you have a water pump bearing going . If not try moroso deep groove pulleys if you plan to rev your motor high ....

gordie1465

oops just saw your pic you had a bad water pump bearing which caused bad vibes then caused brake in casting which is hard to do .Upon replacing pulleys check for warpage and good luck.

thegazman

If your looking for a performance pulley kit after you get your problems fixed, Summit Racing and Jegs Racing sell a March billet performance pulley set for a C3 Vette for a little over $200. I'm converting my C3 to an electric fan and using the pulley kit. It's a slight HP gain and less strain on the water pump shaft with out the big fan.
Ken

Aggitated Monkey

Wow!! I have never seen this happen before. I hope other parts are not damaged.

77vettejeff

Thanks for the replies. I will probably rebuild with stock pulley system. My crank pulleys are damaged and water pump pulley is slightly damaged. Also, small chip out of the shroud and fan is bloken. Luckily block, radiator and hood are okay.
I noticed and confirmed at the parts stores that the fan/alt belt is thinner than the fan/AC belt. As a result, the fan/AC belt rides up higher in the groves (near top). I think this is the one than may have jumped out at 5500 rpm. The fan/alt belt rides lower in the pulley groves. Can I run a thinner belt for fan/AC? This way both would ride lower in the grooves and I would have some of the pulley up above the top of the belt. Comments are appreciated. Anyone have stock pulley for sale?
Thanks,
Jeff

Desert68

You wouldn't happen to have a p/n for the kit, would you? TIA

BigBlockTank

I tried installing the March serpentine belt system on my 69 big block. No way, bottom pulley hit cross member, $1800 back to Jeg's.

thegazman

My March performance pulley system is a belt system. I've heard stories about how people have to modify their cross member to accommodate a serpentine system. These part number are for a 1977-82 Vette. I don't know why it won't go back to 1971. I think that's when Corvette started putting unique water pumps on (3/4" shaft).

Anyway here's the numbers, Jegs...655-5050, 655-5030, 655-5070. Summit Racing...MCH5050, MCH 5030, MCH 5070. The different parts are for different pulley configurations (number of groves on the crankshaft and water pump pulley) One thing I like is the groves are deeper than stock to help prevent belt from coming off during high RPMS.

Ken

Desert68

Thank you. I should have been more clear - mine is a '68 L79 w/ A/C - solid starting point - thanks.

molldog12

Question (TheGazMan)? I was think of puting that pully system on my 78 vette. Do the belts slip at high RPM?

thegazman

Molldog12....I haven't had any problems with mine. However, I must admit I don't really drive my car very hard. The belts fit fairly deep into the groves and seem like they would slip less than original pulleys.

Ken