Is there anything wrong in this picture?

[Sparky dave]

Please will an experienced eye look at my photos of my accesory drive and see if you spot anything wrong. If a couple of symptoms mainly belt ratio related i think

[Sparky dave]

Another

[Sparky dave]

Have to post separately for some reason

[MAC71Cheyenne]

On the wrong pulley

[Sparky dave]

Thanks mac!which one is wrong? Is it the water pump pulley?

[Rickysnickers]

I don't know, but you can remove that spacer for the mechanical fan if you like. There's no need for it with the electric fans

[68Gold/white]

The top of your water pump belt is setting above the top of the the pulley, it should be fully inside the pulley, like the power steering belt.

[MAC71Cheyenne]

Water pump belt is too wide and as stated, does not fully seat into the pully groove. Measure the width and depth of the groove and belt length. Good parts store should be able to hook you up.

[1971 GMC SHORTY]

Power Steering Top Brackets Wrong WATER pump Pulley Crooked Belt Cog To Fat,
Get Rid Of Spacer

[Sparky dave]

Thanks everybody gives me a few jobs to tidy up! I think I have a problem with slow water flow on idle which is 550rpm. It is not flowing fast enough for my fan switch to knock off. It's a 165-185 fan switch installed in the thermostat neck which is a 160stat. There is a huge temp drop across the rad and when I press gas I feel the heat rush through. I have a 7/78 crank pulley and 6.5 inch water pump pulley. I read approx 130% overdrive ratio was good on the water pump for street and I'm a bit under. Not sure which pulley to change. To add to the confusion my alternator is kicking out 16v and is being driven from the same 7/78 crank pulley and wondered if i was overspeeding it. Thanks for all your help iv confused myself and doing Google searches has just added to the confusion

[GASoline71]

Hard to piece together all the front bracketry to line up. For parts sourcing, that is a later model (1973+ for trucks) SBC setup. The 67-72's all had alternators on the drivers side.

Gary

[RustyPile]

Originally Posted by Sparky dave

Thanks everybody gives me a few jobs to tidy up! I think I have a problem with slow water flow on idle which is 550rpm. It is not flowing fast enough for my fan switch to knock off. It's a 165-185 fan switch installed in the thermostat neck which is a 160stat. There is a huge temp drop across the rad and when I press gas I feel the heat rush through. I have a 7/78 crank pulley and 6.5 inch water pump pulley. I read approx 130% overdrive ratio was good on the water pump for street and I'm a bit under. Not sure which pulley to change. To add to the confusion my alternator is kicking out 16v and is being driven from the same 7/78 crank pulley and wondered if i was overspeeding it. Thanks for all your help iv confused myself and doing Google searches has just added to the confusion

You're overthinking this. You feel that hot air because the radiator and fans are doing their job of removing heat from the coolant. You need a 180 or 190 thermostat.. Never mind overdrive or underdrive the water pump.. Get the correct belts and straighten out the bracketry.. 16 volts is way over voltage, not because the alternator is spinning too fast.. It's high because the voltage regulator isn't doing it's job...

[Steeveedee]

Originally Posted by RustyPile

You're overthinking this. You feel that hot air because the radiator and fans are doing their job of removing heat from the coolant. You need a 180 or 190 thermostat.. Never mind overdrive or underdrive the water pump.. Get the correct belts and straighten out the bracketry.. 16 volts is way over voltage, not because the alternator is spinning too fast.. It's high because the voltage regulator isn't doing it's job...

Yup. If the regulator is external, you can adjust it. 14.5V would max at idle. (13.5V is minimum for these trucks, but you might need more if electric fans are in the mix).

[Sparky dave]

Originally Posted by RustyPile

You're overthinking this. You feel that hot air because the radiator and fans are doing their job of removing heat from the coolant. You need a 180 or 190 thermostat.. Never mind overdrive or underdrive the water pump.. Get the correct belts and straighten out the bracketry.. 16 volts is way over voltage, not because the alternator is spinning too fast.. It's high because the voltage regulator isn't doing it's job...

Ok thanks for straightening me out I'll get a new alteenator as it's internally regulated and not get too hung up on theorys.

[Sparky dave]

Originally Posted by GASoline71

Hard to piece together all the front bracketry to line up. For parts sourcing, that is a later model (1973+ for trucks) SBC setup. The 67-72's all had alternators on the drivers side.

Gary

Thanks Gary thats useull info will keep that in mind

[Sparky dave]

Originally Posted by Steeveedee

Yup. If the regulator is external, you can adjust it. 14.5V would max at idle. (13.5V is minimum for these trucks, but you might need more if electric fans are in the mix).

thanks steeveedee it's internally regulated so I take it I have to buy anew alteenator then. Thanks for the info

[68 P.O.S.]

Originally Posted by GASoline71

The 67-72's all had alternators on the drivers side.

Ummm, what??

[GASoline71]

Originally Posted by 68 P.O.S.

Ummm, what??

All the V8 trucks did. Also all the V8 trucks (SBC and BBC) had short water pumps.

Gary

[68 P.O.S.]

Wow, I never noticed Learn something new everyday. For some reason I had it in my head that only a/c trucks have it on the drivers side. So trucks with passenger side alts were using later model bracketry?

[72c20customcamper]

Originally Posted by 68 P.O.S.

Ummm, what??

Alternator on drivers side 67-72 like this . Mine has an aftermarket ac system

[72c20customcamper]

Originally Posted by 68 P.O.S.

Wow, I never noticed Learn something new everyday. For some reason I had it in my head that only a/c trucks have it on the drivers side. So trucks with passenger side alts were using later model bracketry?

Or the engine was replaced at some time . My 72 is on the passenger side the engine from what I can decifer came from a 74

[GASoline71]

Originally Posted by 68 P.O.S.

Wow, I never noticed Learn something new everyday. For some reason I had it in my head that only a/c trucks have it on the drivers side. So trucks with passenger side alts were using later model bracketry?

Yep... usually at some point an engine swap was done with a later model truck or car V8 and all the bracketry from that engine was left in place.

Gary

[Sparky dave]

Well the block is an 010 so I thought it could be 69 to early 70s engine. So prob is a 73. Heads are 991 76cc small valve deals. Obviously no engine vin on these's trucks so guess I'll never know

[GASoline71]

Originally Posted by Sparky dave

Well the block is an 010 so I thought it could be 69 to early 70s engine. So prob is a 73. Heads are 991 76cc small valve deals. Obviously no engine vin on these's trucks so guess I'll never know

"010" means nothing really. Look on the bellhousing flange on the drivers side. It's probably numbered 3970010. Which is the most common 350 block ever made.

Also the machined pad in front of the passenger side head will have some alphanumerics as well. They can be decoded to break it down even more.

Gary