Chevy Nova Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Hi all, Im new here and of course I have questions.:0) I have a 496 stroker motor and Im running a Jesel belt drive, Engine never installed in car. but now I want to add a blower. Talking with the Tech at :The Blower Shop: he said he thinks that the belt drives lower crank gear/pulley is thicker than a chain and moves out the balancer on the crankshaft a little.
Does anyone know if this is true and how much is the balancer pushed out.
The Blower Shop needs to know this because of the blower belt alignment issue.
Thanks :
Tom
 

·
Registered
Joined
·
178 Posts
I run a Jessel belt drive on my blown SBC I do not know this answer off the top of my head but I wouldn't think it would be anymore then .125. on my engine there is plenty of room on the pulleys for some adjustment.
 

·
Registered
Joined
·
238 Posts
Hi all, Im new here and of course I have questions.:0) I have a 496 stroker motor and Im running a Jesel belt drive, Engine never installed in car. but now I want to add a blower. Talking with the Tech at :The Blower Shop: he said he thinks that the belt drives lower crank gear/pulley is thicker than a chain and moves out the balancer on the crankshaft a little.
Does anyone know if this is true and how much is the balancer pushed out.
The Blower Shop needs to know this because of the blower belt alignment issue.
Thanks :
Tom
The crank pulley for a belt drive is thicker overall in order to accommodate the wider belt as compared to a conventional gear for a timing chain. However, the face of the pulley is recessed so that the harmonic damper hub actually fits inside of the crank belt pulley. This recession allows for OEM-dimensions on damper protrusion. The blower drive will not have any belt alignment issues. TBS's standard BBC blower drive will provide you with the correct dimensions and alignment.

Also, just as FYI, if your engine is internally balanced then you can ditch the harmonic damper completely when using a Roots supercharger and simply run a solid hub with timing marks on it. The blower belt will provide all the harmonic damping that your engine requires.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #4
The crank pulley for a belt drive is thicker overall in order to accommodate the wider belt as compared to a conventional gear for a timing chain. However, the face of the pulley is recessed so that the harmonic damper hub actually fits inside of the crank belt pulley. This recession allows for OEM-dimensions on damper protrusion. The blower drive will not have any belt alignment issues. TBS's standard BBC blower drive will provide you with the correct dimensions and alignment.

I called TBS again today and asked the same question to a different tech and he said there are no specs on the lower pulley. If the pulley was larger, than I would think the spec would be listed for the tech man.
I dont have a stock type lower pulley to measure but I will take your word for it since you are running one and have no issues, others say about a 1/8" or less.
When I built my engine I went for a internal balance, but I also bought a internal supercharger damper already just if I decided to take off the blower or get a ticket and a donation slip from my local police dep.:(
Thanks;
Tom
 

·
Registered
Joined
·
238 Posts
The crank pulley for a belt drive is thicker overall in order to accommodate the wider belt as compared to a conventional gear for a timing chain. However, the face of the pulley is recessed so that the harmonic damper hub actually fits inside of the crank belt pulley. This recession allows for OEM-dimensions on damper protrusion. The blower drive will not have any belt alignment issues. TBS's standard BBC blower drive will provide you with the correct dimensions and alignment.

I called TBS again today and asked the same question to a different tech and he said there are no specs on the lower pulley. If the pulley was larger, than I would think the spec would be listed for the tech man.
I dont have a stock type lower pulley to measure but I will take your word for it since you are running one and have no issues, others say about a 1/8" or less.
When I built my engine I went for a internal balance, but I also bought a internal supercharger damper already just if I decided to take off the blower or get a ticket and a donation slip from my local police dep.:(
Thanks;
Tom
Worst case scenario if for some reason your belt drive crank pulley is dimensionally different or wider you can simply use a lathe to turn down the back side of the harmonic damper hub accordingly. This is a simple and quick operation for any machine shop or anybody with access to a lathe and basic machining experience.
 
1 - 5 of 5 Posts
Top