7” crank pulley

SVT1077

SVT1077

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Looking for so advice. Unlike most of you running centrifugal super chargers, I have an old school Kenne Bell. After talking to Jon Bond the other day he suggested that I use a larger crank pulley rather than a smaller pulley on the SC due to slippage and belts coming off. This means I need a 7” crank pulley instead of the stock 6.5”. I have been searching all weekend in the internet and can’t find anything.

My current SC pulley is 2 5/8. I can get a 3 or a 4 but that is it. Jon said the max I should be spinning the KB is 14,700. A 7 in crank with my current SC pulley would be 1:2.666 which is about max.

Any help would be appreciated


1994 Black #1077
CI 351 H rods DSS TW pistons
Trick Flow 170s
Bassani 1 5/8” headers
KB 1.5L Supercharger
Meth Injection
Coil Near Plug
PiMPxs ECU
US SHIFT QUICK4
Punisher VB
WWW.Gen1Jonny.com
 
Is the Blower run on a separate belt from you accessories? ASP use to make a 7" with an underdrive for the accessories.
 
That has always been a real challenge with the Lightning KBs. They don't really have enough displacement, so you end up with a small pulley and belt slip is an issue.

Your hotrod really needs a 2.2l, but they're so rare. I know that wasn't much help.

You may have to get a custom crank pulley made that can be used with off the shelf under drive pulleys on the accessories.


Sent from my LM-G820 using Tapatalk
 
I'd just call ASP and tell them what you need and have them build it. Also, and I am speaking from experience, get the stock diameter accessory pulley size. With the electrical loads we put on these trucks now you need a good charging system over the negligible gains of under-drive.
 
Blue Oval Forever said:
Is the Blower run on a separate belt from you accessories? ASP use to make a 7" with an underdrive for the accessories.
Click to expand...

No, that’s the issue.


1994 Black #1077
CI 351 H rods DSS TW pistons
Trick Flow 170s
Bassani 1 5/8” headers
KB 1.5L Supercharger
Meth Injection
Coil Near Plug
PiMPxs ECU
US SHIFT QUICK4
Punisher VB
WWW.Gen1Jonny.com
 
Raymond_B said:
I'd just call ASP and tell them what you need and have them build it. Also, and I am speaking from experience, get the stock diameter accessory pulley size. With the electrical loads we put on these trucks now you need a good charging system over the negligible gains of under-drive.
Click to expand...

I have a Power Master high output alternator so that will not be an issue. I figured it would come down the a custom pulley.


1994 Black #1077
CI 351 H rods DSS TW pistons
Trick Flow 170s
Bassani 1 5/8” headers
KB 1.5L Supercharger
Meth Injection
Coil Near Plug
PiMPxs ECU
US SHIFT QUICK4
Punisher VB
WWW.Gen1Jonny.com
 
High output alternators are great but if they are spinning too low at an idle they won’t put enough voltage out and if you spin any alternator too high the bearings will fail.
 
FMOS Racing said:
That has always been a real challenge with the Lightning KBs. They don't really have enough displacement, so you end up with a small pulley and belt slip is an issue.

Your hotrod really needs a 2.2l, but they're so rare. I know that wasn't much help.

You may have to get a custom crank pulley made that can be used with off the shelf under drive pulleys on the accessories.


Sent from my LM-G820 using Tapatalk
Click to expand...

I know now that I need the 2.2 unfortunately when I purchased it, I was brand new to all of this. The whole reason I spent the ridiculous amount of money for the KB is because I was trying to keep all the upgrades period correct. Yes I know I am running CNP which is way off that last statement. That is why I bought the PiMPxs, the KB requires a vacuum module that can no longer be found. The way around that was an aftermarket ECU. I have been seriously been thinking of saying F it and go turbo.


1994 Black #1077
CI 351 H rods DSS TW pistons
Trick Flow 170s
Bassani 1 5/8” headers
KB 1.5L Supercharger
Meth Injection
Coil Near Plug
PiMPxs ECU
US SHIFT QUICK4
Punisher VB
WWW.Gen1Jonny.com
 
Jamie V said:
High output alternators are great but if they are spinning too low at an idle they won’t put enough voltage out and if you spin any alternator too high the bearings will fail.
Click to expand...

Agreed


1994 Black #1077
CI 351 H rods DSS TW pistons
Trick Flow 170s
Bassani 1 5/8” headers
KB 1.5L Supercharger
Meth Injection
Coil Near Plug
PiMPxs ECU
US SHIFT QUICK4
Punisher VB
WWW.Gen1Jonny.com
 
Thanks once again for sharing your knowledge with me it is greatly appreciated.


1994 Black #1077
CI 351 H rods DSS TW pistons
Trick Flow 170s
Bassani 1 5/8” headers
KB 1.5L Supercharger
Meth Injection
Coil Near Plug
PiMPxs ECU
US SHIFT QUICK4
Punisher VB
WWW.Gen1Jonny.com
 
Period correct would also be a powerdyne or Vortech kit.

Turbo is the most money up front but in my opinion the best setup in the long run if done correctly.
 
SVT1077 said:
Agreed


1994 Black #1077
CI 351 H rods DSS TW pistons
Trick Flow 170s
Bassani 1 5/8” headers
KB 1.5L Supercharger
Meth Injection
Coil Near Plug
PiMPxs ECU
US SHIFT QUICK4
Punisher VB
WWW.Gen1Jonny.com
Click to expand...

Yeah my giant 220A alt was not charging as it should at idle due to the underdrive crank pulley.
 
Raymond_B said:
Yeah my giant 220A alt was not charging as it should at idle due to the underdrive crank pulley.
Click to expand...

Good to know. If the pulleys way over priced I may just sell the KB.


1994 Black #1077
CI 351 H rods DSS TW pistons
Trick Flow 170s
Bassani 1 5/8” headers
KB 1.5L Supercharger
Meth Injection
Coil Near Plug
PiMPxs ECU
US SHIFT QUICK4
Punisher VB
WWW.Gen1Jonny.com
 
slow94 said:
I vote turbo.... But I'm biased
Click to expand...

Part of that problem is that I just had a custom cam ground and it’s designed for a SC. It may still happen one day but not right now.


1994 Black #1077
CI 351 H rods DSS TW pistons
Trick Flow 170s
Bassani 1 5/8” headers
KB 1.5L Supercharger
Meth Injection
Coil Near Plug
PiMPxs ECU
US SHIFT QUICK4
Punisher VB
WWW.Gen1Jonny.com
 
Not a lot of difference in a turbo cam and a supercharger cam. Slight difference in the intake to exhaust lobe ratio and timing. They both run a pretty wide LSA to keep boost from going out the exhaust valve during overlap and favor the exhaust side compared to a naturally aspirated cam. A rowdy naturally aspirated cam wouldn't be a good option, but supercharger to turbocharger isn't a big stretch.
 
SVT1077 said:
Part of that problem is that I just had a custom cam ground and it’s designed for a SC. It may still happen one day but not right now.


1994 Black #1077
CI 351 H rods DSS TW pistons
Trick Flow 170s
Bassani 1 5/8” headers
KB 1.5L Supercharger
Meth Injection
Coil Near Plug
PiMPxs ECU
US SHIFT QUICK4
Punisher VB
WWW.Gen1Jonny.com
Click to expand...

So is my cam.. heck it's a SD cam. Boost overcomes all.
 
slow94 said:
So is my cam.. heck it's a SD cam. Boost overcomes all.
Click to expand...

LOL, no your right it would still work it just wouldn’t be as efficient.


1994 Black #1077
CI 351 H rods DSS TW pistons
Trick Flow 170s
Bassani 1 5/8” headers
KB 1.5L Supercharger
Meth Injection
Coil Near Plug
PiMPxs ECU
US SHIFT QUICK4
Punisher VB
WWW.Gen1Jonny.com
 
shaunditty said:
Vortech pulley I use is 6.87” and I believe is referred to as a 7”.
Click to expand...

Is that a single pulley or stacked pulley?


1994 Black #1077
CI 351 H rods DSS TW pistons
Trick Flow 170s
Bassani 1 5/8” headers
KB 1.5L Supercharger
Meth Injection
Coil Near Plug
PiMPxs ECU
US SHIFT QUICK4
Punisher VB
WWW.Gen1Jonny.com
 
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