Testing a 4.7L KB before buying it? (on a hurt motor)

SLT Kota · 04-27-2009, 08:38 PM

Hey, I was told to come ask you guys about this and there seems to be more KB supercharged jeeps then KB dakotas.

I'm looking at getting a KB for my 4.7L dakota. I found a guy that is selling one off of his truck that spun a main bearing. Is there any way to test the kenny bell before I pull it off his truck? Is there a way to make sure the optamizer is working correctly?

The guy doesn't seem to know anything about the truck or the supercharger (I don't even think he knows it is a kenne bell) as he just bought it already built. I'm hoping the motor spun a bearing cause he was stupid and not cause of the KB and I would really like to make sure before I buy it and put it on my truck.

Any guesses why it would have spun the bearing? the truck has 97K on it and 12K on the KB.

I would normally drive the truck that it was on first to make sure it is ok but it has a spun bearing, Could I still drive it if he says ok? What should I do to test it?

I know the optimizer sucks for modifying but at this point I don't really want to up the boost at all as my truck has 90K on it. Only other things I might do before rebuilding the motor with better internals would be things like TB and exhaust. Would it be SAFE to just run the entire kit as it came from KB? I know the optimizer and boost-a-pump suck but would the work decently for a "stock" applacation.
Thanks in advanced,
Stuart

scjeep4.7HO · 04-28-2009, 03:03 AM

They do suck but as long as they are functional it will work. I would not drive anyones truck (personally) just to stay away from any egal litigation that may stem from it. His engine could have spun a bearing for many reasons. Lack of maintenance, over revv, over heat, who knows what all may have contributed to it. If you bought the kit it is always able to be rebuilt and reused.

Endless · 04-28-2009, 07:45 AM

Only thing I can think of is to take the belt off the sc and feel for play in the pulley/nosedrive. But like scjeep said, they can be rebuilt.

Wideband and fuel pressure gauge would be a good investment so you can monitor when its on your truck.

Glitch · 04-28-2009, 12:39 PM

Yes making sure that the blower spins freely by manually rotating the snout pulley and checking for any slippage is always a good thing to do. Also check how the oil looks in the supercharger itself, any metal shavings and it will have to be rebuilt. Really the only way to check the optimizer is to wire it into your rig and see if your vehicle starts. I have been 0 for 2 in working optimizers that i have either installed myself or helped install. The good news is all you have to do is buy some bigger injectors about 100-200 bucks off of ebay to replace all 8 of your stock ones and then get an SCT tuner and a wideband and it will fix the problem and actually give you better performance.

i have had just about every problem imaginable happen to me while installing my KB kit. I know that the jeeps and dakotas are different but almost identical when it comes to the KB kits. If you need any help when it comes down to the install feel free to post up again.

SLT Kota · 04-28-2009, 07:57 PM

he just told me that that he has no boost gauge and that it was suppose to be boosting 12 Lbs.

Guess I know how he messed up the motor.

how much does a new pullie cost? Arn't they like a grand to rebuild? I think I may get it anyway just cause it is stupid cheap. I'll probably wait til I can get fuel pressure, wideband, and boost gauges before putting it on (only want to boost 8psi though)
Thanks for all the help!

Glitch · 04-28-2009, 09:16 PM

Hahaha ya 12psi is probably how he did it. Depending on what the pulley diameter is I would be willing to trade you a used one for it. I have several sizes and I am looking for one smaller than 2 3/4 inches. I have a 3", 2 7/8, one in between, and 2 3/4. The 2 7/8 or the one in between will be the one that will give you 8psi of boost. If the kit you are going to purchase comes with a 2 5/8 or a 2 1/2" pulley I would be more than happy to trade you straight up.

Edit: To answer your question yes they are about a grand to rebuilt but with only 12000 miles on it i highly doubt it does. Also a new pulley from kenne bell costs like 70 bucks plus shipping. I ordered one like 6 months ago.

SLT Kota · 04-28-2009, 10:21 PM

Thanks! If he still has it and I can get down to get it I will probably pick it up. I hope it doesn't need rebuilding but it is stupid cheap so I think it is to good of a deal to pass up. I'll probably wait a few months to put it on though until after I get a boost, wideband, and fuel pressure gauges. I have no plans on running more then 8 or 9 lbs as I want my motor to last a few more years.
thanks for all the help, If the pulley really is the 12psi size I would be more then happy to trade you. I have exams this week so I won't be able to go down there to check it out until late next week. I just hope he hasn't sold the truck by then.

SLT Kota · 05-11-2009, 02:24 PM

Quote:

Originally Posted by Glitch

Hahaha ya 12psi is probably how he did it. Depending on what the pulley diameter is I would be willing to trade you a used one for it. I have several sizes and I am looking for one smaller than 2 3/4 inches. I have a 3", 2 7/8, one in between, and 2 3/4. The 2 7/8 or the one in between will be the one that will give you 8psi of boost. If the kit you are going to purchase comes with a 2 5/8 or a 2 1/2" pulley I would be more than happy to trade you straight up.

Edit: To answer your question yes they are about a grand to rebuilt but with only 12000 miles on it i highly doubt it does. Also a new pulley from kenne bell costs like 70 bucks plus shipping. I ordered one like 6 months ago.

Where do you measure the pulley? On the outside (over the rails on each side) it is about 3 and 2/3's inches but on the inside (where all the groves are) it is under 3inches. Also I can only measure the top of the groves, my dial indacator won't fit between them.

Would you be willing to just sell one of the smaller ones outright as I'm not sure if the pulley it came with will be one you want or not.
Thanks,
Stuart

Glitch · 05-12-2009, 11:23 PM

how I measure it is by just laying a tap measurer across the face of the pulley and measuring the diameter. As soon as I get tuned and veryify that I have two 7psi pulleys and not a 7psi and an 8psi I would be more than happy to sell you one straight up.

04-27-2009, 08:38 PM	#1
SLT Kota Member Join Date: Apr 2009 Posts: 41 Rep Power: 0	Testing a 4.7L KB before buying it? (on a hurt motor) Hey, I was told to come ask you guys about this and there seems to be more KB supercharged jeeps then KB dakotas. I'm looking at getting a KB for my 4.7L dakota. I found a guy that is selling one off of his truck that spun a main bearing. Is there any way to test the kenny bell before I pull it off his truck? Is there a way to make sure the optamizer is working correctly? The guy doesn't seem to know anything about the truck or the supercharger (I don't even think he knows it is a kenne bell) as he just bought it already built. I'm hoping the motor spun a bearing cause he was stupid and not cause of the KB and I would really like to make sure before I buy it and put it on my truck. Any guesses why it would have spun the bearing? the truck has 97K on it and 12K on the KB. I would normally drive the truck that it was on first to make sure it is ok but it has a spun bearing, Could I still drive it if he says ok? What should I do to test it? I know the optimizer sucks for modifying but at this point I don't really want to up the boost at all as my truck has 90K on it. Only other things I might do before rebuilding the motor with better internals would be things like TB and exhaust. Would it be SAFE to just run the entire kit as it came from KB? I know the optimizer and boost-a-pump suck but would the work decently for a "stock" applacation. Thanks in advanced, Stuart

04-28-2009, 12:39 PM	#4
Glitch Member Asteroids Champion! Join Date: Jan 2009 Location: Wenatchee, WA Posts: 827 Rep Power: 12	Yes making sure that the blower spins freely by manually rotating the snout pulley and checking for any slippage is always a good thing to do. Also check how the oil looks in the supercharger itself, any metal shavings and it will have to be rebuilt. Really the only way to check the optimizer is to wire it into your rig and see if your vehicle starts. I have been 0 for 2 in working optimizers that i have either installed myself or helped install. The good news is all you have to do is buy some bigger injectors about 100-200 bucks off of ebay to replace all 8 of your stock ones and then get an SCT tuner and a wideband and it will fix the problem and actually give you better performance. i have had just about every problem imaginable happen to me while installing my KB kit. I know that the jeeps and dakotas are different but almost identical when it comes to the KB kits. If you need any help when it comes down to the install feel free to post up again. __________________ 2002 Jeep Grand Cherokee 4.7l with 2.1L Eaton supercharger,Labonte motorsports stage 2 meth kit, Ross forged pistons, H-beam rods, ARPs, behive valve springs, 50lb injectors, SCT custom tune, 3'' Kolak Exhaust, high flow cat, high flow muffler, modified y-pipe,180* Thermostat, Autometer wideband and NV guages, addco front and rear sway bars, alpines all around. Last edited by Glitch; 04-28-2009 at 05:31 PM.

04-28-2009, 09:16 PM	#6
Glitch Member Asteroids Champion! Join Date: Jan 2009 Location: Wenatchee, WA Posts: 827 Rep Power: 12	Hahaha ya 12psi is probably how he did it. Depending on what the pulley diameter is I would be willing to trade you a used one for it. I have several sizes and I am looking for one smaller than 2 3/4 inches. I have a 3", 2 7/8, one in between, and 2 3/4. The 2 7/8 or the one in between will be the one that will give you 8psi of boost. If the kit you are going to purchase comes with a 2 5/8 or a 2 1/2" pulley I would be more than happy to trade you straight up. Edit: To answer your question yes they are about a grand to rebuilt but with only 12000 miles on it i highly doubt it does. Also a new pulley from kenne bell costs like 70 bucks plus shipping. I ordered one like 6 months ago. Last edited by Glitch; 04-28-2009 at 09:18 PM.

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04-28-2009, 03:03 AM	#2
scjeep4.7HO Moderator Join Date: Jan 2009 Posts: 1,122 Rep Power: 13	They do suck but as long as they are functional it will work. I would not drive anyones truck (personally) just to stay away from any egal litigation that may stem from it. His engine could have spun a bearing for many reasons. Lack of maintenance, over revv, over heat, who knows what all may have contributed to it. If you bought the kit it is always able to be rebuilt and reused.

04-28-2009, 07:45 AM	#3
Endless Huge Member Snake Champion! Hexxagon Champion! Breakout Champion! Archery Champion! Call of Duty 2 Champion! Kill Me Champion! Carnival Shooter Champion! Tournaments Won: 1 Join Date: Jan 2009 Location: SW Ohio Posts: 839 Rep Power: 12	Only thing I can think of is to take the belt off the sc and feel for play in the pulley/nosedrive. But like scjeep said, they can be rebuilt. Wideband and fuel pressure gauge would be a good investment so you can monitor when its on your truck.

04-28-2009, 07:57 PM	#5
SLT Kota Member Join Date: Apr 2009 Posts: 41 Rep Power: 0	he just told me that that he has no boost gauge and that it was suppose to be boosting 12 Lbs. Guess I know how he messed up the motor. how much does a new pullie cost? Arn't they like a grand to rebuild? I think I may get it anyway just cause it is stupid cheap. I'll probably wait til I can get fuel pressure, wideband, and boost gauges before putting it on (only want to boost 8psi though) Thanks for all the help!

04-28-2009, 10:21 PM	#7
SLT Kota Member Join Date: Apr 2009 Posts: 41 Rep Power: 0	Thanks! If he still has it and I can get down to get it I will probably pick it up. I hope it doesn't need rebuilding but it is stupid cheap so I think it is to good of a deal to pass up. I'll probably wait a few months to put it on though until after I get a boost, wideband, and fuel pressure gauges. I have no plans on running more then 8 or 9 lbs as I want my motor to last a few more years. thanks for all the help, If the pulley really is the 12psi size I would be more then happy to trade you. I have exams this week so I won't be able to go down there to check it out until late next week. I just hope he hasn't sold the truck by then.

05-12-2009, 11:23 PM	#9
Glitch Member Asteroids Champion! Join Date: Jan 2009 Location: Wenatchee, WA Posts: 827 Rep Power: 12	how I measure it is by just laying a tap measurer across the face of the pulley and measuring the diameter. As soon as I get tuned and veryify that I have two 7psi pulleys and not a 7psi and an 8psi I would be more than happy to sell you one straight up.