Engine Precautions for centrifugal blower

[zeeboost]

I've decided to take my widebody project a different direction. I've been planning on installing a magnacharger mp122 on top of a forged 370 I have waiting to be dropped in, mated with a built t56. However, after much consideration, I've decided that it would be waay too much low end torque for any traction below 4th gear, so I sold the blower a couple of weeks ago. I'm now in the pursuit of a F1 procharger (most likely F1-C). After reading through ls1tech archives on procharger-associated failures, (I use procharger as a general reference term for any centrifugal supercharger), I noticed one thing a lot of people were having issues with premature front bearing wear and snapping the crank snout. But then others would run their setup without a hiccup for tens of thousands of miles. Is it just because some people adjust the belt too tightly? What are the biggest / most common reasons for these failures?

 

I know that everyone says to pin the crank, but that can't be the only fix...and I'm sure that doesn't prevent front bearing wear either.

 

While I have the engine still on a stand, what other precautions can be taken to prevent excessive wear from a centrifugal? I know the old school guys put a BBC snout on, but I haven't read any lsx guys doing that (maybe they have a better cast crank?). That reminds me, I'm using the factory crank, which I've been told should support my power goals.

 

Anyways, main questions:

 

What are the biggest / most common reasons for the crank bearing / snout failures?

 

What other precautions can be taken to prevent excessive front bearing wear from a centrifugal? (About all the engine catastrophes related to roots blowers came from the SBC guys, and their fix would be the BBC snout. I didn't really find any internal LSX failures derived from root blower stress, so I'm assuming centrifugals put more of a load on the crank...or maybe it's just the constant side load.)

 

 

 

 

AS A SIDE NOTE! I know I've been talking about this project for a few years, and I've slowly been working on it, but my goal by the end of this summer is to take care of the bodywork/paint and have her driveable. So, after finals are over this week, I'll be getting started pronto. This will be the summer of Zs. I also gave my '77 to my brother since he's turning 16 at the end of the month, so I'll need to finish assembling that one as well. Gonna be a busy one!

Edited May 12, 2010 by zeeboost

[SUNNY Z]

SOOO, how much HP are you planning on? You don't think you'll have traction problems with a forged 370 and an F1?

 

Lets be real, you can make upwards of 800 horses on a D1. What are your power goals anyway?

 

Pinning the crank is always a good idea if you plan to run alot of boost from a centrifugal. Also, running a 12 rib setup, or even a cog drive. I have about half a dozen friends making 600+ whp, with no issues whatsoever. They drive their cars to the track, and drive them home, (unless the drive train fails )

 

I know some of my mustang friends (few) with prochargers have an issue of it eating belts, but normally due to the fact that its misaligned.

Edited May 12, 2010 by SUNNY Z

[zeeboost]

I will be having traction problems either way. First I was wanting to achieve 700-800hp with the maggie and a small shot of nitrous. The ungodly amounts of immediate, low-end torque will be fun at first, but no traction gets old pretty quick. So, I'd prefer to run the centrifugal because it's a more gradual power curve. I'm sure I'll still have wheel spin, but it won't be near the extent of a maggie. Plus the maggie couldn't provide top end pull, which is great about the centrifugals. That, and procharged cars almost always run better times at the track than the maggies. The roots blowers are fun and they have their place, but I've decided it's not what I'm going after right now. With the F1C I should be able to hit 800rwhp pretty easily, and still have more room to grow. There are smaller prochargers achieving the same numbers, but they have to work harder to get there. With the F1 it should be a breeze. From searching ls1tech, the people with cog drives and more aggressive belt setups are the ones who are damaging the crank. I was looking at a SDCE tensioner setup - it's a proven setup that doesn't seem to put much stress on the crank.

 

Yup, those pulleys need to be perfectly aligned to operate without issue...but I'm not worried about that part yet. While the engine is still on the stand, I'd like to make whatever necessary extra preparations I can - hence the reason for this post

Edited May 12, 2010 by zeeboost

[SUNNY Z]

If you're wanting in the 800 horse range, with room to grow, then I guess an F1 might be right for you. Is this thing going to see the strip at all? Because an 800 horse, < 3000 lb car is knocking on the door of 8's. Does the car have a cage in it? I'd almost put one in for a piece of mind. .... .02

 

Is there a thread about your car?

[zeeboost]

I haven't been making steady-enough progress on the car to deem it worthy of its own thread (though I'm aware others have years behind their belt). However, I'm considering starting one once I get the ball rolling with the project. Yes, I'm planning on taking this car to the strip. It won't be a strip only car, but I would like to see how low in the 9s I can get. The car will have a cage...not a full one so that I can still comfortably get in the car, but enough of one that I'll feel I've secured its structural integrity.

 

Anyways, I'm hoping either BRAAP and/or the doc will chime in here. Instead of studying last night, I searched the internet for these problems and ways to prevent them. I really didn't find any info on how to prevent the main bearing wear, but just several people saying that it happens with superchargers. Surely it isn't that inevitable...there must be some way to help minimize the wear.

[SUNNY Z]

Just food for thought, but if you want your cage to be NHRA legal (depending on how strict your local track is) You will have to have a full cage to go faster than 9.99. A 5, or 6 point is required for all cars quicker than 11.49, and this includes door bars.

[zeeboost]

It's been a while since I was messing with it, but I have at least a 6 point cage set up for it...may go more, not sure yet. But, I'm not planning on any door bars. I'm 6'5" and enjoy the roominess of the s30 too much to take it for granted. Besides, I know of at least one track around here where I could get away without one (or at least much of one)

[SUNNY Z]

Ah, gotcha. The tracks around here are pretty strict, so when I do put a cage in mine, it's going to have removable swing outs, so i can just take the door bars completely out whenever i'm not using them.

[zeeboost]

bump

 

 

As a side note, here's the kit I'm looking at buying:

 

http://www.ls1tech.com/forums/parts-classifieds/1282511-complete-f1-procharger-kit.html

 

I don't have any experience with procharged setups, so I was wondering what your opinion of this kit is? If anything looks suspicious about it, or maybe that tensioner setup is prone to failure (I don't know - I didn't find much info on it). I think $6k is a bit too much, and $4500 should be a better ballpark. I don't wanna go higher than $5k.

 

Another thing that gets me is why almost every procharged kit I see for sale, barely has a thousand miles on it. Most are 400-800 miles or something like that. These are off street/strip cars. That always bugged me...gives me the impression that they're problematic, but most people seem to be happy with them.