This can't be good...
12-26-2008, 10:20 PM
#41
OK, understood, the valve springs should’ve been checked. However, I’ve had a good number of built engines over the years with hot cams and specific springs and such and they’ve never needed checking, I’ve never been recommended to check them and they’ve all lasted a good long time.
Nowhere have I said that AI was at fault. Perhaps Comp Cams is as they had a known issue with a batch of these springs and it appears that my springs fall in that time frame. Regardless, with the time passed and the milage on them, I would doubt if they (CC) would offer any coverage for me.
Agreed, having go fast cars involves a higher risk of breakage regardless of the brand of car. It’s just that these engines have certain quirks and difficulties as well as a limited supply of aftermarket parts for them. While aftermarket R&D for these engines ended years ago, R&D for LSx engines is going strong considering GM still has years of use of these engines on the books. Going to an LSx car opens up a whole new world of performance parts. Going to a 71 Monte moves me to an old school small block. Plus, half the engine’s not buried under the cowl.
This is all putting the cart before the horse. In a week or two, I’ll be pulling off the heads and evaluating the full scope of the damage. If one bent valve and a set of springs is all that’s needed, I’ll hang on to the thing.
Nowhere have I said that AI was at fault. Perhaps Comp Cams is as they had a known issue with a batch of these springs and it appears that my springs fall in that time frame. Regardless, with the time passed and the milage on them, I would doubt if they (CC) would offer any coverage for me.
Agreed, having go fast cars involves a higher risk of breakage regardless of the brand of car. It’s just that these engines have certain quirks and difficulties as well as a limited supply of aftermarket parts for them. While aftermarket R&D for these engines ended years ago, R&D for LSx engines is going strong considering GM still has years of use of these engines on the books. Going to an LSx car opens up a whole new world of performance parts. Going to a 71 Monte moves me to an old school small block. Plus, half the engine’s not buried under the cowl.
This is all putting the cart before the horse. In a week or two, I’ll be pulling off the heads and evaluating the full scope of the damage. If one bent valve and a set of springs is all that’s needed, I’ll hang on to the thing.
12-27-2008, 09:45 AM
#42
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LS1EDDIE, you've dealt with AI and I'm sure you know as I do, they're stand up guys. If they need to stand behind anything, they will.
The CC spring problems aside (that surely affected any shop using them), I would still give the boys at Advanced Induction an A-number one rating.
The CC spring problems aside (that surely affected any shop using them), I would still give the boys at Advanced Induction an A-number one rating.
12-27-2008, 01:26 PM
#46
Paul, you should consider sending your heads as they are (assembled) down to us. That way, the same people who assembled them 35k ago can compare measurements & freshen as is necessary. At that mileage your setup may need it.
I do not recall seeing a blue stripe on your photo which would be indicative of the old "comp" 918's. Of course, after that many miles the paint could have eroded. We went directly to PAC approximately a year before everyone began talking about their product online. Our transition to dealing directly with PAC coincided with Comp's transition away from PAC. This was done as an attempt to stick with US manufacturers, not because of any issues with either product. The ill fated run of 918's would come later down the road. In any regard, whether your "918" was "Comp" or "PAC" is obviously beside the point after ~35k miles. It could not be more clear that the springs were not from the "bad" run of Comp 918's because of the mileage they have lasted. At the price point they were both sold at, you are only going to get X wire with Y operations applied to it, and Z level of inspection from either manufacturer. The "bad" ones with wire inclusions etc. are typically going to fail in short order (very low mileage, rapid load/rate loss followed by failure).
In our opinion, everyone on the forums should understand that none of these springs should be relied upon for that kind of mileage in most applications. We have put a great deal of time and money into "insuring" the valvetrain when this grade of spring is used via custom lightweight valves, milder lobes, and going to the 918's big brother designed for heavier BBC components. Our LT1's have been sold with nothing but our custom light valves & the larger 1220's for years now.
With the majority of lobes we suggest that everyone swap out any of the Comp or PAC springs at 15-20k. At a minimum the spring pressures should be checked every 10-15k. This is standard preventive maintenance for any top-end. As you increase the quality of the spring (we offer upgrades), the intervals can be extended. Conversely, if you are a road racer or specifically ask for more aggressive drag race oriented lobes then we'd recommend shortening the service interval.
Regarding yours specifically, it is worth consideration that the spring itself may not have simply failed on it's own. With multiple failure points it is possible that it was broken by contact with other components. Presently all that can be determined is the effect (broken spring, lock, beat up rocker, etc.), not the cause. While track performance numbers can vary significantly, if the dyno numbers and track times listed in your signature were with heads and even a small/mild cam something may have been off from the beginning. Definitely send an email our way to get an estimate for freshening up your set of heads & valve replacement after New Years. They could probably use guidework, a valvejob, milling, etc.
We'll be back in the shop after New Years. Have a nice Holiday, guys!
I do not recall seeing a blue stripe on your photo which would be indicative of the old "comp" 918's. Of course, after that many miles the paint could have eroded. We went directly to PAC approximately a year before everyone began talking about their product online. Our transition to dealing directly with PAC coincided with Comp's transition away from PAC. This was done as an attempt to stick with US manufacturers, not because of any issues with either product. The ill fated run of 918's would come later down the road. In any regard, whether your "918" was "Comp" or "PAC" is obviously beside the point after ~35k miles. It could not be more clear that the springs were not from the "bad" run of Comp 918's because of the mileage they have lasted. At the price point they were both sold at, you are only going to get X wire with Y operations applied to it, and Z level of inspection from either manufacturer. The "bad" ones with wire inclusions etc. are typically going to fail in short order (very low mileage, rapid load/rate loss followed by failure).
In our opinion, everyone on the forums should understand that none of these springs should be relied upon for that kind of mileage in most applications. We have put a great deal of time and money into "insuring" the valvetrain when this grade of spring is used via custom lightweight valves, milder lobes, and going to the 918's big brother designed for heavier BBC components. Our LT1's have been sold with nothing but our custom light valves & the larger 1220's for years now.
With the majority of lobes we suggest that everyone swap out any of the Comp or PAC springs at 15-20k. At a minimum the spring pressures should be checked every 10-15k. This is standard preventive maintenance for any top-end. As you increase the quality of the spring (we offer upgrades), the intervals can be extended. Conversely, if you are a road racer or specifically ask for more aggressive drag race oriented lobes then we'd recommend shortening the service interval.
Regarding yours specifically, it is worth consideration that the spring itself may not have simply failed on it's own. With multiple failure points it is possible that it was broken by contact with other components. Presently all that can be determined is the effect (broken spring, lock, beat up rocker, etc.), not the cause. While track performance numbers can vary significantly, if the dyno numbers and track times listed in your signature were with heads and even a small/mild cam something may have been off from the beginning. Definitely send an email our way to get an estimate for freshening up your set of heads & valve replacement after New Years. They could probably use guidework, a valvejob, milling, etc.
We'll be back in the shop after New Years. Have a nice Holiday, guys!
I need an edjamication
12-27-2008, 02:23 PM
#48
Advanced Induction,
What makes you guys like the 1220 spring over the 1218 or 1518? With the larger diameter it is heavier and requires cutting the spring pockets. Is it just the added spring pressure leads to a longer spring life and durability?
I noticed you guys use Manley pro flo valves. Do you use standard 11/32 valve stems? If so have you ever considered moving to 8mm? The valves are lighter, smaller, and will pick up flow. You could bush the guides or install new ones. I'm sure you get a lot of heads in that you have to replace the guides on. If so why not make the move?
I noticed you guys port All Pro LSW 12* heads. I had a set of their 15* heads and am looking at getting another set of bare castings soon. Do you have a CNC program for those? If so is the cost associated with the machine work only the same as what you have posted for your factory castings?
Thanks
What makes you guys like the 1220 spring over the 1218 or 1518? With the larger diameter it is heavier and requires cutting the spring pockets. Is it just the added spring pressure leads to a longer spring life and durability?
I noticed you guys use Manley pro flo valves. Do you use standard 11/32 valve stems? If so have you ever considered moving to 8mm? The valves are lighter, smaller, and will pick up flow. You could bush the guides or install new ones. I'm sure you get a lot of heads in that you have to replace the guides on. If so why not make the move?
I noticed you guys port All Pro LSW 12* heads. I had a set of their 15* heads and am looking at getting another set of bare castings soon. Do you have a CNC program for those? If so is the cost associated with the machine work only the same as what you have posted for your factory castings?
Thanks
12-28-2008, 02:43 PM
#50
Very good words from AI, thanks guys for addressing this.
Folks following this at home, AI’s response here is indicative of a company that keeps tabs as to what’s going on and cares enough to respond in a mature and businesslike manner. These are signs of a good company. Sorry to say, I’ve experienced more than my share of bad companies. AI is run like I try to operate my business.
It looks like I got my head/intake/valvetrain package from AI January of 2006. I found the invoice. I'm not exactly sure of which valve springs were included as they're listed as:
"High Performance Ai .570" Lift Spring Kit With Machined & Hardened 4130 Steel Components"
They are beehive springs, no paint stripes exist on them now, I don't recall if they ever had stripes on them.
I’m not yet sure if I’ll take AI up on their offer to re-work my heads, I think I’d rather have my local high performance machine shop work on them. I’ve been dealing with them for over twenty years and the reason I went with AI is their experience and proven results with the LT1 heads and intake. Few shops really excel in the intricacies and quirks of the LT1. The CNC head work has been done and repairing the bent valve and replacement of the springs/testing can be done by any competent shop.
Unrelated, my shop was a bit disappointed and miffed as to why I went to a far away shop despite our long term good relationship. They understood after I explained that AI was well experienced and highly recommended as a LT1 engine specialist.
Of course, this may all be moot if I pull the head and find a busted piston.
Folks following this at home, AI’s response here is indicative of a company that keeps tabs as to what’s going on and cares enough to respond in a mature and businesslike manner. These are signs of a good company. Sorry to say, I’ve experienced more than my share of bad companies. AI is run like I try to operate my business.
It looks like I got my head/intake/valvetrain package from AI January of 2006. I found the invoice. I'm not exactly sure of which valve springs were included as they're listed as:
"High Performance Ai .570" Lift Spring Kit With Machined & Hardened 4130 Steel Components"
They are beehive springs, no paint stripes exist on them now, I don't recall if they ever had stripes on them.
I’m not yet sure if I’ll take AI up on their offer to re-work my heads, I think I’d rather have my local high performance machine shop work on them. I’ve been dealing with them for over twenty years and the reason I went with AI is their experience and proven results with the LT1 heads and intake. Few shops really excel in the intricacies and quirks of the LT1. The CNC head work has been done and repairing the bent valve and replacement of the springs/testing can be done by any competent shop.
Unrelated, my shop was a bit disappointed and miffed as to why I went to a far away shop despite our long term good relationship. They understood after I explained that AI was well experienced and highly recommended as a LT1 engine specialist.
Of course, this may all be moot if I pull the head and find a busted piston.
03-29-2009, 05:23 PM
#53
damn that sucks. any plans to rebuild? i know when i blew my motor the first time it took me like 3 months to pull the motor. just couldnt get up enough to mess with it.
03-29-2009, 05:28 PM
#54
I can't tell if the bore is damaged or if it is reflections of the piston.
If you want a single stock piston I have some spares.
What casting is the head, I know a junkyard north of me that has a single LT1 aluminum head for sale. I have no idea if your's is repairable.
If you want a single stock piston I have some spares.
What casting is the head, I know a junkyard north of me that has a single LT1 aluminum head for sale. I have no idea if your's is repairable.
