Supercharged Frankencar; Dem Throttle Responses and Typical BS
#45
I'm having a hard time following you guys on this one (and its not because I'm here to hate on the sc, I actually had one myself recently), but how is the supercharger failing not a supercharger issue?
I mean if it ingested something then sure, but other than that, its a self contained, self oiled unit....
I mean if it ingested something then sure, but other than that, its a self contained, self oiled unit....
#46
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I'll throw it out there that the blower overheated, the rotors expanded and touched the fore and aft parts of the casing.
BTDT....
BTW, Dual throttles don't help this issue in the slightest as they cause the blower to run quite a bit hotter. Particularly if they're not perfectly balanced.
#47
I'm having a hard time following you guys on this one (and its not because I'm here to hate on the sc, I actually had one myself recently), but how is the supercharger failing not a supercharger issue?
I mean if it ingested something then sure, but other than that, its a self contained, self oiled unit....
I mean if it ingested something then sure, but other than that, its a self contained, self oiled unit....
Sure, because nobody has ever had a turbo fail. (I actually just replaced one)
I'm just saying that the comedy of errors isn't caused by supercharger in this case.
#48
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I don't think the blower overheated since I still could touch it after coming off the track. Need to get a better thermometer than "ow it hurts must be hot." Either way I plan to pull it today and look at it.
#51
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So dived a bit into the car. Started off checking the blower. Spun freely. I took the rotor pack out and it looked as good as when I assembled it so doubt the boost issue was blower related. Noises in the blower may be a bearing. Need to investigate that further.
Only leak I could find was the BOV which did not want to actuate either. My BOV sits upside down on the IC so I found the leak by filling the IC with water and watching for drips. Possible source of my 7 psi leak.
The bad news is the motor. Decided to do a compression test so idled the car until up to temp. 150-172-165-170 which is a bit down from the 185 all across after it was broken in. Pressurized number one to see why compression is lower than the others and I have leaky intake valves on that cylinder. Checked it against number four which I could not pressurize since it just spun the motor. So boo
Only leak I could find was the BOV which did not want to actuate either. My BOV sits upside down on the IC so I found the leak by filling the IC with water and watching for drips. Possible source of my 7 psi leak.
The bad news is the motor. Decided to do a compression test so idled the car until up to temp. 150-172-165-170 which is a bit down from the 185 all across after it was broken in. Pressurized number one to see why compression is lower than the others and I have leaky intake valves on that cylinder. Checked it against number four which I could not pressurize since it just spun the motor. So boo
#54
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Finally got time to do a proper leakdown test. Leakdown on one was 70% cold on number one with very audible leaking from the intake valves. I rechecked compression and it was 120 cold. I then added oil and still 120. I then took the valve cover off and checked the lash on the number one intake valves. One was in spec and the other I could not get any feelers under. Decided to take the cams out to get around the lash issue and redo leakdown. Results were 18%-10%-6%-4% still with some audible leakage from the valves.
The cheap bastard part of me wants to reset the lash and go but I have a feeling there may be bigger issues. I find it odd that on the same cylinder the lash stayed in spec for one valve and not for the other. My concern is something may have happened to the valve or seat which then allowed it to sit higher up. I am thinking the next step may be to pull the head and see what is up.
The cheap bastard part of me wants to reset the lash and go but I have a feeling there may be bigger issues. I find it odd that on the same cylinder the lash stayed in spec for one valve and not for the other. My concern is something may have happened to the valve or seat which then allowed it to sit higher up. I am thinking the next step may be to pull the head and see what is up.
#55
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So the problem was with the intake valves pounding themselves to death. The exhaust were fine.
Head is now rebuilt and going in soon. Also now has supertech dual springs in it and deshrouded valves. I am curious to redyno it since I figure the valves were already starting to go when I got the last dyno.
Also learned that my exhaust is smaller than I thought when I measured it to double check the size. I have a 11+ year old racing beat that my car came with and apparently they were 2.25" instead of the current 2.375. I am going to sell it and build a 2.5" for it which based of off how the car performed on the dyno this should help a lot. Just removing the dyno sniffer picked up 5 hp.
Head is now rebuilt and going in soon. Also now has supertech dual springs in it and deshrouded valves. I am curious to redyno it since I figure the valves were already starting to go when I got the last dyno.
Also learned that my exhaust is smaller than I thought when I measured it to double check the size. I have a 11+ year old racing beat that my car came with and apparently they were 2.25" instead of the current 2.375. I am going to sell it and build a 2.5" for it which based of off how the car performed on the dyno this should help a lot. Just removing the dyno sniffer picked up 5 hp.
#56
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I had the exact same problem this past season. Checking valve lash before Summer Nationals and noticed that one of the valves had zero lash. Pulled the head and found the exact same issue. Replaced the valves with Supertech Valves and put in stronger valve springs.....so far so good.
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I think blowing the welds speaks more about my welding ability lol. Although it cracked where cfd seemed to show what was the most restrictive part of the manifold design. The plan is to get it together for autox at ACS on the 15th. If it survives that day then run the big track the next. Figure this is the closest track to me so best to go there.