FE Power Forums
FE Power Forums => Drag Week 2015 => Topic started by: jayb on September 16, 2015, 01:07:07 AM
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Today was an exhausting, brutal day at Drag Week, and I don't have time to write a full report, just a quick synopsys. I will try to fill in the blanks tomorrow. The only good news was that the car went a little faster, 8.88 compared to the 8.91 on the first day. But coming down the return road the car quit, and it turned out to be an electrical problem that took several hours to debug and repair at the track, before we could get on the road. Then at the first trip checkpoint the car started making a horrible sound, and it turned out that one of the Watts linkage bars holding the rear end in place had loosened up and extended, moving the rear end over in the chassis and forcing the driveshaft against the loop. That was also probably why the car didn't leave the same today as it had been doing at Gateway. Fortunately that one was an easy fix, but at the second check point at 9:00 PM tonight, my #5 rocker arm gave up and the engine started making all kinds of racket as a result. We had to diagnose and fix that problem with one of my spare rocker arms. Several other minor issues came and went today also. Just made the hotel at 1:00 AM, but will be at the track in the morning. I will try to write more detail with some pictures tomorrow night, assuming that I get into the hotel at a reasonable hour ::)
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Glad you made it, but sorry to hear another rocker arm problem bit you. Best of luck and wishes for tomorrow!
Joe
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Glad you were able to get back, and sorry for the troubles. It would be so much easier with an 800 inch pushrod engine LOL, but you've got to do it the hard way.
Give Freiburger the finger during the next run for us...
- Bill
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Most of those are sounding like pretty much typical "new car" problems that come up from not having a ton of laps on the car. I think you can work through them and keep moving forward. Cheering for you from the sidelines...
Rocker arms are something of an "Achilles heel" for the Cammer - you know how I approach them. If its still eating adjusters you might consider doing the conversion over the winter. FWIW - your two piece timing cover is on this year's EMC entry.
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Today is "hump day"............hang in there. Downhill after today's track time. Best of luck to you, Mr. Jay.
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Most of those are sounding like pretty much typical "new car" problems that come up from not having a ton of laps on the car. I think you can work through them and keep moving forward. Cheering for you from the sidelines...
Rocker arms are something of an "Achilles heel" for the Cammer - you know how I approach them. If its still eating adjusters you might consider doing the conversion over the winter. FWIW - your two piece timing cover is on this year's EMC entry.
Barry, while I know Jay has written about past SOHC rocker issues, why is it that they are so troublesome? Admittedly, he's pushing the spring pressure envelope here but is it lack of mass, materials, cam/rocker stands or the very low rocker ratio inherent in SOHC's?
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The elephant foot adjusters on the SOHC cannot handle high rpm - over 6,000 - for very long. The problem is the flat foot scrubbing across the valve stem/ lash cap eventually squeezes out the oil film. The resulting heat burns everything up. High spring pressure makes things worse. I've shown that you can wreck a new adjuster in less than 2 minutes sustained at 7,000 rpm.
The non-adjustables with their curved tip surface are far better at keeping the oil film intact. (The old-timers knew this, and never ran adjustable rockers at the drags.) Better yet, Barry's roller tip rockers are da bomb!
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Jay will be better at explaining all he went through yesterday, but until he gets a chance to write his blog I'll say that it was a roller that failed on his rocker arm last night, not the adjuster. Thankfully though I'll paraphrase a movie line - "He has the tools, he has the talent!" And luckily he has the spare parts ( so far ) He's heading to staging right now.
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The elephant foot adjusters on the SOHC cannot handle high rpm - over 6,000 - for very long. The problem is the flat foot scrubbing across the valve stem/ lash cap eventually squeezes out the oil film. The resulting heat burns everything up. High spring pressure makes things worse. I've shown that you can wreck a new adjuster in less than 2 minutes sustained at 7,000 rpm.
The non-adjustables with their curved tip surface are far better at keeping the oil film intact. (The old-timers knew this, and never ran adjustable rockers at the drags.) Better yet, Barry's roller tip rockers are da bomb!
Thanks Bill! Doh! I did forget your wonderful videos some time ago now of a cam doctor running the SOHC valvetrain and the smoke, holy cow, coming off the valve tip and rocker pad. Yikes!
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That Watts linkage bar might have been a big player in the nasty pull you had to deal with on the road too? In any event, enjoying your usual cataloging and taking the time to allow us to ride along on the trip. Here's to much more success and minor to no failure issues the rest of the way.