Just so no one's confused There was no issue that I can see with the guide The only reason you see the croil around there is because of the way it drip down the port onto it because the head was upside down..

Also yes cast iron will last a lot longer than bronze but the bronze will hold more oil than the cast iron therefore better lubrication of the stem..

 

Are you referring to the 6700 RPM limiter or the 5900 RPM lender? Because even though it was set to 6700 I consistently hit 6850 on my shifts.. I got this information from my Power Vision data logging..

The most important thing I need to do is to control throttle coming off the line I have seen that I've been in the 70% and above throttle range coming off the line which would indicate me having quite the difficult time keeping the front end on the ground..

So I did take everything apart and and cleaned it up the best I could... I use the head itself to determine whether or not the valve is bent at all and by rotating it by hand in the cylinder head You can see that the valve is not eccentric in the video below.. So with that and leakage I would say yeah it's definitely bent..

 

I don't believe that. I suspect it depends on the bronze used.. HRFB heads likely have AVnV parts in them.. The guides on these wear very well. I had a set of Syke ported heads with AVnV valves in them, 180 lb springs and put maybe 10000 miles on them in a 02 RK with the WT26 and W8 with then swapped the heads over to 07 EGC and put another 55000 on them with a SnS570, W5, Syke Dick Ripper, and W777 cams. Pulled the valves out of the heads and they were worn maybe 1/2 thou..

I've not seen Rowe or Kibblewhite cast iron wear that well with the same nitrided valves.. I did see a set of guides in SnS Superstock with iron guides wear really well with a 640 lift cam after over 50000 miles.. Stock SnS valves.

I think some of the issues are in how you set them up.. I have a set of Pev Perf heads that had AVnV stuff and some horrendous valve springs that wore the stems and guide down but I didn't assemble the parts.. The AVnV stuff needs solid carbide reamers to get the proper fit..

BTW HRFP saying that high lift is unreliable is a little off. I got over 50K with 640 lift.. Springs were shoot tho.. My FXDX had 40000 miles on it when it blew up. Kibblewhite guides and guides are at the limits.. Springs were shot on it also..

 

So got a pic of the piston?

You clayed on assy?

 

No no pic of the piston because everything was pretty carboned up and if I would have had valve to piston contact it would have been seen somewhere and I didn't see any trace of that at all anywhere, so I didn't bother with that or even any witness marks on the edge of the valve..

I do know that the seats were sunk really deep into the heads to make sure my valve the valve clearance would be okay and yes I did clay these upon original installation and I had .086" valve piston.. I also opened the radius of the valve relief on the Pistons to confirm that there would be no contact there as well...

Here's another pic showing the leakage down through the valve and seat after everything was cleaned up..

When I get the extra money I'll send the heads up get them repaired and go from there... I probably won't be till next year..

So till then I'm just going to run stage II heads and the woods 888 cams

 

So the question is, "How did it bend?"

 

The only thing I could imagine is that when the rocker support plate broke that that end of the rocker shafts actually lifted changing the geometry on the valve and increasing the side load, that's about my only explanation..

 

If that were the case, wouldn't the valve be sticking in the guide? The other end of the valve would be bent..

 

Yes I totally agree..

 

I hate to say it but this is the price you've got to pay to play. When you push things you can make the power but the reliability goes down the drain. Is it fun...... Hell yea is it expensive Hell Yea.