Max RPM 383?

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Chevelle70
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Joined: Wed Jan 14, 2009 7:44 pm
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Max RPM 383?

#1 Post by Chevelle70 » Sat Mar 03, 2012 8:44 pm

Today during testing I took my 383 well past my shift point of 6300 to 7300 RPM. My shift light is set at 6000 for the delay effect and I never saw the light. I saw 7300 and shifted. So back in the pits I noticed clacking coming from the right bank head, the sound of loose rocker arms. Oh, not running a stud girdle at the moment but have one to put on.

So here is the question. What did I bend if anything or could vibration loosened the poly locks?

Here is the engine internals.
Eagle 4340 crankshaft.
Eagle H beam rods.
Comp cams valve train roller setup.
Mahle pistons estimating 13.1 compression.
AFR 220 race ready heads.

I think I'm okay but won't have the chance to look it over until Wednesday. I'm hoping for lose only poly locks so I can be ready for the big money bracket race Saturday. Oh yeah, gonna look into that shift light as well.

Rich

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Craig W.
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Re: Max RPM 383?

#2 Post by Craig W. » Sun Mar 04, 2012 1:25 pm

If you're bottom end is 4-bolt main (perferrable splayed caps), 7300 rpm isn't a problem.

It might have floated the valves a little, hard to say without any more info.

I'd roll the pushrods across and good flat surface and see if they're tweaked. Also, the stud girdle idea is a good one.
Craig Watson
2QuickNovas Racing
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spib
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Re: Max RPM 383?

#3 Post by spib » Sun Mar 04, 2012 5:16 pm

my 385 is built a lot like yours I have a 7500 chip in it and it sees it every run
I have shaft rockers on my afr heads
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Chevelle70
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Joined: Wed Jan 14, 2009 7:44 pm
Location: Dallas, TX

Re: Max RPM 383?

#4 Post by Chevelle70 » Mon Mar 05, 2012 3:00 am

Thanks for the replies. So nagging was the question of what was causing the clacking that I got up this morning and took a look into it.

Come to find out the the exhaust poly lock on the number six cylinder hadnt seated entirely when I assembled these AFR heads and when it did, most likely during that run, it started clacking and valve lash was lost. To make sure nothing was bent I did a compression check on all eight and all produced great compression.

I decided to go with different poly locks and will install the stud girdle. The way I got this engine setup I couldn't see 7300 rpm as a problem but you never know.

Thanks, Rich

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