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New stroker noise, flexplate or other (with video)

Posted: July 7th, 2014, 12:12 pm
by knever3
This is my 4.7L stroker, I have put about 1000 miles on it since new. I have thought my flexplate was to blame but I am doubting that now. My flexplate cracked before and I sourced one from the Junk Yard since somehow it was different than mine. (The timing windows didn't line up causing a NO START) "87 renix electrical, '94 block, '96 head, '99 intake, stock throttle body right now since the one from Jeepers Creepers didn't work out.

Anyway, this is the noise I am referring to, it seems to be more than just a flexplate. A strange occurance, the other week it was 90 degrees out for one day and it was hardly noticable like it had expanded.

https://www.youtube.com/watch?v=gJ1VbtAWZrw

Re: New stroker noise, flexplate or other (with video)

Posted: July 7th, 2014, 12:53 pm
by SilverXJ
The sounds odd. Have you checked your lifter preload? But, it really doesn't sound like its valve related, at least from the video.

What happens when you rev the engine? Obviously it increases in speed, but does it get louder or quieter?

Re: New stroker noise, flexplate or other (with video)

Posted: July 7th, 2014, 2:12 pm
by knever3
When you rev it it does get louder, if you ease on the throttle in park it really clatters about 2k I think from memory. I asked the engine guy if my pushrods were the right length because that's about the only thing that I didn't have to buy new on for the rebuild. It sounded odd to me that they were still the right length. This was a different situation, I took the engine to a shop that subbed out the machine shop portion, the machine shop assembled the short block and the shop installed the head. The kicker is "someone, either the shop or the machine shop" let my block I gave them fall off the stand and broke my NVH block. They never said anything until I picked up the motor. They said we had a slight problem and showed me my freshly machined broken block. So I said "ok, I guess if you sourced another NVH block I'm still good with it." Well it's a '94 block so I was quite unimpressed. I was backed into a corner without a way out, they didn't give me any break on price or the option to source the right replacement block during the debacle. I am still regretting pushing that bad decision. It has been a long road and I am so hoping that there isn't something wrong with the motor because I don't want the stress in going back through memory lane.

Re: New stroker noise, flexplate or other (with video)

Posted: July 7th, 2014, 2:58 pm
by SilverXJ
How much was it decked? Any other build details?

When did the noise start?

I would pull the valve cover and see if anything is a odd there. You might need to run the engine with the cover off to isolate the sound.

Re: New stroker noise, flexplate or other (with video)

Posted: July 15th, 2014, 2:32 am
by BADASYJ
Any news?
I think it's valve related. Did you run a comp. test?
Like an idiot I ran push rods that were to long in my last race and it developed a miss and the same clanking sound your hearing.Mine still makes the same noise, just started it yesterday after a yr long transmission build #2 spark plug was dry fouled so I'm tearing it apart today.

Re: New stroker noise, flexplate or other (with video)

Posted: July 15th, 2014, 2:01 pm
by knever3
I have not got a chance to check the flexplate yet. I have all the paperwork for the rebuild that I got back, I still need to scan everything and upload it so you guys can see it. To be honest if I could just change the flexplate to a new one to eliminate one probability I would go straight to the shop to have them listen. I will get back with you as soon as I dig into it. I haven't ran a compression test yet, don't have one but I can rent one sometime.

Thanks for all the support guys.