motor problem help.

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Nov 13, 2010 | 10:40 AM

r572cobra

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From: Mesa,az

motor problem help.

Im having problems with the car at the track,not pulling in third gear and miss firing.took it to the dyno,power is taking a dive around 5800,both with nos and na.motor 383,ls6 heads,comp cam,248/615 lift,114,patriot valve springs,fp was no lower than 58 psi,plugs looked good.dyno guy said it may be a broken valve spring,motor used to rev to 7000,with no problem.any ideas.

Nov 13, 2010 | 10:53 AM

Darkman

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From: Spring, Texas

Sounds like valve float. Assuming the plugs look okay - pull the valve covers and look at/test the springs/pushrods/etc.

Nov 13, 2010 | 01:50 PM

r572cobra

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I asked the dyno guy if it was valve float,but he said,it did look like on the on the computer,would a broken spring cause it,motor only has 5k on it.

Nov 14, 2010 | 05:59 PM

r572cobra

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all the springs looked okay,did a commpression test,every cyl. around 180.pulled 2 springs and goint to have them tested.

Nov 15, 2010 | 01:08 PM

r572cobra

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pulled all the spring,they checked good,i entered pinks on nov.20th,anybody have any ideas.

Nov 15, 2010 | 01:44 PM

TurboBuick6

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whats the pressures on your springs? Seat and open?

Nov 15, 2010 | 01:47 PM

XtraCajunSS

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What rocker arms are you using?

Shane

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Nov 15, 2010 | 05:58 PM

XtraCajunSS

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From: Baton Rouge, LA, USA

You don't have enough spring for Yella Terras with XE-R lobes. I'd put stock rockers back on it. You're problem should remedy itself.

Shane

Nov 15, 2010 | 06:01 PM

#10

r572cobra

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From: Mesa,az

i understand what you are saying,but the motor never had this problem,used to rev to 7k.no problem.

Nov 15, 2010 | 06:02 PM

#11

Whiteaw57

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Is that due to the extra weight of the yella terras? sorry if thats a dumb question i just feel like i had a lightbulb moment here

Nov 16, 2010 | 06:53 AM

#12

r572cobra

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From: Mesa,az

anybody else,running out of ideas.

Nov 16, 2010 | 07:05 PM

#13

XtraCajunSS

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From: Baton Rouge, LA, USA

Those springs are done.

Yes, it is due to the extra weight of the Yella Terras.

I know for a fact you don't have enough spring pressure for your setup.

Shane

Nov 17, 2010 | 06:33 AM

#14

r572cobra

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I order the extremes,should be here today,i dont have the stock rockers anymore.

Nov 17, 2010 | 11:40 PM

#15

XtraCajunSS

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From: Baton Rouge, LA, USA

They should get you another season. Check them often. They will not last long in your application.

Shane

Nov 17, 2010 | 11:57 PM

#16

Whiteaw57

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good luck!

Nov 18, 2010 | 10:19 AM

#17

r572cobra

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thanks,for all the help.should have it back together tonight,hope that fixes it.

Nov 18, 2010 | 10:32 AM

#18

TurboBuick6

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Hopefully that cures your problems. Make sure you install to correct coil bind. I dont know what partiot recomends but I would say about .060 from coil bind.