Internal Help Needed!!
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Teching In
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Internal Help Needed!! Had a bent valve today! It was the exhaust valve on cylinder 2. I recently installed a trex v2 cam and pp stage 2 heads with 2.055 and 1.57 valves and 59cc chambers and stock head gaskets. I did no fly cutting, but I checked ptv clearance and it was ok. Was it valve float? I thought it may be since the intake valve did not bend. I am using 7.4 pushrods, comp pro mag lifters (which I dropped in as OEM replacements), stock rockers, and the patriot gold springs and retainers. Any help is appreciated!! My first h/c swap and I am going nuts!!! 
Your first problem is that you used magnum lifters as a stock replacement with stock preload when the preload should be .003 on those lifters. magnums are not a OEn replacement lifter the preload is different.
What size cam are you running and what heads? What was your PTVC when you measured it and did you use a solid lifter whne you took the measurement?
What size cam are you running and what heads? What was your PTVC when you measured it and did you use a solid lifter whne you took the measurement?
Thread Starter
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My cam is a trex 242/248 608/612 110 lsa. I first installed 7.45 pushrods and when I rotated the assembly it was close so I changed to 7.4s. I installed patriot stg 2 assembled heads with 2.055 intake and 1.57 exhaust valves 59cc chambers and stock gaskets.
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Originally Posted by bwil6488
the rocker is not touching the valve... could it be just a broken valve spring???
Also you should not have been running that cam with those big valves and 59cc heads without flycutting.
Last edited by brad8266; Apr 2, 2007 at 07:03 AM.
Originally Posted by bwil6488
My cam is a trex 242/248 608/612 110 lsa. I first installed 7.45 pushrods and when I rotated the assembly it was close so I changed to 7.4s. I installed patriot stg 2 assembled heads with 2.055 intake and 1.57 exhaust valves 59cc chambers and stock gaskets.
Sounds like you jacked up that install pretty good, just tear it all back apart and do it right this time. If PTVC isnt correct then you run a thicker head gasket, change cams, change heads, or flycut.
Once again i will ask you how much PTVC did you have when you measured it?
Once again i will ask you how much PTVC did you have when you measured it?
Thread Starter
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I don't remember the measurement. I'll have to pull it apart and check it all out again. I talked to a few people and the told me I might just have a broken valvespring and that is why the rocker is not touching the valve. I'm gonna pump up the cylinder with air and check it out. If it was ptv clearance, why would the exhaust valve bend and not the intake? If it was valve float, wouldn't it have been the intake valve? I hope it is a spring.
Originally Posted by bwil6488
I don't remember the measurement. I'll have to pull it apart and check it all out again. I talked to a few people and the told me I might just have a broken valvespring and that is why the rocker is not touching the valve. I'm gonna pump up the cylinder with air and check it out. If it was ptv clearance, why would the exhaust valve bend and not the intake? If it was valve float, wouldn't it have been the intake valve? I hope it is a spring.
What kind of springs, or there could have been a weak one too
There are pro stock cars running almost NO clearance, but they change springs every pass, so there is always that possiblility of a weak one that floated..
There are pro stock cars running almost NO clearance, but they change springs every pass, so there is always that possiblility of a weak one that floated..
Originally Posted by nmp27
There are pro stock cars running almost NO clearance, but they change springs every pass, so there is always that possiblility of a weak one that floated..
