03-20-2013, 01:02 PM | #1 |
pro-jackstand racer
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Problem with new valvesprings/retainers CRANE
Ok guys, I've had these springs/retainers etc on my sons motor for AWHILE (still on engine stand) I had the machine shop do the work on the heads and install the new springs. The heads are GT40s from an Explorer.
Problem is this: All of the retainers on the exhaust valvesprings hit on the bottom of the rockers (stock crane "cobra" rockers, I believe I got from someone on here but don't remember) before the tip of the rocker hits the top of the valvestem. I noticed all the exhaust springs have a shim under the springs so I went and got a valvespring tool (which works pretty well actually) and took the shim out and put the locks back in and it is still the same. I will update with some pictures as soon I can post them from my phone. Just not sure what to do with this as this is above my "paygrade"....I am pretty much just waiting on resolving this issue to put the motor/trans (needs a VB and convertor) into my son's Fairmont....
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03-20-2013, 01:34 PM | #2 |
pro-jackstand racer
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Model number on the retainers Stock Cobra rockers Difference in spring height (bad angle but you get the idea) Difference in retainers These are the beehive springs that were recommended to me at Summit, brand new, never run, the valves "far as I know" are the stock ones 11/32" stems, as you can tell the intake and exhaust have different retainers The tops of the valvestems are all even, it's the tops of the springs that are NOT and are causing the interference with the rockers.... Any help would be appreciated.... Brad
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~~~~~~~~~~~~~~~~~~~~~~~~~~~ Last edited by ncontt; 03-20-2013 at 01:36 PM. Reason: added picture |
03-20-2013, 03:05 PM | #3 |
3v's are slow
Join Date: Dec 2004
Location: Here and There
Posts: 17,152
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Is there a difference in the locks?
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2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy |
03-20-2013, 03:16 PM | #4 |
pro-jackstand racer
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I think....Let me check, but ya if you just look at them they look different to me! I'll check and see if I can find the spring (kit) on summit's site...
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And God created Neil Peart so that lightning would make sense to the world.
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03-20-2013, 03:50 PM | #5 |
Dazed and Confused
Join Date: Mar 2009
Location: Northport, Al
Posts: 778
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The GT-40 heads have different stem heights for the exhaust and intake valves, why I don't know (beancounter), you can put lash caps on the short ones and that should solve your problem.
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Proud owner of 93 Cobra #1928 306ci Forged flat tops, Windsor Sr iron heads, FMS X-303 cam, OE Cobra upper and lower, 65mm tb, 70mm maf, 24lb injectors, BBK shorties, Summit H-pipe and Flo-bastards |
03-20-2013, 07:45 PM | #6 |
3v's are slow
Join Date: Dec 2004
Location: Here and There
Posts: 17,152
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Was this specific to the P heads? I don't recall my cobra heads being that way
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2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy |
03-21-2013, 12:24 AM | #7 |
Senior Member
Join Date: Apr 2005
Posts: 895
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I used to run gt40 heads back in the day, and I measured my valves and they were the same length... and I wouldnt advise to NOT running lash caps...thats a worse disaster waiting to happen.. They do have a diff style of lash caps that you can run! are you sure the installed heights are the same?
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03-21-2013, 07:06 AM | #8 |
3v's are slow
Join Date: Dec 2004
Location: Here and There
Posts: 17,152
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I think the locks are the problem. I always use the same locks on all valves on the heads I have run
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2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy |
03-21-2013, 07:48 AM | #9 |
pro-jackstand racer
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after doing some research, it is because the groove in the exhaust valve is lower than the groove on the intake valves. Valves are stock valves. Install height now is 1.99" (top of the head where spring sits, to the top of the spring/bottom of retainer) I "believe" they call for an installed height of 1.94" therefor requiring that the spring come down another .o50" which would give me the room I need on the rockers....I "think"
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03-21-2013, 08:01 AM | #10 |
pro-jackstand racer
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they have offset keepers that are either + .050" or - .050" so I'm thinking I need the -.050" s
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