bbc exhaust valve rotator eliminators
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bbc exhaust valve rotator eliminators
hello all,
i am putting together a pair of oval port "049" heads for a mild hydraulic roller street/strip car. the problem i am having is when setting valve spring heights my exhaust rotator eliminators are too thick. they are .300" and are too thick by .040" and my installed height would be 1.835" instead of 1.875".the intake valve spring heights are all good at +- .010". the springs are Howard Cams #98636 with 130@1.875 and 330@ 1.300. i don't have access to a lathe to turn .040-.060" off the bottoms of the hardened spacers so my question is can i stack 3 .060" shims under a .060 spring cup and then final shim to the expected install height? i believe the i.d. of the shims and spring cup are .640" with 1.687" o.d. and set up for 1.550" springs, mine are 1.514". i believe these will locate off the guide and prevent the spring from moving but i would like to hear answers from people with more experience than myself. thanks in advance for any replies, they would be greatly appreciated.
thanks, gary
i am putting together a pair of oval port "049" heads for a mild hydraulic roller street/strip car. the problem i am having is when setting valve spring heights my exhaust rotator eliminators are too thick. they are .300" and are too thick by .040" and my installed height would be 1.835" instead of 1.875".the intake valve spring heights are all good at +- .010". the springs are Howard Cams #98636 with 130@1.875 and 330@ 1.300. i don't have access to a lathe to turn .040-.060" off the bottoms of the hardened spacers so my question is can i stack 3 .060" shims under a .060 spring cup and then final shim to the expected install height? i believe the i.d. of the shims and spring cup are .640" with 1.687" o.d. and set up for 1.550" springs, mine are 1.514". i believe these will locate off the guide and prevent the spring from moving but i would like to hear answers from people with more experience than myself. thanks in advance for any replies, they would be greatly appreciated.
thanks, gary
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Re: bbc exhaust valve rotator eliminator
I would get a cutter to take .040" out of the heads seats or have a shop do the same.
The drill powered cutters are about 95 bucks before shipping and I think that most shops will get 35 to 45 bucks per head to do the same .
The drill powered cutters are about 95 bucks before shipping and I think that most shops will get 35 to 45 bucks per head to do the same .
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Re: bbc exhaust valve rotator eliminators
Just use a simple low cost set of hardend +.050" valve locks. Your retainers move up .50" ,problem solved.
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Re: bbc exhaust valve rotator eliminators
Thanks for the replies.the machinist I'm using says he might hit water if he cuts .040 off the spring pockets and so far I haven't been able to locate +.050" retainers for a 3/8" valve stem. Anyone with experience know how much the spring pockets can cut before there is a problem? Thanks, gary
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Re: bbc exhaust valve rotator eliminators
I have been informed that Comp Cams makes +.050" 10 degree valve locks for a 3/8" valve and that this looks to be the answer to my dilemma. Thanks , gary
Re: bbc exhaust valve rotator eliminators
Isky makes a roto coil eliminator that is .050 thinner than the POS comp eliminator. We cut the comp eliminator often in the lathe.
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Re: bbc exhaust valve rotator eliminators
That would work a little better than the .050 locks. Do you have a part number the Isky shims? Thanks, gary
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Re: bbc exhaust valve rotator eliminators
I found the Isky part #390-rc but they list that as .300" thick same as the Comp Cams part .do they run smaller as measured? Thanks,gary
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Re: bbc exhaust valve rotator eliminators
I just put together a set of 781 heads and had a similar problem. The comp 911-16 springs i purchased were way stronger than they were supposed to be. Possibly boxed wrong? Anyways with stock length competition products valves i could not get the 1.900 installed height. I needed another .100 and yes i should have just bought +.100 valves. I ended up having the machine shop cut .050 off the rotator eliminators, cut .050 out of the intake spring seats and use the .050 offset keepers. It all cost me an extra $400 . By the way there isn't much valve stem sticking above those .050 offset keepers. The engine is running now and working fine and i never hit water with cutting the spring seats. That extra $400 i spent put the total investment into the 781 iron heads at $1830. Not very far from a pair of Edelbrock E-street BBC heads (talking in canadian dollars).
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Re: bbc exhaust valve rotator eliminators
A helpful source for a lot of cylinder head and valve train parts is PEP -Precision Engine Parts in Las Vegas. Many times if its not on the shelf, they eill make it for you.
Keep them in your source files. JMO
Keep them in your source files. JMO
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Re: bbc exhaust valve rotator eliminators
Sorry,
Www.precisionengineparts.com
Www.precisionengineparts.com
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Re: bbc exhaust valve rotator eliminators
What are rotator eliminators? Why would you want the valve to not rotate?
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Re: bbc exhaust valve rotator eliminators
I got into this and found out that BBC valve springs have two installed heights!
Old, early at 1.88" and later, newer at 1.80" so please keep this in mind.
I have the 1.550" dia. Manton valve springs, (from Comp. Products), on my heads along with the +.050" locks because I installed an old CC 282S solid cam and wanted to drop my seat pressure down from about 135 pounds to more like 125 pounds is all.
pdq67
Old, early at 1.88" and later, newer at 1.80" so please keep this in mind.
I have the 1.550" dia. Manton valve springs, (from Comp. Products), on my heads along with the +.050" locks because I installed an old CC 282S solid cam and wanted to drop my seat pressure down from about 135 pounds to more like 125 pounds is all.
pdq67
Re: bbc exhaust valve rotator eliminators
Yes .050hammerdamage wrote: ↑Wed Dec 13, 2017 10:26 am I found the Isky part #390-rc but they list that as .300" thick same as the Comp Cams part .do they run smaller as measured? Thanks,gary
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