460 valve spring height problem

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Apr 11, 2001 | 04:24 PM

f 250 mike

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460 valve spring height problem

I had big valves installed in my D3VE A2A heads(2.19"In.&1.76"Ex.)
Now here's my problem.
The installed height for my dual valve springs is 1.875" and I have 2.098".
The difference is .223" that I have to reduce my Installed spring height.
I can make spring shims that are .223" without causing problems?
Will shimming this much cause problems somewhere else in my valve train?

Please help I don't want to trash this new motor.

Thanks,
F 250 Mike

Apr 11, 2001 | 05:01 PM

whomrig

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From: SF Bay area

460 valve spring height problem

Hello Mike, I have to ask...are your new vales correct for your mill? If they are, then shimming .223 shouldn't pose a problem. You should check the compressed spring height and compare "stiffness" between old and new springs. If your new springs are stiffer than old by a lot, this can induce undue wear on your cam. Hope this avice helps...

Wayne

Apr 11, 2001 | 10:22 PM

f 250 mike

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460 valve spring height problem

Wayne
Thanks for your reply.
The new valves are for a 460 and are longer than the stock valves.
+.098" intake
+.059" exhaust
I don't have the old springs to compare with the new springs.
The cam spec.card says I need 120lbs.@ 1.875"closed and 312lbs.@ 1.375"open.
The springs,retaines,locks,and camshaft are from Crane. I called Crane today to make sure all my parts match and they do.
Thats about all the info I can give you until I pick the heads up and double check the shops measurements.

Thanks,
F250 Mike

Apr 12, 2001 | 07:08 PM

bb79ranch

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460 valve spring height problem

If I understand the question right, you have an additional .223" of clearance from your valve spring retainer to the valve springs' seat on the head? You are almost shimming a 1/4" that is ALOT, TOO much in fact! Remember a valve moves both up & down, but also slightly side to side.
There is tremendous side load friction on a stock valve guide with the factory valve installed height of 1.810" with weak springs, now that you are increasing this height by almost a 1/4" & using stronger springs, the valves & the guides might not be able to handle this increased side loading.
There is also another potential problem, rocker arm geometry! You will undoubtedly have to change to longer pushrods as well as making sure that the body of the rocker arm doesn't strike the valve retainer and allow a valve to drop into combustion chamber causing BIG problems. Also if you do find longer pushrods and rockers that work, look at how much further away from the head your rocker arms are located. This increased height will cause flexing of the bolts or studs and quite possibly failure in them. I hope I read the ? wrong, cause I'd hate to see someone throw money away on a problem that could be avoided!
I hope this helps in any way.

Todd
BB79RANCH

Apr 15, 2001 | 10:25 AM

dinosaurfan

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From: SW Michigan

460 valve spring height problem

Mike, some engines, like my 427 MR, have a spring seat cup under the valvespring. Mine are about 1/8" thick. You might be able to swap your retainers with crane for a different style to get the hieght the rest of the way down. The big fords are weird on valve train geometry, if you explain the problem to crane they should be able to offer some help, you are by no means the first guy to run into trouble setting up one of these engines. DF

Apr 17, 2001 | 08:43 PM

MSTRAWN

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Joined: Aug 1999

Posts: 166

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460 valve spring height problem

I am not up to speed on 460 engins but I saw that you mentioned having dual springs. If the stock springs were not duals, You may have to have the spring seats machined to let the new dual springs set further down on the head. I had to have this done to some GT40p heads that I am building. .223 inches sounds very close to what I had to have cut off of my spring seats. Just a thought to look into. Michael Strawn

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