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FE Power Forums => FE Technical Forum => Topic started by: chris_r on June 22, 2017, 07:45:22 PM

Title: I need help with exh. valve size
Post by: chris_r on June 22, 2017, 07:45:22 PM

Can i run 1.65 exh. valve in g heads on 4.050 bore?  thanks for the help

Title: Re: I need help with exh. valve size
Post by: My427stang on June 23, 2017, 08:01:12 AM

I would think so, assuming you aren't running a ton of lift.  Lots of 445s out there with CJ valves.  I run a 1.67 in a D2TE-AA head without any issue.

Years ago I played around on the bench with a C8AE head with a 1.67 and it didn't hit a standard bore on the exhaust side until the valve was well below the guide (no spring of course).  I would expect yours to be the same.  Be sure to check that and radial clearance on the pistons though, some 390 pistons have pretty small eyebrows

Title: Re: I need help with exh. valve size
Post by: CaptCobrajet on June 23, 2017, 06:41:09 PM

4.050 and 1.650 no problem.  1.600 and 4.000 okay.