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Flycutting flat tops for SE Heads?

1730 Views 8 Replies 5 Participants Last post by  nidan
I was reading over on the HD Tech forum that they recommended clearancing (flycutting) the SE flat top pistons when being used with the SE performance heads. Harley does list this as a compatible set , has anyone here run into problems? Would the head gasket thickness effect this ?

I haven't had the motor assembled yet , and can go with the SE forged for the build (PN 22868-00) . I stayed away from them because of the opinions on forged pistons and the higher compression. My cam will take the 10.5:1 .

Opinions gladly welcome , it will be after tax time before I can get it assembled , so there is time to switch out the pistons.
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The pistons that need fly cutting are the cast se h/c piston. No reason to have to cut the f/t unless you are running huge lift
Phew ! Thanks a million Steve, I was hoping I was safe.
fly cut pistons

So if I want to use SE flat top #22851-99A I will not have to cut for clearance if I go with 211 cams and SE per heads?? Is this correct??
Gools88 , those are the flat tops I have (#22851-99A ) , so HDWrench says OK. Your build will be similar to mine , except for the gear drives.
IF you are running SE flattops and heads with oversize intake valves like the SE performance heads, and a .055" head gasket, you will probably be Okay with the stock valve pocket. If you choose to run a thinner head gasket, like the .030" Cometic to get the right quinch, you better open them up. I've seen pics of where the piston and intake have contacted.
For the thinner head gasket combo the intake pocket needs to be opened up to within .275" of the edge of the piston. Not deeper, just wider. If you want to have someone do this for you, SBC charges $40 a set.
They are doing mine right now. I'm not chancing a teardown and new valves for $40.
If you don't think this is necessary, call SBC for yourself. 800-597-0922
Joe, thanks for the insight. I received a reply from one of the guys on the HD Tech forum who did the same build I've got . "I did not have to clearence pistons. I am using Cometic .030 gaskets. I have 10.25:1 compression ratio" He's run the heads with two sets of cams so far ,no problems, I'm checking on how many miles on his build(s). The stock HD gasket is .05 , I'm thinking of splitting the difference with a Cometic .040
gools88 said:
So if I want to use SE flat top #22851-99A I will not have to cut for clearance if I go with 211 cams and SE per heads?? Is this correct??
I have a dumb question. Why go through the time to put in chain drive cams when they cost you about 3 to 4hp over gear drive cams?
I went with gear drives not only for thier better efficiency , but also for durability , seen enough of the cam chain tensioner horror stories and pics.
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