259e cam in a 107
HDF Community Team
Joined: Jun 2006
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From: san antonio
Originally Posted by bedelman
I have a good tuner that has alot of experience on the dyno and with the tts just trying to figure out the best piston to use without having to cut the heads. And yes, i am having compression releases installed on the new heads. Would the 10.75:1 pistons be good for the 85-86cc stock chamber with .045 gasket? Also i thought CP made a 10.25:1?
Originally Posted by bedelman
also the guy i been talking to about buying pistons says that he has a +3cc domed CP piston. Shouldnt this work the same as taking out 3cc's of the combustion chamber by decking the heads?
Both situations you outline above, i.e., a 3cc domed piston or the 10.75:1 piston with an 85-86cc chamber and .030" head gasket will put CCP just over 200psi and corrected CR at about 9.6. Pushing the envelope for me on a "street" motor but it should be a runner. You could drop both CCP and corrected CR into a more "comfortable" zone with a .040" head gasket but that's your call.
HDF Community Team
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From: san antonio
Originally Posted by djl
Both situations you outline above, i.e., a 3cc domed piston or the 10.75:1 piston with an 85-86cc chamber and .030" head gasket will put CCP just over 200psi and corrected CR at about 9.6. Pushing the envelope for me on a "street" motor but it should be a runner. You could drop both CCP and corrected CR into a more "comfortable" zone with a .040" head gasket but that's your call.
Last edited by djl; Jun 27, 2016 at 07:22 PM.
Road Master
Joined: May 2008
Posts: 1,196
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From: connecticut
Nope. Final drive on a 2010 FLHTCU is 32/68. This SE259 cam dyno bike lists a 31 pulley that must have been installed (it's listed in the dyno run details). So minus 3% from that sh^tty SE cam sets results. plus decked heads and still so so lower end. give me a break.
Road Warrior
Joined: May 2011
Posts: 1,956
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From: florida
Rate of acceleration would increase with the less tooth pulley being a torque multiplier. I have seen that mod increase peak tq in certain applications on a dyno but never hp. But technically yes number should not increase but come on sooner.
That SE cam still sucks down low.
HDF Community Team
Joined: Jun 2006
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From: san antonio
Not a big fan of HD cams, although the SE204, 211 and 259 are decent runners if setup properly. Two charts in this thread showing 100TQ line crossing between 2250 and 2500 rpms; far from "sucking" IMHO. Are there better aftermarket cams? Absolutely, but for any variety of reasons some prefer to stick with the HD branded stuff. Pretty plain to see that the MoCo is upping their game when it comes to performance with the successful intro of the bolt in 110" and 117" kits which are doing very well and putting up some decent numbers. We will see what the 2017 models bring but I expect to see some major changes in '17 and '18; the TC motor is getting long in the tooth............
HDF Community Team
Joined: Jun 2006
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From: san antonio
That has been the experience in my area. There are four dealerships within a 25 radius in my area and two of the dealerships have dynos. There is one of the best tuners in the country within that radius and 75% of the tunes he does are re-tunes of bad dealer tunes. He used to do a dyno day on the second Saturday of the month; $30 gets a couple of pulls, a chart and some suggestions on how to improve the tune; no tuning. Most of the guys that show up are guys that have had builds done at a local independent or a dealer and are not happy with the tune and think the motor should perform better; they are usually right. Dealerships do not have a good track record of tuning dealer builds which is the point I think you are making.
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HDF Community Team
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From: san antonio