I am planning on a 95" mild build for my 05 FLHRCI. I have a set of jugs bored to 3.875 and a set of CP Pistons (M0517), +4.6cc. Am planning on installing an Andrews TW26a cam.

I have used the compression calculator and found that my compression will be to high (193#). I do not know the CC of the heads, am planning on getting them budget ported (used 85cc for head volume). Can I get the piston's milled to attain 175 - 180 CR, or should I purchase a new set of pistons.

I am looking for a reliable build, any input is appreciated!

 

I would not worrie about that until after your heads have been CCed and you know for absolute sureness what your volumes are.

i run that same piston in my bike, im at 83 CCs with a way bigger cam than yours and im at just under 200 lbs of cranking cylinder presure.


If your injected you will need to have a means of pulling a little timing out maybe just 5 degrees or so.

the other issue of major importance is getting your quench set properly around .030 thou or so. get the proper gaskets nessary for the job.

this is half the battle to not having pinging issues!

belive me, you want that cylinder presure, thats your torque, but the timing needs to be managed.

 

sell me those pistons and buy the ones you want.

 

take txtec up on his offer or get the domes machined off

 

I would reconsider your cams before backing out of your pistons.

If your already planing headwork, get some upgraded springs and run the Firestorm cams that I have, and you will be at your desired cylinder presure, and have boatloads more power.

 

Plan on designing build around tw26a cam's! I may be pulling a trailer in the future so I am looking for the torque down low. Once I get the heads ported and CC'd I will know where I am at compression wise. Not looking for maxxing out the motor, just want to build for more torque than I have now. Thank's.

If compression is high enough to cause detonation, I want to avoid it.
I have race tuner installed and I hope to have it tuned properly.

 

You can have detonation at even relatively low compression ratios and CCP. The key is the tune, but sometimes you defeat the build if the components all do not work together, then you are pulling out timing just to eliminate detonation rather than timing to get the power you are after. I am at close to 220ccp, starts easily, good mileage tons of torque and no detonation. Tuning is the key.

 

Dalton,

With the build that I am doing, with a proper tune, will the tw26a cams at a 190#CCR work ok. The cams say they are designed for stock compression. I appreiciate your feedback. Thanks.

 

Dalton and I run the same cams as well. But hes using chain drive I think.

 

190 is a lot for that cam .
trade him those pistons and go with flat tops that would be a better choice