Engine modification questions
Seasoned HDF Member
Joined: Sep 2012
Posts: 6,570
Likes: 590
From: almost there
i am not tying to get into a thing with you about it but you own one bike
in a shop we address this almost every day and since 1965 i have built a couple of motors and seen the changes that have come about with the fuel we now use verses the days of 100 leaded gas
if yours works - well thats great - the buying public usually dont want to be on the razors edge when it comes to the engine they drive every day
in a shop we address this almost every day and since 1965 i have built a couple of motors and seen the changes that have come about with the fuel we now use verses the days of 100 leaded gas
if yours works - well thats great - the buying public usually dont want to be on the razors edge when it comes to the engine they drive every day
Last edited by aces&8s; Jul 7, 2014 at 02:28 PM.
Seasoned HDF Member
Joined: Nov 2006
Posts: 12,878
Likes: 5,449
From: la la land jerzey
I understand and agree with you, and the OP can make his own decision on what Cr he chooses. So as I asked you before, did your melted pistons happen because of Pinging or what caused it? Could have been ran too lean, could have been sitting in city traffic over heating or maybe any combination of neglect. Hi compression engines are not for everybody because they have special needs and special tuning and a lot of people wont keep up with it, hence the problems. It's really not rocket science to make a 10-1 work correctly and without problems, but then again it seem to be for some.
somtimes it goes like all - and sometimes its just not on its game
what we found AS you know the Evo cylinders grow and have a memory as well as having an alloy wrapped cast iron sleeve who's design was 8 to 1 compression, the cylinder was not coming back to the original shape that it was honed at with torque plates
having said that - some cylinders never did go way off it's torque plate's roundness but some do and no way we have found to tell what one will and what one wont stay round, SoOOO we dont go to that edge and we have had to eliminate that comeback issue and that is a big one -
BTW - the pistons we had talked about earlier were from other shops after all the storys they showed up and they recieved the best reliable performance available as we see it
again i am glad yours is great - jz
Thread Starter
|
Advanced
Joined: Apr 2013
Posts: 91
Likes: 2
From: Japan
Johnjzjz--I bought the Axtell cylinders and Wiseco pistons as a set--both are brand new, but I got an unbelievably good deal. What would you do? I can afford to spring for new pistons. I just had most of the other parts on hand and want to know if they would work together. Its just a shame to have everything just laying around as parts and difficult to sell because of my location. I have a small budget left over from my bike, but my wife is going to poop a cinder block if I get carried away though.
Seasoned HDF Member
Joined: Nov 2006
Posts: 12,878
Likes: 5,449
From: la la land jerzey
i hope that does not happen to the wife - you will pay for that if she does
you need to have a shop put the torque plates on the axtell cylinders
than measure the lower section of your piston to get its size
than you transfer that measurement ( the pistons ) to the bore gage before installing it into the cylinder
and from that you can tell if they are a match --- if not maybe a little honing and they become a set at the correct clearance - i would say off hand .003 to .0035 in inches
remember to keep the front and rear as sets dont mix the pieces after they have been fitted - good luck
you need to have a shop put the torque plates on the axtell cylinders
than measure the lower section of your piston to get its size
than you transfer that measurement ( the pistons ) to the bore gage before installing it into the cylinder
and from that you can tell if they are a match --- if not maybe a little honing and they become a set at the correct clearance - i would say off hand .003 to .0035 in inches
remember to keep the front and rear as sets dont mix the pieces after they have been fitted - good luck
Seasoned HDF Member
Joined: Sep 2012
Posts: 6,570
Likes: 590
From: almost there
I think you said you had a stroker so I would get some 9.5 weiscos forged pistons.
Seasoned HDF Member
Joined: Dec 2010
Posts: 7,736
Likes: 1,524
From: Coromandel Peninsula New Zealand
Some just mill the top off the pistons to reduce the compression. Johnjzjz could probably tell you how much to mill off.
Seasoned HDF Member
Joined: Nov 2006
Posts: 12,878
Likes: 5,449
From: la la land jerzey
you can shave the tops of the pistons in some cases to reduce the ratio - you need to find out if the pistons you have are ( solid dome ) or are they ( hollow dome ) if they are solid than you can adjust the compression to what ever number you want - hollow dome you need to be able to measure the inside hollow pocket to the dome top so as not to make it too thin when cutting the shelf area on top - a real shop needs to look at that for you
But you could contact wiseco and ask them about removing material for reduced compression
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
Jason Momoa Is Turning Classic Harleys Into PHEVs
Verdad Gallardo
Harley-Davidson Fat Boy Becomes a Dark, Decepticon-Inspired Custom
Verdad Gallardo
6 Weirdest Harley-Davidsons Ever Sold to the Public
Verdad Gallardo
7 Times Harley-Davidson Chucked Tradition Out the Window
Verdad Gallardo
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Road Master
Joined: Feb 2014
Posts: 913
Likes: 5
From: indiana
I have a ? what's the part number is on those pistons. if there 3.625 pistons wiseco doesn't make 10.5:1 they only offer 9.25:1 in that bore. if there 3.498 they only offer 10.5:1 for the screaming eagle heads. I tried to get 10.5:1 from them for my build
they told me they would make them for me if I ordered 500 sets. so how did you get so lucky.
they told me they would make them for me if I ordered 500 sets. so how did you get so lucky.
