compression test results
Thread Starter
|
Cruiser
Joined: Sep 2007
Posts: 157
Likes: 0
From: South Carolina
compression test results
I have a 2002 lowrider that I did a Head Quarters Dyna Sport package rebuild to. After one year I have just put on 10,000 miles since the rebuild. Just checked compression. I wish I would have done a compression test immediately after the build to have a point of comparison, but I didn't.
Both cylinders are at 220 psi exactly, then both are at 240 psi exactly after adding 1/2 oz oil. This build is rated as 11:1 compression.
My factory manual says anything above 90 psi is ok and if there is a significant jump in psi after adding oil it is an indication of worn rings.
Questions: Obviously my manual's specs are for a stock bike. Does 220 seem appropriate for 11:1 compression?
Also, assuming 220 is reasonable, is the 20 point jump to 240 psi significant or am I ok there?
Thanks for your opinions.
Both cylinders are at 220 psi exactly, then both are at 240 psi exactly after adding 1/2 oz oil. This build is rated as 11:1 compression.
My factory manual says anything above 90 psi is ok and if there is a significant jump in psi after adding oil it is an indication of worn rings.
Questions: Obviously my manual's specs are for a stock bike. Does 220 seem appropriate for 11:1 compression?
Also, assuming 220 is reasonable, is the 20 point jump to 240 psi significant or am I ok there?
Thanks for your opinions.
Banned
Joined: Mar 2007
Posts: 3,706
Likes: 7
From: Woodstock, Ont , Can
Adding oil will always raise the numbers some. Doing a leakdown test warm to hot engine to show what's really going on, but it sounds excellent to me. As for 11-1, don't know but you are up there. Not a lot of point on checking a new engine for leakdown or compression, since it's not seated . Once broke in is the best time to get the numbers.
Ron
Ron
Last edited by rbabos; Nov 7, 2009 at 05:34 PM.
Ultimate HDF Member
Joined: Feb 2007
Posts: 7,663
Likes: 7
From: Northeast Ohio
Your CCP will depend on static (11.0:1) compression and then the cam you are running. Earlier intake close, higher the CCP.
For a HQ build at 11.0:1 and a cam such as the HQ0039, your CCP is right in the ballpark.
For a HQ build at 11.0:1 and a cam such as the HQ0039, your CCP is right in the ballpark.
Thread Starter
|
Cruiser
Joined: Sep 2007
Posts: 157
Likes: 0
From: South Carolina
Thanks Dalton. For a cam I have the HQ0033 (tornado) - gear.
Thread Starter
|
Cruiser
Joined: Sep 2007
Posts: 157
Likes: 0
From: South Carolina
Another question: forgive my ignorance, but what is the difference between CCP and PSI? What is CCP? I don't have it with me right now but I could swear my compression gauge measures PSI.
Trending Topics
Road Master
Joined: May 2007
Posts: 851
Likes: 5
From: Mitchellville, Ia.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
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
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
