Gregor 4,847 #1 Posted March 28, 2021 I am following a thread on another forum. Guy claims to have 200 PSI Compression on his CV 490. First, is it possible to spin a Kohler fast enough, with the starter, to overcome the ACR? Second The book says 8.5 : 1 compression ratio. Is thee any way to calculate the correct PSI, knowing the compression ratio? Share this post Link to post Share on other sites
ebinmaine 69,691 #2 Posted March 28, 2021 Not to downplay the individual but that seems about 60 or 80 psi too high. Share this post Link to post Share on other sites
Gregor 4,847 #3 Posted March 28, 2021 I simply don't think it's possible to spin it fast enough with a starter to overcome the ACR. If you could, what would be the point of having ACR in the first place? Especially, with 200 PSI. That's a LOT ! But all that being said, I am not an expert. I may be all wrong. 3 Share this post Link to post Share on other sites
ebinmaine 69,691 #4 Posted March 28, 2021 I'm not familiar with the CV series. If it has acr it ISN'T getting a proper test with the starter. Much less getting 200... Share this post Link to post Share on other sites
Gregor 4,847 #5 Posted March 28, 2021 7 minutes ago, ebinmaine said: I'm not familiar with the CV series. If it has acr it ISN'T getting a proper test with the starter. Much less getting 200... He says he can "hear" the ACR click out. I think he's hearing something alright. He may need a tin foil hat ! 3 Share this post Link to post Share on other sites
ebinmaine 69,691 #6 Posted March 28, 2021 17 minutes ago, Gregor said: a tin foil hat ! Those are handy because it keeps the aliens from reading ones thoughts. Share this post Link to post Share on other sites
ranger 1,770 #7 Posted March 28, 2021 1 hour ago, Gregor said: I am following a thread on another forum. Guy claims to have 200 PSI Compression on his CV 490. First, is it possible to spin a Kohler fast enough, with the starter, to overcome the ACR? Second The book says 8.5 : 1 compression ratio. Is thee any way to calculate the correct PSI, knowing the compression ratio? Is it a twin cylinder? He’s probably running it on one cylinder and checking compression on the other, then swapping over! 😀 Share this post Link to post Share on other sites
Gregor 4,847 #8 Posted March 28, 2021 no single cylinder, 17 HP Share this post Link to post Share on other sites
Gregor 4,847 #9 Posted March 28, 2021 For the record. https://www.google.com/search?client=firefox-b-1-d&q=how+to+figure+psi+from+compression+ratio Share this post Link to post Share on other sites
ebinmaine 69,691 #10 Posted March 28, 2021 5 hours ago, Gregor said: For the record. https://www.google.com/search?client=firefox-b-1-d&q=how+to+figure+psi+from+compression+ratio Ok yeah.... NO WAY IT'S 200 Share this post Link to post Share on other sites
tom2p 2,394 #11 Posted March 28, 2021 (edited) 8 hours ago, ebinmaine said: Those are handy because it keeps the aliens from reading ones thoughts. Edited March 28, 2021 by tom2p Share this post Link to post Share on other sites
.jpg.8ca755f0175140fd974a8b033d7f3501.thumb.jpg.71f06ed90f3a14a3b565d8387e418b61.jpg)