Posted By |
Discussion Topic:
Compression drop
-- page:
1
2
|
|
ken ct. |
03-22-2019 @ 5:13 AM
|
|
|
Senior
Posts: 1513
Joined: Jan 2010
|
IMO your being overly concerned about a 10# drop compared to the rest of them !!! ken ct.
|
shogun1940 |
03-22-2019 @ 1:23 AM
|
|
|
Member
Posts: 464
Joined: Feb 2010
|
If this engine was just rebuilt then the rings have not seated yet, no synthetic oil until 5000 miles, read up about doing a leak down testfor Moore accurate diagnostics
|
sarahcecelia |
03-21-2019 @ 8:00 PM
|
|
|
Senior
Posts: 1183
Joined: Mar 2013
|
Took a screw driver and started to ground from the top of each plug to the head with motor running and found #2 and #7 weren't firing. Took those 2 plugs out- installed to new plugs. Purring like a kitten now! I am going to replace #1 with the bad plugs, one at a time, which were wet with what looked like a very thin film of 3 in 1 oil, and I cleaned with carb cleaner and let dry out, to see if they are really bad or just fouled. I'll let all know how that turns out! Those plugs only had a max of 150-200 miles on them.There were no cracks visible in the porcelain!!
Regards, Steve Lee
|
len47merc |
03-20-2019 @ 1:47 PM
|
|
|
Senior
Posts: 1165
Joined: Oct 2013
|
Before you spray acetone into an engine try spraying acetone on a new flathead main bearing and wiping it off 1st, then decide whether you'd think it wise to spray it in to your engine, cylinder or otherwise.
Steve
|
sarahcecelia |
03-19-2019 @ 7:05 PM
|
|
|
Senior
Posts: 1183
Joined: Mar 2013
|
50/50 Acetone and ATF fluid were the best old school "rust busters" by far. I'm going to squirt some at the exhaust valve for #3 through the spark plug hole, because I can see the intake valve just to the right and above the spark plug hole and it moves up and down when I use my remote motor starter to to turn the motor over , and I believe that the exhaust valve is to the right of it, since #2 and #3 exhaust both dump out to the center port on the exhaust manifold, and #1 dumps exhaust out of the front of the exhaust manifold, and #4 dumps out of the back of the exhaust manifold.
Regards, Steve Lee
|
sarahcecelia |
03-19-2019 @ 5:53 PM
|
|
|
Senior
Posts: 1183
Joined: Mar 2013
|
I already put one half a bottle of Marvel Mystery oil in the gas tank. (I think it is ATF fluid!)
Regards, Steve Lee
|
sarahcecelia |
03-19-2019 @ 5:51 PM
|
|
|
Senior
Posts: 1183
Joined: Mar 2013
|
Thanks for all of those tips!!. I'll check them out 1 by 1.
Regards, Steve Lee
|
len47merc |
03-19-2019 @ 12:44 PM
|
|
|
Senior
Posts: 1165
Joined: Oct 2013
|
Steve - a wet vs dry test can make a huge difference. My daughter's '99 Honda Accord is close to turning 400,000 miles on the original engine and started losing oil with no leaks or smoke at the rate of 1 qt per 750 miles. Dry compression test yielded 2 cylinders are 205 psi, 2 at 65. Wet test all 4 were 205. Problem solved - rings worn out in 2 cylinders. Time for complete rebuild. Yours is a different bird but a dry vs wet test can isolate the issue to rings vs valve issues. Steve
This message was edited by len47merc on 3-19-19 @ 3:02 PM
|
37RAGTOPMAN |
03-19-2019 @ 7:58 AM
|
|
|
Senior
Posts: 1958
Joined: Oct 2009
|
wet compression test vs dry compression test, wet , adding oil to the cylinder, then take compression test it will seal the rings temporally and will increase the compression, if it does not there might be something else going on, in that cylinder, like valve, bad head gasket ? my 2 cents, 1937 RAGTOPMAN
|
37RAGTOPMAN |
03-19-2019 @ 7:58 AM
|
|
|
Senior
Posts: 1958
Joined: Oct 2009
|
wet compression test vs dry compression test, wet , adding oil to the cylinder, then take compression test it will seal the rings temporally and will increase the compression, if it does not there might be something else going on, in that cylinder, like valve, bad head gasket ? my 2 cents, 1937 RAGTOPMAN
|