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jims53
11-19-2005, 07:02 PM
I need a little help with my 1953 Commander. The engine was very hard to start cold or hot. I started a tune up, pulled the old plugs (H 10) they had alot of soot on them. So I went with RH18Y, a new set of points and condencer from NAPN they had them in stock...The plug wires had a mfg. date of 1953 on them, so I ordered a new set. I also found that the (neg)- post on the coil went to the distributor, so I changed that to (pos)+. Rebuilt the carb. There was no check ball in the accelator pump so I installed a new check ball. When the spark plug wires came I put it all back together. Set the dwell and timming. While adjusting the idle with a vacuum gage and tack, the engine only has 14 inchs of vacuum...I found that the vaccum advance has a leak. So I ordered a new one from S.A. When the new one came, it picked up about 1 more inch of vacuum, 15inchs now. So I pulled the plugs back out and did a compression check, 80 psi on all eight cylinders...Pulled the valve covers and checked the valve clearance! OK. The car starts very good now and seems to go down the road OK. It does not use any oil between changes (1500 miles) and leaks very little. Should I be concerned about the low vacuum and low compression??

Jim
Go Bucks

Alan
11-19-2005, 07:30 PM
Sounds like the rings are stuck in their groves you need to drive it around for a while to get them loose. May also want to put a little kroil or Marvel Mystery oil in the cylinders and let set and then blow out by cranking before putting the plugs back in, otherwise it's time for a ring and valve job plus new guides and seals.

studegary
11-19-2005, 08:53 PM
How did you do the compression test? Did you have all the plugs out, engine warm, throttle & choke held open, use three or four revolutions per reading, use a known good gauge? If you used that method, your readings seem very low. After you make a reading in a cylinder, squirt some oil in that cylinder and see if the reading comes up appreciably. Is your timing correct? If either valve is partly open on part of the compression stroke, your reading will be low. Of course if a valve isn't seating well it will also give you a low reading. Normally, you won't get such a uniformly low reading across all cylinders with either valve or ring problems. That is why I questioned your compression test technique and the engine's timing. The hard to start could be compression, but it could also be timing. Timing would also affect your vacuum reading, but valves and rings could also. I notice that you said that you set the timing. Was this done by the book? The lack of use of any oil also makes me think the rings are okay. If it starts good now, runs down the road well and doesn't use oil, I would just drive it.

curt
11-20-2005, 08:54 AM
I know the Kaiser flat head engines needed to be driven to keep the rings free. In the spring they needed to be run at interstate speeds for a 100 miles . The rings seemed to reseat after a long winters rest.

Alan
11-20-2005, 10:42 AM
We need more information as how long ago was the engine rebuilt. How long was it sitting if at all. There are a lot of other things that could affect the readings, including your gauge. I have got 3 different gauges one a Cal Custom Hawk, one a Sears Craftsman and a Snap-on. Each one will read diferent on the same engine.

jims53
11-20-2005, 08:10 PM
Alan
The engine was overhaled in 1993 on the way to South Bend it thru a rod. The engine was pulled a NOS 259 crank was installed with new rod and main bearings. Two new rods and four new pistons, new cam bearings and a new aluminium timing gear. The valves were faced and the seats were ground. The car had 27,000 miles at that time, it now has 35,000 miles. Ive had my compression gage for over 50 years and never had it calibrated, so that could be my problem...I drive the car every week and somtimes every day with good weather.
Jim

Alan
11-20-2005, 08:25 PM
See if you can get another gague to try. Also you could try a leak down test. You can hear where it is leaking if it is. 8,000 miles in 12 years isn't too many miles.

jims53
11-20-2005, 11:04 PM
Alan
Thanks for the help, I'll try a different gage...
Jim

jims53
11-22-2005, 08:56 AM
Alan,
Nice call!!! who would have thought my 50 year old gage could have been bad. Used my son's (MAC) compression gage, now reads 140psi on all eight cylinders...Thanks
Jim