Posted March 15, 200420 yr comment_72765 Checked compression and there are 4 cylinders at 160 psi, and 2 at 60 psi. Any tips for that? is that worthy of a more expensive engine re-build or can i do a cheap individual rebuild? Link to comment https://www.classiczcars.com/forums/topic/10751-compression-problems/ Share on other sites More sharing options...
March 16, 200420 yr comment_72841 * Link to comment https://www.classiczcars.com/forums/topic/10751-compression-problems/#findComment-72841 Share on other sites More sharing options...
March 16, 200420 yr comment_72857 Did you adjust the valves before you did the comperession test? Link to comment https://www.classiczcars.com/forums/topic/10751-compression-problems/#findComment-72857 Share on other sites More sharing options...
March 16, 200420 yr Author comment_72907 How would adjusting the valves mess with the compression? Link to comment https://www.classiczcars.com/forums/topic/10751-compression-problems/#findComment-72907 Share on other sites More sharing options...
March 16, 200420 yr comment_72921 If your valves aren't adjusted right, they either won't seat properly or open far enough to allow the proper amount of air into the combustion chamber, depending on whether they are too tight or too loose.Next thing you should do is put a spoonfull of oil in the 2 cylinders that were low, and re-test them. If they show higher compression than before, the rings or cylinder walls are the cause as the oil will work to seal the rings to the cylinder walls. If they still show a low compression like before, then you know the problem is either the headgasket, or in the head itself such as the valve seats or valves. Of course, it could end up it is a combination of worn rings and headgasket/valves, but until you check it, you won't know what to be looking for when you remove the head.How much you have to do will be a result of what you find when you do this test, you may only have to rebuild the head and/or replace the headgasket. Link to comment https://www.classiczcars.com/forums/topic/10751-compression-problems/#findComment-72921 Share on other sites More sharing options...
March 16, 200420 yr Author comment_72928 so if the compression is higher after i oil them...do i hafta replace anything? Link to comment https://www.classiczcars.com/forums/topic/10751-compression-problems/#findComment-72928 Share on other sites More sharing options...
March 16, 200420 yr comment_72934 Probably.....:disappoin By checking it this way, you'll know how to best save time.If it checks out better with the oil in the cylinders, you'll know you have a lot of wear in the bottom end (rings and/or cylinder walls) and the best thing to do is pull the entire engine and rebuild it. Probably be best to just go ahead and rebuild the engine from the bottom up, or replace it with a reman engine if you can find one for a reasonable price.If it tests out nearly the same, you know the majority of the problem is above the block, so you'd only have to pull the head, and only need to rebuild the head by checking it for straightness, doing a valve job, replacing the valve seats and then putting it back together along with a good top end gasket kit. Link to comment https://www.classiczcars.com/forums/topic/10751-compression-problems/#findComment-72934 Share on other sites More sharing options...
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