Chris Barbrow

Ok so i did a mini me swap in a 98 civic lx, auto. After getting the motor in i drove the car for about a week and it suddenly lost compression in 2 & 3, 4 had about 80psi and 1 had about 135-140psi. Needless to say after reading so many options of what the problem could be i pulled the head to do a thorough inspection of cam, valves & pistons. Theres no indication on piston heads or bottom of valves that contact has been made to bend them, and my seals on my pistons arent leaking so i know its not thru the block and no air is coming thru the radiator, and the head gasket is fine. Ive checked timing and adjusted the cam 1 tooth at a time for about 2 days. Set my cam at 1 tdc & crank at 1 tdc w dizzy set to spark on 1 and still have no compression. Doin a leak down test at each piston it seems like my exhaust valves arent closing all the way and letting the air escape. Could my valve seals be that screwed or am i jus totally missing somethin? And yes dizzy works fine, got spark on all 4 plugs, and timing seems to be adjusted right. And not sure if they are all valves are suppose to close after cam & rocker arms have been removed, but all intake valves are closed and all exhaust valvles are slightly open

mk378

The valve springs need to pull the valves completely closed when nothing is pressing on the top of the stem. That is really bizarre, perhaps someone put the head together with the wrong parts.

TomCat39

Can you post a picture of the valve stems, keepers and top retainers? And is any of the cylinders TDC in the picture you posted?

JRCivic1

Regardless of whether a camshaft is installed in the cylinder head pictured above or not... there is no point in the cam rotation where ALL eight exhaust valves are open. Something is significantly wrong here. My first thought would be an improper valve adjustment... but this looks way too tight, and it would be unlikely that it ever would have run at all. Loosen the tappets all the way and see if the valves close completely. If not, the valves may be the wrong ones for the head, or something is bad wrong with the valve seats... which incidentally, appear to be missing. How about a close-up pick of one chamber at a slight angle to show the gap between the exhaust valve and valve seat.

TomCat39

I was thinking, bent or trashed retainers. Much like improper fitted titanium retainers that drop valves... Then again, it's not likely to happen to all 8..... Good point.

Chris Barbrow

Thanks for to input guys. Ill defiantly be pullin the springs off tomorrow and take some pics of everything and repost as well as that close up. Had a feeling something was very wrong considering it was supposedly rebuilt by the who sold it to me and claimed he cleaned and polished the valves and took the intake & header off to discover none of them have been touched so i can only wonder what else could be wrong.