First post here, but not a newbie to corolla on the net. Looks like this is the reason for oldcorolla email list's quiteness, so I'll move with the times and with a bit of luck I won't get nazy moderatored either (ah), Now I've had my bitch, I'll continue on.

 

Got an engine that has low compression in all cylinders, but even in all. its got a good bit of pressure on the oil breather into the air filter. Idling you can cover oil breather and get a good hiss of build up. To give an indication, I reckon I could blo up ballons on oil breather ( not that I've tried, yet).

 

The enngines an old toyota push-rod, so could it be blow through from the rings?

Before you ask, now I haven't tried oil in spark plug oil then try a compression test.

 

Or is this problem a valve guid wear prob??

 

One other point no blowing smoke out exhaust.

 

any good advice is apreciated.

Later

 

Charlie835egg

The enngines an old toyota push-rod, so could it be blow through from the rings?

...

Or is this problem a valve guid wear prob??

...

Before you ask, now I haven't tried oil in spark plug oil then try a compression test.

put oil down the plugholes and compression test it again, that will give you an indication of wether the problem is related to the head or bottom end. nobody could tell you the exact nature of your problem over the internet

 

 

showing no initiative and answering your own question is one of the reason stewart and i moderate people from oldcorollas. and now i've had my bitch too

Or carry out a cylinder leakage test that will tell you,it`ll be rings though blowby at low engine speeds is quite normal.

and at high engine speeds with K engines. the rings seem to float above 6600rpm

yep 4k,

 

blowby at low engine speeds is quite normal

Have not really noticed this much blow by before at low revs. Does it noticeably reduce blow by when you warm up the engine??

 

Is a K engine crankcase in vacuum normally at least with standard carb. Got a weber now so that may have been it, though compression is still down. Can't remember pressure values, will need to do again, and with the oil sealing test. Just need to find a mate to crank it over for me while I do it.

 

Another question, Don't you blow smoke when there is bad blow-by, as you get a bit too much oil in the chambers. Oh by the way the plugs were clean when I took them out to do comp. test.

 

later

 

Charlie835egg

 

PS not expecting anyone to tell me the exact nature of my problem. Just like some people to bounce things off and provide suggestions of issues I may have overlooked.

did you hook up the pcv when you put your new carb on? you need it

there is an order you have to put lifters in? but they're all the same...

nick, the 4k in your ke70 would have had such low compression values because the cam had so much overlap. nothing to do with the lifters. a big cam has low cranking compression, but greater dynamic compression at high revs.

 

something i have heard of is people converting to electric fuel pumps, and using the old mechanical pump to suck crankcase pressure out. also have heard of people using exhaust suction to relieve crankase pressure (need to have a oneway anti backfire valve in the system).

 

maybe consider running the biggest vent possible off the rocker cover. i don't run a pcv system at all. just a hose to the aircleaner, and one to a small catchcan. early 3k rocker covers only have one vent, to the dump pipe, which sprays excess crankcase pressure along the transmission tunnel. maybe modify your oil cap so it also acts as a vent, with a large filter on top.

and how long does your oil last? with two filters on the rocker covers, my oil would go black and drop 10psi in pressure within 500km, not to mention the big f@$king mess on the tappet covers. with the pcv system hooked up and working properly, i could drop the sump after a couple of thousand miles and it was still gold and translucent like new, and would hold 60psi during normal running for ALOT longer

i change oil every 6 months. my motors only cost me like $400 so really i don't care. my last 4k cost $350 and lasted 3 1/2 years and was still going strong. it still has many miles left in it.

 

it ran ryco filters and $15 oil.

 

thinking about it, your problem with your oil was probably due to going to synthetic to early and glazing your bores.

Edited August 22, 200521 yr by Felix

well my engine cost two and a half grand so i do care

and i've had the head off, the bores are unglazed and fine, thanks