valve not seating properly?

DRS1984 · Samba Member Joined: March 18, 2002 Posts: 93

okay, my engine has been making this tick tick tick coming from the left side. i thought that my valves were loose, so i adjusted them a million and a half times, and the engine still clicks. reading the "idiot" book, at the beginning of the engine overhaul chapter, led me to believe that it was a valve not seating properly. why you ask? first it sounds like its coming from the head, and the compression is low on just the number 4 cylinder. 1-110 2-110 3-125 4-105. but then again its not that low, and number 3 is incredibly high. any way thats the best explaination i can think of with out taking anything apart. the book mentions that i can run diesel fuel through the engine for 1000 miles and that could fix it if it is infact the valve. is that safe? by the way, the engine only has about 3000 miles on it. but i'm not too surprised seeing as how it was built by gex. any help or suggestions.........or anything are very much appreciated. oh a couple more things. it runs perfect, just sounds funny, and the sound is there throughout the rpm range. thanks!!!

rlarkin · Posted: Wed Jan 15, 2003 8:11 pm Post subject: valve not seating properly?

You can not run straight diesel.
Diesel requires compression (lots of it), and heat (lots of it).
These little motors do not produce enough compression to ignite diesel, and spark ign. will not get it going.
I have heard of "mixing" a little diesel to add lubricity. But the ratios are small.
Pull the cover and check the rocker. It is possible that the rocker is rattleing on the shaft.

Trayle D. the real oggfk · Posted: Wed Jan 15, 2003 8:24 pm Post subject: valve not seating properly?

Its also possible that one or more of your valves has the tip of the stem beveled. So even though you think you have set your valves tight, there is a gap that you can take up. This has happened on a few of my motors over the years.

keifernet · Posted: Wed Jan 15, 2003 8:37 pm Post subject: valve not seating properly?

Yeah, don't even bother putting diesel in at all at this point. That was an age old tip in the Idiot book meant to help decarbonize an older high milage engine that could have a chunk of carbon stuck on a valve/seat.

Have you changed the oil and if so how many times so far on the "new rebuilt"?
What kind of metal particles did you find on the drain plate? What weight are you running?

GEX and others have been known to put in "reground cams and lifters" which may or may not seat/break in well with one another. They count on them lasting just long enough or do not fear warranty due to their "fine print" (ever read that, the fine print? LOL! ) what a joke.
But before I step in a big pile, are you sure you are lining the engine up correct for the adjustment... Have you re-torqoed the 4 nuts under the rocker arms BEFORE adjusting the valves?
DO IT then re-adjust them. and when you take the rocker assemblies off look closely at the "tips" of the adjusting screws and see if they look good (slightly CONVEX shaped) or bad... and the ends of the valve stems (beat out) and at the rockers arms/shafts for broken spring washers ect.
And pull the push rods out and see if the ends are intact( they can break off on gthe lifter end and you will not see it) and all the same length ect.
If all this turns out to be OK then you pobably (IMHO) have a cam/lifter issue in which they have not yet or are not going to seat in "compatible" ( for various reasons and may well have a "tick" for miles to come.
If it is not all that noisey and the engine runs well, then??? you could leave it. Or maybe more re-adjusting/ tinkering/ checking externals will solve it. If not teardown is immenent....
Judging by the compression you do not (again MHO) have a bad valve/seat.

Good luck and keep checking anything and everything you can.....

DRS1984 · Samba Member Joined: March 18, 2002 Posts: 93

wow, i didnt expect responses so fast. i appreciate that. well, i will take the rocker arm assembly off and inspect everything i can tomorrow, and check the pushrods out. i musta changed the oil 15 times already.

DRS1984 · Samba Member Joined: March 18, 2002 Posts: 93

alright, so i took the rocker arm assembly off, everything looked fine. and then i took the pushrods out, they looked fine as well. then i did the ole roll the pushrods on a flat surface trick. and one wasn't exactly straight. so that would make sense. if the pushrod is bent, it would make it shorter. and if it is shorter, the 006 might be a little more like 008 or something. and would cause the clicking. so, i'll be outta town for the weekend, but when i get back, i'll get a new pushrod, and see if that fixes it. and i'll be sure to keep you all up to date cuz i know you were all up last night worried about my engine. Smile

thanks

j.pickens · Posted: Thu Jan 16, 2003 8:42 pm Post subject: valve not seating properly?

Damn, I'll have to wait 'til Monday!

rlarkin · Posted: Thu Jan 16, 2003 8:54 pm Post subject: valve not seating properly?

What causes a problem with a bent pushrod is that it looses its strength, and will flex when pushed. Eventually, it will prolly break.
If you set it to .006 with the valve closed, it will always be at .006 when the valve is closed, but as the rocker pushes it, and it flexes, its effective gap prolly becomes .010 or more, which means the valve is not opening all the way.
If it bends enough it the right direction, it will slap the inside of the tube.
I would replace all of them though, not just one. Its easier now since you are in there.

DRS1984 · Samba Member Joined: March 18, 2002 Posts: 93

well, its monday, and as much as i don't want to say this. i'm gonna have to. the new push rod didn't fix it. i'm quite sure that its a lifter making the sound now. i'm just not sure why. i think the ends of the pushrods are magnetic or something? but on the lifters that aren't being pushed by the cam lobes i was kinda moving them back and forth with the push rod. and the sound they make when they hit the case, is the sound i'm hearing. so i'm not really sure what that means, they're supposed to hit the case right? so why is 1 of them so loud? any thoughts? Sad

i miss my bus.
thanks

rlarkin · Posted: Mon Jan 20, 2003 10:38 pm Post subject: valve not seating properly?

With the valves set at .004, or even .006, and the way the lifters and followers are designed, you should not have a pushrod slapping the case. If you do, their are other concerns.
Check the spring washers and make sure one has not collapsed. That would allow the rockers to float on the shaft enough to cause a pushrod to hit something.

DRS1984 · Samba Member Joined: March 18, 2002 Posts: 93

o..sorry..i didnt explain very clearly...i meant the sound of the lifters hitting the case, not the pushrod. Smile

rlarkin · Posted: Mon Jan 20, 2003 11:05 pm Post subject: valve not seating properly?

The lifters should not have any side to side movement at all. If they are, it is time to split the case!

keifernet · Posted: Tue Jan 21, 2003 7:53 am Post subject: valve not seating properly?

Are you absolutely, positive you were on #1 cylinder when you begin adjusting the valves????

DRS1984 · Samba Member Joined: March 18, 2002 Posts: 93

well, it seems there's nothing else i can do, with out pulling the engine. kinda sucks but thats life right? i just finished helping my sister rebuild her engine. i convinced her not to go the gex way. so, thanks for all the help, i truly appreciate it.
thanks

keifernet · Posted: Thu Jan 23, 2003 8:34 am Post subject: valve not seating properly?

Let us know what you find... I've seen .020 and .030 early "non crossdrilled" cranks and cams re ground so thin on the lobes it was scary, and dualports built on 40 hp or early F cases! yes all from GEX!
You could have a cam lifter problem or a piston skirt crack, or also a loose fitting wrist pin/ bushing and or the begining of a worn rod bearing... all of these will make deceiving noises...

keifernet · Posted: Thu Jan 23, 2003 8:44 am Post subject: valve not seating properly?

Also forgot to add, like Rlarkin said it could be a worn lifter bore...


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