in place valve lap

[Mr X]

It happened again my intake valve seems to get blocked open about once a year and I dont  feel like taking the head off to lap the valve a,4 hour project. So late one nite as my batteries were suffering the low voltage blues it came to me. Can I take the rocker arm off and grab the end of the valve and turn it to lap the valve??? I tried it and it worked. At first I used an aluminiem soft jaw and vice grips to turn the valve when I thought the cordless drill would work, and it dose. I didnt even need to reset the valves. I marked the left and right push rods and so when I put it back together it was ready to run. A nice simple fix that took less then 1 hr. And it runs again.

Mr X

[oliver90owner]

What engine?  Obviously not a CS.

If it is carbon build up on the stem it will be a short term fix.

It has probably been blowing past it somewhile.  Valve seats usually need a little grinding paste to seat them snugly.

So not really the best way to go.  Any irregularity will not be noted and fixed.

Perhaps better to address the underlying problem.  May need to feed some form of cleaner into the inlet on a regular basis to keep things clean.

Is this 24/7 running or what?  'Once  a year' is fairly meaningless without qualification.  If 24/7, you are doing very well and are exceeding the recommended service intervals.

I think it may deserve being done right.  May be a simple fix for the short term, but not the way to go if you are in this for the long haul.

Regards, RAB

[SteveU.]

Hello Mr X
Long time no hear.
I've lapped in valves with a reversible drill since the mid 70's. Works OK as long as you keep the speed and pressure low and reverse frequently. Much easier now with cordless drills.
I've only done it a few times unassembled. Learned the hard way to keep the piston 3/4 way up after dropping a couple of valves down into cylinders. Fished back up with magnets and lots of patience. Applied grinding paste with a pipe cleaner and fed in rag strips to clean up. These were "I only need 100 hours to plant/harvest/parade!" situations. Owners than either did teardown or park it.

What RAB said about valve stem/head of valve carbon build up is correct.
Since you are in Canada may I recommend MOPAR brand Combustion Chamber Cleaner #04318001AB as an assembled spray in decarbonizer.
Available at any Chrysler/Dodge/Jeep dealer. Instructions on the can. Works great on Dino carbons. Cleaned up the wifes bakeware too good. I had to buy her new pieces and season them in. Ouch.

Regards
SteveU.

[Mr X]

Its a 6/1 and i run it about 4-6 hr/day on veggie.It was a very cold day -35c the glow plug did nt bring it to life so i put the flame of a small propane torch down the intake to help heat up the head so it will fire, it worked in the past but this time it loosened some dirt and it stuck the valve open,no compression at all. so I know its not right but my fix did work and its running well. Im hoping I can make it till spring when ill do its usual tear down.   X

 

[oliver90owner]

To your: I marked the left and right push rods

I replied:  Obviously not a CS.

Tell me more.  Presumably an  'oid if the push rods are the same length?  Which brand is that ? or are they all like that?


'Bout right for a decarbonisation yearly, I suppose.  It must be burning the veggie quite well. Is this veggie esterified, or burned as it is?  Fuel preheat, presumably - or do you thin it with something else?

Regards, RAB

[Mr X]

I have no idea if there is a difference in the length of the push rods but with the quality the way it is it wouldnt surprise me. I was just trying to save my self work. if i took it apart and put it together the way it was then no need for fussy adjustments.; Veggi burns great but u have to pre heat and If I try to Run before the water jacket heated the oil it will kill the roid  so yes I need to pre heat. I burn 4-5 berrals a winter. I also mix 5 gal reg ul in with the oi to thin it and they say it helps to bur the glyserin I can usualy get by a winter with out de carboning.

[Mucke]

I have no idea if there is a difference in the length of the push rods but with the quality the way it is it wouldnt surprise me. I was just trying to save my self work. if i took it apart and put it together the way it was then no need for fussy adjustments.; Veggi burns great but u have to pre heat and If I try to Run before the water jacket heated the oil it will kill the roid  so yes I need to pre heat. I burn 4-5 berrals a winter. I also mix 5 gal reg ul in with the oi to thin it and they say it helps to bur the glyserin I can usualy get by a winter with out de carboning.

I always burn waste veggi filtered but not free of fat. When it gets close to freezing, things become harder.
I mix  about 10 % of dino and also some unleaded gas. Sometimes this will make the glicerine fall out in the filter and I need the torch to smelt it again, more often to wash the filter in diesel, gas won't solve it !

As for the starting probs with sticking valves, this is no big prob since it only happens in a cold engine.
I turn the piston down and give the hanging ( outlet) valve a few short whacks and let the spring snap the valve up into the seat.
Than it starts and after a few seconds everything is fine although the valve stem should heat up before the guide.
But it works !
What about oiling the stem/guide on shutdown ?
Rolf