VAF Forums

VAF Forums (https://vansairforce.net/community/index.php)
-   Traditional Aircraft Engines (https://vansairforce.net/community/forumdisplay.php?f=21)
-   -   Valve stem seals for H2AD ? (https://vansairforce.net/community/showthread.php?t=69483)

airtractor8 03-09-2011 06:57 PM

Quote:

Originally Posted by mike in phx (Post 521381)
when i built my engine i have P10 new overhauled cylinders and 9.5-1 comp pistons total seal rings.
And when you use the rings it will puff smoke on idle.
Because of the added vacum, on intake stroke it pulls oil thru the guide.
So i added valve stem seals on exaust and intake valve. I have over 250
hours on valve stem seals and on the new turbo motor im using 1/4 quart oil on 35 hours.
If you need more info give me a call 602 697 4080

Thanks for the info Mike, sounds like they worked for you.

Did you in fact find some seals made from Viton as Bob suggests or are they like what I have in the photo ?

mike in phx 03-09-2011 09:14 PM

seals
 
yes they are close enough seals are seals and we only run 2700 rpm as long as you have room for the seal at max lift on the valve if not it will smash the seal
good luck

airtractor8 03-10-2011 04:06 AM

Viton seals
 






Found some Viton stem seals today at the local cylinder head re-manufacturer for 20 bucks. These ones fit snugly over the guide so I decided to go with them.

To get the valve springs off I made a fitting for the lower plug hole and pumped compressed air into the cylinder with the piston at the bottom of its travel and both valves closed. This held the valve up nicely while I removed the springs and collets with a modified spring compressor tool thats used on cars. It all worked a treat and took less than 15 minutes per cylinder to do.

Now to see if my $20 investment makes any difference to the oil consumption or not :D

Cheers
Graham

chaskuss 12-03-2011 07:13 AM

Quote:

Originally Posted by airtractor8 (Post 521788)
snipped

Now to see if my $20 investment makes any difference to the oil consumption or not :D

Cheers
Graham

Graham,
So what was the outcome of the addition of the oil seals on your engine?
Charlie

RV Jerry 12-03-2011 08:29 AM

OIL CONSUMPTION
 
ALL THE ENGINES I HAVE HAD EXPERIENCE WITH WILL USE THE FIRST 1 TO 3 QUARTS RAPIDLY UNTIL IT FINDS THE LEVEL IT LIKES. AND THEN THE CONSUMTION STABILZES YOU MAY HAVE THE SAME ISSUE. LYCOMING EVEN AGREES WITH THIS YOU DO NOT HAVE TO KEEP THE OIL SUMP FULL

RYOUNG 12-03-2011 02:30 PM

The lycoming flyer you reference says use AD oil for break in on the "H" engine, or am I missing something?

airtractor8 12-03-2011 03:50 PM

Quote:

Originally Posted by RV Jerry (Post 602329)
ALL THE ENGINES I HAVE HAD EXPERIENCE WITH WILL USE THE FIRST 1 TO 3 QUARTS RAPIDLY UNTIL IT FINDS THE LEVEL IT LIKES. AND THEN THE CONSUMTION STABILZES YOU MAY HAVE THE SAME ISSUE. LYCOMING EVEN AGREES WITH THIS YOU DO NOT HAVE TO KEEP THE OIL SUMP FULL

Believe me, I've tried all oil levels from full to the 4 quart minimum with no change in the consumption. I also checked the dip stick calibration to make sure it was accurate (tailwheel instillation).

airtractor8 12-03-2011 04:07 PM

Quote:

Originally Posted by chaskuss (Post 602306)
Graham,
So what was the outcome of the addition of the oil seals on your engine?
Charlie

Hi Charlie

I have flown about 40hrs since fitting them and can only see a small reduction in consumption. They certainly didn't fix the problem totally. I think the cylinders are probably near the outer limits as mentioned in one of the previous posts. I will probably run them a while longer and change them out with new cylinders if consumption increases.

mahlon_r 12-05-2011 08:24 AM

Are the combustion chambers wet with oil? If the cylinders are burning the oil they will be wet. If not then the cylinders aren't the cause of the consumption.
Cylinders can be in limits, but as said, what limits. You need to keep the ring gaps in the new limit range and the skirt clearance at less then .012.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

airtractor8 12-05-2011 06:35 PM

Quote:

Originally Posted by mahlon_r (Post 602890)
Are the combustion chambers wet with oil? If the cylinders are burning the oil they will be wet. If not then the cylinders aren't the cause of the consumption.
Cylinders can be in limits, but as said, what limits. You need to keep the ring gaps in the new limit range and the skirt clearance at less then .012.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

Yes all four of them are wet with oil. After removing the plugs and shining a light in there I could see oil laying in the bottom of the combustion chambers. The lower plugs also show signs of oil but the engine still seems to run fine. The mag drop is probably a little on the high side of normal at 75rpm at this point. The leak downs are all in the mid 70's which is why I was thinking oil past the valve guides but this is clearly not the full story. Consumption is still well within limits but I sure am sick of tipping oil in this thing! New cylinders coming up I think :)

Cheers
Graham


All times are GMT -6. The time now is 07:12 AM.