1916 compression issues after head gasket replacement

[bobs1916]

Got my 1916 running after 50 years with about 30lbs compression in all cylinders . At that point decided to pull the head off and check condition of valves and gasket. Good that I did that as the car was in need of a valve job and also a mouse had nested in the water jackets and had nearly completely obstructed the passages. OK ckeaned out the water jackets, completed the valve job, cleaned up the head studs and nuts, new composition gasket placed ,Replaced the hood .torqued to 55lbs and ...........cylnder 1 40 lbs, #2 35, #3 25lbs #4.......ZERO and there is a sound of air. IDEAS??? I will machine the head to be absolutely sure of it being true . Should I replace the head bolts as perhaps they are "stretched" and not holding down the head . Should I increase torque on the original studs. ANY HELP APPRECIATED Thank you

[nearchoclatetown]

I'd recheck the valve adjustment first, and make sure the valves are not sticking. New valves? Guides OK? If not, by cleaning everything it may have increased the valve clearance.

[Jan Arnett]

I agree with valves probably being the problem but if that does not solve the problem check your gasket. You can take and old spark plug and remove the element, put a 3/8 nipple in it and connect it to an air source. Put about 40 # of air to your cyc. and see where it is comming out. You can do this with out removing anything and it is a good test. When you ground the seat do you use an old seat grinder or a new multi step unit. You may have sunk you seat too low and now the valve is setting to high.

[Guest Jack27]

Are the head bolt nuts the acorn type or a typical nut? If the head bolts are too long the acorn nuts can hit the top of the bolt and not be seated.

[bobs1916]

Well I sent the head out to be machined to be sure that it was not altered when I removed it It took a good bit of prying to get it off!! We used new valves and valve guides and lapped them in the old way with grinding compound and a suction types valve spinner! Tonight removed all valves and found a good amount of carbon had not been removed from the intakes and perhaps some got under the valves or valve and did not allow a good seat . I also checked the offending cylinder with brake cleaner to see if the rings were tight and there was no seepage of the very thin cleaner past the rings so Its not the cylinder. The nuts are NOT acorn type so they should seat as far as needed. I am leaning towards and hoping that the carbon situation and the head needing milling is the issue. Any one have a problem with the composition gasket as opposed to copper crush??? Thanks for all the feedback.

[Jan Arnett]

Bob:

You mentioned a coulple of things which concern me. You said that you had trouble removing the head on a just rebuilt engine. Why? The head should just pull off unless you have bent studs holding it on. If the studs are bent you will not be able to properly seat the head. To remove heads you should either make pullers (spark plug with and eyebolt) or buy some and then pull the head straight up. Do not pry and head off. It sounds like you did not grind new seats only seat in new valves. This can cause a poor seat in new valves if the seats are oblong. Using a hand valve seater/grinder will not solve the problem. Did you use compressed air to determine where the leak was. I prefer composition gaskets when avaliable.

[bobs1916]

hello

This is not a newly rebuilt engine OLD OLD OLD original. The head was removed with difficulty because of rusting around the studs It took plenty of penetrating oil and very thin tools not screw drivers or chisels to free up and remove the head . Yes the old seats were used but they really cleaned up quite well when the valves were ground and excellent fit was accomplished . Well thats my situation and I welcome any suggestions or advice

[Jan Arnett]

If you ever run into the same situation you can make a cutter which will go between the head and the stud by taking very thin wall tubing and cutting cutter teeth into the end. Make the tube about tweleve inches long and put it into a slow speed drill. After going over each stud put a lifting eye bolt into the from spark plug hole and one into the back spark plug hole and you should be able to pull the head off. Hope this helps in the future?

[dwollam]

Jan, I like that idea! How you done this? Sounds great.

Dave

[bobs1916]

Jan

I picture that exactly Great idea!!!!! Well head came back an was not warped and the shop merely freshed up the underside SO repainted it and will try again tomorrow. By the way do you all agree on 55 lbs torque on the head bolts???IF PROBLEM CONTINUE I WILL RECHECK THE VALVE SEATS

[nearchoclatetown]

Did you actually cut or grind the seats OR just lap them with compound? I'd make sure everything is squared away before I put the head back on. Turn the engine over and watch to make sure a valve in the bad cylinder isn't hanging up. Are you POSITIVE the block surface is clean, especially around the stud area? Start your torque pattern with the center stud and work outward in a circle, in 10-15 lb. steps. And my opinion would be to not overtorque the bolts. I had 2 strip out of my block when I was torqueing mine at 45-55. I made new head studs and installed heli-coils to fix it, not a big deal. I still have more heli-coils if you need them.

[bobs1916]

yes

you guys who thought valve seats are the problem ARE RIGHT !!! Lapping in new valves with old seats won't work even though they appeared and felt tight. .SO now we will have to get the correct tool and grind in new seats. Any suggestions welcome

[nearchoclatetown]

New-Way makes an excellant CUTTER, it has carbide inserts that you turn by hand. The kit with the right sized cutter for DBs might be about $100, but it does a perfect job. I won't have seats ground anymore. Like everything else, it's just an opinion. Having the seats done correctly is critical to compression. If you don't feel comfortable doing it, a machine shop should be able to do the seats pretty cheap. Then reinstall everything yourself.

[Jan Arnett]

I alway use a cutter and then touch it up with a stone. You might to consider having hardened seats up in if you are going to a machine shop. You will never have to worry about it again.