After finally driving my truck all of 4 miles (first miles in 10 years on the truck!), it was blowing smoke big time and seemed to lack power. Checked compression and two cylinders were zero. One of these came up to around 30 psi after a squirt of oil into cylinder. Other cylinder stayed at zero. So we removed the heads to check it out.

First issue, on the cylinder with zero compression---On the drivers side, second cylinder from the front (I am unclear on the cylinder numbering), the exhaust valve seat was loose. No longer in the recess in the block. Needless to say, the valve is all beat up from banging on the unseated seat. The recess in the block is slightly dented, but looks okay, I think.

Has anyone come across this and successfully replaced the valve seat without pulling the engine and taking to a machine shop (I don't want to spend the time and money on that now). We removed the valve assembly and would replace the valve and guide, if can replace the seat.


Second issue, on the cylinder that came up to 30 psi---Put very thin feeler gauge down between cylinder wall and the piston. On this one, the feeler can go in a couple inches, so it does not seem to get stopped by the rings (other cylinders we cannot do this). Seems to us to be broken rings. Does that make sense?

If rings, does it make sense to just replace rings on this engine. I'm guessing that a complete overhaul would be ideal, but again I don't want to spend the time on that right now. (after more than a year working vey slowly on brakes, I want to drive the truck at least a little before major engine work.)

Any suggestions appreciated.

Duane.

 

Just like the old commercial - You can pay me now or you can pay me later
The valve seat pocket most likely will need resized - it involves grinding or cutting - both produce residue that needs to be cleaned from the block.
You're guessing on the rings
Pull it out and fix it right.

 

Seconded opinion, and this relates to the way I think you want to do this, rather then maybe the right way as Dick has suggested, (now or latter) and this is just my experience.

I owned a shop and a guy had inherited his father in laws 1950 ford car and wanted a new engine, I ordered a Ford rebuilt and after installing and upon starting there was a major clicking noise. Pulled one head and a valve seat was loose in its seat, re-staked the seat and it was good.

Anytime that a valve grind or anything else increases compression pressure on an old engine it is not long before a worn connecting rod bearing starts to knock or worse. So if you’re going to replace the rings (one cylinder) and even not taking into consideration cylinder wear etc. that is a recipe for an eventual disaster unless you do the bearing and at that point is when you do a complete overhaul.

If you absolutely have to do a “patch” at this time and depending what is going on in the bad piston hole you could replace it with used / worn parts, it’s been done before but that great shudder you just heard was a collective one from purists.

 

I hope you all don't mind me chiming in here. I've been doing this since 1967 and during that time, I have seen and tried just about every fix imaginable. I'm lucky in that I fire most all my engines on a dyno and it acts as a quality control measure. I have several race customers and we usually tear all them down in their off season and again I get to see what is going on. I do much machine work as well as several engines a year. I do many restorations and luv each one of them. My thoughts on the above are 1:if a seat came out , it lost its press fit. Can be from the seat getting hammered or the seat hole becoming over-sized. Irregardless, at the least I would re-cut/re-size the seat to restore a press fit. Yes I have heard people staking the seat, but you can never get a .002 to .003 press fit and eventually it will loose any press fit but the largest problem is that the seat has no way of carrying the heat out of the valve. The seat needs that press fit to carry off the heat back into the head. 2:On the ring and feeler gauge; my thoughts are that the rings are either stuck back in the groove or they are broken, but irregardless AINT working. I know some one mentioned that this could lead to a damaged rod bearing if you repair. That will always depend on the condition of the rod bearing to begin with. If it is loose or damaged the compression will accelerate that condition more rapidly. That comes from the thought process of if I do a valve job on an old engine and I increase the cylinder pressure, it will start to use oil. Yep it can conceivably do that. Always the gamble. Up to the owner. Some times short cuts are just that; short cut. Your gamble. If your wrong just don't tell any one and they cant say"I told you so". I hope this helps. If it doesn't then lets all have a better day. I got to play with a flat head on the dyno today. I believe it is going to make over a 1000 horsepower. Then I think I will start it. Then I got to fire a GTO engine and then a older 442 engine. God I luv this crap. Man you should see this 1929 engine I have here to do that has no oil seals and the customer wants a small turbo put on it. I got to make the rods on my CNC mill.
racear

 

Is the cylinder wall scored? If so then its the rings.

 

I appreciate the input. Normally, I would like to do it right (pay now). It is just a bit hard to get to that decision right now-I was very much wanting to drive the truck a bit this summer and rebuilding or replacing the engine will take a lot of time (for me, anyway). If I do it wrong (pay later), the info helps me know what might/will be down the road.

fifty_two_f1, the cylinder wall does not appear scored, visibly or by feel. I do notice a relatively significant ridge at the top of each cylinder, meaning plenty of wear.

Duane.

 

You can just take it apart, pull that rod and piston out and see if you can free up the rings, clean up the bore a little, worst case put a set of rings on that piston. You'll also know what shape the con rod bearings are in, and can decide whether to mess with them now or later. Clean up the oil pan, new gaskets, you might get a summer's use out of it.

 

I Really want to see and hear some more details of this 1000+ horsePower Flathead V8.
Sounds like some firebreathing machine for sure! what has been done to get 1000 HP?

 

I smell some Bovine feces
I want to see the dyno sheet for this and the dyno run on video.

 

Jmadsen, if you read the very next line, you will understand. It means I am going to dream about a 1000 hp and then I will wake up and start it and be back to the real world. The owner, Steve, would luv to see a 1000 hp but the only way to do that is put another engine in front of it. Heck I can do that. I got a 622 cu in Chevy that made 1100hp at 6000rpm. You think the flat head will hold up if we buckle them together and fire both. Damn I gots to take a look at that. Lets see 1100hp plus 105 hp. Yep lets try it.
racear

 

Now wait a minute freakboy. Bovine feces??? I am trying to retype the dyno sheet now. I am trying to put anudder 0 in with the 100 hp and the dang thang keeps rejecting it.
racear

 

hahaha lol, I got ya, Helps if I read (and comprehend) what I'm reading....
I was thinking kinda along the lines of what freakboy said,

Cheers

Josh

 

Josh
Aint it nice to be able to let a little loose in this world. As quick as I had posted the first post about his flat head, Steve called and wanted to know how much DID it make. I told him my dyno dont read DOWN that far. I just got a Briggs and Stratton off before his. Geez he looked like some one poked a hole in his ballon. HaHaHa
racear

 

now thats funny right there!

 

Ohh ok i see now.. lol the smell of the feces went away now