I would suspect #3 and #6 had valves standing open for an extended period of time. They had condensation crust grow on the valve and or seat keeping the valves from making a good seal when now moved into the closed position. It will run with the numbers showing of todays test. I say put the plugs in and give it some fuel and light it up. It will either clean itself up while burning fuel or take take out a valve. At any rate your not going to know what direction it will go till it makes Smoke and Noise. Just do it, you can't damage anything past where it's at as of now. Yes it will run on all 8 with the numbers showing and probably get better as it does.
That is pretty much what I thought. I think next weekend we will try to light it off if trevor can stand the wait. I started working on the block off plate for the fuel pump this evening between breaks of fitting the drivers side quarters on my project. Good stuff!
Yeah it has great compression. But any juice poured in its plug hole drains straight out the exhaust. Not sure what’s up.
It looks like the valves are moving, but (I think?) that doesn't mean they are closing all the way. I guess I will just keep doing what I'm doing. Maybe it will decide to act right on its own. So far this engine has been good about that. What confuses me is that as far as I understand it, if the valves were not closing all the way or were stuck/broken, it shouldn't have good compression? I'd think if there was any hole that liquid could just flow through as freely as it does it'd show 0 psi on the gauge.
Agree - might do that to the early 8N I have with the front crab mounted that's in line to b brought back to life. My 8N bucket tractor does okay on a 6 volt but think that' due to low compression.....my other 8N bush hog tractor like's the 12v - those points have been in about 5 yrs.
If I was certain I had oil pressure, I would fire it up or a few seconds. All the soaking and turning over of the engine you have done is about as much caution as is practical. Like Pistn-n-broke has indicated it will run with those numbers and probably get better as a heat cycle or two loosens up rings ect.
Yep... going to keep soaking and turning in the meantime, just to see if I can get any more numbers up, but RMONTY and I are meaning to try and start it next weekend. Plug wires are on the agenda... not sure if the ones that are on it are gonna be any good. They are pretty rough. The fuel pump pushrod I got to plug the hole in the block stands proud of the hole in the intake manifold by quite a bit.
trevor, take a picture of the pushrod at it's highest point, and then rotate the engine and take a pic of it at it's lowest point. Also, take a pic of the pushrod all by itself if you dont mind.
The actual throw is so short that it’s impossible to take a picture that really shows the difference between highest and lowest points. The lines in the second pic were drawn above the rod at its highest & lowest. Here is the pushrod by itself.
@alchemy, did you cut the pushrod off and put a cover over the fuel pump boss? How did you make sure that the pushrod didnt somehow come out of the hole and get up into the valve train?
Results of today's testing are in: Cylinder 3 made a massive improvement and 7 is still coming around, but I'm seeing pretty big drops on 4 and 5, and something of a drop on 2. Expecting some variation from test to test but 4 and 5 are kind of alarming.
trevor, i think that there is probably carbon and just plain old crud in the valves, rings starting to move around again, etc. that is allowing the pressure to leak by. Once we fire that thing off, everything will stabilize I would be willing to bet. As Pist-n-Broke mentioned, those numbers are more than sufficient to get that thing to light off.
Yep. Should I keep messing with it and recording numbers or just let it soak til next weekend? I doubt whether there's anything else to learn from testing it.
At this point, I don't it is going to get much better without lighting it off. It cant hurt to keep soaking it. That engine hasn't run in at least 10 years according to what the guy you bought it from said. It seems healthy enough to make some smoke anyway.....
I have my stock breather stand on my engine (a 59A style engine) so I didn't need to make any flat cap. If you've done the raise it and glob a weld method like I described, then just cut it off a quarter inch below your cap. If it bounces up a quarter inch it won't fall out of the bushing. In fourteen years mine has never bounced out of the bushing.
Very interesting thread. Makes me wanna fire up the old ´47 V8 that is sitting in my garage, just for fun.
I got a set of plug wires. Gotta trim them and whatnot. I think they're too big around for the original P-shaped wire holder things. Not sure if there's a technical term for those.
Really enjoying ready this thread and have picked up some great info regarding the 6 and 12 volt details as am getting close to going through the same process with the flathead I have. I have an engine similar to Trevorsworth and am fitting some twin plug heads and Nash 8 dizzy to and was a bit confused about the 6 versus 12 V coil points condenser thing. I have also had to drill and re tap broken head studs with great advice from the HAMB as far as guides for drilling etc. go. Great for you to have a guy like RMONTY to help you out, thats what makes this hot rodding thing so great, the people you meet and the generosity of like minded people.
Taking a breather. Got the firing order worked out. Just need to cut to length and fit boots now. Definitely can't fit 4 in the factory wire holder deals but I know I need to suspend those 4 somehow so they aren't resting on the heads. Hmmm.
For no longer than we are going to run the engine, it isnt going to hurt the wires for now. Once we get it to where you can run it for extended periods, then it becomes an issue. Going to have to find a radiator and at least one water pump before any of that happens though!
Having torn more than my share of intakes off flat heads - that is easy and gives a good idea of what's inside. That was some good advice early on from some of the guys. Should be able to get a intake gasket at Napa for not all that much. You don't want by chance a rats nest in there - in case the breather was left off awhile. Just cleaned out a dead one under my Studebaker intake that hadn't been there for very long. With the intake off you can get a good idea of the sludge factor and see what the valves are doing as it turns over. Usually I end up replacing a valve - a guide - spring or a KEEPER - sometimes. Finding cheap NOS not that hard or pricey if you get to that point . Not planning a trip over to Weatherford at the moment - PM me your phone and/or address as I do take care of the Brookshires there and Aledo....have a carb somewhere......
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