I'm putting a '51 Mercury Flathead engine in my '53 Mercury and ran into a problem upon trying to fire it up for the first time. The engine (I was told) is a '51 Merc engine with Fenton heads. Before I bought it I checked out the bores and insides while the heads and intake were off and it looked OK. It is a standard bore engine and has adjustable Johnson lifters. Everything looked to be in good shape, and the guy I was buying it from is an engine builder so I trusted his opinion. It was a decent price, so I bought it and dropped it right in after a new set of head gaskets and intake gaskets. First problem I ran into was no spark. I had used my distributor from my other engine and it had a Pertronix unit that worked fine...until now. I replaced that with a set of points and condenser and now have spark. Tried starting it again and nothing. Engine spins freely..maybe too much so. Did a compression check and found it has none in the #1 cylinder. Zero. Doesn't even move the needle on the gauge. Called it a night after that disappointment. What should I look for next? Maybe all the valves are wide open? I'm going to check the other cylinders today and see if they have any compression. Any other suggestions? I'm new to flattys, this is my first..actually my second because I blew up the first one. What should I do first? Spike
I'd start by removing the intake manifold, spin it over and watch the valves. If they're not moving check the timing gear. If timing gear stripped you may have some valves really stuck. If some are and some are not proceed to free up the stuck ones. Next time (on flathead engine #3) while you have the heads off spin it over and see if they're all moving.
my dad's friend had a flattie that wouldnt fire, finally took off a head and found a rag down in the cylinder, no rod or piston, musta been WAY outa ballance Probably in your case its a stuck valve or hole in a piston pull a head check the piston and crank it and see if the valves move Also Blown is right i'd be one of the fiber timing gears and it coulda came apart, but then the distributer wont spin
Most likley a stuck valve.Test the rest of the cylinders.If only that cylinder is stuck open it still should start.Also if the adjustable lifters are adjusted too tight may be holding valves open.
could be the valves are not adjusted correctly and are staying open, pull the intake and make sure they are operating... just a thought RED
...Spike......also, look for any valve stems that may be bent.....that will keep the head of the valve from seating properly and cause no compression.......I had one of those once... Otherwise, I go along with the guys who say check the valve adjustment.........some may not be able to close, and hanging open they cannot make compression..... Good luck.....get that thing running.....we need another flathead on the road! CB
Damn, that is a tough one. No compression in #1, and I assume that if it is spinning easily that there is no compression in any of the cylinders! Can't be cam gear as you say you are getting a spark which means that the cam is moving the disributor. Check your compression gauge! Pull the plugs and crank the engine to see if you are getting pressure out of all of the cylinders, Piston went up an down when you checked the engine? traderjack
Otherwise, broken crank at front main. LOL Nope, otherwise distributor would not turn when cranked. Leaves broken rod on #1 cylinder at crank. Most I can think of. Let us know1 traderjack
Does it crank normally, or kinda erratic?? Had a flathead with numorous stuck valves, no compression, but cranked funny. Pulled the heads and valves, cleaned the guides, oiled everything up and put it back together. Still runs like a top....
We had the same problem with a flatty that sat for many years. Pull the spark plug of the offending cylinder and have a look at the valves. My guess is that one of them is staying open and never closing. I put some ATF in a plastic squirt bottle and using the stream setting I was able to hit the valve stem with a squirt of oil. A screwdriver provided the extra oomph to snap the valve closed again. Don't pry too hard it could be up on the cam. I had to repeat the process a couple of times before the guide got enough lubrication to opperate smoothly. Once it did it ran as smooth as silk. Flatheads don't have a lot of spring pressure so they are more prone to sticking in the guides than the over heads that we are now used to. I'd at least give it a try before I tore the engine apart. It worked for me.
Thanks Tommy! Thanks everyone! I was thinking valves staying open myself so I'll check on that first! I got more help here than anyone I've talked to in person! HAMB rules! Spike
Take the plugs out, all of them, spray some oil in the cylinders and start it up!! You'll be fine! Thanks, Gary in N.Y. P.S. Happened a few years back on a 225" Mopar! Unit sat for some time, needed a "prime" at the rings!
Thanks Gary! I sprayed some PB blaster down the spark plug holes a few days ago. Trying the valves next.. Spike
Hmmm... Motor fires? Does it even sound like it might start? Backfire? A V8 can run on just a few cylinders, I've run them just with one side of the engine firing.
Pull the spark plug out & crank the engine while looking thru the plug hole with a flashlight. You can see most of one valve & a small portion of the other just as a preliminary indicator as to if it's a stuck valve or not. Billy
Any luck yet? Remember it doesn't take much to keep the compression down. I just replaced a head on an off topic car, because of no compression in one cyl. When I pulled the head I was expecting very bent valves, but they only really had a couple thousandths gap and could only tell that they were not seating properly when I shined light through the ports. It scared the crap out of me when at first it looked like everything was working right!
Just follow Tommy's post! Gravity dries the valve stems quickly on an unused flathead... oil, tappem down, keep turning engine over by hand until all will close with spring pressure. Be careful--valves are much easier to bend than seems possible! Add MMO to pan and first tank of gas to gettem really oiled.
Thanks Bruce! I haven't had a chance to work on the car again since my last post. I've been having a rough life in the past few months and everything is going wrong it seems. I may just sell the engine and car and call it quits for a while. This economy is taking its toll on my family and I may need to get away from cars for a while. Hate to sound so negative but its how I'm thinking at the moment. Spike
A flathead with all or most valves stuck will just crank very fast ans smooth endlessly. If it has had decent storage, sticking may well be minor, correctable as above.
Bad economy...OK, next we will cover the no-dollar Okie Valve Job, straight from Hooverville! Been there and done that... a flathead can be the right engine to work on in bad times...do it like it's 1935. seriously! We get into the habit of replacing everything in sight when times are good. If this engine rotates, we will get it going for nada.
So true!! Everyone thought i was crazy on my 'camino daily to toss in the unknown SBC that hadnt ran in years and came with the car. After rotating it it over by hand i decided it must be okay to get it running, it runs great, burns a bit of oil, but good enough till i get my new motor done
How about a visit from Bruce? LOL. The car IS in New Jersey after all..South Jersey (Audobon). I need a drink. I'm gonna party like its 1935....ha ha ha Thanks Bruce for all your advice and kick in the ass. I need that sometimes! Spike
I think everyone should learn about engines on a Ford V8 flatthead. It is so hard to do anything wrong to them! TrderJack
The Jalopy Journal
