We have compression... working on ignition next!

[Chris-R]

So, I got my 6v starter armature rewound by these guys. They claim to be the last firm who can do this work in the UK, and whether or not that's true (it's believable having called around all over the place, but still surprising to me!) I can't recommend them highly enough. Rather than ship it in, I delivered and collected my unit in person, and can confirm they are very nice people who take a lot of pride in what they do -  http://www.robsonandfrancisrewinds.co.uk/veteran/

Anyway, with the working starter installed, we put a little glug of oil in all the cylinders and turned the engine over for a wet compression test.

1 - 110psi
2 - 115psi
3 - 115psi
4 - 115psi
5 - 120psi
6 - 115psi

As the engine isn't thought to have been run for 30+ years we didn't do a dry test, so I'm ready to be told/discover that my optimism is wildly premature...   ?

[Sniper]

Well, my 51 had around 50 psi per cylinder when I bought it and it ran, still runs, fine.  So I am optimistic for you.  Just have a fire extinguisher hand, just in case.

[Chris-R]

4 hours ago, Sniper said:

Well, my 51 had around 50 psi per cylinder when I bought it and it ran, still runs, fine.  So I am optimistic for you.  Just have a fire extinguisher hand, just in case.

That's encouraging... it's going to be a while before I find out if mine runs though. The carb is choked with petrol residue and I need to get a carb gasket kit posted from the US (or more likely a full rebuild kit.) 

[keithb7]

Consider running a heavy 1:1 oil/gas mix ratio not  unlike a 2 stroke? Lol. Just kidding. Do not do this! She’ll fail quickly. 
 

I’ve personally never seen 120 psi in a flathead mopar engine. I wonder if you have severe carbon build up in there? Or maybe I just need to drive down to sea level and perform a compression test. That’s a tall order. I’m probably a 4-5 hour drive each way in my ‘38 to get to sea level.  That’s a pricey compression test. Lol. 

[Chris-R]

1 hour ago, keithb7 said:

Consider running a heavy 1:1 oil/gas mix ratio not  unlike a 2 stroke? Lol. Just kidding. Do not do this! She’ll fail quickly. 
 

I’ve personally never seen 120 psi in a flathead mopar engine. I wonder if you have severe carbon build up in there? Or maybe I just need to drive down to sea level and perform a compression test. That’s a tall order. I’m probably a 4-5 hour drive each way in my ‘38 to get to sea level.  That’s a pricey compression test. Lol. 

Haha I'm pretty close to sea level - maybe that's it. I'll probably develop a carbon problem if I manage to burn all the oil in the cylinders ?

[Art Bailey]

Nice numbers, even if oil or carbon might be boosting them a bit! She'll run. Congrats on the starter--I remember how ragged it looked, they must know their business.

 

One of my favorite things is seeing a flathead cough and sputter back to life, so I hope you keep us posted with videos!

 

[47 dodge 1.5 ton]

Those are great numbers! Might even get a little more once you run it some. The motor I started with had a high of about 70psi on (1) cylinder, (2) with “0” and 35-50psi on the remaining (3)!  First start was using the hand crank and ran pretty smooth with just (1) dead miss. 2nd start was using the starter and I had a fire coming back through an intake valve, never had that experience before but learned that would be a common occurrence until the valves were free. Once running for a year, got 90psi on all cylinders.

 Have another one that had never been open, 125-130psi on all (6). So we know some of these engines will produce good numbers. I am @ 375ft above sea level.

Edited October 4, 2022 by 47 dodge 1.5 ton

[Chris-R]

7 hours ago, 47 dodge 1.5 ton said:

Have another one that had never been open, 125-130psi on all (6). So we know some of these engines will produce good numbers. I am @ 375ft above sea level.

Now I have compression envy ?

[Chris-R]

10 hours ago, ratbailey said:

Nice numbers, even if oil or carbon might be boosting them a bit! She'll run. Congrats on the starter--I remember how ragged it looked, they must know their business.

 

One of my favorite things is seeing a flathead cough and sputter back to life, so I hope you keep us posted with videos!

 

They know what they're doing, and they're nice humans too. It's refreshing to find somewhere that doesn't automatically associate the words 'classic car' with that cash register 'kerr-ching'! (Or maybe they felt sorry for me as I turned up scruffy!) ?