Troubles Starting a 241 Dodge Hemi Engine - That's Hot Rodding
Today it is easy to turn on your TV and watch a wide assortment of television programs which make building a car seem really easy. All it takes is the right amount of money, ordering the parts, and presto the car basically builds itself right? Well, not always!
Just recently I was reminded once again that no matter how hard you try to get everything right, the never-ending list of variables present when building a car can bite you. This is a tale of how a simple failure caused heartache but then was solved with a little patience and friendship.
If anyone out there has followed my tech videos or articles, you may already know that I am working on a 1929 Ford roadster built like it is 1956 with a 241 Dodge Hemi from a 1954 Coronet. I love baby Hemis and have been meticulously building this one over the past couple of years. I had done all of the research, ordered all of the best parts, became friends with the local machine shop, and put everything together slowly and carefully ensuring not only did it look good, but it would be a strong dependable engine to power my little roadster.
Because the chassis had been undergoing some final welding and installation of final parts, like brakes and fuel lines, I decided to build a test stand so I could run the engine and check for any issues prior to mounting it in a car. I hooked up the fuel, electronics, and filled it with oil. Everything was looking good. I had my 8-year-old son helping me. While I primed the oil pump with the distributer off, I had him crank it over until there was fuel pressure. Everything was going well. I dropped the distributor back in when I remembered one more thing…….coolant! I filled it up with water so she could stay nice and cool while we broke it in on the stand. I was giddy with anticipation wanting to hear my little masterpiece fire to life with its special cam and two deuces feeding a vintage Edmunds aluminum intake. I was sure it was to be the sweetest and most satisfying sound I had ever heard!
My son watched me, learning from my every move how to be a hot rodder. He had a smile on his face as the radiator was nearly topped off. Then I heard the words……
Dad, why is the water pouring out of the exhaust pipe?
No, how could it be? A frost plug perhaps, or maybe it was the drain cock on the radiator. Surely it was something simple? I looked up and saw it instantly. A steady stream was indeed coming out of the LH exhaust tube! I had that sinking feeling. I had the feeling you get when all of your expectations for a wonderful outcome completely evaporate in front of your eyes. I quickly realized that water coming out of the exhaust was a sign of a very bad issue and things were rusting quickly.
My instinct was it to do something dramatic, like yell horrible words no kid should hear then throw something for added relief. Before I succumbed to initial primal instinct, I remembered that my son was nearby and watching my every move. This would be a teaching moment for him that not everything in life goes as planned. I pulled up a lawn chair and thought about it. My first thought was the worst possible causes like a cracked block or bad head gasket. I knew I couldn’t turn the engine over full of water or it might lead to a more catastrophic problem like a bent rod. I pulled the exhaust off the side of the engine and could see it was just one wet cylinder. At least it is only one cylinder, I thought to myself trying to be positive. Before contemplating much more, I knew I had to get the water out of the cylinder. With the plug out, I used a breaker bar on the crank to bring that cylinder’s piston all the way to the top. A giant jet of water sprayed out of the sparkplug hole. I then went and grabbed my wet vacuum cleaner and used it with a combination of a blow gun hooked to my air compressor to pull all of the remaining water out. My last step was to fill the cylinder with engine oil, then bring the piston down and up just to ensure everything had a protective layer of oil while I pondered the issue.
My son said, “Dad, you should call your friend Zach and ask him what he thinks!” No way, I thought to myself! I wasn’t ready for the embarrassment of telling one of my cool car guy friends that I don’t have a clue what I am doing. I typically wouldn’t think like that, but let’s face it, I was having a bad day!
Then Luke said I should call grandpa, my dad in South Dakota, and ask him what he thinks. To appease my son I decided this was the way to go. My dad is the guy that taught me to love cars. A hot rodder, tri-5 restorer, and circle track racer from back in the day, he has always been a great go-to. I gave him a ring and put him on speaker so Luke could hear. He patiently and carefully told me what I needed to hear; he said I should check the intake manifold for issues, make sure the bolts are all tightened down tight and be sure the gasket is sealing.
I checked the bolts and had some that were not as tight as they should have been. They weren’t bad, but the more I thought about the intake, the more I agreed it had to be the culprit.
The part that started the entire 241 hemi adventure had to be the problem! I found this old Edmunds intake at a swap meet when I was 14 and always wanted an engine for it. It had always been in decent shape, but it had a hole in one of the runners, drilled in the early days for some unknown sensor or water port. I machined a plug for it and welded it up long before bolting it to the engine. Problem was, I never checked the mating surfaces to make sure they were square to the heads after all of the welding. I wondered if the heat had caused enough warpage to be the issue.
I went to work pulling the intake. It wasn’t easy; not only did all of the carburation need to come off, but I also remembered I had put a light layer of silicone on the gaskets. After all of the bolts were removed, it wouldn’t budge. I heard of a handy trick for removing intakes in this situation. Rather than pry on it, or try to cut it off, I used an engine lifting strap hooked to my cherry picker. It didn’t take much before it slowly gave way and came off. I was careful that no material fell down into the ports, and then examined the intake. Looking at the gaskets, I could see areas where the water seemed to be sneaking from the water port which warms the intake into the number 7 cylinder.
Once I had the gaskets cleaned off of the intake, I called my friends at Speedway Racing Engines and asked if they could fly cut the intake just to be sure it was right. They were on it right away, and a $20 bill later, I had an old intake with beautiful mating surfaces. They mentioned it wasn’t off by much, but there was a low spot between the water jacket and the #7 port.
I brought it back home in a flash and bolted it back up making sure to follow the right torque sequence and spec for each bolt. This time it just felt right. After I put everything back together; it was the moment of truth again. I filled it up again thinking I had it whipped. I had the radiator topped off when, once again, I heard the rush of water running out of the exhaust pipe. Not again!!! The idea that the water was leaking between the intake gasket ports was not the problem after all. Again, I removed the exhaust and looked to see what was going on. Water was coming from the same port. This time I used a small inspection camera to look into the port and find out if I could see where the water was coming from. To my surprise, I saw it clear as day, making me wish I had used the camera the first time! Tucked behind the valve guide was a gaping hole in the port, right into the water jacket.
There was no way around it now, the head had to come off. I was sick at the idea, so I simply cleaned the water up and went into the house for the night. Twice now my dream of hearing the engine fire had been squashed. I decided I would tear the head off the next morning when I was feeling better!
Once I removed the head and removed the valves from the problem cylinder, the problem was clear. A hole about the size of a pencil, just like I saw with the camera was peering back at me. I thought for sure I would need a new head.
I brought the head with the hole and a junk-yard head down to my friendly machinist. This is the same shop that did all of the engine work during the rebuild. When I showed him the hole in the head, he couldn’t believe it. Because the heads had a substantial amount of porting done to them, he didn’t like the idea of starting over completely on a new head but instead said he could repair the hole in the original head.
I asked him about cost, and he simply said: “don’t worry about it, I’d do anything to help out another hot rodder”. I thought that was really cool. I didn’t blame the machine shop for the problem, it is all part of working on antique engines. He called me a week later and explained his expert cast iron welder had welded the hole and when pressure tested, it held up great.
I brought it home immediately and reinstalled it on the engine. After a few new gaskets were installed and everything was torqued down, it was time to try it again. The third time is the charm!
It was the charm indeed because this time, once I had it filled up with a fresh break-in oil, coolant, and fuel, it fired to life with music more beautiful than I could have imagined. Sure, a 241 Baby Hemi isn’t a fire breathing monster, but it had the sound of an old school hot rod. Cast in 1954, driven the last time in 1961, dragged home by me in 1995, and machined in 2015, it is now ready to extend its story as it powers my little roadster into the future. The moral of this story is that hot rodding is not always easy, and issues are always bound to pop up. The important thing about hot rodding is to enjoy the process even with things go horribly wrong. Just think of it as an opportunity to learn something!