Snow engine thoughts

[Rustkolector]

Gordon,
At the time Doug, and many others, built the Snow engine a company in FL called MJN Fabrication was selling all the Bruce Satra designed ignition components including the distributors. Many of us bought the distributor bases with a set of points installed. The four lobe ignition cam is an integral part of the distributor rotor shaft and operated the MJN installed points. A lot of builders used the points with any number of transistor ignition systems and a separate coil and battery. MJN closed up their operations about the time the more compact CDI ignition was introduced. Most everyone now seems to prefer the CDI systems using a Hall magnetic sensor in the flywheel or distributor base. They are as simple and compact as it gets.
Jeff

 

[Gordon]

Gordon,
At the time Doug, and many others, built the Snow engine a company in FL called MJN Fabrication was selling all the Bruce Satra designed ignition components including the distributors. Many of us bought the distributor bases with a set of points installed. The four lobe ignition cam is an integral part of the distributor rotor shaft and operated the MJN installed points. A lot of builders used the points with any number of transistor ignition systems and a separate coil and battery. MJN closed up their operations about the time the more compact CDI ignition was introduced. Most everyone now seems to prefer the CDI systems using a Hall magnetic sensor in the flywheel or distributor base. They are as simple and compact as it gets.
Jeff

I have the S&S distributor. I am not sure what the problem is but I have burned out the transistor on a TIM 6 twice now. I have it running using the S&S ignition module. I was just thinking that a straight forward point ignition would be simpler. If it requires making a new distributor with internal points it certainly is not easier. I guess I will just stick with the existing setup. Thanks.
Gordon

 

[Gordon]

Update: I just made a new intake manifold, straight line 7/32 dia tube. Due to a screw up on tapping the carb mount block I ended up using another existing single throat non throttled carb and the engine starts and runs well. I do not have the coolant system reinstalled yet so I cannot run it for more than about 4-5 minutes before it starts to get too hot. I figured that coolant was not a priority until I could get it running consistently.

 

[Rustkolector]

Persistence pays off. Congratulations!
Jeff

 

[Rustkolector]

Gordon,
How are your Snow modifications coming?
Jeff

 

[Gordon]

Gordon,
How are your Snow modifications coming?
Jeff

I have it running but it keeps getting out of adjustment. I cannot keep the set screws tight enough. At this point it is no longer my problem. Due to some strange circumstances I ended up selling it. I was working with a guy to sell him one of my engines and the next thing I knew he bought 15 of my engines. I have been thinking about thinning out my stock so that my kids did not have to try to figure out what to do with them and the whole thing went down a lot quicker than I anticipated. That is good. I have been just working on previous engines to tweak them because I did not want to add to the problem. Now I will probably take on another larger project which hopefully will be year long project. My kids are also glad.

 

[burn0170]

Rustkolector - Do you have any pictures or details of how you did the updated intake manifold? We are building the snow now and will be using your suggested updates to hopefully lessen the frustration in getting it running.

 

[Rustkolector]

The intake manifold was made by soldering two 3/8” x 3/16” rectangular cross section brass tubes back to back. See photo of the open end cross section before closing it up. The center carburetor cross section sketch shows the coolant water path at the carburetor. I suggest you put a drain fitting at the bottom and end of the outer fuel manifold to be able occassionally to remove any collected fuel and oil.

Also, see other HMEM forum thread on the same subject My Improved Snow Engine

 

[burn0170]

Rustkolector - We are assembling our Snow, and I noticed on one of your posts that you mentioned that you pinned the pistons, or that you were thinking of switching to half dog set screws. What did you use for pins? Spring pins, taper pins, or ?? I was thinking about using green loctite, but I also like your idea of pins. Any advice on securing the pistons is appreciated. We aren't to the point of starting it quite yet, but I assume once we get the pistons centered in the bores, we should never have to remove them from the piston rods?

 

[Gordon]

Rustkolector - We are assembling our Snow, and I noticed on one of your posts that you mentioned that you pinned the pistons, or that you were thinking of switching to half dog set screws. What did you use for pins? Spring pins, taper pins, or ?? I was thinking about using green loctite, but I also like your idea of pins. Any advice on securing the pistons is appreciated. We aren't to the point of starting it quite yet, but I assume once we get the pistons centered in the bores, we should never have to remove them from the piston rods?

They probably will have to be removed at some point. You are probably going to have to replace the seals or the head gasket.

 

[burn0170]

They probably will have to be removed at some point. You are probably going to have to replace the seals or the head gasket.

Thanks Gordon, just to clarify, we wouldnt need to remove the piston from the rod to replace seals or gaskets, right? I modeled my center coupling after Rustkolector's design and that worked great so far.

 

[Rustkolector]

burn0170
Most Snow builders have encountered set screw loosening at the center rod connector and sometimes the pistons. Most of that comes from tired set screws that are worn from assembly and reassembly. The heavy recip masses in the Snow really stress all the piston rod assembly set screws. For the center connector you can thread the rod ends and connector. I chose to make my rod ends with full end to end contact between each other and use a clamp type connector. One of my other Snow threads shows a sketch of the clamp connector. The clamp type allows for easy disassembly. If you use this method you will need to also make a small single cut split delrin filler piece for the rod clamp shaft relief to prevent damage to the lip seals when assembling.

The pistons are not as hard on the set screws as the center rod connector but there is a good chance one of them might come loose. On my rebuild I also installed a spring pin (size ?) to retain each piston after finalizing the piston positions. In my experience the pistons do not have to be precisely positioned, just very close. There maybe a tiny usable adjustment allowance left in the crankshaft block position that can help.

CAUTION: I have enjoyed my Snow engine and it had accumulated lots of both short and long run time cycles. I never paid much attention to how I left the engine after shutting it down. As a result I noted that upon disassembly my cylinders and piston rods (drill rod) showed significant corrosion had taken place although the engine was still running fine. Upon rebuild I decided to use TGP stainless steel piston rods. I have also adopted an engine shutdown procedure to mitigate cylinder bore damage from combustion moisture (which can be significant). I now spin the Snow engine over about 20-30 revs with ignition OFF, throttle OPEN, and fuel ON to rid any residual combustion moisture and hopefully lubricate the cylinder.
Jeff

 

[burn0170]

Thanks Jeff, that is very helpful. I've reviewed your other posts have incorporated all of your findings (center clamp connector, stainless piston rod, new cam design, intake manifold, etc). I'm hoping to learn from your experience and have a good running engine without too much frustration. I really appreciate everyones help!

 

[burn0170]

I just wanted to drop a quick note and say thank you to Jeff, Gordon, and the others that have documented their experiences with the Snow engine, we started ours last night for the first time. Your input and experience really helped move our project along and help us avoid issues. Once we get it tuned in, I'll post some pics/videos. Thanks again.