I just have one question that I had never heard of before and was wanting some clarification if possible. I have a 50 barneywagon and I thought it had the original motor in it but I have found out that it has a hot shot motor is what I am being told. I was at a car show in Knoxville TN. and I had a guy ask me if I had anymore hotshot motors. I told him I didn't know the difference. he said that the Crosley name is set back on the block where as the motor for the other cars the Crosley is at the front of the block. he said that the hotshot blocks were what he used for racing. is this true about the writing on the block?

My understanding is the locations of the Crosley stamp identifies whether or not the block is a TURBULATOR or not. If the name is forward then you have a turbulated block. Turbulator blocks are preferable in the racing environment.

I thought I knew quite a bit about Crosleys, but this is all new to me. Could you expand a little? What is a "turbulator" block? When were they made, and in what models were they used? (The only engine variant I've ever heard about was the "Quicksilver" high-compression, water-injected unit used in some roadsters. I've never seen one, and wouldn't know how to identify.)

Turbulator Block--has a raised area in the combustion chamber. The other doesn't. The purpose of the raised area is better fuel mix--higher compression. However--when using hi-dome pistons watch out for the raised area.

Flat Top

Turbulator

I just came in from the shop where I did a quick survey of 20+ cast iron blocks and engines. Only 2 had the raised Crosley lettering shifted back, so with this great sampling, it looks like only 10% are of this style. Both were complete or partially assembled engines so I couldn't look at the combustion chamber. The interesting thing is one was on a crankcase with an engine number from in the 1948 run of engines so this would probably be a replacement block for a tin engine. The other was on a 1951-52 crankcase. I don't know the history of either engine so they could have been built from parts years ago. I can say for sure the placement of Crosley has nothing to do with flat verses turbulator, of the 8 Crosley blocks that were free of pistons all had the Crosley forward on the block and some were flat and some were turbulator. As far as racing, I think Chuck already answered, turbulator is a better block for general use but if you want to go high compression either with dome pistons or just shaving the block or crankcase you want flat. I have seen high compression pistons that were machined to fit around the turbulator. It would be interesting to know why a few blocks were cast with the Crosley back. If you want another variant , a few years ago(20) I saw an engine that was for sure the engine that came with a 52 Super Sports because the original owner had pulled it out. It had a raised X towards the rear on the same side as the Crosley lettering (forward position). Could it be a Quicksilver block? Beats me, it is the only one I've seen. By the way the Quicksilver used an alcohol injector not water, so it could run 10:1 compression on regular gas.

Here is some more information to expand on Chuck and Jim response: "...the cast iron blocks are made in two forms, one with a flat head combustion chamber, and one with a raised portion in the head, known as the turbulator. The only way these two blocks can be identified from each other from the outside is that the flat head block at the rear has one opening, into which the heat indicator gauge is screwed. The turbulator block has another opening in the rear which is plugged up with a pipe plug...." This section was from the H Modified Racing guide for Crosleys. The turbulator block is preferred. Sorry about the misinformation! I was wrong and I am suprised that I have not got bit on this sooner when looking for engines.

Cast blocks with forward "CROSLEY" are all that I've seen; when rearward how far back? Past the thermostat housing? What about different types of lettering? When they went to "turbulator" what did they do to keep compression ratio the same, or did it go up? Can the pistons interchange?Braje states that Quicksilver engines got the 10:1 comp from factory milling of block surf [where bolts to crankcase] .062. Did not recommend using these blocks for high performance as made block too weak. I think I read somewhere that it was water and alcohol mix for the vitameter, alcohol to keep water from freezing. Or maybe this was used in other systems.

I posted some pictures under Engine Blocks. They show the two styles of logo placement, the flat top and turbulator combustion chambers, several styles of blocks from the rear and some strange numbers that show up in the valve area. cacracer quoted some material that the single rear outlet was flat top and 2 were turbulator combustion chambers. I have a 2 outlet block with flat top chambers so my guess is the singles outlet can be depended on as flats but the change to two outlets was independent of the chambers and can be either. The pictures showing numbers inside the valve area is the latest mystery, some blocks have no number others a 1 and some 2s. They do not seem to be year dependent since I have flat top and turbulator blocks with numbers and without. Maybe this is just which mold was used in doing the casting. Anyone else have a guess. One last thing, I noticed that the flat top blocks I have, all have thinner lower flanges, is this how they fixed the compression ratios for the turbulator blocks.

Link to the Crosley Engine Family Tree

I added a picture of an engine I saw at Wauseon this year. It has a different casting number than the standard Crosley R209501 instead of R209900. The Crosley name is smaller, back and down from the normal location. Any ideas on what this is? It has been suggested that this was for industrial use, but no info on what is different.

Also doesn't have the two plugged holes above the spark plugs...My guess is that it is a later block-look at relief around nuts-seems to be more material around cylinders, between water jacket covers and mounting flange, for planned bigger bore? Anyone ever see a block with "Aerojet-General" cast in place of Crosley? Maybe name moved so "user" could rivet nameplate in place..Can't think of an example right now.