Inherited castings of the v8 engine, decided to work on it. Any advise? I am no stranger to machining as I have been doing it for 50 plus years. Can any of these castings be had anywhere anymore? What happened to Lancer Engineering?
Lancer Engineering v8 engine
- Thread starter gmiller
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Sorry Mark, My siblings and myself bought the castings back in the 70's for my Dad. He did not get to it as he was doing a steam engine at the time. Because I also have done a steam engine and enjoy this hobby I plan on working on it. I have the engine block about 60% completed.
Greg
Greg
As I continue with the Challenger V-8, I am at the point of boring out the cylinders now that the sleeves have been press fit. Anyone tell me the proper piston to cylinder clearance? From the prints it would appear the pistons will be .992 and the bore 1.000. Is that correct?
Hi
This from the planes I have
This from the planes I have
Sounds way too small to me. I have a .750 bore and I made my pistons Between .749 and .7493 using 7075 aluminum. If you use 6061 I would leave a little more room for expansion. .7487 to .749.
I would think you would want to be somewhere between .7485 and .749 with an aluminum piston in a 1 inch bore.
The pictures that i put up are from the challenger plans, but it seems like there could be a mistake in them, as the piston is .997 and the bore is .990, or am I looking at wrong
I have built several I. C. engines with 1" cylinder bores and aluminum pistons with cast iron rings. One constant has been a piston dia. of 0.997" above the top compression ring and a skirt dia. of 0.998 - 0.999". The reasoning is that the top of the piston runs hotter than the skirt, thus more clearance is needed. The design has worked very well for me.
WOB
WOB
Dr Jo
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The Lancer instructions on the bottom of page 4 explain that you leave it small until after it has been installed by freezing liner/heating cylinder and then do the final boring to size.
Jo
Thank you for that info Jo
Commercial piston rings are not very good in my experience, but it has been years since I bought any. I learned to make my own from an article in "Strictly IC " magazine many years ago( issues 7,8, & 9. http://www.strictlyic.com/pit01.htm It is called the Trimble method of fabrication and does require you to make your own tooling. The only real difficulty is the need to heat treat the rings after fabrication. They need to be heated to approx. 1000 deg.F and cooled slowly. A temp. controlled furnace is ideal. Whatever the method, the rings mist be protected from oxidation as scale formation would alter the surface finish and also change dimensions. The other tooling required is within the reach of a hobby machinist. Good quality cast iron bar stock is available from several metal suppliers. I think I got mine from McMaster.com. It machines easily with HSS tools.
This method is somewhat involved but if the maker takes pains to follow the steps exactly, he will be rewarded with top quality rings. They will break in to make a near perfect seal in the first few seconds of a new engine's first run. Of course, the cylinder bores must be round and have a uniform, fine cross-hatch finish from the final honing.
Many makers want to buy rings, but I urge them to make their own as it is a very satisfying aspect of engine building, plus they are not bound by commercial ring proportions which are not optimum, but instead are designed to ease commercial fabrication.
WOB
This method is somewhat involved but if the maker takes pains to follow the steps exactly, he will be rewarded with top quality rings. They will break in to make a near perfect seal in the first few seconds of a new engine's first run. Of course, the cylinder bores must be round and have a uniform, fine cross-hatch finish from the final honing.
Many makers want to buy rings, but I urge them to make their own as it is a very satisfying aspect of engine building, plus they are not bound by commercial ring proportions which are not optimum, but instead are designed to ease commercial fabrication.
WOB
Dr Jo
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Rings are easy to make: Turn cast Iron to size. Hold the ring in a vice and use a pair of pliers to break it just above the vice. Spring the ring open around a piece of metal and hang them on the metal spaced just off the surface in your furnace. Heat the rings using your propane torch to red hot and as the cast Iron sets in the new size they will loose their spring and fall off the metal. Leave to cool. And you will find they have set with the right size gap - simples 
Jo
Jo
