SAC
Go on out and find a car. Either buy a competitive Mini Sprint (as fast of faster on the small tracks) or convert a Midget roller over. The little independent guys like Johnny Murdock, Jay Tender and Wayne Davis are probably ahead of the curve as far as tec and being out front with the racer. Purses are not going to be too large starting out. If you are racing for money stay away from National Midgets, D2 Midgets and for that fact Mini Sprints. If you are going to be racing as a hobby and for fun, then for many racers, (not all racers) the thing to consider is how to race with out selling the farm or spending the kids lunch money. If you want to race National Midgets better have two or three farms and a big time sponsor or two on board. In the past Mini Sprints have been the alternative race car of choice. We have raced them for 20+ years, however the economy and competition for the popular motors and the design of the newest and fastest motors is going to cause the price of motors to rise for the Mini Sprints.
That leaves us with the D2 Midgets. While not as fast as the Mini Sprint in most cases the cost of the initial motor expenditure is usually less than a $1000.00 with most hovering around 3 to 5 Hundred dollars. The good thing about motors from wreck vehicles is they tend to get better each year (competition between manufactures). Unfortunately the National groups have ruled out the newer motors with the displacement limits.
An old engine builders saying is that Horsepower is in the cylinder head. This is very true and is the reason D2 motors perform so well even in their stock condition. Because of the 4 valve design they perform equally well from Idle to WOT and require a very mild camshaft to accomplish this task.
The national guys have chosen to allow after market rods, camshafts, valves and valve springs I believe. As long as they prohibit porting and larger valves most of these changes will not add much more power but let the racer brag a little bit about how tec his motor is as compared to his fellow racer. Keep the ports STOCK).
Now as far as tec:
Testing for rods and crankshafts>>>Drill and tap a 1/2" FPT hole in the crankcase in front of any rod. Insert a 12AN fitting and cap into that hole. Remove the cap and insert a bore scope and if you want to be hi-tec stick a magnet in there also, visual inspection should tell you all you need to know.
Testing bore>>>these little engines can not be pumped like push rod motors because you would have to disable the cam shafts and that would cause costly piston to valve contact on the other cylinders. However the spark plugs for the most part are all located directly in the center of the combustion chamber. They make a gauge to put in the cylinder through the plug hole to measure bore with.
Stroke is even simpler just stick a 12" vainer from Harbor Freight in the spark plug hole and take a direct reading.
Compression ratio>>>usually a bore scope will detect raised piston crowns and or aftermarket pistons. If the camshafts were kept stock then a compression gauge could also be used.
Camshafts>>>The best and easiest way to check camshafts would be to just measure gross lift. You would install two 3/8 x 1" bolts that had been drilled through the center of the bolt. Attach these directly over the intake and exhaust camshaft lobes using a O ring and standard nut. Make a fixture to hold a dial gauge and take your readings. When done the bolt could be covered with an acorn nut to keep dirt out.
Porting>>>We use a bore gauge again. Open the throttle body insert the bore gauge. Stock ports are cast and not ground or polished. Grinding and polishing is easy but getting that cast finish back is nearly impossible.
The D2 concept is new and is going to take a little time to get up to speed, it needs guys wanting to get into Midget racing to get involved to get it up and running. Once they prove their ability to put on a good show the purse will get larger>>>it is all about competition and supply and demand.
Honest Dad himself
