Project "Old Skool"

[BPjunk 184]

My Raider 10 a '69 year model has never run correctly since the day I bought it, the engine has the surging during idle and a blown head gasket. When the cylinder head was taken off it was found the cylinder bore was just worn out ..... so it's time for a rebuild.

Now this Raider 10 was repainted a long time ago and the incorrect decals put on .... plus somebody drilled holes in the hood stand for the throttle lever ..... hummmmm I start thinking .... Could the Raider 10's Tecumseh model HH-100 be made into a pullin' engine and then returned back to stock when the tractor gets restored????

OK Here's what I have done so far.

The blocked hot tanked

Cylinder bored .010

Valve job

Porting on intake and exhaust

grade 8 5/16th studs for the cylinder head

cylinder head milled .020

Vogel regrind cam with more duration

Crankshaft turned .010

.010 piston , .010 connecting rod and gasket kit (Tecumseh parts)

With more compression from the milled head the grade 8 studs were needed, these studs have 5/16 x 14 threads per inch (course thread) on one side and 5/16 x 24 threads per inch (fine thread) on the other. This thread set up was used so the head can be torqued down real slow and easy to get a good uniform torque to keep the head in place. (the block is course threads and fine threads nuts will be used with washers on the head)

When the intake and exhaust ports were ported I opened up the intake for greater flow but left a small amount of roughness to create swirl so the gas and air will mix better. The exhaust port recived a smooth port right down the the threads for the exhaust pipe, this took some carefull work as there is a head bolt hole that is right close to the exhaust port and I did not want to cut into the thread area.

Wild Bill in Richmond, Va.

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[BPjunk 184]

The machine work was done by a shop that specializes in high perfomance work, it cost me $100.00 to get the cylinder bored out, vavle job and cylinder head milled. I could have handled the vavle job in my shop but since it was in this shop it was easyer to let them do it.

Here is another picture of the intake port.

Wild Bill in Richmond, Va.

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[rustyoldjunk 127]

i like it BP.im curious as to how strong it runs when you get done.do you know how to calculate the new hp and torque numbers?(i dont)im would like to know how much increase you get.

[Electro12WH 50]

When you port the intake there is a 'counterbore' around the valve guide. Should that be filled in?

[BPjunk 184]

When you port the intake there is a 'counterbore' around the valve guide. Should that be filled in?

That was a early photo, when finished I did not fill in but polished down around the guides bore. If this was a all out competition engine the porting would have been more exstencive and used epoxy to help reform the port.

Wild Bill in Richmond, Va.