Crankshaft Pics

[Fish]

Soak the crank in the acid, don't sand. Acid will only remove the aluminum, while sanding will remove aluminum and iron, changing the diameter.

Nah, I have to disagree, just buff out the aluminum......... Slap on a new rod, check for slop..... If you buff out all of the aluminum transfer, you will be good to go!!!

 

[Rivets]

Mr. Fish my spelling may not be right in the other thread you commented on, but it is the engine control cable. Also, I have been rebuilding engines for more years than you would give me credit for and sanding or buffing any rod shaft is going to remove material. Trying to buff out that kind of damage is a waste of time and effort and could result in more damage.

 

[Carscw]

I would acid clean it. Then wet buff it.

 

[reynoldston]

Mr. Fish my spelling may not be right in the other thread you commented on, but it is the engine control cable. Also, I have been rebuilding engines for more years than you would give me credit for and sanding or buffing any rod shaft is going to remove material. Trying to buff out that kind of damage is a waste of time and effort and could result in more damage.

I sure have to agree with Rivets here. I have rebuilt enough engines to know better. But seeing everyone knows so much I say go for it so what way you can do it over. I haven't got any of my money or time into this job what so ever. I am sure glad you aren't rebuilding that engine for me.

 

[reynoldston]

I would acid clean it. Then wet buff it.

Now is this something you would do on one of your racing engines?

 

[Carscw]

Now is this something you would do on one of your racing engines?

No this is not what I would do on my race engine.

I would acid clean then turn the journals down and rebalance the crank. Install new rods and bearings.

When ever you spin a crank bearing I always replace the connecting rods.

 

[Carscw]

On a small engine crank I would just clean it then buff it with a buffing strip not sandpaper.

 

[reynoldston]

No this is not what I would do on my race engine.

I would acid clean then turn the journals down and rebalance the crank. Install new rods and bearings.

When ever you spin a crank bearing I always replace the connecting rods.

It sound like you have a complete machine shop set up. Why wouldn't you do the same thing with a small engine? I wouldn't rebalance a small engine but I would have the other work done. I don't have the set you do so I have a machine shop do my work. I pass the cost onto the customer but its done right.

 

[Rivets]

In the very first post the OP stated that the journal was already .003 undersized. That was with the aluminum transfer still on. When removing that aluminum it will be even more undersize and there is no undersize rod available for that engine. Cleaning and putting in an original rod is throwing away money. It just won't last long enough to make it cost effective. Only smart way to savage this engine is to obtain a good crank somewhere and then install a new rod. In my opinion the OP would be better off finding a different engine to use on the unit.

 

[davbell22602]

In the very first post the OP stated that the journal was already .003 undersized. That was with the aluminum transfer still on. When removing that aluminum it will be even more undersize and there is no undersize rod available for that engine. Cleaning and putting in an original rod is throwing away money. It just won't last long enough to make it cost effective. Only smart way to savage this engine is to obtain a good crank somewhere and then install a new rod. In my opinion the OP would be better off finding a different engine to use on the unit.

I found used crankshaft for $50 on ebay. These engines are hard to find. This is a twin cam engine. They dont make twin engines anymore since Tecumseh got bought out back in 2007.

10HP Tecumseh Engine 7 8" Crankshaft 35980A LH358SA HM100 HMSK100 HMSK80 | eBay

I got few other people looking and asking around to various people in my area for complete engines that might still run but been sitting.