Engine rebuild do & don't

Hey guys, I have two F4.6 engines that I am rebuilding. Is there any rule of thumb to rebuilding with new sleeve, piston, & rod?

Cost of parts vs cost of new engine. If over 50%, buy new.
Other wear and tear on motor, bearings etc.
Break in after rebuild.

GAJ said:

Cost of parts vs cost of new engine. If over 50%, buy new.
Other wear and tear on motor, bearings etc.
Break in after rebuild.

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Thanks GAJ, I have the new sleeves, pistons, & rods, about $68.00 a piece. The engine bearings feel tight, I'm guessing this will be the first rebuild on both of these engines(eBay purchased). Other than visible wear or scaring/scorching on the crank, how many rebuilds can it take. I would think the rod journal On the crank would wear down at some point? Given that the crank steel will wear slower than the rods.

Ahaa, found a post from AoD from 2008, I'll read that.

JVT73 said:

Ahaa, found a post from AoD from 2008, I'll read that.

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Sorry, I do not know how many rebuilds, rank amateur here.

Ok, so my engine is almost ready to break in! All that is left is the one way bearing and pull start. The LHS sold me a O.S. LC3 plug (hot) for the fresh F4.6. Is this a ok plug to break in my motor with? I am/will be running O'Donnell 20%.
So close I can almost smell the nitro!!!

JVT73 said:

Ok, so my engine is almost ready to break in! All that is left is the one way bearing and pull start. The LHS sold me a O.S. LC3 plug (hot) for the fresh F4.6. Is this a ok plug to break in my motor with? I am/will be running O'Donnell 20%.
So close I can almost smell the nitro!!!

Click to expand...

I would use a medium to medium hot for that engine......

Ok, thanks

Quick question, the savage I just got and rebuilt came with two different pipes. The one is the stock two piece plastic & the other is the ribbed aluminum pipe. Any preference between the two on a fresh engine break in? I don't think the ribbed is a tuned pipe.

I would use the ribbed pipe over that plastic trash for sure, and yes the ribbed is still a "tuned" pipe although most guys say they are too loud...

Got it, thank you.