New Vs. Rebuilt Motor

[broncoguy26]

I just bought an 85 bronco and the motor is just weak and not trust worthy at all. Its been taken care of its whole life except the year and half it sat in the yard. Should I have the motor rebuilt or just flat out replaced? and why?any suggestions would be great.

 

[bluesman17]

Thats really just preferance, I had mine rebuilt since you can upgrade easier.

 

[mustangman65_79]

Rebuilt motor r better because the blocks r seasoned. Why means the block is not going to warp at all. When the bore and hone the cylinders, they will be a true O and not 0. That is if u do bore it correctly. I can't remember what it's called, but there is a device they shops use to get a true bore, it torques the block to where is acts as if it had the crank and heads bolted on, so u get atrue bore, and it stays that way when u bolt everything on.

 

[Justshootme84]

I agree, you should tear down the present motor and see what problems you may have. That is, of course, if it's not running well. If it is, I would drive it until it quits. You might find that the camshaft has a few flat lobes, a burnt piston, or the insides might look good. You can have all sorts of work done at a machine shop, like the align-bore, deck work, etc. Have the cylinders bored 0.030" and have the block Magnafluxxed for any cracks. This is still cheaper than buying a longblock kit or complete new motor. In my case, the oil pump quit on the original motor, and the dude had a $1700 NAPA longblock all ready to go. Just plan ahead a little as to what you want out of the motor, whether it be stock for daily drving or you want more performance. Might even consider a stroker kit if it's a 351W. Good luck, and welcome to BroncoZone!!! JSM84

 

[hawk2100n]

Most of the time, a "new" motor is just a rebuilt block. making fresh blocks is pretty wasteful so most are just bored and honed and brought back to factory specs. I had my motor rebuilt because it is an HO and i wanted the same motor back in the truck. I would recommend that you have your motor rebuilt because you know what its been through, hopefully nothing very serious. some rebuilt motors have been through a lot and there is really no way to find out the cause of death for that motor before it was rebuilt.

 

[mustangman65_79]

I had to sleve #8 cyl because I hydro locked the motor, so to be on the safe side, they bored it to .060 and sleved it.