To many miles?

**04yellowcobra** · 02-13-2007, 04:07 PM

Hey guys,

Due to limited funds, my plans for the 87 are changing as I would like to get the car back on the road. Considering a GT40 headed exploder engine. That I will convert to carb and put a nice cam with good valvetrain. Now onto the issue.

Hypothetical for you to consider:

How many miles are to many? IE when normally would you need to bore.

I know the easiest and simpliest way will be to pull the cylinder heads and check the tolerances on the bores. Well I highly doubt a junk yard will let me do this prior to purchasing a motor. And I also know that lower the better (all depending on how well the motor was cared for).

I am asking this because my stock block out of the car needs bored and I don't have the cash right now to have it done.

Thanks

**Killercanary** · 02-13-2007, 04:55 PM

I'd personally try to stay under 75K for a used shortblock.

**04yellowcobra** · 02-13-2007, 05:03 PM

Thanks Paul!

You gonna have your beast out and about this year?

**Pure Stock** · 02-13-2007, 05:06 PM

Originally Posted by 04yellowcobra

Hey guys,

Due to limited funds, my plans for the 87 are changing as I would like to get the car back on the road. Considering a GT40 headed exploder engine. That I will convert to carb and put a nice cam with good valvetrain. Now onto the issue.

Hypothetical for you to consider:

How many miles are to many? IE when normally would you need to bore.

I know the easiest and simpliest way will be to pull the cylinder heads and check the tolerances on the bores. Well I highly doubt a junk yard will let me do this prior to purchasing a motor. And I also know that lower the better (all depending on how well the motor was cared for).

I am asking this because my stock block out of the car needs bored and I don't have the cash right now to have it done.

Thanks

It really "depends". There are so many variables that contribute to wear and mechanical failures. I've seen 5-Liter longblocks with an excess of 150,000 miles and then again I've seen 60,000-70,000 mile engines that are oil burners. The 1993's hypereutectic design's high silicon content and lower coefficient of thermal expansion allows these pistons to be fitted with tighter-than-usual-piston-to-skirt-to-wall clearances. The close fit provides a more stable ring platform, to improve sealing and oil control.

Trying to locate a 1993 and newer 5-Liter engine aside from the fact that it is newer, may be a better choice.