I'm selling my old I6 to a guy and he asked how much it's been bored. I believe it is stock and original. He says he's already bought an engine where the block was already 0.040 over so he doesn't want anything past 0.030. Without taking off the head, is there any other way to determine if it's been bored?

I've been working with cars for about the last 30-35 yearsand I've never heard of a way but maybe one of you guys know of a way. I realize I could probably take off the oilpan and maybe get a measurement that way, anyone had any experience with that?

All help appreciated, I just don't want to pull the head.

 

Only way to know is to pull the head.

The saving grace here is:
1. If it is running wellthere is no need to pull the head because it is not in need of a rebuild
2. If it is need of a rebuild because it is not running, pulling the head will not diminsh the value any

And since it is your 'old' motor which I would have to assume means it is sitting in the corner and the current state of it is (running or not) is unknown, pulling the head sounds like a non-issue to me with the only caveat of being you seal the deal. "I will pull the head and check the overbore for you as long as you agree to buy this motor from me if it is standard bore like I believe it to be"

 

The best way is to sonic map the block. But there is an easy field test you can try to see what wall cores were cast into the block. the test is called the "drill bit test". You need to knock out the blocks freeze plugs (three on each side) to access the cyl wall cores. You will then see the cyl wall cores and the gaps between them. Years of crap and crud can buildup so you need to scrape away some of that to get an accurate reading. I cant remember, off hand, what each bit "reads".....i know you use ?/64 bits and i post the link as soon as i find it.

-Hawkins

 

The engine is still in my car and I really don't want to remove it until it is sold due to lack of space to store it. He has a new head he wants to use (maybe one of the Aussie 250's, not sure) but his block is bad. Although he could use the engine as is, he's planning to rebuild right away.

If I take the head off and he doesn't buy it, then I can't start it for the next guy that is interested. Hence my quandry .........

 

No quandry there. The motor is running (assuming well) so no head gets pulled. Tell him to pull the trigger and buy it orpound sand because someone else will buy the car.

 

Yep, you're probably right. If he wants it, he'll buy it.