[localfiend]

Got a dial bore gauge today and I'm in the process of checking out the bores of my 289 to see if I can get away with a hone, pistons, and rings without needing to rebore. It's already 40 over, so I don't want to go further if it's not needed. If it turns out specs are too far out, I'll find another block to build.

I don't have the correct sized micrometer with me, so I'm using relative measurements with the bore gauge to figure out how round the bores are, and to see how they compare with each other.

There's a big mass of numbers up there, but I can condense it down a bunch. I measured each bore 3 times on the top, and 3 times on the bottom, rotating the gauge by a third each time. The greatest distance any of the measurements are off from each other is essentially .001". Anybody know how much variation is acceptable for a re-ring job? Greatest taper amount seems to be .00083"

 

[LSG]

rings, bores, pistons

Fiend, yeah, you can do just the hone if you want. .001 is not so bad. but I fear you are laboring under some misconeptions. There is absolutely no problem running at .040. There is also absolutely no problem running at .060 over. Whoever told you that .060 over causes problems, in and of itself, doesn't understand whats happening or how their engine works. The little Windsor block is tough and can take the .060. The shop for which I work has bored DOZENS of small Fords sixty over, we warranty them, and I don't know of one ever coming back because of an overbore.

and if you switch the pistons, be certain to get the right ones. Many replacement flattops are only 1.585 tall, instead of the correct height of 1.605. I recommend Silvolite 3101HC pistons, and Hastings 2M139 rings in whatever bore size you decide to run. LSG

 

[localfiend]

Fiend, yeah, you can do just the hone if you want. .001 is not so bad. but I fear you are laboring under some misconeptions. There is absolutely no problem running at .040. There is also absolutely no problem running at .060 over. Whoever told you that .060 over causes problems, in and of itself, doesn't understand whats happening or how their engine works. The little Windsor block is tough and can take the .060. The shop for which I work has bored DOZENS of small Fords sixty over, we warranty them, and I don't know of one ever coming back because of an overbore.

and if you switch the pistons, be certain to get the right ones. Many replacement flattops are only 1.585 tall, instead of the correct height of 1.605. I recommend Silvolite 3101HC pistons, and Hastings 2M139 rings in whatever bore size you decide to run. LSG

That's good news. I had no idea how far out these things could be, getting away with just a hone will be nice as I know someone who has the tools to do it. I've got more research to do, but it sounds like I have a direction now.

No heating issues at all with the block at 40. Good to know going further may be possible if needed.

Now I know I can get pistons with more compression I need to start looking for a good set of heads that fit my budget. Was hoping to not spend more than 1000 bucks, but if I have to go over that so be it.

I'll check out those Silvolite pistons and start trying to figure stuff out.

 

[LSG]

heads

Fiend, what heads do you have now ? Any reason you can't work with what you have ? LSG

 

[Woodchuck]

Maximum out-of-round is .001". Wear limit is .005".
Maximum taper is .001". Wear limit is .010".
The standard bore variance is 4.00 - 4.0024". From Ford's specs on the SBF and FE it would seem 24/10,000 is the "standard variance". That said, if a hone puts you at 4.0424" or less it would seem reasonable to assume that .040" oversize pistons could be used. I would expect that variance, however, to possibly be too wide if using hypereutectic pistons. When choosing your piston pay particular attention to compression height to obtain best piston/deck clearance.

 

[localfiend]

Fiend, what heads do you have now ? Any reason you can't work with what you have ? LSG

Not sure, the block is from a 65 galaxy. The heads say 289 on the inside, and have the numbers 8B20 cast inside as well. They could possibly work after being rebuilt (bad valve seals). I'm not looking for a massive amount of power, I don't want to blow up my T5z. So whatever the T5Z can take would be the my max power limit.

Maximum out-of-round is .001". Wear limit is .005".
Maximum taper is .001". Wear limit is .010".
The standard bore variance is 4.00 - 4.0024". From Ford's specs on the SBF and FE it would seem 24/10,000 is the "standard variance". That said, if a hone puts you at 4.0424" or less it would seem reasonable to assume that .040" oversize pistons could be used. I would expect that variance, however, to possibly be too wide if using hypereutectic pistons. When choosing your piston pay particular attention to compression height to obtain best piston/deck clearance.

Cool, thanks for the actual numbers. Sounds like I'm fine but I need to get a micrometer so I can get actual and not just relative measurements.