Disassembling the 250

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65_Stang_170
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Disassembling the 250

Post #1 by 65_Stang_170 » Sun Jun 10, 2018 2:50 pm

Howdy Y'all!

Just got around to taking apart the 250 I bought a while back. The purpose of me tearing it down is to learn about how this engine functions, and give me an idea about doing a rebuild in the future. I have taken a few pictures to document, and have a few questions.

First, orange valve springs the norm? I didn't expect to see much color on the inside. Also, how do you remove them?


Second, are the pistons supposed to be that grimey? or is that a leak issue?

Third, what do you use to clean/polish the valve areas on the head? Is this something a machine shop would normally do? I am most likely going to get a valve job (3 angle/back cut) done once I get back from my deployment.

Lastly, the front 2 rods seem to be damaged (see picture). They both have some nicks, and the 2nd is a little bent. What might cause this?

It had the steel shimmed gasket, so I think that it has not been touched/modified from stock.

Thanks for the info!

-Shawn
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falcon_master
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Re: Disassembling the 250

Post #2 by falcon_master » Sun Jun 10, 2018 6:44 pm

Hello. First of all.i want to thank you for your service, what branch? And secondly I'm in no way an expert one these sixs I'm still learning my way but from my knowledge this pistons look ok it just seems like there's alot of carbon build up. Of it was leaking coolant the cylinder would be almost spotless. As for push rods being bent I'm thinking it's possible it wasn't adjusted right and it can cause valve to piston contact which can bend pushrod. Check the valves see if there is evidence of any damages. Hope this helps
Jarod
High School AFJROTC cadet and car enthusiast. Likes all things ford and engines of any company. 64 falcon 2dr sedan with 144 six and "3 on the tree" column shift manual transmission. Still in make it move stage.

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rbohm
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Re: Disassembling the 250

Post #3 by rbohm » Sun Jun 10, 2018 7:26 pm

65_Stang_170 wrote:Howdy Y'all!

Just got around to taking apart the 250 I bought a while back. The purpose of me tearing it down is to learn about how this engine functions, and give me an idea about doing a rebuild in the future. I have taken a few pictures to document, and have a few questions.

First, orange valve springs the norm? I didn't expect to see much color on the inside. Also, how do you remove them?


sometimes parts suppliers do paint their valve springs to color code them so they can spot the ones that match at a glance. removing them requires a valve spring compressor tool, and a magnet to remove the keepers. its an easy enough job, just time consuming. the spring compressor you need is a C clamp style like this one from summit racing;

https://www.summitracing.com/parts/wmr-w89409/overview/

Second, are the pistons supposed to be that grimey? or is that a leak issue?


with the environment the pistons run in, they get loaded up with carbon deposits, your are normal.

Third, what do you use to clean/polish the valve areas on the head? Is this something a machine shop would normally do? I am most likely going to get a valve job (3 angle/back cut) done once I get back from my deployment.


once the heads have been cleaned, you can use cartridge rolls and a die grinder to polish the ports. there are a number of sources for porting tools, look around the summit racing site and you will find several kits.

Lastly, the front 2 rods seem to be damaged (see picture). They both have some nicks, and the 2nd is a little bent. What might cause this?


yes it is bent. a stuck valve, a valve that contacted the piston, or even just a weak push rod can all be the culprit here.

It had the steel shimmed gasket, so I think that it has not been touched/modified from stock.

Thanks for the info!

-Shawn


it seems you caught a problem before you had any symptoms. the head gasket was starting to leak in several spots. look at the dark spots between cylinders three and four, a common issue since those cylinder tend to run hotter than the others, and you can also see other dark spots that also indicate a developing problem.

if you have any questions regarding the rebuild, feel free to ask, better to ask questions than correct mistakes.
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