250 Block Evaluation

[65_Stang_170]

Howdy,

Some of y'all have followed a couple of my threads about my "new" aluminum head and 250 block (with broken piston). I have finally got the block on an engine stand. I drained the oil (had coolant in it...), removed the oil pan, and removed the #6 piston which was busted up and caused damage to the aluminum head. Here are some pictures:


















The pistons look to be custom; they say Dan's Machine on them with some numbers that probably have some sort of meaning unknown to me. The rods appear to be stock '69 250 rods (forged?). ARP studs/bolts. The pistons appear to come flush with or maybe a little above the deck of the block, so the deck has been machined. The water pump bolt head bolt was shortened to help confirm that as well.

1. I'm hoping a blown head gasket was the cause for the coolant in the oil. That or they didn't drain it very well when disassembling and coolant from the head went into the oil when they took it off... Other than that, what could be the issue or a way to check?

2. I need to degree the cam shaft to confirm what it is: do I need to remove the balancer and/or timing chain cover to do that? or can I attach the degree wheel to the balancer and it work the same?

3. There appears to be damage on #1 piston that was covered with grime. What does it look like caused that? Valve interference?

4. Do you think a machine shop can match the piston? or is it better for me to buy a new set?

5. Any idea what the number on the bottom side of the piston means? It says "w/o-228-16"

I'll leave it at that for now. Thanks in advance!

-Shawn

 

[powerband]

... I get questionable results using questionable parts.

Pistons are really interesting as no one really makes 'off the shelf' alternate pistons for the 250 and Dans' Machine may be a machine tool company not aftermarket mfg'.

Enough problems visible to look into Rods and suitable rebore for new Pistons.

What the current bore is key

Deck height may or my not not be milled/altered. the IHC 258 pistons in my 250 require .070 overbore but IHC 258 piston compression height provides zero decking without deck milling.

have fun

250 turbo OEM piston after too much.. :

. .

... detonation and slight scratch on #6 cyl wall . ( oily mist across windshield)

"w/o-228-16" - Work Order # 228 - 2016 ?

 

[bubba22349]

Howdy,

The pistons look to be custom; they say Dan's Machine on them with some numbers that probably have some sort of meaning unknown to me. The rods appear to be stock '69 250 rods (forged?). ARP studs/bolts. The pistons appear to come flush with or maybe a little above the deck of the block, so the deck has been machined. The water pump bolt head bolt was shortened to help confirm that as well.

1. I'm hoping a blown head gasket was the cause for the coolant in the oil. That or they didn't drain it very well when disassembling and coolant from the head went into the oil when they took it off... Other than that, what could be the issue or a way to check?

2. I need to degree the cam shaft to confirm what it is: do I need to remove the balancer and/or timing chain cover to do that? or can I attach the degree wheel to the balancer and it work the same?

3. There appears to be damage on #1 piston that was covered with grime. What does it look like caused that? Valve interference?

4. Do you think a machine shop can match the piston? or is it better for me to buy a new set?

5. Any idea what the number on the bottom side of the piston means? It says "w/o-228-16"

I'll leave it at that for now. Thanks in advance!

-Shawn

X2 yes in deed those are a custom forged piston and yes the stock 1969 Ford 250 connecting rods are forged. Some excellent parts in your 250.

1. Do you have the head gasket to be able check for signs of being blown? How dose the # 6 cylinder wall look? Examine the blocks deck and all the other cylinders for signs of a crack might have a little rust line showing if it hasn't been cleaned yet.

2. Yes you can check the camshafts install (timing degrees and events without pulling Dampner or timing cover. However you won't be able to make any changes to it without take it apart.

3. If a screw or bolt went into the #6 cylinder causing its damaged then it could also travel through the intake into the #1 to cause that damage. Do the marks line up were the valve positions would be? Usually this isn't caused by valve contact on these small six'es however with very high lift cams it possible. Until you check the cams timing events and it lift you can't know if it's possible though.

4. & 5. Yes some machine shops may be able to match your pistions but usally the cost for one or two is high. Your best bet is to contact the pervious owner and ask about were they got the pistions from (Dans Machine) and their address location and or their phone number they will probably have the job number that's on those pistions and can I'd them and make you one or two pistions cheaper than anyone else. As a referance though you can get a new set of custom forged pistions from Auto / Race Tec for about $550 to $600 they are about the most reasonable for a new set. Good luck

 

[65_Stang_170]

Enough problems visible to look into Rods and suitable rebore for new Pistons.
What the current bore is key
Deck height may or my not not be milled/altered.

Current bore looks to be 3.702. Is there another way to check deck height to see if it has been milled?

X2 yes in deed those are a custom forged piston and yes the stock 1969 Ford 250 connecting rods are forged. Some excellent parts in your 250.

1. Do you have the head gasket to be able check for signs of being blown? How dose the # 6 cylinder wall look? Examine the blocks deck and all the other cylinders for signs of a crack might have a little rust line showing if it hasn't been cleaned yet.

2. Yes you can check the camshafts install (timing degrees and events without pulling Dampner or timing cover. However you won't be able to make any changes to it without take it apart.

3. If a screw or bolt went into the #6 cylinder causing its damaged then it could also travel through the intake into the #1 to cause that damage. Do the marks line up were the valve positions would be? Usually this isn't caused by valve contact on these small six'es however with very high lift cams it possible. Until you check the cams timing events and it lift you can't know if it's possible though.

4. & 5. Yes some machine shops may be able to match your pistions but usally the cost for one or two is high. Your best bet is to contact the pervious owner and ask about were they got the pistions from (Dans Machine) and their address location and or their phone number they will probably have the job number that's on those pistions and can I'd them and make you one or two pistions cheaper than anyone else. As a referance though you can get a new set of custom forged pistions from Auto / Race Tec for about $550 to $600 they are about the most reasonable for a new set. Good luck

1. I don't have the previous head gasket, so no clues there... The cylinder 1-5 walls look immaculate. Here are some pics of Cylinder 6:









2. Great! I'll get that done as soon as I can to see what I've got. Not looking to make changes at this point...

3. I'll mock up the head to see if the valves line up with the damage. There are 2 separate marks, but it looks as though connecting them would make a circle... could just be coincidence though.

4/5. I guess once I get all of the details of what I have currently, I will ask for advice and make the decision on the pistons.

 

[B RON CO]

Hi, google Dans machine shop. They are in California. Can you measure the bore and piston? How about some pictures of the head.
Good luck

 

[bubba22349]

Number six cylinder looks fairly decent just a little surface rust and light piston scoring, but that surface rust could be from a bad head gasket or not compleately draining the block before disassembly. I can't make out anything that looks like a jagged rust line so it's probally not a cracked cylinder wall and such very light damage from the failed pistion. With such a low run time on that block if it were me I would likely just do a light deglaze / or hone (with a bottle brush type hone) reassenble with a new matching pistion if your able to get one and rings and run it. But if you have to get a compleate new set pistions then I would bore it just enought (next size) to clean it all up.

 

[65_Stang_170]

Hi, google Dans machine shop. They are in California. Can you measure the bore and piston? How about some pictures of the head.
Good luck

I tried googling it earlier, and didn't get the results... But thanks to you, I tried again and found their website and emailed them with the description and pictures to see if they could reproduce the piston and the cost associated. Thank you! I had the bore at 3.702 and the piston at 3.680 (a bit tough to measure the broken one). Here are some pictures of the head. I had to clean up some damage as a result of the broken piston on the bottom side. I plan on putting a Holley Sniper on it:

Number six cylinder looks fairly decent just a little surface rust and light piston scoring, but that surface rust could be from a bad head gasket or not compleately draining the block before disassembly. I can't make out anything that looks like a jagged rust line so it's probally not a cracked cylinder wall and such very light damage from the failed pistion. With such a low run time on that block if it were me I would likely just do a light deglaze / or hone (with a bottle brush type hone) reassenble with a new matching pistion if your able to get one and rings and run it. But if you have to get a compleate new set pistions then I would bore it just enought (next size) to clean it all up.

Bubba, that's what I'm hoping for: a quick clean up and pop the new piston in and go. There is still good cross-hatching on all of the cylinders.

 

[chad]

"...Current bore looks to be 3.702. Is there another way to check deck height to see if it has been milled?..."
I might have said "there's alot of measurments to take B4/as dissasembling." Even listed some of them. This is 1, measure frm C/L of crank to top of deck. This gives "deck hight". Most of us say "never deck a 250". We want all the stroke available. That is Y the known (not Dave's) 2 pistons choices (minimum) are selected. We DO want good quench or squish.

BTW: were "the ford6 guy's known adaptations" completed: pedistal change, oil block off, etc or duz this 1 have oe ford rockers and not need any of that?

If I have time I'll look at the alu head damage. U just put it up & that was my nxt Q. Thank you.

 

[bubba22349]

Hi, google Dans machine shop. They are in California. Can you measure the bore and piston? How about some pictures of the head.
Good luck

I tried googling it earlier, and didn't get the results... But thanks to you, I tried again and found their website and emailed them with the description and pictures to see if they could reproduce the piston and the cost associated. Thank you! I had the bore at 3.702 and the piston at 3.680 (a bit tough to measure the broken one). Here are some pictures of the head. I had to clean up some damage as a result of the broken piston on the bottom side.

Number six cylinder looks fairly decent just a little surface rust and light piston scoring, but that surface rust could be from a bad head gasket or not compleately draining the block before disassembly. I can't make out anything that looks like a jagged rust line so it's probally not a cracked cylinder wall and such very light damage from the failed pistion. With such a low run time on that block if it were me I would likely just do a light deglaze / or hone (with a bottle brush type hone) reassenble with a new matching pistion if your able to get one and rings and run it. But if you have to get a compleate new set pistions then I would bore it just enought (next size) to clean it all up.

Bubba, that's what I'm hoping for: a quick clean up and pop the new piston in and go. There is still good cross-hatching on all of the cylinders.

If the cylinders measure 3.702 that's a .020 oversize. Are you measuring the pistion skirt at 90 degrees to the pin location. or at the ring lands? The first will be the closest to the true bore size less its bore clearance of about .004.

 

[pmuller9]

Those look like Autotec pistons made for Dan's machine shop.
Autotec writes the customers name on the bottom of the pin boss.
https://www.dropbox.com/s/2xo9ifff2cjna ... .JPG?raw=1

 

[62Ranchero200]

I noticed that you have very little deck height. Rods from a 300 (4.9) can be used in a 250 with custom short pistons to give near zero deck height (I have this setup with Autotec pistons and have .005 deck height). Measuring length of your rods could rule that out.

Thanks
Bob

 

[chad]

I looked @ #6 c.chamber on the alu head as shown above, Looks good 2 me. U?

Now is time 4 nother measurement. Time 2 "CC" the head. U R slowly gatherin more'n more
data on this motor. Soon time to make some decisions. Not yet (prts, machining) as 'application', end product, use =
80% of RPMs as driven, octane choice have not been comunicated here. CR yet to B determined...

Getting closer'n closer, dude. Exciting to me.

 

[bubba22349]

If Dans Machine gets back to you they probably can tell you most everything about your 250 such as the camshaft used, head CC's and pistion CC's, parts used, if it was balanced etc. This would save you a bunch of time having to do the detective work, if you could get a detailed build sheat!

 

[65_Stang_170]

If Dans Machine gets back to you they probably can tell you most everything about your 250 such as the camshaft used, head CC's and pistion CC's, parts used, if it was balanced etc. This would save you a bunch of time having to do the detective work, if you could get a detailed build sheat!

They didn't seem to recall the work done. He asked for the name of the previous owner, but I do not know that info as I bought it from his brother-in-law or something.

I am on vacation, so I won't have any updates for a couple weeks. I'll jump back on when able. Thanks all!

 

[65_Stang_170]

If Dans Machine gets back to you they probably can tell you most everything about your 250 such as the camshaft used, head CC's and pistion CC's, parts used, if it was balanced etc. This would save you a bunch of time having to do the detective work, if you could get a detailed build sheat!

Those look like Autotec pistons made for Dan's machine shop.
Autotec writes the customers name on the bottom of the pin boss.
https://www.dropbox.com/s/2xo9ifff2cjna ... .JPG?raw=1

I took another look at the bottom of the piston after I got back from vacation. It is an Autotec piston with a number A1616F (at least from what I could tell). I am talking to the machine shop where the work was done; he recalls the build, but not the customer's name which is what they need to look up the specs apparently... The number for the piston wasn't in the Autotec/Racetec catalog which makes sense since it was likely a custom order. I am going to try and contact them to see if I can get a replacement.

I looked @ #6 c.chamber on the alu head as shown above, Looks good 2 me. U?

Now is time 4 nother measurement. Time 2 "CC" the head. U R slowly gatherin more'n more
data on this motor. Soon time to make some decisions. Not yet (prts, machining) as 'application', end product, use =
80% of RPMs as driven, octane choice have not been comunicated here. CR yet to B determined...

Getting closer'n closer, dude. Exciting to me.

Chad, I'm going to try and find time to CC the head, but we're in the process of moving to Korea in the next few weeks. My project is about to be on a 2-year hold. Hopefully, I can make some significant progress before then.


Thanks all,
Shawn

 

[bubba22349]

Great now that you know it's an Autotec Piston contact them to see how quickly they can make you a matched replacement piston. AutoTec A1616F is only the number of the Forging Blank that they start with to machine the finished Piston from. The other number on the bottom of the conecting Rod pin boss should be the biggest help for AutoTec to be able to I D the job and the pistons specs. Good luck

 

[chad]

got venier calipers?
Yer measuring friend !
Dialed in - the company will know which to pull from the shelf.
Now, who will machine it 2 yer spec? Them? U could even leave another (or that, didn't C how dammaged) with them. Then if done wrong they can not blame U for the problems...

If going to Korea U better leave the rig w/me...I'll get it squared away 4 U.