All Small Six I have a few questions about the 250ci

[cheapshotfrenzy]

Hello! You guys are apparently the Ford Six experts, so I made an account to pick your collective brains for a bit.

Backstory:
My 66 Mustang's transmission went out not too long ago. So, I figure it's a good opportunity to make some improvements. This old car even when it was running well would top out at about 60mph. I checked the casting number on the engine block and I can't remember what it says off the top of my head, but I do remember it came back to a 63 Falcon. Research says it's probably a 170ci. The car has some pretty obvious signs it was in a wreck at some point, so I bet someone just snagged a straight six that looked similar, slapped it in, and got it sold.

So anyways, I have the C4 that came out of my dad's 302 mustang when he swapped it to a manual. My plan is to find a 250ci because it has the SBF bellhousing bolt pattern, pop this C4 to it, and drop it in the mustang. My goal is to be able to take it on road trips or maybe enter it in the Hemmings Great Race some day. I don't really care a whole lot about power, other than it needs to get up to highway speeds comfortably and cruise. I figure going from a 170 to a 250 will give me all the power boost I'm looking for.

So my questions:

Is there an ideal 250 I should be looking for?

Is there an easy way to tell a 250 from a 200 just by looking at pictures? I've seen a few for sale ads that were listed as "either 200 or 250, idk".

What all can I save from my 170 to reuse on the 250?

And is there anything I should do while I have the engine out?

Thanks in advance, guys.

 

[powerband]

"I don't really care a whole lot about power, other than it needs to get up to highway speeds comfortably and cruise. I figure going from a 170 to a 250 will give me all the power boost I'm looking for."

... setting up a well tuned 250 will get you anvil strong torque that can be applied to the 1to1 output C4 or preferably an Overdrive tranny so the low RPM powerband can be matched to some 'low' rear gears for performance and acceleration or 'high' rear for modern hi-way cruise-comfortably.
.
which ? - 250 was used intermittently but blocks are identical AFAIK.
.
250 / 200? the starter below the bottom of block is a 250 with a rare 200 exception but doesn't have SBF bellhouse pattern like 250.
.
actually 170 head slapped on the 250 would increase CR but has smaller valves than most later 250 heads - they all interchange dimensionally ..
.
250 with larger SBF bellhouse needed firewall slightly formed in '61 Comet, 250 is almost 2" taller block / overall also at valve cover rear. . ( BFH therapy ) .
.
the mentioned SBF - FW / Starter / Clutch / Tranny used is a BIG advantage to get an early car up to modern interstate drivablity and the 250 can provide the essential power.

have fun

 

[Invectivus]

Also, I'm pretty sure the 250 has a 4 bolt water pump while the 200 has a 3 bolt.

 

[awasson]

A word of consideration about motor mounts. About 6 months ago I was considering putting a 250 in my 66 Mustang so I did some research (asked a lot of questions). As far as I know there is no off the shelf motor mount for the 64-68 Mustang for a 250ci and the 1969-73 Mustang 250 mounts don’t exist at the usual parts houses.

The problem is that the 250 engine deck height is 1-1/2” higher than a 200 so using the original 200 mounts puts it too high and the hood won’t close. More importantly the engine will be at an angle and the engine to driveshaft geometry is off.

Fortunately a member here @John Ha has done all of the work and documented it here: http://harcinske.users.mitchelltelecom.net/Engine_Mounts.html

It’s going to take some doing to put a 250 in your car but if you’ve got a 170 in your mustang, it will be a step up.

I decided to stick with the 200 for mine and will be fitting a T5 to replace the 3-speed manual it has currently. Mine will cruise all day at 60/70 MPH and I’ve taken it up to 90 MPH for short blasts. It’s still got some pedal left but it’s a new engine and there’s no point in abusing it. I am certain it’ll have lots of headroom on the highway with the T5 and the right gears.

 

[bmbm40]

Hello! You guys are apparently the Ford Six experts, so I made an account to pick your collective brains for a bit.

Backstory:
My 66 Mustang's transmission went out not too long ago. So, I figure it's a good opportunity to make some improvements. This old car even when it was running well would top out at about 60mph. I checked the casting number on the engine block and I can't remember what it says off the top of my head, but I do remember it came back to a 63 Falcon. Research says it's probably a 170ci. The car has some pretty obvious signs it was in a wreck at some point, so I bet someone just snagged a straight six that looked similar, slapped it in, and got it sold.

So anyways, I have the C4 that came out of my dad's 302 mustang when he swapped it to a manual. My plan is to find a 250ci because it has the SBF bellhousing bolt pattern, pop this C4 to it, and drop it in the mustang. My goal is to be able to take it on road trips or maybe enter it in the Hemmings Great Race some day. I don't really care a whole lot about power, other than it needs to get up to highway speeds comfortably and cruise. I figure going from a 170 to a 250 will give me all the power boost I'm looking for.

So my questions:

Is there an ideal 250 I should be looking for?

Is there an easy way to tell a 250 from a 200 just by looking at pictures? I've seen a few for sale ads that were listed as "either 200 or 250, idk".

What all can I save from my 170 to reuse on the 250?

And is there anything I should do while I have the engine out?

Thanks in advance, guys.

Could be a 144 if you have not confirmed a 170. The 250 would be a solid motor with good performance but as stated a bit of work and that link awasson provided is a good guide I had not seen that before. A slightly modified 200/C4 would likely be a decent performer based on your driving expectations. Might not get comfortable higher freeway cruising speeds as without od the 200/C4 combo will be at higher rpm depending on what speed. If you want a 250 start looking right now they are getting harder to find.

 

[cheapshotfrenzy]

"I don't really care a whole lot about power, other than it needs to get up to highway speeds comfortably and cruise. I figure going from a 170 to a 250 will give me all the power boost I'm looking for."

... setting up a well tuned 250 will get you anvil strong torque that can be applied to the 1to1 output C4 or preferably an Overdrive tranny so the low RPM powerband can be matched to some 'low' rear gears for performance and acceleration or 'high' rear for modern hi-way cruise-comfortably.
.
which ? - 250 was used intermittently but blocks are identical AFAIK.
.
250 / 200? the starter below the bottom of block is a 250 with a rare 200 exception but doesn't have SBF bellhouse pattern like 250.
.
actually 170 head slapped on the 250 would increase CR but has smaller valves than most later 250 heads - they all interchange dimensionally ..
.
250 with larger SBF bellhouse needed firewall slightly formed in '61 Comet, 250 is almost 2" taller block / overall also at valve cover rear. . ( BFH therapy ) .
.
the mentioned SBF - FW / Starter / Clutch / Tranny used is a BIG advantage to get an early car up to modern interstate drivablity and the 250 can provide the essential power.

have fun

Yeah, I briefly thought about putting an AOD behind that 250, but then saw how much work was involved. I'm still confused about what flywheel I'd need. It looked like there were 3 different options, and you had to use the one with the correct amount of teeth, or it'll destroy the engine. But every guide I found was for a V8. That'll probably eventually be in the works, though. Maybe. Small chance.

 

[cheapshotfrenzy]

A word of consideration about motor mounts. About 6 months ago I was considering putting a 250 in my 66 Mustang so I did some research (asked a lot of questions). As far as I know there is no off the shelf motor mount for the 64-68 Mustang for a 250ci and the 1969-73 Mustang 250 mounts don’t exist at the usual parts houses.

The problem is that the 250 engine deck height is 1-1/2” higher than a 200 so using the original 200 mounts puts it too high and the hood won’t close. More importantly the engine will be at an angle and the engine to driveshaft geometry is off.

Fortunately a member here @John Ha has done all of the work and documented it here: http://harcinske.users.mitchelltelecom.net/Engine_Mounts.html

It’s going to take some doing to put a 250 in your car but if you’ve got a 170 in your mustang, it will be a step up.

I decided to stick with the 200 for mine and will be fitting a T5 to replace the 3-speed manual it has currently. Mine will cruise all day at 60/70 MPH and I’ve taken it up to 90 MPH for short blasts. It’s still got some pedal left but it’s a new engine and there’s no point in abusing it. I am certain it’ll have lots of headroom on the highway with the T5 and the right gears.

Oh, that's a hot tip. At first I was like "Well, I guess I'm being forced into doing a shaker hood. *Totally* not my fault guys!" -angry angle grinder noises...

But if the engine is going to be cockeyed, then it sounds like I'll be fabricating new mounts. And if I'm doing that anyway, then I may as well make them sit lower, I suppose.

But if I find 69-73 Mustang 250 engine mounts, those will work?

 

[John Ha]

Fortunately a member here @John Ha has done all of the work and documented it here: http://harcinske.users.mitchelltelecom.net/Engine_Mounts.html

I'm surprised that's still up - I've not had service from that company for several years. I posted the gist what I did in this forum a while back. With these mounts my 250 sits with room to spare under the stock 66 Mustang hood.

With the T5 behind my 250, I used a M6375D302B flywheel from Summit. It works well with the later model bellhousing I bought to use with the T5. With pretty much any 6 cylinder you need a flywheel for internally-balanced engines (no weights on the flywheel). The number of teeth (and diameter) is dependent on which bellhousing you end up using.

Happily, since the 250 back side is basically the same as the small-block V8, pretty much any bellhousing and starter used on the pushrod 302/351 will work. For manual transmissions that would include most any stick shift Mustang through the 1995 model year.

The 250 does have 4 bolts holding the water pump to the engine. Guidelines for distinguishing a 144 from a 170 from a 200 are in the Tech section.

I'm running my 250 through a T5z and an 8" open differential with 3:1 gears. It's been getting around 24 mpg in mixed city/country driving and is perky enough to satisfy my needs. I've been up to 75 on the freeway but have not gone higher. There's no mechanical reason - I just don't normally care to drive over that speed.

I looked into the later Mustang engine mounts and they did not appear to me to be workable in the 66 chassis without major changes being made. Also, some of parts of the mounts from that era are no longer available as new or reproductions, so one would have to ensure that some provision for future maintenance is accounted for.

 

[powerband]

for anyone contemplating 250 motor mounts - from previous post:

, another 250 engine mount solution is to use the early Right-Angle engine/frame mounts used on @ 60-61 cars. The 250 is @ 1-1/2 wider than the 170/200 . Simply re-drilling the 60/61 OEM engine mount rubber isolator @ 3/4" wider each side the 250 fits and puts the 250's crank height (and tranny/pinion ) about same as original location. The 250 is also (@ 1.66") taller than the 170/200 and may need hood clearance checked .
.
... modifying mounts for alternate cars can be made simpler.

. v . . .
( also are 'pinned' for torquey launches )
.
have fun
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