New build for '65 Mustang

electrorc

Well-known member
Hey everyone, I posted a few months ago about some major problems I was having with the 200 in my '65 Mustang. I eventually came to the conclusion that it would probably be best to just rebuild the engine, and it's about time for me to be having the build started and what not. I wanted to get some opinions on some things first, though. This is going to be fairly long.

First, plans for the car: It's going to be my daily driver and will also be making 800 mile trips between home and college a couple of times a year, so I'd like fairly decent gas mileage (in the mid-20s, hopefully) and it needs to be reliable. I'd also like a little bit of power, but nothing crazy. 200hp at the flywheel would be great, but it seems like I'll be lucky to get 150 without going to the aluminum head or a turbo.

1) I'm having a lot of trouble deciding between the 200 and 250. The biggest problem is I can't find anything consistent on what is involved in putting the 250 in a '65 Mustang. I've looked at the swap page on FordSix and read the pertinent part of the Falcon Six Handbook on swapping it in a Falcon.
a) Just for reference, I'm mainly looking at the 250 for the extra power and torque potential, as well as the easy availability of clutches, flywheels, transmissions, etc.
b) Since the Mustang has a longer engine bay than the Falcon (I think?), will I still have problems length-wise, and need to go to an electric fan or move the radiator forward?
b) Motor mounts--are the stock 200 mounts going to work or not? I keep seeing answers all over the place on this. I'd rather not drill holes in the frame if I don't have to.
c) Hood clearance--I'm guessing this will vary based on the motor mount situation. If I go to a low profile air cleaner or carb hat, should I be ok or do I need to lower the mounts and what not?
d) Something I haven't really seen mentioned anywhere--the clutch linkage. Since the z-bar goes into a mount on the engine block, will the factory setup still work on a 250 or is the mount in a different place or not even there?

2) Parts: This is tentative and I may change things based on specific prices I find, but here's the plan right now:
264/274-110LC hydraulic cam from CI, STY springs, adjustable rockers if I can afford them, direct mount H/W 5200 2brl, basic rebuild kit from CI, 1.75/1.5" valves, double roller timing chain if I keep the 200, zero decked block, and I might try a little bit of head porting if I have time. Head hopefully will be a late 70s 250 head, depending on availability.
I haven't really decided on compression--I'd like to keep the possibility of a turbo later on open so that I can add one if I'm not happy with the power. However, I don't want N/A power to suffer too much. Would somewhere around 9:1 be a safe bet for a small turbo later on and decent performance now? Or should I just go ahead and bump it up to 9.5:1 or so and hope I'm happy with it?

Would all of this make a decent combination? Thanks for any input!
 
electrorc":3u5dv08u said:
Hey everyone, I posted a few months ago about some major problems I was having with the 200 in my '65 Mustang. I eventually came to the conclusion that it would probably be best to just rebuild the engine, and it's about time for me to be having the build started and what not. I wanted to get some opinions on some things first, though. This is going to be fairly long.

First, plans for the car: It's going to be my daily driver and will also be making 800 mile trips between home and college a couple of times a year, so I'd like fairly decent gas mileage (in the mid-20s, hopefully) and it needs to be reliable. I'd also like a little bit of power, but nothing crazy. 200hp at the flywheel would be great, but it seems like I'll be lucky to get 150 without going to the aluminum head or a turbo.

1) I'm having a lot of trouble deciding between the 200 and 250. The biggest problem is I can't find anything consistent on what is involved in putting the 250 in a '65 Mustang. I've looked at the swap page on FordSix and read the pertinent part of the Falcon Six Handbook on swapping it in a Falcon.
a) Just for reference, I'm mainly looking at the 250 for the extra power and torque potential, as well as the easy availability of clutches, flywheels, transmissions, etc.
b) Since the Mustang has a longer engine bay than the Falcon (I think?), will I still have problems length-wise, and need to go to an electric fan or move the radiator forward?
b) Motor mounts--are the stock 200 mounts going to work or not? I keep seeing answers all over the place on this. I'd rather not drill holes in the frame if I don't have to.
c) Hood clearance--I'm guessing this will vary based on the motor mount situation. If I go to a low profile air cleaner or carb hat, should I be ok or do I need to lower the mounts and what not?
d) Something I haven't really seen mentioned anywhere--the clutch linkage. Since the z-bar goes into a mount on the engine block, will the factory setup still work on a 250 or is the mount in a different place or not even there?

2) Parts: This is tentative and I may change things based on specific prices I find, but here's the plan right now:
264/274-110LC hydraulic cam from CI, STY springs, adjustable rockers if I can afford them, direct mount H/W 5200 2brl, basic rebuild kit from CI, 1.75/1.5" valves, double roller timing chain if I keep the 200, zero decked block, and I might try a little bit of head porting if I have time. Head hopefully will be a late 70s 250 head, depending on availability.
I haven't really decided on compression--I'd like to keep the possibility of a turbo later on open so that I can add one if I'm not happy with the power. However, I don't want N/A power to suffer too much. Would somewhere around 9:1 be a safe bet for a small turbo later on and decent performance now? Or should I just go ahead and bump it up to 9.5:1 or so and hope I'm happy with it?

Would all of this make a decent combination? Thanks for any input!

1. The decision between a 200 and 250 gets down to personal preference. I did the swap over thirty years ago so I'm looking back through bifocal glasses, so bear with me.
a) You will definitely get more HP and torque with the 250 over the 200. The only transmission you wouldn't be able to use on the 200 that you can on the 250 is the AOD, but if you had a 200 with the low mounted starter then that one would be possible.
b) The 250 will fit in the 65 Mustang engine bay with the stock fan and without moving the radiator. A electric fan would be a good upgrade however.
b) The 200 motor mounts can be used, but it will cause the 250 to sit higher than if you used the Maverick mounts. One way to get a little more clearance with the 200 Mustang mounts are to slot the mounts that bolt to the side of the engine.
c) Hood clearance-- Go with low profile air cleaner or carb hat.
d) Clutch linkage. Use a 289 V8 z-bar on the 250; the 250 uses the same bellhousing. The factory setup won't work on a 250 because the cross piece on the 200 z-bar is too wide; it will take to much modification and it is cheaper to purchase one for a V8.

2. Here again, to turbo or not to turbo is a personal preference. Hopefully someone who has put a turbo on a 250 will chime in.
Usually you would want to go with a lower CR than 9-1, probably 8-1 or 8.5-1. Personally, I would recommend up the CR to 9.5-1 and forget the turbo.

Hope this helps.
 
Since your looking at a 2bbl, a carb hat for cool intake would work/look great.
In my opinion, stick with the single pattern, 264/264 and try the 108* lobe, this will let you rev faster, and enjoy the longer duration.
aim for 9.3 CR, this let you stay with the 87oct.
 
If you are aiming at the mid-20 for gas mileage then you should stay with the 200 and a highway friendly gear like 2.79. I don't know about the 250 but the bigger the engine the more thirsty it will be typically.
 
:) Hi Mugsy.Now I COULD be WAYYYYYYYYYYYYYYYYYY off base with the following comments.
If so,someone with MORE knowledge than I PLEASE speak up.
Larger engine does not necessaryily(?) mean less MPG.PROVIDING the driver does`nt get throttle happy. :eek: You should be able to get the same HP at LOWER throttle settings with the larger engine,simply because of higher torque development,IF the engine is set up properly for the type of driving that will be done the most.
Such as town,hiway and ect.
Oh,the AOD sounds like a pretty good idea.Just guessing,but maybe,a 4:11 to 1 rear setup
would give pretty good around town performance along with pretty good hiway MPG to boot.
Just my spitballing and wandering thoughts.
Like I said,if I`m wrong,PLEASE correct me.
Thanks.
Leo
 
8) when looking at fuel economy, smaller is not always better. what you want is adequate power to minimized the amount of throttle opening you use to maintain speed. this can also manifest itself in proper gearing as well. running a 3.50 final drive gear is not always a negative deal with fuel economy.

that said, here are my recommendations;

1: send your head off to classicinlines.com for proper head work. this means having some porting done to improve airflow, and have the log modified to bolt on a 2 barrel carb. the holley/weber is a good one for a mild engine build.

2: run a cam that operates best in the 1000-5000 rpm range, and spec the lobe centers at either 110 or 112 degrees depending on what compression ratio your engine has. wider lobe centers means a high dynamic compression ratio as it tricks the engine into thinking it has more compression than it really has.

3: for engine displacement, i would stay with the 200 myself for a mild daily driver build, as it is easier overall since you dont have to try and gain hood clearance, however slight.

4: for a transmission, i would go with a T5 if you want a manual trans, and run a 3.50 final drive ratio. this will give you the best overall set up for fuel economy and performance.
 
General thinking towards mpg, is you want the most torque possible, or your peak torque to occur at the same rpm as your cruise rpm.

Larger ci engines may have more potential to use more fuel, but they also have the potential to perform at a lower rpm with less effort (less fuel consumption).

Id say you would be better off, performance and mpg wise, going with the 250.


or a newer v8..dont hate me, its just reality. :D
 
b) The 200 motor mounts can be used, but it will cause the 250 to sit higher than if you used the Maverick mounts. One way to get a little more clearance with the 200 Mustang mounts are to slot the mounts that bolt to the side of the engine.
the 250 was optional in the 1969-73 mustang.i wonder if these engine mounts might work better?btw a 250 is 1.5"wider at the engine mounts and an inch longer at the front.
 
I went back and forth on this same issue. Length and width of the 250 are no problem it's the engine height that finally pushed me to keeping the 200. The ideas for your rebuild are sound, I forgot if you mentioned what transmission you are using. If you have the three speed do yourself a favor and spend the money to upgrade to the five speed, it will be one of the best updates you will ever do.

Gary
 
early ford fan":ez8b7xpa said:
b) The 200 motor mounts can be used, but it will cause the 250 to sit higher than if you used the Maverick mounts. One way to get a little more clearance with the 200 Mustang mounts are to slot the mounts that bolt to the side of the engine.
the 250 was optional in the 1969-73 mustang.i wonder if these engine mounts might work better?btw a 250 is 1.5"wider at the engine mounts and an inch longer at the front.

I've heard of people using the mounts out of a 69 Mustang in the 65. The problem is finding a Mustang of that year with a 250 to get the mounts out of.
The Maverick mounts are easier to find.
 
First of all no offense taken. I just brought the 200 vs. 250 comparison to bring the conversation back to one of your parameters: MPG. The discussion had been all about POWER (insert Tim Allen grunt here) to that point.

Now... WITH ALL THINGS BEING EQUAL... the 250 will consume 25% more air than a 200 at the same rotational speed. Now if the Air/Fuel ratio is "constant" then the gas mileage will decrease. But as the other posters have pointed out, you can play the A/F game, or the gear ratio game and the VE game to make the 250 sip less gas per mile than the 200. Nothing is automatic or cast in stone as to which will get the better mpg. But you have to ask yourself, do you want to play those games? You would have a better chance of hitting your mpg goal with a smaller displacement engine in my opinion.

My personal experience has been this. The engine when I bought my car (I found out later) had lower compression due to the newer 0.045 " composite HG instead of the original steel shim one, a 2.5X:1 rear-end, a 1970 model 1940 service replacement FoMoCo carb with a "blueprinted" LOM dizzy and, finally, no top ring on piston #6. It got an estimated 13 mpg (speedometer/odometer is wrong). I then rebuilt the engine to 9.1:1 compression, gapless rings, a 2.79:1 rear-end, a '69 YF carb with a DSII dizzy. I drove it 300 mile from my old home near Detroit to my new place in Pittsburgh and got an estimate 22 mpg. That was a constant 70 mph following a '10 Continental driven by my brother down the OH and PA turnpikes.
 
Alright, thanks for the input everyone. I've thought about it some more, and pretty well decided I'll just do another 200, as nice as a 250 or other newer, more powerful engine would be. I really need to get it running over winter break; if I have to put it off any more by little problems that I can't get fixed before break is over, I'll probably lose interest in the car.
For the 250, I'd need to basically do a total drivetrain upgrade along with everything else I still need to do, so trans, driveshaft, the z-bar, clutch, flywheel, bellhousing, the engine mounting,... It'd all be several hundred assuming I could find most of it used. I don't think I can pull all of that right now financially, nor do I really want to risk running into a issue with it all fitting. The 200 basically will just need to be rebuilt and get a new clutch to be back on the road.

If I'm not happy with the power, I'll make some small changes if it's just a little low, or turbo it later on if I want quite a bit more.

I have the 2.77 trans right now, so I'll just leave it in there for a bit and try to go easy on it. When I get more time and money I'll swap to something better. On that note, what does it take to swap to the 9" clutch, and is it usable with the 2.77 trans? I have the recessed 8.5" right now, and wouldn't mind something a little better if I'm replacing it anyway.
 
electrorc":3ufbgsxt said:
I have the 2.77 trans right now, so I'll just leave it in there for a bit and try to go easy on it. When I get more time and money I'll swap to something better. On that note, what does it take to swap to the 9" clutch, and is it usable with the 2.77 trans? I have the recessed 8.5" right now, and wouldn't mind something a little better if I'm replacing it anyway.

In order for you to go with a 9-inch clutch, you will have to have a 66 or later 200 block. The 65 block only has the bolt holes for the 8.5-inch bellhousing.

You could upgrade the 8.5-inch pressure plate with one from an Alfa Romeo or Mercedes Benz. Advantages are that the pressure plates are diaphragm (which is easier on the leg), and you can find them brand new (no multiple rebuild/weak springs). Check it out here: viewtopic.php?f=76&t=42556

Hope this helps.
 
I don't have much experience with alot of this but a t5 trans and the right rear axle ratio should make a noticeable difference in your performance and mileage. Also it is possible to find a 77-80 Maverick or similar with good running 200 too either bolt in for a performance upgrade or modify it to the specs in your original post. The later years have more of what you want like apparently the 9" clutch. I put a Centerforce clutch and pp in my Bronco and am quite pleased with it. I would add a header and DSII to ypur list. Having another engine helps decrease down time.
 
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