All Small Six 200 inline 6 horsepower upgrade help

This relates to all small sixes
I'm still considering my next step in Ford Inline-6 200 HP domination (kidding about the HP domination part). I realize there’s no replacement for displacement, even if we get past the issues of the log head so if I wasn’t so enamored by the little 6, I’d just chuck in a 289/302, a decent carb, cam and exhaust and be done with it…

but… I’m completely hooked on this engine, I built it from its seized scored and scuffed origins. Due to the cam/carb combination I selected, it doesn’t like to idle smoothly when it’s cold but it just purrs when it’s at temperature and warm or cold, it’s happy to accelerate smoothly. It’s definitely more economical to drive than a carb’d V8 too. It’s pretty quick compared to a stock engine and it’s definitely fine for modern traffic and road conditions (5-speed for the win) but it’s not V8 quick. It just isn’t.

After I refine the handling and brakes, I will probably turbo mine and other than adding 1.6 adjustable rockers, I will probably not change the head (unless I can find a large log). I’ll pull the crank and have it checked and balanced and gap the rings at .025”; I gapped them at .015”, not considering that I might want to add boost. I’ll also put in ARP mains cap and rod studs. The rods are forged and hopefully the Silv-O-lite pistons will be up to the task of handling some boost. This is the long game so it’s not going to happen for maybe another year or two. If I decide to go any further, I’ll look for an Aussie or Argentinian head or a VI head now that there is some movement on those.

There have been a few YouTube videos of guys putting a u-bent pipe on their exhaust manifold on a 200 and adding a turbo of some sort without a lot of preparation or planning and they’ve reported “huge” power increases but I don’t know that I’ve seen any Dyno results that show real, rear wheel power and at what boost levels. I’d really like to see what power results we can reasonably expect from strapping a turbo on one of these while keeping the boost at levels that won’t torpedo the engine. I did see a YouTube guy build an engine similar to mine with a turbo and somewhere just north of 15lbs of boost he blew up at least one piston. I suspect a ring gap closed and jettisoned the ring land.

I’ve got about $2,000 - $2,200 US dollars into my engine for parts and machining so far. I don’t think that’s a lot of money considering it is a complete build with new pistons, performance camshaft, electronic ignition, performance carb and header. I had to assemble it but that was all part of the fun. If I could add a turbo and net 250 HP out of it (I don’t know if that’s a reasonable goal) then I’d probably only be looking at another $1000 in parts and fabrication.

I’ll be sticking with a six in mine for the foreseeable future.
Ok, 250 honest BHP will need at least 20psi manifold pressure, given that your seeking more than double what the current engine is likely to make. I can get that with my blown engine and it has a lot of torque. At that level of boost if used occasionaly, you might get away with stock pistons.
 
Ok, 250 honest BHP will need at least 20psi manifold pressure, given that your seeking more than double what the current engine is likely to make. I can get that with my blown engine and it has a lot of torque. At that level of boost if used occasionaly, you might get away with stock pistons.

Thanks for the insight. That’s about twice the boost I thought I’d need 🤔

My pistons are Silv-O-Lite flat tops but they’re cast 332 alloy, so if boosted, they’ll be safer closer to 10 lbs. I think if I plan to boost more, I’ll want forged pistons of a more resilient alloy ($$$).

Word on the street is that the engine made about 120 HP in stock trim. Before I do anything, I’d like to put mine on a dyno to get a baseline of where it’s at. With the cam I installed, HEI ignition, Weber 38/38 and header with big exhaust, it’s pretty quick and fairly torquey but I have no idea how much actual power it has at the wheels. It would be good to know for sure and to document.
 
Ive had both, I can tell you there is little difference in RPM capability, the 302 has a bit more torque. given the age of the 289, you would be lucky to find any good ones now. The pick is probably the roller cam 302, with gt40p heads. We had them here as a XR8 engine, rated at 220kW, roller cam, roller rockers gt40p heads, last well.
The 1966 Mustang 2+2 4 speed K code engine is a different animal than a stock 289 or 302. I wish I would have known back then what the car would be worth today. Sold it in 1976 or 1977.

It wasn’t all about hp and torque. It was about the fun factor. That engine liked being worked in the 3,500 through 6,000+ rpm range. What a fun car to drive.

In the US, A 289 High Performance replica engine can still be built at a decent price. 2.87” cranks are still available. Definitely go roller cam.
 
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The 1966 Mustang 2+2 4 speed K code engine is a different animal than a stock 289 or 302. I wish I would have known back then what the car would be worth today. Sold it in 1976 or 1977.

It wasn’t all about hp and torque. It was about the fun factor. That engine liked being worked in the 3,500 through 6,000+ rpm range. What a fun car to drive.

In the US, A 289 High Performance replica engine can still be built at a decent price. 2.87” cranks are still available. Definitely go roller cam.

How about a 289 at 7,600 RPM?

 
Thanks for posting the clip. It sure brings back memories. I’ve seen up to 7,000 when I missed a shift. But I never had the intestinal fortitude to push it near 6,500 with a good load on it. I’m just thinking back how fun the car was. I sure miss it.
 
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Thanks for posting the clip. It sure brings back memories. I’ve seen up to 7,000 when I missed a shift. But I never had the intestinal fortitude to push it near or at 6,500 with a good load on it. I’m just thinking back how fun the car was.

I always figured if I had a small block ford, it would be a 289 and that video sure seals the deal. What a beast that car is. It just sings when it’s at the top of the RPM.

I found a video a while back of a pre-cross flow Aussie 250 in a Cortina street and track car that revs way up to 7,000 RPM and it sounded really similar to that 289. I was hoping to post it as a comparison but I couldn’t find it when I went looking for it this morning. It had solid lifters, carbureted and pretty steep spring rates to rev that high. It takes some good engineering to keep a pushrod engine together at those rates. My 200 is a couple of thousand RPM below that mark.
 
In order to truly appreciate a built 289, A person has to drive one. A normal response from some passengers is they close their eyes and hope that it holds together. After a drive they might say something like wow! Or they might say you’re nuts, or say nothing at all. Most people are not prepared to be in a car with an engine turning high rpm’s.
 
In order to truly appreciate a built 289, A person has to drive one. A normal response from some passengers is they close their eyes and hope that it holds together. After a drive they might say something like wow! Or they might say you’re nuts, or say nothing at all. Most people are not prepared to be in a car with an engine turning high rpm’s.
The most impressive car I ever rode in for acceleration from a stop was a '65 'Stang with a moderately-built 289. "WOW!", for sure. (Still using the Ford 4100 carb). . . An engine with only a 2.87" stroke is going to sing a pretty tune up high.
 
The most impressive car I ever rode in for acceleration from a stop was a '65 'Stang with a moderately-built 289. "WOW!", for sure. (Still using the Ford 4100 carb). . . An engine with only a 2.87" stroke is going to sing a pretty tune up high.

Same here but by impressive, I use the word frightening. I had a very fast for the time 67 Camaro with a built engine and power glide 2-speed. This was the early 80’s. I could absolutely dominate a run of the mill 60’s small block Mustang but… One day, a friend of mine who was extremely talented in building hot rods rolled up in a 65, 289 4-speed Mustang. I don’t know all of the ins and outs of his build but that car was scary fast. There were 4 of us in the car and the acceleration was like nothing I had ever experienced up until that point. It made my Camaro look like a family sedan. I can still remember the feeling to this day. It sounded as scary too. Headers, glass packs. It howled.
 
Thanks for the insight. That’s about twice the boost I thought I’d need 🤔

My pistons are Silv-O-Lite flat tops but they’re cast 332 alloy, so if boosted, they’ll be safer closer to 10 lbs. I think if I plan to boost more, I’ll want forged pistons of a more resilient alloy ($$$).

Word on the street is that the engine made about 120 HP in stock trim. Before I do anything, I’d like to put mine on a dyno to get a baseline of where it’s at. With the cam I installed, HEI ignition, Weber 38/38 and header with big exhaust, it’s pretty quick and fairly torquey but I have no idea how much actual power it has at the wheels. It would be good to know for sure and to document.
If your talking about real honest dyno BHP, its more likely to be around 80 on a good day, the head and carby will hold it back. So to get 250, thats nearly 3 times as much, basicaly you need to increase mass flow by 3.
 
If your talking about real honest dyno BHP, its more likely to be around 80 on a good day, the head and carby will hold it back. So to get 250, thats nearly 3 times as much, basicaly you need to increase mass flow by 3.

Maybe I’m being too cautious but I think that’s probably going to be too much boost for the longevity of the engine. Even with blower pistons, hardened fasteners and roller rockers, all that added force is going to take its toll on a 1960’s engine. Whatever is weakest will make its presence known, one way or another.

At the end of the day, regardless of what we do for power, with an inline-6 Mustang as a base, if we add power (or even if we don’t), it needs better brakes and suspension so that’s not really part of my calculations; it’s just an inevitability. If an increase in power was my only objective or @Tmacdagreat only objective, hands down, it’s more cost effective to drop in a V8. They are plentiful around here as cores for not much money on Facebook Marketplace and Craigslist and all of the rebuild parts are commonplace. I could definitely have built of found a reasonable 289/302 for what I’ve got into my 200 and that’s really not a lot of money. I’m still under $2,500 US but the V8 would be many times more powerful and still dependable.

I had a V8 Vega in my 20’s so I’ve already had that adventure. I’m sticking with the 6. I literally can’t leave the house without having someone comment on how great the car sounds. That’s literally every time and they have no idea what’s under the hood. They all just assume it’s a V8 and to it’s credit, my car is quick.

I believe I’ve got mine running as good as it’s going to get with the recipe I chose so, I’ll either need to be satisfied with a modest (less than 250 BHP) by boosting up to maybe 10 lbs and having a reliable but still impressive ride or I’ll need to do something about the intake and get an Aussie 2V head, an Argentinian or a VI alloy head. Any one of those will make more NA power and would make substantially more power when modestly boosted. They’re still available but it’ll more than double my engine cost for the head, intake and header. It’ll probably double the NA power though as well.
 
Maybe I’m being too cautious but I think that’s probably going to be too much boost for the longevity of the engine. Even with blower pistons, hardened fasteners and roller rockers, all that added force is going to take its toll on a 1960’s engine. Whatever is weakest will make its presence known, one way or another.

At the end of the day, regardless of what we do for power, with an inline-6 Mustang as a base, if we add power (or even if we don’t), it needs better brakes and suspension so that’s not really part of my calculations; it’s just an inevitability. If an increase in power was my only objective or @Tmacdagreat only objective, hands down, it’s more cost effective to drop in a V8. They are plentiful around here as cores for not much money on Facebook Marketplace and Craigslist and all of the rebuild parts are commonplace. I could definitely have built of found a reasonable 289/302 for what I’ve got into my 200 and that’s really not a lot of money. I’m still under $2,500 US but the V8 would be many times more powerful and still dependable.

I had a V8 Vega in my 20’s so I’ve already had that adventure. I’m sticking with the 6. I literally can’t leave the house without having someone comment on how great the car sounds. That’s literally every time and they have no idea what’s under the hood. They all just assume it’s a V8 and to it’s credit, my car is quick.

I believe I’ve got mine running as good as it’s going to get with the recipe I chose so, I’ll either need to be satisfied with a modest (less than 250 BHP) by boosting up to maybe 10 lbs and having a reliable but still impressive ride or I’ll need to do something about the intake and get an Aussie 2V head, an Argentinian or a VI alloy head. Any one of those will make more NA power and would make substantially more power when modestly boosted. They’re still available but it’ll more than double my engine cost for the head, intake and header. It’ll probably double the NA power though as well.
Yes, all true, just for your amusement, here is my 200 inline, around 250bhp
 

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