Straight 6 Power Upgrades

[cjperry81]

I have a 66 couple with an inline 6 200 with an auto. I have been looking into doing an I6 to V8 conversion. But ive decided that instead of all that I should hot rod the I6. This car is bone stock. I was wondering if I could get some advice on have to hot rod this I6 and what parts/companies to use. Im on a budget so im trying to keep the cost down a little but im not beyone putting a few grand in the engine to get it cookin. If anyone could give me some ideas. I have looked at some of the straight 6 websites but its a bit over whelming and i dont know which direction to go.

CP

 

[Rusty67]

If you want to get really crazy with it I think at one point the made a 300 I6. Get a Straight 6 Datsun turbo setup out of an 80s 280z and get that to bolt up. That would be fun/different/fast.

 

[2+2GT]

I've spent a lot of time dealing with "most improvement for the least cash".

You can do it in stages. Nothing will work well with the crap stock exhaust, so start with dual headers running into a stock 2" GT dual exhaust. When you take the manifold off, install a 3-4 port splitter, and install the headers. You can also get a 289HP-style air cleaner, not as much power increase as the exhaust, of course, but looks great.

Front disc brakes and a suspension upgrade (GT) should be on your list.

One of the most effective and least expensive is to lower the upper control arm bolt holes 1". All this costs is four holes and a wheel alignment, and it will immediately improve handling. An export brace should be installed at this time to get the best benefit of the improvement.

My only other suggestion would be to swap out the C4 and install a T5 manual 5-speed transmission. You'll get better acceleration and better gas mileage.

 

[Wart]

Found a site, FordSix.Com

This website is for inline enthusiasts looking for ways to update and/or modify the “small block” (144/170/200/250ci) or “big block” (240/300ci) inline six-cylinder engines. These great little motors have been overlooked for their performance potential, and what little knowledge there is, has been sparse and hard to find. Until now.....​

The sites FAQ


I didn't look much past the front page, it's at least a good place to start.

From what I remember reading a long time ago the I6 could make pretty good power.

I remember reading an article in Hot Rod (?) years ago. A guy cut one chamber from 2 Cleveland heads (?) and welded the heads together to make an I6 head. (?) I don't remember much more.

 

[woodsnake]

All I got for you is cliffords...

Clifford Performance: Ford 200

 

[rbohm]

i am a moderator at fordsix.com. we have a lot of good information there, and we have people working on more. for instance the admin over there also owns the website Classic Inlines Performance Parts - Home where he sells performance parts, and has more tech articles, for the small six. you can also pick up a copy of the falcon six performance handbook, it is loaded with good information as well.

as for upgrading your six, start with adding a duraspark ignition system. you can get a rebuilt distributor from checker of autozone for a reasonable amount of money, i think one guy picked one up the other day for like $53. you can use a duraspark ignition box with the blue wire strain relief for best performance. when you add timing to the engine, advance it until you get pinging, then back the timing off a couple of degrees. a timing light often wont help as the dampner ring often times slips as the engine ages.

the next thing you can do is add a 2bbl carb, the holley/weber or the carter/weber is the most common, but the autolite and 2300 holley are coming up fast. classicinlines has the adapters you need to mount them to the stock head. if you are going to pull the head off, classicinlines also has an adapter that will allow you to direct mount a 2bbl autolite carb with a little machine work

if you pull the head you can add the port divider if you want, but it hasnt been shown to improve things enough to be worth the effort. likewise with a header on a basically stock engine. it helps, but not much until you start getting into real power output, about 1 hp per ci.

if you are planning to rebuild the engine, then check out the line of cams that are available specifically ground for the inline six by clay smith. classicinlines is also starting to branch out by doing head rebuilds, and when he finds a new supplier, he will have new aluminum heads again. mike is also trying to get heads from australia and argentina that have removable intakes.

there was a three part article done in mustangs and fords i think where they built a turbocharged 250 that made 323hp with mike aluminum head. there is also a guy going by the user name does10s that has a falcon with a turbo 250 that runs 10s in the 1/4 mile, and is still driven on the street and the track by his wife.

 

[rbohm]

All I got for you is cliffords...

Clifford Performance: Ford 200

yeah, i would stay away from clifford these days until they get their customer service issues fixed. in the old days clifford was the premier six cylinder performance place, but now classicinlines has passed them by.

 

[KiwiGT]

I've long thought the Australian Ford Falcon XR6 turbo engine would be wicked in an early mustang. Google Image Result for http://www.atholparkfordwreckers.com/images/uploads/BAXR6TURBOENGINE.jpg

These alloy engines are pushing Falcons into the sub 10 sec bracket on Australian dragstrips. They are available from the factory with T56 six speeds, or ZF 6 speed autos. If you don't fancy the turbo, the same block can be had in non turbo setup. The Australian Falcons these engines came in are from about 2003 onwards, and are still being made. The latest version puts out a factory 415 horsepower; and there is plenty of room to turn up the boost and extract more http://www.caradvice.com.au/51486/fpv-f6-e-road-test-and-review/

 

[2+2GT]

Let's not get too far into the weeds, he did say "I'm on a budget".

 

[rbohm]

I've long thought the Australian Ford Falcon XR6 turbo engine would be wicked in an early mustang. Google Image Result for http://www.atholparkfordwreckers.com/images/uploads/BAXR6TURBOENGINE.jpg

These alloy engines are pushing Falcons into the sub 10 sec bracket on Australian dragstrips. They are available from the factory with T56 six speeds, or ZF 6 speed autos. If you don't fancy the turbo, the same block can be had in non turbo setup. The Australian Falcons these engines came in are from about 2003 onwards, and are still being made. The latest version puts out a factory 415 horsepower; and there is plenty of room to turn up the boost and extract more http://www.caradvice.com.au/51486/fpv-f6-e-road-test-and-review/

yep, the aussie sixes are the bomb when it comes to making power, unfortunately the cost of shipping a complete engine from australia is rather probitive, not to mention the cost of buying the engine in the first place, and converting the US dollar to the aussie dollar(done that when i bought a dist from a guy in australia).

 

[Georgia Snake]

HiPo 6

Ok I have done this on my 65 Mustang. First off you need a 250. That will allow you to run any of the V-8 transmissions. Clifford Research is a good source of parts. If you can find one, get a 170 head from an old Falcon. This head has slightly smaller flatter combustion chambers and the adjustable rocker arm set up is more flexable. I would run a manual transmission. I have a close ratio Borg Warner T-10. The V-8 flywheel works with this but you will have to have it balanced. I would have the whole rotating assembly balanced. Once balanced, and with the crank supported with 7 mains and if you run a solid lifter cam as I have, you will be surprised at the rpm's you can run it up to. Her is the basic run down on my mods: Offenhauser intake adapter allowing you to run either 3 Autolite single barrel carbs or 3 webbers, Hooker duel exhaust header, Mallory YC duel point distributor (obsolete I am afraid), my cam came from Lunati along with the dampened valve springs, 13.75:1 compression (too much for the street, but I use my car for SCCA racing but it is street legal), Hays aluminum flywheel, 11" clutch. Now here come the bad part. These engines develope gobs of torque in addition to the HP increase you will achieve. This means you will have to upgrade the rear end to an 8" or a 9", and that also means you will have to change the front end to V-8 spec to match so you can run matching wheels (that will give you better brakes anyway). the U-joints size should also be increased to match. Remember that extra torque you are increasing. You will end up breaking the weakest link if you ever romp on it if you dont do these changes. I found out the hard way. My 65 is in the Stang Net garages section if you want to see it (1 FAST 6). You can mod the intake for a 2 barrel carb but you are not really giving the intake of these engines much more flow effecancy through the "log". With the tri-power set up, you have a carb setting directly over two intake valves. This set up is very effective and you dont need an engineering degree to see that. Almost any intake mod will effect your hood clearances too, so you may have to cut and put a scoop on the hood or run a scooped fiber glass hood. The carb or carbs will be off set compared to the V-8. From my experiance the two scoops that work best for the off set is either a hood with a 67 style Shelby scoop or the old air extracting Tear drop design. I dont know about any of the cowl styles as I havent had one of those but I have had the other two. personally I prefer the 67 Shelby style. I hope I have helped. If you have need of more info e-mail me at [email protected]

 

[Pony66]

We just spent a weekend pulling a 250 out of my buddies 1966 coupe. The 250 is crap. Mostly its because the 200 makes more power and the 250 is so tall that you cannot use an aircleaner. We will take the big Weber carb off the 250 and junk the rest.
We used the Clifford headers with dual exhaust. I dont have dyno #s but it sure sounds good.
I agree 110% with the 1" shelby drop. It only costs time. It makes a drastic difference driving these mountain roads in Colorado.
I also like the DuaSpark conversion. I have the parts but have yet to install it.
I also would get an electric fan and fuel pump. Its cheap and easy to free up some HP.
If you have the cash, they respond well to turbos.

 

[Georgia Snake]

HiPo 6

I must disagree. The 250 is far better than the 65-66 200. Yes the stroke is a bit shorter on the 200 which does allow for a bit quicker to rev engine but I think we are splitting hairs on that one. The biggest and best difference on the 250 vs the 200 is in the back of the block. The 250 is cast exactly like the V-8 in the rear and the 200 never was. This allows you to be able to run any of the V-8 transmissions, flywheels, and a scattershield (as I have, I strongly recommend the scattershield if running any manual transmission). Since when did the 250 or any Ford come with a Webber? The carbs used were either Autolites, Holleys (usually an over the counter replacement), Motorcraft, or a Carter. For a stocker or nearly stocker, keeping a single barrel, the old Autolite 1100 series carb is the best anyway. I have had both a Clifford and a Hooker Header on mine. he headers are exactly the same, bend for bend, except that Clifford puts a little tube for the heat riser at the 3/4 cyl tubes. My assumption is that Clifford is getting their headers from Hooker. I have seen other headers from other sources and the bending is always different and not as well thought out. The dura apark is a good ingnition system but I wouldnt take anything for my old duel point. The Mallory YC series is and was the best duel point out there. Its big, allowing for ease of maintenance, and with the addition of the Marine water proof cap, looks trick as hell. If you have never seen one of these old Distributors you should. In addition, mine has a cable driven tach off the distributor, another old school mod. I know my 6's. The 200 is fine, but in the end it has draw backs that bump the 250 in favor if you look at the total picture.

 

[Max Power]

I thought the 250 and the 200 were the same basic block?

Anyway, the key to making the small block 6 come alive if the intake and what you can do to it. The cast in log style integral intake is really restrictive.

 

[rbohm]

georgia pony, pony66, the 250 is a good solid engine that can make a lot of power, just like the 200 can. pony, the problem most people have with hood clearance when swapping a 250 into an early mustang is that they forget to drop the front of the engine about an inch. it is easy to do you just drill new holes in the mount. a better way to go would be to use maverick 250 mounts. you will have to drill a couple of new holes to use them, but they will drop the engine the needed amount also.

as to using the early 170 head, the later 200/250 head is better as is has the larger log volume. granted it does have large combustion chambers, but you can mill the heads to get the compression ratio you want. just remember to mill an extra .025" when using composite head gaskets as they are that much thicker than the original steel shim head gaskets.

as to having to use the 250 to use a V8 transmission, not true. there are adapter plates you can get to run the T5 behind a 200. the 67 and later bell housings are already set up to use the 3.03 top loader three speed, though you need a 66 and later dual bolt pattern block to use that bell housing. if you are stuck with the 2.77 bell, you can still use the T5 or even the 3.03 or top loader four speed with the right adapter plate.

as to clifford performance products, when jack clifford was there, they were the source for performance six cylinder parts and information. and their customer service was excellent. however since jack died, they have gone down hill. the place for ford six performance parts now is classicinlines.com. mike has done something that clifford has been talking about for more than 20 years, but never did, come up with a new aluminum head for the ford small six. classicinlines also has a cylinder head service where you can send your stock head for simple rebuilding, to having it modified by guys who are experts at the ford six head, including having adapters installed for putting on two barrel carbs if you want.

classicinlines also has performance camshafts ground by clay smith that were designed for the ford six, and not just an off the shelf design. you can also have classicinlines have clay smith custom grind a cam for you if you want. i dont remember if there is an extra cost for this or not, ask mike at classicinlines to be sure. mike is also developing a new full roller rocker arm system that is inexpensive, about $350 is his target price as i recall, and i believe they are adjustable. mike also has headers not from hooker though, his own design that actually fit properly. he may still also source headers from pacemaker, an australian parts supplier.

so check out Classic Inlines Performance Parts - Home and dont forget to pick up a copy of the falcon six cylinder performance handbook available from them. a lot of good information in the book.