300 hp N/A 250

[69stang_250]

Has anyone here built a 200 or 250 inline that is pushing 300hp +-25 to the wheels?
All of the builds I have seen or read about seems to either be in the low 200s or the other extreme with a turbo or supercharger.
My goal for the 250 in my mustang is 300hp to the wheels. Also if there are anythings you guys would like to see done on a build or curious
about the power gains from some components please let me know. I will be documenting the entire build of my 69 mustang coupe and will be sharing the restomod on here.

Thanks Y'all!

 

[rbohm]

due to the restrictive cylinder heads, its difficult to get more than about .90hp per ci in normally aspirated form.

 

[69stang_250]

Even with the Aluminum head or shaving the log off and fabing an intake?

 

[xctasy]

Has anyone here built a 200 or 250 inline that is pushing 300hp +-25 to the wheels?
All of the builds I have seen or read about seems to either be in the low 200s or the other extreme with a turbo or supercharger.
My goal for the 250 in my mustang is 300hp to the wheels. Also if there are anythings you guys would like to see done on a build or curious
about the power gains from some components please let me know. I will be documenting the entire build of my 69 mustang coupe and will be sharing the restomod on here.

Thanks Y'all!

Yes. But the prove postive is chassis dyno runs.

AzCoupe (the late great Mike Winterboer) and Does10s (Kelly's husband Will) were never able to produce a final dyno info profile of a non turbo EFI 6i. It would have been 351 hp flywheel, though. Mike B was busy making sure he looked after his customers, and Kelly and Will were busy making sure there ventures survived in a very tough economic climate. So the final numbers were not able to be run.


Hot Rod Bob's 250 triple carbed Weber with 2V 250 head would have done that.

In Australia, plenty of 250's with way more than 300 rwhp N/A are around. Normally in factory Ford Cortina Sixes with big Ivan or Dean Tigue/Tigue Engineering roller cams, 4-bbl intakes with double pumper 650 cfms, and they are stand out cars. There was a 3.3 liter Cortina TC that did pretty good too.


In Argentina, everywhere on the net, even with single 2-bbls, those 188 and 221' are tipping the scales at huge numbers. As T


The best indications of power are what the US guys here like Fast64Ranchero 443 or Does10s 423 rwhp levels of our best turbo 250's would be without 18 to 16 psi of respective boost, a boost ratio of about 2.25 or 2.08. Unboosted, those engines would be about 198 to 203 rear wheel horspower engines with there 490 lift Clay Smith cams with not more than 292 degrees lash duration. They are 165 cfm and 210 cfm at 500 thou lift cylinder headed 4-bbl engines.

Fast64Ranchero made the power by rod ratio changes (forged h beam Mitsubishi), and having a custom cam, custom forged pistons, and reduced loss T56 manual gearbox.

Does10s had a huge loss with the automatic geabox, but had an early development intake on a standard CI head and very mild camshaft with stock rods and HSC pistons.

With more lift, Does10s Classic Inlines headed engine would kick out the jams to over 300 rwhp.


You have to understand that the best ClassicInlines standard cam grinds are just 490 lift max. Any cam restricts rear wheel hp without supercharger, turbo, nitrous. A street auto in addition will loose a lot more rear wheel horsepower than a manual.

On a 200, that kind of cam actually came out to 211 rear wheel hp with a T5, or a stunning 266 FLWHEEL HP.

Two independently varified 4-bbl 3.3 liter engines have made 235 flwheel hp, one with a 110 lobe center 264 cam, the other with a 112 lobe center. One at 5100 rpm, the other 6200 rpm. These were examples of how conservative Mike's initial engineers calculations were.

On the website, a 250 with port EFI and a 600 lift cam was calculated as reading 351 flywheel hp.

The listed S-78/78-110 cam was Classic inlines planned radical lift solid flat tappet custom cam that didn't exceed 600 thou lift. On a port injected 250 with just 10.5:1 compression, that would give 351 flywheel hp, which is about 278 rear wheel hp with a T5 or Toploader. And thats very conservative.


Some basic restrictions. Stock US 200 in line small sixes are limited to 490 thou absolute valve lift as they have a -15 to-30 thou piston shortfall, and very short valves that can only take a basic 289 or 302 Windsor valve spring a few thou off 490 before binding up. The stock valve gear is very restrictive because the valves are so short.

The stock US 250 can take up to 590 thou lift because it has a minus zero deck register of about -103 to as much as-120 thou down the bore. Again, in Classic Inlines intial development, a 600 thou lift 250 engine will make a conservative 351 flywheel hp.


With a Zero piston top to block deck (head planed 120 thou, block decked 120 thou, 11.5:1 compression), the engine will go to way over 220 fly wheel hp with iron log head, but piston to valve clearance then resricts lift on a zero deck engine back to a 470 lift cam. With just 440 cfm at 1.5" Hg of three 1-bbl Tripower, it will make 160 rear wheel hp with an automatic with ease. Thats able to make mid 14 second , 100 mph passes with a shift kited C4 auto in a 2600 pound Mustang. Even with a shift kitted automatic, RWHP on a counterweight chassis dyno is always no more than 60 % of the SAE net dyno figure (40% loss). A manual T5/TopLoader, 73.6% is the average total rwhp figure (26.4% drive train loss). In a drag racing situation, a shift kited auto with a transbrake can show RWHP figures as much as 85% of the flywheel figure (15% power loss), but if you measure it on a chassis dyno, it drops to that 60 % of the SAE net dyno figure.

The Classic Inlines head is as good or better than the best Australian or Argentine alloy heads, but the total horsepower of the best Australian 4-bbl equiped 250's and even the smaller 2-bbl Weber 48 IDA equiped Argentine 183 to 221 is also about 350 to 395 flywheel hp.


Why the difference if the heads flow similar CFM at 28"H20?

Well, the Aussie and Argentine engines have

1. pistons relieved for valve lifts of over 590 thou (15.5 c to even 27.9 cc factory piston dish "troughs" with stock 1.531" comprssion decks that avoid piston contact at 490 thou lift)
2. valve lifts of over over 590 thou, and
3. roller cams with 50 thou durations past 250 degrees.
4. The Aussie X-flows have FE/ Cleveland/ Lima 385 style 1.73:1 or greater rocker ratios, so they make a lot more power.
5. They use NASCAR style inlet to exhaust duration and lift, so the engine doesn't over scavange, and this builds power with a restricted carburator which may only flow 650 CFM.

Rear wheel hp's are way over 300 hp with cams like this, easily.

The figures on the Classic Inlines website are 100% accurate, but very conservative, for the camshafts and cfm for the alumininum CI heads as supplied.


Under http://classicinlines.com/alumoverview.asp

Aluminum Cylinder Head - Overview

- Estimated Performance Gains

You want more than 351 flywheel hp? (You probably will get way more than what is listed on the chart above)


To be sure, you have to get a more radical, Aussie/Argie or late 70's style US in line six roller cam profile, and rocker gear changes that optimizes those 5 things above.. A transbrake auto or a manual gearbox will ensure the least drivetrain losses. You have at your disposal the smartest engine builders in the known universe in the USA. A few of them are on the FordSix.Com website, and they will gladly help you dial in the best cam to make the Classic Inline head meet your targets.

Or get a turbo, a supercharger, nitrous oxide...

 

[rbohm]

X as usual has put up a lot of good information. and it is quite possible to get the performance output he indicates, but you are going to have to compromise a lot to get that output. can you live with a 1200rpm idle speed? can you live with an engine that has a lopey idle even at that speed? can you live with an engine that has a soggy bottom end power curve, but goes like gangbusters on top? can you accept an inline six that gets 8 mpg at best?

remember that an engine like this will be a high strung, high maintenance engine that is best left for the race track. if this is what you want, then by all means get X to help you build this engine, and make the best of it on the track.

 

[xctasy]

Ford engines aren't known to be smooth when you start to cam them up, but they are smoother than other 300 rwhp engines.

Like this..https://www.youtube.com/watch?v=BLnMgrF1-v8


The best thing you can do is find a way to supply fuel to the cylinders evenly. On the Slant 6 forum, read up on what Chrysler US did all the development when the HyperPacks cam out in 1961, the way to make a 390 cfm 4-bbl vac sec or 4 bbl AVS Carter supply fuel. Chrysler Australia then sealed the deal from 1970 to 1972 with the US designed D series carburation. They went to DBS Vantage Aston Martin 45 DCOE's, a 325 hp twin cam six cylinder 4 liter engine!

Chrysler also released a few 4-bbl sixes, which we very underated engines.


The work they did was to put flow ramps in the intake to improve front to rear fuel settling on 4-bbls. The 1970-1972 E34 Valiant Pacers 4-bbls were state of the art. In Australia, the 302C 4-BBL 2V and 351c 4-bbl 2V carb for 188 to 216 hp engines. It was run the Fireball 318 and 340 and US 360. Its a Thermoquad 9800 4-bbl carb, a carb which had, in later years, a plastic float bowel and some isues with its throttle shafts. Not a great carb, but you can find them around, and they are the savoiur of many a small Buick Olds Pontiac Rover V8, and when you alter the flow ramps for low velocity fuel supply, they work great on an inline six.


TheEdelbrock 140x series is near as good. Anyway, one of those is pretty much ideal for a 4-bbl six out of the box..

Idle problems with Fords are due to the flow velocities of feeding six cylinders through 1, 2 or 4 barrels. As the cam goes up, so does the idle chop. A 4-bbl generally meets the fuel supply problems, the 2-bbl generally idles better. Four crner idle adjustment or cracking open the secondary barrels of a vac sec 4-bbl will take care of idle lumpiness. I does on 4 cylinder cars like my old 4 cylinder Pinto engined Cortina.


EFI engines are normally the best. One throttle is the US solution to idle, but even factory 1983 to 1987 4.1 EFI's were still never magically smooth at idle.

With a lot of extra work, twin or triple SU's and triple Webers can be rock smooth if you are able to unify the curb idle with a proper manmeter gague. They supprise a lot of people.

The wrongly mounted Carter AVS and Rochester 4MA in the Valiant E34 4-BBL Pacer and Pontiac 230 and 250 4-bbls were exceptionally easy to tune.

http://www.speedtalk.com/forum/viewtopi ... =1&t=24490


Roller cam cars are tame...untill you stand on the gas.

These are all fairly stock 250's with upgrades.

Bitzas was 332 rwhp in 2nd. Auto

https://www.youtube.com/watch?v=ziyy-lmZq5U
https://www.youtube.com/watch?v=lpPXM9Lq2g4
https://www.youtube.com/watch?v=k5JQwgGmnS4
https://www.youtube.com/watch?v=YK7tJg99zjA
https://www.youtube.com/watch?v=uPEARAE-CbA
https://www.youtube.com/watch?v=qddvSNm4H04

 

[xctasy]

Flywheel Hp per cube is 1.4 hp per 250 cubes with just 231 cfm of intake flow. RWHP per cube for an auto 250 with a 600 thou lift cam of just 278 to 292 degrees duration and the right intake would be about 0.9.


A sawn off log ported would go above 175 cfm at 500, maybee 200 at 600 thou if you could thin down the casting without hitting water. The alloy head is worth a serious amount of extra hp and carefree low speed torque.

The difference is head porting, cam lift, induction and proper valve gear to get the 300 hundred trifecta ponies at the axle.


Gearing (to cope with the mild loss of low speed torque) and idle are your compromises. The are so easily over come.

Your worried about many things, but only one thing is important...others are performance disciples, and Ford six owners need to learn how to do it the way others do, with what parts, and how to avoid the obstructions..

Here's how simply some others do it.

This is a modern knock off of the E34 Mopar 4-bbl intake on a 4.3 liter Chrysler D series engine, a canted valve engine.

https://www.youtube.com/watch?v=AKdcX6ZIXV4


And that's what your aiming for Hemi 6 power, with a 4bbl. These Ford engines are the cheapest engines to modifiy. The road map is all there. You won't get it if your worried about a smooth idle, but it will idle pretty good all the same.

 

[hotrodguy]

I am just getting started on a 250 strictly for drag racing, 69 engine , log head, turboed on E 85, in a 62 Ranchero with a C-4. We will see. Minimum goal, mid 12's 100 mph. Randy

 

[CNC-Dude]

Even with the Aluminum head or shaving the log off and fabing an intake?

Even with a highly modified log head with the log removed in N/A form, you'll likely fall way short of your 300 HP goal, it just doesn't have the flow potential to support that HP level. The only way you'd come close to that HP range is to replace the log head with one of the better alternatives such as the Classic Inlines aluminum head, Aussie Crossflow or even the Aussie 2V head. Any of which with moderate porting and other mods will get you closer to your goal, but also increase the cost of the build considerably.

 

[69stang_250]

All of this information is very helpful and some of what I have been looking for.
My budget is not too low for this build and I am well aware it will be expensive, however I am lucky enough to have a fairly large budget for the car.
I am going this rout for the same reason everyone here is. It is different and not as many people are exploring these engines as the V8's. I find this exciting and
fun. It seems it will take more brain work to build power into these engines , where as you can go to most parts stores and buy tons of bolt on stuff for the SBFs.
My main goal with this build is to explore new territory with the engine and thing outside of the box as much as possible.
That is why I say,if there are any ideas floating out there that no one has tried out yet, please let me know and I will be glad to do the leg work and see how these ideas workout.

Thanks again for all of the great information.

"You can do anything you want, as long as you put your mind to it!"

 

[xctasy]

Even with the Aluminum head or shaving the log off and fabing an intake?

Even with a highly modified log head with the log removed in N/A form, you'll likely fall way short of your 300 HP goal, it just doesn't have the flow potential to support that HP level. The only way you'd come close to that HP range is to replace the log head with one of the better alternatives such as the Classic Inlines aluminum head, Aussie Crossflow or even the Aussie 2V head. Any of which with moderate porting and other mods will get you closer to your goal, but also increase the cost of the build considerably.

.....You have at your disposal the smartest engine builders in the known universe in the USA. A few of them are on the FordSix.Com website, and they will gladly help you dial in the best cam to make the Classic Inline head meet your targets.....

Get to it!


You won't get better advice.


The difference between stock and modified is port area. A Hemi 265 has 2.7 sq inches at the gasket face, the 250 2V, 2.2 sq in, the Classic Inlines, less, the Alloy Head cross is just 1.3 sq in stock. The saw off log is better than the the Claasic inlines, but the upside down cathedral shape is awfull. The way to cheat air flow is to work on the cam and the 15 to 5% loss due to the wrong induction. Pulse tuning is a great answer to the bad air flow. Another is three carbs with staged secondaries. That's how I get power out of mine with horrible port angles and lousy cfm rates.

Key to my success was


1. David Vizards and a Jack Roush talk on flow efficency ( cylinder to cylinder air flow)


2. the Bill in Indy Engine Anlyser run he did in the Big Six section. I asked the rod ratio and independent runner questions, and got exactly the answers I needed. Stan57 gave me a free scread of info, and I followed up on it. You just need one light on the Christmass tree to win. I spent the next two years away from the forum, working on how to improve those two facets

3. The third was what sort of performance boost NASCAR got from 1991 to 2007 on the Roush Yates 45 series engines, started off at 650 hp, and ended up at 850, but with restrictor plates and 390 cfm 4-bbls. So there are ways to cheat air flow.

4. Control systems. Ford USA spent about 60 years perfecting EEC systems (they started in 1968, but the throttle synchronisation had been optimized when they decided to use one throttle to serve the whole engine in the 4-bbl era). All the foreign independent runner systems needed a US reliablity solution, and that solution was Detroits Speed Desnity and MAF versions of electronic port EFI.


5. David McNeil was the 1996 nz 1600cc land speed winner in a Honda CRX. He worked with a Gearing optimisation guru. Ford started copying the 930 Porsche Turbo 2.7 gearing, and the AOD apped that. The idealised quarter mile and top speeds can be taken care of by just some old cobled up manual T10/Toploader gearing spacings, with an added T5 style over drive if needed. But the sacred axle ratio and gearing choices. Ran the basics through that in 1997, and it works!


Your results may vary. Although you can't make power without air flow, you can make power with the right range of factors that work to your advantage. They are small ones to be sure, but there are some free lunches in air flow. You just have to prove them, and then use them.

Back on to it:-

The type of induction/carbs/efi/ turbo or nitrous verses machining cost thing again. The Hogan style 4bbl intake features on all of the hotest turbo 250 engines. The best worked log head 'cut off log' air flow rise from 160 at 400 thou, to 168 at 500 thou, and perhaps 185 at 600 thou. There are only six inlets, and they don't flow any better than a set of iron 289HP/351W 4V HO or GT40P heads. The key is lift and Velocity. CNC Dude understands this more than most. I know the lower side of these log engines, and with just better cam you meet the flywheel hp levels below in my FAZER engines. The cost of a small turbo and its ability to be run off a stock EECV module would mean I wouldn't bother with anythinh except an Eaton or GT35

For every dollar spent, an aluminum head would do it. Its just about flow, getting that 200 cfm plus flow at 600 thou, you might get a lot closer than you may realise, but the time cost is comparing at least 25% more cfm on the table with a Classic Inlines head compared to the best sawzall log head. Versus. If you aren't working on the easy gains of the SBF, working the log head is like trying to bolt a jet pack on a Velocifero with these engines, to find a new road Ford every day.

JGTurbo's Turbo Ford 250 I6



fast64ranchero
http://fordsix.com/forum/viewtopic.php?f=22&t=52695

1975 250 head, 1.75 and 1.5 valves, mill'd head with my own hand made intake, and exh 168cfm @ .5 intake 128 cfm @ .5 exh. flow numbers 1978 250 block, 3.718 bore (so I could get a good set of rings), crank offset ground to 4.125" from 3.91, 1.88" rod journals, Manley H beam rods for a Mitsubishi 4G turbo motor, CP custom dished pistons 8 to 1 comp with block decked to -005 block height I don't remember the comp height of the pistons off hand, Clay Smith Cam custom ground for me, but is now a stocked item with Mike, I think it's called a 292 grind, Terra Yellow rockers, 9.18" push rods, custom fab'd oil pan by myself, 1975 timing set to get the cam deg'd in correctly, Turbonetics turbo 62-1 P trim .81 A/R, 3" hand fab'd exhaust all the way out the drivers rear, billet steel flywheel 4 safety! Road Race TKO 550 3.27 first with a .82 OD, 8.8" rear end with 3.08 gears and a factory limited slip, I won't get into the suspension on the car as it has way to much stuff (93 Mustang GT swap with Steeda components)
all this in a 1978 Fairmont worth $500.