How many real world hp and torque are increased on the following 300 as compared to stock?

1967 F100 with on tree with a 3.50 rear end:


Duraspark II with HEI module, 42,000 volt coil and new copper plugs
Electric fan
Offenhauser DP
Autolite 4100 1.08 (480 cfm)
EFI exhaust manifolds
2.5" single exhaust

I ask, because throughout the time I've owned the truck, I've continually upgraded the truck. My Edelbrock 1v intake is being swapped for a new Offenhauser DP, and I bought an Autolite 4100 1.08. I know I'll feel the difference, but wondered what real world numbers would show if you compared it to a stock engine.

 

probably not the answer you want to hear, but in order to get real world numbers, you've gotta log all the data and make dyno runs and tests drive to validate your initial goals. fuel mileage, unscheduled maintenance repairs, HP and torque numbers, 1/4 mi times, etc.....the list goes on and on. i'd recommend trying to find a local and reputable speed shop, have them run the truck on the dyno in direct drive and analyze the results. there are rules of thumb and equations available for estimating flywheel numbers vs. rear wheel numbers online. there are plenty of folks out there that make certain claims (and some may very well be accurate and truthful) but the only surefire way to really see the results for your setup is to get her on the rollers and see what she'll do. every truck is different.

 

Exactly! "...the only surefire way to really see the results for your setup is to get her on the rollers and see what she'll do. every truck is different.

 

Biblethumpncop, not only the vehicles, but every owner/modifier is different. Guys buy manifolds, headers, cams, you-name-it, and are disappointed when the improvements in performance or mpg or both are not what they expected, not what others had reported, and not what the manufacturers had led them to expect. Most of the time this is not because they (the buyers of the components) had been misled, but because they just bolted on the new parts and went for a drive, without understanding that any change from the factory configuration requires pretty careful re-tuning. For a very common example, getting rid of the log intake manifold and exhaust manifold of an older six and putting on good aftermarket manifolds and headers has significant, well-proven beneficial results. BUT, the increase in cylinder-filling at a given throttle setting that these free-flowing manifolds provide requires that the ignition curve be modified for the new conditions (in general, better cylinder filling calls for less spark advance, but you don't know by how much nor where along the rpm curve until you test for this).

Bolting on parts is easy. Tuning is complicated. Testing the results of tuning is a hassle. But that's how you get the results you want. Everybody is not equally good at tuning. Example: search for Ford six owners' opinions of the Offy Dual-Port manifold, and you'll find lots of controversy, with guys who are happy and others who hate the D-P. Yet it's the same manifold. My guess is that this wild variation in owner experiences has less to do with the differences in their engines and vehicles, and more to do with whether they actually (by skill or by accident) got their engine completely and correctly re-tuned.

Finally, improvements are generally small, but they are cumulative. Young guys frequently want to know what are "the best" one or two components they can buy. They need to heed the old Hundred Pound Rule of Motor Racing. This states, "There is no place you can take a hundred pounds out of the car; but there might be a hundred places you can take out one pound."

Regards,
--(atheist)

 

Smitty,

Thanks for the thorough reply.

 

I think your going to be pleased with the results, but as Smitty mentioned, a good tune will probably go a long way.

I donno about using an efi head in that mix, but I really like it's fast burn thing as it allows me to really play with the ignition timing map across the rpm and map range (aftermarket efi)

 

Cop, FWIW I think you have a good combination there.

For a little boost in mid-range power and up, many guys are going to higher-ratio (1.6:1) rockers with the factory cam (and new springs); do a search at www.fordsix.com for that. You can get another power boost, from fast-idle on up, if you're willing to pull the head, do some port and bowl clean-up, and get slightly oversize valves installed; again search www.fordsix.com. And if you ever do a full engine rebuild, you can do a few more things. One of the big changes there, done for reliability and not power, is to get better pistons. People rave about how reliable the Ford Big Six is; well, the 240 was, but the 300 commonly breaks pistons. You probably already know that they shred the phenolic cam-drive gear, which should be changed out on a high-miles engine (over 120kmi).

Are you often carrying big loads with your F100? If not, you might be happy and get better mpg with a taller rearend than 3.5:1, considering the extra power you've built into your engine, but get other opinions than mine on this.