hi all:
i'm not sure if this is the correct forum but here goes.

i would like to hear some opinions on getting a little more from my carbed I6. although a great engine it does tend to fade on the hills, even more so when the a/c is on. i would like to hit the top of the hill with just a little more oooomph.

i have an 82 f100, the engine is stock I6(good condition), 110k, 4sp manual, 3.50 rear, 235r75 15" tires.

from reading the forums i'm thinking of:
electric fan, 2 1/2" cat back exhaust with glass pack (current exhaust is 2"), 2bbl carb with clifforord adapter to stock intake manifold.......perhaps performance plug wires and coil, free up the intake with a k&n, or similiar, air intake.

would this help my little truck over the hilltops? any other suggestions outside of more major engine mods?

 

switch the exhaust manifold to the dual headers found on '87+ models with EFI. they are a big improvment over the originals. plus it gives you the oportunity to add duals.

switching the carb will be the best improvment you can make. that 1bbl just doesnt cut it for the torque monstor straight-6. a 2bbl is nice, but i hear lots of guys running 4bbls on straight-6s.. thats something you may want to look into.


the duraspark igntion is one of the greatest ignitions i've ran upon.. but a high-output coil can do wonders, along with 9mm wires. i havent noticed much of a difference with spark plugs, so i always stick with copper core Motorcrafts.

 

Definitly go with headers, I've noticed a large difference in power on my 83 f150. Also, I'd check any emissions gear that you have on there, see if it is working properly. The smog pump on my pickup was seized up when I purchased it. I could notice a power difference when the belt was removed to the smog pump. Also, if a 2bbl carb is out of your price range, rebuilding your 1bbl for now will help a little as well.

 

I thought the Clifford intake came with a 4 barrel intake. Never heard of a 2bbl adapter for the stock intake, but it sounds like a pretty good idea. If you go with a 4bbl, don't go too big. A little 500 cfm w/ vac secondaries and an electric choke would work fine.

When I had an '81 with the I6, the 1 bbl carb was always coming loose from the intake flange. Is that a common problem with these motors? Hanging off to one side like that, it probably got lots of vibration.

 

My 84 I-6 that I have owned since new has renewed power. I put a 4 barrel manifold and a Carter afb carb along with the old dura spark distributor with a msd 4a ignition box and a set of EFI exhaust manifolds off a 95 which allowed me to run duals. (All smog stuff gone) The performance differance is unbelievable. The 6cyl has plenty of low end torque especially with the granny low of the 4 speed and once it's moving the regular torque of the 6 takes over.

 

I wnat to thank everyone for their suggestions. Most were right in line with what I was thinking and attempting to gain.

Although all the emissions components working correctly today I removed the belt on the air pump. It may be my imagination but it seems like it made a lot of difference.

Tomorrow the exhaust will be changed to from 2" to 2 1/4" pipe with a longer glass pack (single pipe). Tomorrow also the mechanical fan will be replaced with a 16" electric "puller" with an adjustable thermostat. We've got to order the new air intake so it'll be a couple of days on that.

i'll wait a bit to see what this does before deciding on the carb. A 4bbl is probably more than i want. If it seems to need more I'll probably go with the clifford 2bbl adapter to stock intake with the holly 350cfm.

thanks again for your help

fred

 

I'm not real familiar with the I6, and I read the other advice forums, but I would love to add my 2 cents.
On top of all the stuff your gonna do, pull the head and have it machined up! shave it to the max! Get a valve job 3 angle competion. Bolt her up and that should be worth 15 or 20 hp!

 

It's not your imagination. On my Cobra I tested a short belt that bypassed the airpump and I picked up about a tenth of a second at the track. Most people that I've talked to say a tenth is equal to 10hp, so I'd say it helped. That was with about 45k on the car so I highly doubt that it was seized. I now have 148k on the car and it's still the same pump...

 

hey f100beatertruck

thanks for the confirmation! now i'm anxious to see what that electric fan does

 

Well this is what I did while rebuilding my 300 inline six. Had the block hot tanked, magnafluxed, and checked. Then had it bored .040 over, had the deck resurfaced, line honing on the mains and camshaft area. The original head was cracked so I bought a remanufactured piece with no extra machining done to it. I had the crank, rods, and pistons all balanced. When we put the engine back together we installed: a Crane Blue Racer RV cam and lifter set, Mellings high volume oil pump, Clevite bearings, and Sealed Power pistons and chrome rings. I am still currently running the stock carb and intake, and exhaust manifold. I installed an Accel high output coil, 8.5 mm wires, double platnum spark plugs, a 160 degree thermostat, and a K&N air filter. I cut the stock exhaust just before the first cat and installed 2.5 inch pipe into a 40 series Flowmaster muffler and 2.25 inch duals out the rear (sounds great) of the truck. Of course as you all know an old truck is never done. I have already ordered a 2bbl adapter from Cliffords, and I am concidering installing a set of EFI manifolds that have been polished. I built my engine to be used in a 4wd pickup (more torque), the acceleration is much better; however it isn't much faster than it used to be. It sure pulls like a mule!

 

hi pkupman82:
thanks for the response! u have really done a lot with your truck. the exhaust work sounds (no pun intended) like something i'd like to try. although i'll probably try some 3ft glass packs for the sound and see what that does.

speed is not my main objective......just looking for some more "mule" power.

thanks

 

In order to get more top end on a 6, you have to put in a fairly big cam with a 500cfm carb. I had clifford headers, 4bbl intake & carb, accel ignition, and stock 2.47 gear cam (smaller than the normal 6 cam, it sucks BIG time) & 3.50 gears. I raised my top speed from 85 to about 105. If I had went with a big cam, shaved the heads and rebuild the bottom end, I almost bet I could hit 125 with it.

If you want to keep the bottom end, go with the above mentioned RV cam (or the next step up), shave the heads (more compression, more hp&torque), go with the 4bbl intake&headers, and put in 3.55 gears to match your 31x10.5s, and guaranteed you'll have some pullin power.

 

One of my future mods includes 3.55 gears and a straight axle conversion.

 

that would be the ticket, unless you are going to bigger tires.

 

I will probably go no bigger than a 32x11.50 on this truck, for gas mileage and performance reasons. Also it's harder to tow with a truck that has been lifted to crazy proportions. The 84 is my daily driver and will be for quite a while, the cost of buying a new truck is outrageous!