i just dyno my truck
it has the offenhasuer intake dynomax heaers and a new 390
it had 148hp 283tq
but it was lean very very lean
i think the ****ty gasket that came with the intake is leaking
has anyone ver had to up jet the 390
what are your 390cfm's tuning setups

 

Hey, thanks for posting it. Unfortunately, I can't give you good advice on tuning, as I seem to suck at it. Right now, I have the stock jets, a 28 squirter, stock acclerator pump cam, and a brown secondary spring. I am running about 9 degrees timing. That's all I can think of. I upjeted and it ran worse, so then I went back down.

 

im gunna replace the gasket and put an air fuel gauge in it. once it is tuned i'll try to get it on the dyno again. i'll end up putting the chevy rockers on it too. i supose

 

I am toying with the Chevy rocker idea too. Not until I have a few more $$, though.

 

air:fuel ratio gauges are a waste of money unless you get a wide band.

How lean was it and what rpm was it lean at?

 

its hard to say. the pickup tube kept falling out of the exhaust. so i dont know when it was accurate and when it wasnt. it may not have been lean at all. but from what i seen i think it was.I also pull till 6000rpm or maybe higher

what is the deal with non wide band o2's , I'd rather a wide band but id rather not spend the money on the truck. i just figured a regular o2 would be fine. i do plan to buy a wide band for my mustang so maybe ill just use it on the truck first. i was looking for something cheap and permanent for the truck.

 

The problem with them is that they are only accurate right around 14.7:1, which is way too lean to be of any use. You need something that will read down to about 12:1 to be of any use. A wideband will do that and more.

 

What year is your truck? Im guessing this was with the engine in the truck on a chassis dyno? Can you tell us a little more about it? Like auto or manual trans, rear end gearing, stock engine? Im glad to see you got to dyno your 300. Any more info would be great.

 

From the begining. this is an 1981 F100, 3spd with an overdrive, call it a 4spd, i believe it is a t-18. the truck belongewd to my friends grandpa, when he died he gave it to my friend troy. Troy killed himself in 2002. i ended up buying the truck from his parents. i think i am the only one who would hgave kept it going. maybe a year later the tranny and rear end blew out. 3rd gear gone, and spider gears shattered. dunno what gear are in it but it is a 31 spline, i replaced both from junkyard but the rear end had 2 chunks out of the ring gear. i installed any ways. the rear seals are gone so any grease above the bottom of the axle tubes is in and out of the drum.i plan to rebuild completely and gear it. bla bla bla in dec 2004 it blew some rings and some ring lands but bores where still mint and i mean mint. i installed new ring pistons and rod bearings. and i didnt care enough to even hone it. ( i figure if it dont work then i'll just make it better.) they seated perfect. singel barrel carb = POS
i got tired of f'n with it. so i bought the offenhauser and dynomax hears and a 390 carb. I tried a stock 85 gt carb( 585 cfm holley model. vac. sec. tabs removed to axcess idle/air/fuel mixture screws). i think that might work better if i want to go 6000rpm. with some modification and tuning. and i can get free dyno runs until i'm done with the school. i want to see what i can do with the 300. then maybe a bick block, man. vavle body. trans brake. and some major! suspension tuning.did i say major!

 

bick block.. lol.. sorry too much to drink and it's 537 am

 

well i put the truck on the engine analyzer and did a bunch of test here a re some results
ignition is good very good
air fuel is rich very rich like 10-1 to 12-1
everyhting else is good
some idle adjustments and some jetting and she'll be good
im gunna take her on a road trip this weekend so im not gunna tweak with her until after that . then on with the rockers

 

No need to make Excuses, the 300c.i.er IS a Big Block I-6.

 

Not sure if this'll help you any, but this is what was done to my Big Block Inliner.

300 H.P. @ 4600 rpm & 400 Torque @ 3200 rpm w/ a 9.5 to 1 C.R.
It idels @ 675 & is smooth as glass.

Ross Pistons 4.060
Hastings Power Flex Rings .060
Federal Mogul Mains .020 Under
Clevite Performance Bearings Std.
Federal Mogul Cam Bearings Std.
Melling Torque Cam
Melling H.V. Oli Pump
Eagle H-beam Rods 6.300 2.100 Rod Journal
Crane Gold Race Roller rockers
ARP Main Stud Kit, Rocker Studs,
Fisher International Ballancer
Bore 4.060
Power Hone 4.060
Full P&P Intake & Exhaust
Performance valve job
Performance Balance job on Steele Crank w/ in 7 grams
Grind Rod Journals to 2.100
Plumb Intake for Heat via Water Pump
Deck Block to Square
Align hone to Factory specs
Deck block for Zero Deck
Offenhauser C Intake
Holley 1850 600 CFM
S.S. Borla 2 into 2 Header
8' of 3" tubes attached to Flowmaster 40's
4 Core Desert Radiator mated w/ the Original Radiator Housing
2 1,200 CPU Electric Fans, on @ 180*, off @ 170* mounted diaginally
MSD 6A Eclectronics Package & Coil
D.S. II Electronic Ignition

 

Can you give me an estimate of the total cost of this engine set up below?

Thanks,Carlton

 

W/O the Exhauste System & the New Radiator Core the cost was $4246.00.