390 need info
#1
390 need info
im currently a tech student just getting interested in fe motors. i picked up a long block 390 a while back for $80 and plan on using my schools resources to build it. some info about it: its out of a 64' t-bird, it has the two bolt motor mounts, it has c1ae heads on it and came with an extra set of d2tea truck heads...just wondering what kinda info/input i can get on the motor. are the heads any good or could i do better? any and all input is much appreciated! thanks!
#2
Some FE info:
FE Cylinder Head I.D. and Application Chart
Not sure about your C1 heads, probably just ordinary car heads. The D2 heads have hardened valve seats--important for running unleaded gas.
Either set of heads will allow a decent amount of power, probably topping out in the high 300s or better depending on all the other stuff in the motor and what you do to the valve train.
The T bird motor would have been rated at 300 hp, SAE gross, so figure about 240 net, give or take. CR supposed to be 10.1, but who knows what it is--could have been rebuilt several times by now.
Read the FAQ's at the top of this thread also.
What else? Any plans and a budget?
FE Cylinder Head I.D. and Application Chart
Not sure about your C1 heads, probably just ordinary car heads. The D2 heads have hardened valve seats--important for running unleaded gas.
Either set of heads will allow a decent amount of power, probably topping out in the high 300s or better depending on all the other stuff in the motor and what you do to the valve train.
The T bird motor would have been rated at 300 hp, SAE gross, so figure about 240 net, give or take. CR supposed to be 10.1, but who knows what it is--could have been rebuilt several times by now.
Read the FAQ's at the top of this thread also.
What else? Any plans and a budget?
#3
well, right now the budget needs to be reasonable. im shooting for a dirty street motor thats reliable enough for a daily driver. rotating assembly is going to be balanced, only going with .010 over flat tops cuz the bore is in good shape, intake and exhaust ports are gettin cleaned up. as far as the intake, cam and valvetrain im not sure, havent done enough research on them to be sure what i want yet. any input on them would be appreciated!
#4
390's were good engines over all. they had a relitivly large bore and relitivly short stroke which makes for increased piston velocity. if you use a moderate cam, a 750cfm (or 2), aluminum intake, headers with a 10.5-1 cr or so along with d2 heads, home ported and pollished. you can expect up to 450lbs/ft of torque at mid to high rpm for under $2,000 if you shop around. if the engine is properly balenced it can run 8-9,000 rpm without much trouble.
if you desire to go all out on the engine and your wallet, you can get 650lbs/ft of torque on racing fuel and some forced induction like a super charger and stroker kit. of corse i wouldn't go all out on a 390. i'd go with a 429 or something like that.
if you desire to go all out on the engine and your wallet, you can get 650lbs/ft of torque on racing fuel and some forced induction like a super charger and stroker kit. of corse i wouldn't go all out on a 390. i'd go with a 429 or something like that.
#5
You sure don't want 2 750 cfm carbs or to run 8-9000 rpm's even with a balance. I wouldnt run that rpms without a billet steel crank ($2000+), high quality rods and pistons, awesome aluminum heads, full roller cam, etc. That's like Super Stock drag racing rpm's.
Keep it simple, like you are doing. When you want a cam, just call comp cams or lunati, or someone and they will tell you the cam for your setup. Have info and specs ready for your vehicle and they will match you with the right cam. I deal with comp cams a lot and like their quality/service. With either of those heads I'd just go with a dual plane 4bbl and a 600 holley.
Keep it simple, like you are doing. When you want a cam, just call comp cams or lunati, or someone and they will tell you the cam for your setup. Have info and specs ready for your vehicle and they will match you with the right cam. I deal with comp cams a lot and like their quality/service. With either of those heads I'd just go with a dual plane 4bbl and a 600 holley.
#6
One of the best bolt on carbs for the 390GT mustang engine was the 69 428CJ carb. It is a 735cfm carb (made by using different booster venturiis in the front of a 780cfm body). Unfortunately they are rather rare. The factory carb on a 390GT was a 600cfm Holley. I had a 390 in a 77 F150, it was the camper special engine from a 75 or 76 truck. with the stock carb, Duraspark distributor, but retaining the Duraspark II secondary sytem, 3.25:1 rear it would go around 13 flat in the quarter and go fast enough to scare even my then 17 year old son. He passed a car on a back road, got pulled over by a state trooper for an improper pass. He got a warning, and was asked "what have you got under the hood son?". He had gone from 45 or so to over 80 passing the car. BTW, stock manifolds and a my design right side only dual exhaust system.
#7
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#9
What do you want out of this build? if you could give us a hp number your shooting for, or at least the intended use, we could better help you with an appropriate build and budget.
As far as 8-9k rpms....that is a pipe dream! No twin 750's either. You wouldn't need more than 600cfm on a mild build, 750-800cfm on something stroked and breathing fire.
An example: my 445 uses a 750holley. There's a small gain by using an 800cfm, past that no gains.
As far as 8-9k rpms....that is a pipe dream! No twin 750's either. You wouldn't need more than 600cfm on a mild build, 750-800cfm on something stroked and breathing fire.
An example: my 445 uses a 750holley. There's a small gain by using an 800cfm, past that no gains.
#11
i dont mind lol! im lookin for about the same hp numbers, and i wanna be able to run the dog **** outa it...i was also wondering if the 2 bolt motor mounts are somthing i should worry about. i did find a 512 lift 320 duration cam for cheap, im not familiar with cam dimensions so what would that cam be good for?
#14
now you're talkin! you can toss that 350hp number out the window. With the most tq minded build you'll still be at 400hp. So the next question is, is this going into a car or truck? Basically there is a range in the hp/tq ratio from 400/575 to 545/500. You have to decide where you want it. The higher hp number you go the higher rpm your powerband will be.
I chose something in the middle at about 450hp @ 5500 and 535ft lbs. @ 2600. When I get some different heads that'll go to about 475-480hp and 540ft lbs. At least that's what the desktop dyno and BarryR says.
That cam has a $#!T load of duration. Definitely wouldn't use that one. A new cam is only like $150 so I would try to save money in other places.
Camshaft 101- Car Craft Magazine
Here's a link to an article explaining some basics about how a camshaft works and what the terminology means. Your intended use (race/tow/cruise) and your desired power will determine what cam you go with.
I chose something in the middle at about 450hp @ 5500 and 535ft lbs. @ 2600. When I get some different heads that'll go to about 475-480hp and 540ft lbs. At least that's what the desktop dyno and BarryR says.
That cam has a $#!T load of duration. Definitely wouldn't use that one. A new cam is only like $150 so I would try to save money in other places.
Camshaft 101- Car Craft Magazine
Here's a link to an article explaining some basics about how a camshaft works and what the terminology means. Your intended use (race/tow/cruise) and your desired power will determine what cam you go with.
#15
Lets get started!