Inliners International Forums General Discussion Engines where to start with a 292+390

hello folks. ive been reading through the posts and i had a few questions. i have a holley 390 i picked up used on ebay, and id like to use it on my more or less stock 292. its in pretty decent shape, but it needs rebuilt... both the 390 and the 292. but lets start with the holley. i saw they have a tric kit and a renew kit, and was wondering what one i should purchase. also what springs, pumps, accel cam, jets ect should i use? should i upgrade to those center hung fuel bowls at 200 bucks? will the stock fuel pump handle the 390?

i suppose i might be getting a bit ahead of myself. the 292 is in pretty much stock trim, save for a pertronix elec. ignition. shes sitting between the rails of a 1969 c10 weighing in at ~4000 lbs including me. she is equipped with a granny-1st four speed and what i believe is a 4.11 one tire fryer rear end runnin 235/75/R15's. she will top out at about 85-90 ish at ~4K RPM, but i think that might also be slightly downhill, heh. this truck has manual everything, except a vac. brake booster.

what id like to do with this truck... heated up daily driver...
id like to get the holley cleaned up and bolted on. i think im going to go with an offy intake first, because it will bolt up to a stock exhaust manifold. would it work ok if i only had stock valves and cam? eventually i will have the head rebuilt with 1.94 int. and 1.60 exh. valves, add a bit bigger cam, and eventually throw some lumps in... but first just the bigger valves, and mebbe shave the head a tiny bit.

i would also like to add long tube headers but i think i read that offys dont play nice with headers unless they are fentons. i also read somewhere that clifford makes a better intake for street applications. again the only real reason i picked offy over clifford is they bolt up to the stock exhaust manifold, and i dont need to plumb the coolant into it for heat.

i actually have 2 trucks,2 292's, and about 3 or 4 heads to play with. so i guess im kind of building two seperate projects in one, except the second will eventually turn into a turbo.

if i win the lotto, id like to grab an MY6 or mebbe mount a camaro 5 spd with that s-10 tail shaft. as for right right now, just getting the holley rebuilt and bolted on will be a major victory.

sorry for the long post, and thanks for your time.

Congrats!
Whats the list # of the 390 Holley and does it have metering blocks on primary and secondary or just a metering plate in the back?

Yup I've run a bone stock 292, Offy or Clifford intake, 390 Holley but all stock otherwise, runs great. The engine only "wants" about 300cfm so the secondary only opens maybe 1/2 or 2/3 of the way.

Mine is a 6390 Holley, I run 52 Jets pri and sec, the pri PVCR is .028 and the sec PVCR is .031, runs good that way so it just depends on what carb details are.

I think the List 6299 is the "Pinto/Vega" version set up for 4cyl so you might have to fiddle if you have that one.

It makes a big diff on the top end, the 292 wont starve any more.

$200 to upgrade the bowls????!!
Well, those side hung bowls were good enough for the 427 Ford and the 327 L76 and L79 so they should be good enough for a 292!
I'd save the #200 for that doggone expensive intake!

list # 8007... thatll do, right? date code 0445, if that number under it is infact the date code.

*grabs screwdriver* jusssec.... its got a metering plate on the secondary side and the primary bowl holds the two jets....it looks to me that the jet says 512, or 215. with the one in the proper orientation, its 51 then an upside down looking 2....or mebbe its a 5...i dunno. it sure doesnt say something like 028 or 054.

the lil nozzle thing you take out with a phillips sort of under the choke plate, that says 25 on it.

does that mean im gonna hafta specifically order the small jets, or will a standard renew kit genuine from holley have a few different pairs included?

also the fastners holding the metering plate in look like they have some sorta you-ought-not-to-mess-with-me-unless-you-really-know-what-your-doin heads on them. am i going to need to buy that from holley too?

or is it all in there just sorta sitting in there, not bolted in but its laquered and rusted in place?

i know how this is gonna sound but the only carbs i know inside and out are the crummy monojets that came on my truck, so looking at the innards of a holley ..... its kinna greek to me.

"you mean theres TWO floats i gotta adjust?? D'oh"

there was too much month at the end of the money this time, but next payday im going to buy a manual for the carb and study up. is there one that is...well....better than the other ones? ive also got leos book as well, the second version, but somwhere in my girlfriends house it seems to be lost in the ether.

thanks for your time!

Yup the 8007 sounds good.
Ok the 51.2 jet is a #51 jet, the extra 2 means "close tolerance".
The 25 is on the accel pump shooter. It controls the RATE that the accel pump shot goes into the carb. I think mine is also a 25, works good.
The secondary jetting is controlled by the number stamped on the plate with the funny screws (actually a phillips works pretty good on those). Should be a #34 or #59 plate which has .052 holes for "jets". From there its a bit complicated, but it seems your 8007 should be a tad richer than my 6390. Probably jetted just about right if you also run headers.

The jets wont come in any of the Holley rebuild kits, you have to get those small ones pair at a time.
I'd get a pair of #48 and a pair of #54 jets.
Try the #54 first (safer to go richer), use a Gtech or dragstrip or even a stopwatch or butt-meter. If its faster, leave em in. If not, use the #51s. If its slower, try the #48s, etc.

You can also try different springs in the vac secondary tho watch out, its easy to tear that $10 diagphragm. Make sure it WORKS if you fiddle with it. I clip a paper clip to the vacuum rod, up high against the housing, then go out and floor it,
then see how far down the rod the paper clip got moved. That tells you how far the secondary was opening.

Beyond that and setting the floats, if its a new Holley I wouldnt mess with it much.

Check out the Holley website too. I havent bought a Holley book in over 20 years so not sure which is the best one now.

thanks for the info deuce!

its not a new holley, thats for sure. shes old, a lill dinged up and crusty. i got it for a pretty good price on ebay. its funny too cause at the local 'yards theyre selling them used, beat up, as-is for about 50-60 bucks less than the cost of a brand new one to your door. sickening...

espescially since rebuild kits dont replace worn throttle shafts or warped base plates or damaged metering blocks cause someone drilled something they shouldnt have...

what cam are you using for your accelerator pump? it looks like the one on mine is red.... lots of grime and it looks like the sun bleached it out a bit.

my plan is to get some long tube headers eventually. i chose to go with an offenhauser intake cause im pretty sure it will bolt to my stock exhaust manifold. i hope this will provide adequate heat. with the headers im probably going to have to buy a heat plate, or if im super lucky, the offy has it built in. and put it all back together with some of those nice remflex carbon crush gaskets.

you guys seen those? i like em better than the thin steel felpro gaskets. they seal up very nice. only problem is they run about 50-60 bucks to your door, and mostly only "speed shops" carry them, not your napas or what have you.

so i did some google homework and read a few times that folks have been using the throttle pedal and cable assemblies off of later trucks like the 70's models,instead of spending alotta money on a fancy lokar setup or something similar.

naturally i was curious as to what type of setups other people had to connect the pedal to their carb.

you gotta pic of yours mebbe?

i was also wanting to ask about a wideband o2 sensor. my thought is it will tell me alot more about what is going on with my a/f mixture and give me a better understanding of what im doing to the mix when i tinker with the carb.

since im using the stock exhaust manifold, id only have one bung to get welded in. i have a good buddy of mine who could do it for a coupla beers, or at the very least,i can take it to the muffler shop.

my questions are: is there a particular kit that would work best for this application?

if i swap over to headers, am i going to have to buy a different kit, or will i be able to just add another sensor?

thanks again for your time.

found this before work today, its the exact modification i was hoping to do.

http://67-72chevytrucks.com/vboard/showthread.php?t=530828

Well I havent used Photobucket in a while but let give it a try.
Here is what I did-
* 4bbl is mounted sideways, primaries outboard so the "runners" are closer to same length.
* Not sure how much diff this makes. It would however if anything make the fuel level slightly higher on acceleration.
* Bellcrank is just a spare universal bracket from my junk metal box. Mounts to a threaded stud. The stud has to be VERY stiff for linkage to work right, so the stud is long, braces way down below against the block itself.
* Kickdown rod for powerglide is same, hooks to a bracket like the old 1bbl linkage, below intake. Kinda complicated but I wanted the kickdown as I like the consistency of auto upshift.
* There are TWO of the stamped throttle arm brackets both slipped onto the throttle shaft. Both are six cyl. One is stock, used for the downshift rod. The other is flipped over and operates the throttle, straight shot to the bellcrank as shown.
* Clearest photo is the one with the carb off
* With the others you can see how the carbs mount.
* Fuel line wouldnt pass tech but I was trying so many different carbs (Autolite, Holley, Carterbrock, Rochester), and both intakes (Offy and Clifford). Thats a lot of Hookenstuffen already so I took a few liberties.

http://s396.photobucket.com/user/WerbyFo...016060142532628

The sensor may not be as helpful as you would like. Mixture distribution, even in a stock manifold, varies between cylinders much of the time, and (worse) the degree of difference varies with RPM and throttle opening.
If the sensor is in the headpipe (after the merge of all cylinders), a meter is going to give you the average of all conditions, in which all 6 equal will look very much like 6 all over the place but in different directions.
Remember, you're tuning for the 1st cylinder to knock which means hottest, leanest, and (probably) the loosest quench clearance.

como se huh?

i was with you up until this part, would you care to elaborate a bit?

is it anything like when tuning the carbs idle circuit with a vac. gauge, you adjust the mix till just a hair before the vac drops off from being too rich? so like i tune it for #1 cylinder to knock then back off a tad?....lol im probably not even anywhere close...

Deuce, thanks for the pics!

and thank you to everyone taking the time to help another wayward newbie!

If you're lucky or diligent you'll find which cylinder is likely to knock 1st (probably 5 or 6 by the water circulation, but some other feature can change this such as smaller chamber, shrouded exhaust valve, worn lobe etc.).
That one has to be protected even if it means running the other 5 too rich and retarded for best power - unless you'd like to try popsicle sticks and dams in the manifold?

hmmmm...popsicle sticks.... thats a new one...i DO have a spare engine just sitting there....lol.

thanks panic. im fairly certain i have a worn cam lobe or two, it has this kind of miss. it idles just fine but every now and again it has this miss....sort of a murmur if you will. it doesnt have a low end hesitation per se, i can take off just fine, but there is also a snort if i get on it say, downshifting and snapping the throttle to the floor, or just snapping the throttle to the floor from idle. its like it backfires out the carb, or perhaps its the carb not keeping up with the fuel for that split second.

itll idle and drive, top end, power, all that. im pretty sure im at 10* timing with advance off and vac line plugged.

it just has this sort of a miss. also i can hear a tick that sounds like it increases with rpm, i think its cam / lifter cause the head is freshly remanned and brand new pushrods too. i even had the guy verify all the rocker studs were straight. running valve adjustment, etc...

all that to say im not sure what, if any, effect this will have with the info you gave me, but it is also something im factoring in to the equation.

adding the carb wont help the miss or the tick, but may help the throttle snapping issue. but man id sure like to get that slight miss sorted out.

im gonna look into purchasing an hei setup. i saw something about a d.u.i setup and had some thing you wire in and it bumps up the voltage into the ignition system from 12 to 18 or somewhere there abouts. what would be a decent hei setup to go with. i probably dont need the super fancy 18v hei setup, but something i can just drop in and not have to spend another hundred or so to get it re-curved would be nice.

thanks for your time.

"Popsicle stick" is a Mopar term for some kind of obstruction mod added to block or direct fuel droplets in a manifold to cure a mixture distribution error - beginning with factory mods for the original manifolds, then the most common aftermarket (based on popularity and success).
A negative popsicle stick is a ditch, just a shallow grind mark leading across a runner entrance (to divert fuel away) or into the runner (to add fuel), both are used in combination depending on the shape, and which one will be easier to add. Some are directly below the throttles, most affect a single runner or pair. The Mopar boards include some diagrams (but of course only appropriate for that motor and manifold).

thanks panic, very interesting. i havnt made my way to the mopar section yet but i do see alot of cross referencing when looking through various other forums.

hey deuce, what power valve are you using? i get about 19 inches at idle. ill go out sometime today and verify that.

Good questions I never looked til now.
On my 6390 Holley 390cfm:
* See pump cam chart

http://www.holley.com/data/Products/Technical/PumpCamGraph.pdf

My cam looked beige/white but that was just 40 years of color fade. Its a #290 which is the Green/Olive cam, see chart, so its fairly healthy. In the Trick Kit they give you a #266 Orange cam which looks pretty close.

My power valves IIRC are 6.5 primary and 4.5 secondary. No particular reason, I just grabbed the two new ones that were in my spares box. The PVCR's on this carb are fairly small and the carb is so responsive, it really doesnt care when the power valves open, theres no flat spots.

Ideally I'd lean the primary jets down from #52 to say #50 or #48 for gas mileage, then drill the PVCR to match, THEN the PV open vacuum might matter more.

My experience with PV timing is it is very dependent on car, engine, cam, timing curve, jetting, even weather. No "rules" you just have to give each car&carb what it wants.


EDIT
On searching a little more, now I'm not sure if I trust the Holley chart or not, it is inconsistent with their own "light to heavy" list
http://www.holley.com/20-12.asp

Further discussion here

http://www.theturboforums.com/threads/332213-pump-cam-chart-vs-fuel-volume

http://www.chevelles.com/forums/archive/index.php/t-313242.html

So all I can say is, the 290 Green/Olive cam is working good in my 390cfm carb. I think someday I will have to measure the curves, lift vs throttle, and see if the Holley chart is right or mixed up!

thanks deuce! very informative. the cam i have on now looks red-pink-orange....its faded pretty good. ill hafta take it apart to verify the numbers. new roomates moved in a coupla days sgo, things have been busy.

i purchased a set of .50 jets, like 8 or 9 bucks after tax, procured locally from the general store. .50 was as small as they carried. ill start there and if i need to ill have them sent in from the holley website.

i was also wondering if any one on the board here might happen to have an extra HEI dist. for a mostly stock 292 they would like to sell? id much rather support fellow inliners before taking a chance on the 'bay.

but if not, would someone be willing to point me out to something i could buy and run, without having to re-curve and tinker with the springs and weights?

i have a pertronix (ignitor 2 i think) and that helped alot over the standard points setup, but its no HEI. id like to run a bit wider plug gap. i think im stock at .35 right now. i opened it up to .40 and she didnt like that too much. new plugs even....autolite 404's i think, just some cheapies. sometimes ill run champions equivalent, never really noticed a difference.

Tom builds heis for your car/ engine spceficslly on 12bolt.com

thanks lowboy! ill check him out

He is a really nice guy they are fully rebuilt and customized for your application for a really close timing curve

Either that or redman in the swap meet is selling one i do believe

Ill send him a pm. We actully live pretty close