67Olds442X2

Wasn't going to ask this question but figured what the hay. Since my engine wasn't dyno'd, I don't have any hard numbers for HP/Torque. Maybe someone has a similar build with numbers. My guess is 450ish HP / 520ish torque. All I know is the car pulls hard between 3,000 rpm and 4,000 rpm and when those 8 barrels are open, it's hard to keep the tire from spinning, even at 50 mph. I haven't upgraded the rear yet, running open end 3.08 gear. I'm pulling the 3.91 posi from my other car to install for now.

Specs: not enough info maybe?

'76 455 block .030 over decked .040
Stock "N" crank .010/.010 with reworked stock rods.
Speed Pro L2323F pistons .002 in the hole (barely)
Felpro head gasket .040
"E" heads milled .060, Bowls and runners ported / polished.
Roughly 10.7:1 comp
Milodon Stainless 2.07"/1.710" valves
Melling HV oil pump, Moroso 7 qt pan
Lunati VooDoo 60805 cam 241/249 @.050, .539/.555 , 110/106
Lunati springs and lifters
Comp Cams roller rockers, hardened push rods and dual roller chain
MSD ignition, billet distributor. 17 degrees initial 35 total
Edelbrock (065) dual quad manifold with Carter Comp Series 750's and 2 inch spacers.
Doug Thorley headers (1970's era)
Pypes 3 inch stainless exhaust with X-pipe
SpinTech Sportsman mufflers.
Hughes 3,000 stall converter
TH400 with B&M TransPak shift kit with B&M 4 inch pan.
Running 93 octane with Lucas bootser for now.

Thanks.

Red_Hill

I'm no expert at all, but I think you are being conservative.

cutlassefi

I'd say you're pretty close, the dual quads cost ya.

67Olds442X2

Thanks for the replies.

Mark, When I was breaking the engine in at first, I just had the back carb hooked up and it almost seemed to run just as good as with both. I initially was going to use a Torker and Holley 850. One day I may replace Carters with a set of Edelbrock 550's or go the Torker, maybe Victor route.

GreekDog

sounds like if you bolted some wings on the side of her you'd probably fly!

cutlassefi

Sounds like a plan but unless you have extensive porting I'd do the Torker not the Victor. Better yet, when the RPM Air Gap finally arrives that would work well imo.

geckonz08

What octane would that put you at ?? any idea ?
mike

67Olds442X2

To be honest I don't know exactly. Read reviews and Lucas was good for a couple octanes. Haven't tried straight 93 yet, might try it next fill up and see if there's any difference.
What I need to do is drive 30 miles to Maryland International Raceway and get some good gas.

TripDeuces

470 hp
500 tq

That's assuming 1000cfm through that intake which I think is being generous

ah64pilot

Did you mean to say "conservative"? 1000CFM through a dual quad intake should be easy...I bet he's getting more like 1500CFM through it.

Dan, I think a torker w/ 850 Demon or Holly would be better. These Olds engines don't seem to like too much (more than the engine can use) CFM.

covertolds

I think you are pretty close with your guess of 450/520. I would lose the dual 4's and install a Torker or Port-O-Sonic with a 750 mechanical secondaries.

TripDeuces

Although he has two 750's that intake isn't flowing anywhere near 1500cfm. It's a dual quad dual plane. I stick with my 1000cfm max. Besides, the heads aren't flowing that much either. This isn't a blower motor.

It was 463hp/493tq on my dyno program which I know tends to read low so I gave some more to the numbers

cutlassefi

You hit the nail on the head imo. I'll go with the original estimate.

TripDeuces

I can elaborate even further.

Universal formula for CFM requirements: rpm x displacement/3456 = CFM

~6000 (maybe?) x 461/3456 = 800.35cfm

At WOT that engine can use 800cfm max. Many add 10% to that to account for poor VE, manifold/head design and inefficiency, racing purposes only, etc. So now we have 880cfm MAX. As you can see my 1000cfm is more than generous.

You could put two Holley Dominators on there and that intake and engine wouldn't draw anymore than 880cfm period. Of course with the Dominators your signal strength would be crap and it would run like a pig. If I were you I'd seriously think about running two 500cfm carbs on that intake. The response would be phenomenal and a pure joy to drive.

ah64pilot

You are correct in that the engine isn't drawing near 1000 cfm on that intake/ carb set up. I guess I missed it when you said what the motor was using was 1000cfm...I somehow thought what you said was that the intake combo wasn't flowing that...I assure you that intake is capable of flowing more than 1000cfm whether or not the engine is actually drawing that through it is another story.

I believe my original comment was that Olds engines don't like more cfm than they are capable of using. The dual quad intake is way excessive and it isn't being used to it's full capacity...but given the right engine, I'm sure it is CAPABLE of flowing well over 1000cfm.

TripDeuces

Actual head flow numbers would give us much better results. I just used generic ported wedge heads for the calculations. I know a good set of ported 'E' heads will flow in the 260-280 range on the intake side. That's equivalent to a set of Ebrocks right out of the box. I know I'm in the ballpark with my guesstimate. That's a strong combination regardless. It will be fun to drive for sure.

67Olds442X2

I kinda figured it was over carb'd. I've had this setup for many years. I got progressive linkage and have it set where the second carb doesn't enter the picture until half throttle of the main carb. That way the front will never be at WOT. I tried with both always together and that didn't work. I might set it up where the front one never kicks in. I ran the car at first this way because I didn't have the progressive linkage, it ran like a bat out of h___. Not sure if the front cylinders would be starved somewhat.

I got some pics of the heads. Will it change numbers given, no. I think they probably flow pretty good, don't know any flow numbers. The exhaust side was milled to the point to make the center divider flush. This has made it a pain to keep the headers from leaking. Got two gaskets on and it still leaks.

Thanks for the replies. I am surprised that torque could be 500 or less considering some 455's came from the factory with 500. Course could be the carburetors again. Sometime in the future, I'm going to swap out with a single carb setup or at least get smaller carbs sooner maybe.

Just got done pulling the 3.91 posi from my blue car, can't wait to feel the difference when I install it in this car (3.08 now).

TripDeuces

You have a nice setup and it's unique with the two 4 barrels. I've seen several of these where it runs off the rear carb and pulls the front one in progressively. I'm not sure it matters which one is the primary but it's food for thought. It's important to keep signal strength to the carbs strong on these multiple carb setups. This is why I suggested the smaller carbs than you have. Your head work looks nice, I bet it does scream. Don't get too concerned about the torque numbers. My dyno program is not some high end software and like I stated it tends to dumb down the numbers. I wouldn't be surprised if you're over the 500 lb/ft mark easily. The dual plane will help that too. GL with your combo.

67Olds442X2

Thanks "TripDeuces", I do plan on down grading to Edelbrock's 500 cfm's when I get the extra cash. I'm adjusting these carbs it seems every time I run the car. Thanks for the all the input, this goes for everyone else too.

cutlassefi

Gotta disagree with you here, haven't seen anyone verify more than 245 right out of the box. At the 2009 PRI I spoke with Rick Roberts, lead engineer for Edelbrock. He agreed, 245 is more like it. Told me straight out that the published numbers weren't right, they were generous.
And based on my last two builds, I'd have to agree, Panos's made more hp/tq with a just a little more cam (238/246 vs. 234/240) and compression (.5 point) but stock C heads than Kyles' did with the Edelbrocks.

Jmo.

TripDeuces

I can't account for Edelbrocks propaganda. I went with their published numbers which I've seen verified in other places. Here's a data base. It's huge but the numbers sync with what I was saying.

http://users.erols.com/srweiss/tablehdc.htm#Olds

You and I both know flow numbers can be subjective. One misstep with the grinder or the wrong cut on a valve and you're looking at a 10cfm difference easily either way. Add in the fact that people use other than the standard 28" of water (ei. Rocket Racing) and things change. At least this chart levels the playing field for the most part.

George

cutlassefi

The next set I get my hands on I'll have them checked at 28".
Funny how the first listing of numbers for the Edelbrocks are exactly the same as what's on their website, hmmmmm.
Real world, I'll stick with 250 at best.

Thanks

380 Racer

Funny how my engine builder came up with the same numbers as John did with his heads before reading anything about them. Seems as tho guys with a happy dyno or happy flow bench claim they are both reading low and those readings don't mean anything. They flow them all the same and all brands the same.

sparky44268

Hey whats up? By no means am I an expert, maybe a weekend knuckle buster at best. I had an engine built a little while ago it will go into my 68 442 convert,the specs were close to yours except for the awsome dual quads.
"C" heads milled to 76cc, port polish, some bowl work,mondello rockers,springs and cam JM 22 25 10, hyd int.512 lift@ 274, ex523 lift @ 280 110 lobe center
speedpro L2323F .030 (comp around 10.2 to 1 )
nodular crank .010/.010
68 block
performer intake,
port matched
750 holley, vac secondary
headers
msd ignition
Dynoed 461 hp @ 5000 rpm , 532 tq @ 3750 rpm
Since I am doing a frame off , I am trying to stick to a budget thats why I kept the iron heads, also, I like the stock look. Hope this will help a bit.

67Olds442X2

Thanks for the info.