jimjr

Any advice on where to start looking to adapt the newer "cold air" intake to the 330C.I. w/4bbl. carb. & open air filter (Edelbrock)? How do these systems compare to the old hood scoop with a "Ram Air" matching housing? I'm looking to do one or the other to my '67 Cutlass. Thanks! Jim

joe_padavano

First, "ram air" systems typically aren't. The ram effect is negligible even at twice the speed limit. They DO provide cold air inlet. Depending on who you talk to, you get about a 1 HP increase for every 7-10 degree reduction in inlet temp. The factory O.A.I. systems are a good place to start for design ideas. You can pay big bucks for repro O.A.I. dual snorkle air cleaners like those on the 68-69 W-30 cars, or you can go aftermarket.

FYI, virtually all new cars have some form of outside air induction already. Most of the aftermarket "cold air" systems for these cars actually replace the factory outside air system with a shiny aluminum tube and an air cleaner that actually sucks hot underhood air. There's no underestimating the intelligence of the public...

jimjr

Thanks for the input, Joe. I ran across some old threads addressing the issue and it looks like everyone has steered away from the newer cold air units. I'll keep my eyes open for a dual "snorkel" air filter housing, whether new (after-market) or used. Your data on temp. lowering vs. H.P. gain was a real eye-opener!!! Jim

Boldsmobile

I have an after market OAI hood and built an air box myself.



This was my prelim sketch:
airbase.jpg

The side wall started off as a strip of aluminum about 61" x 5.625" x .030" thk. I bent a 1" flange and than ran the flange through a shrinker. As the flange compresses and shrinks it starts to draw into a circle. Once round i mounted to a base that is .060" thk by about 18.5 diameter.



The sidewall was tough to get round using the shrinker along the flange. We have a hand shrinker in the shop and i must have pulled the lever 300-400 times.
Here is the assembled unit
front.jpg

Looking down into it and mounted to the.060 base.
top.jpg

From the bottom and mounted to a .75" drop air cleaner base. The side wall fits tight to the base plate. You can see a couple of spots where i didnt shrink to 100% correct radius show up as a very slight ripple. bottom.jpg
Sitting on the carb
incar1.jpg
With air filter and top element installed
incar2.jpg
Sealed it off to the hood using a universal seal. The bottom of the gasket has u shaped rigid plastic channel, like a door edge gaurd. The top is a 1" thick rubber gasket that will compress nicely against the hood. Its pretty similar to what stock cars use to seal off their air box to their cowl opening.

I ended up using metal lock nuts with Loctite Blue. I am pretty happy with the way it came out. I added a factory sticker just for a bit of humor. Seal put me over $20.
P1050084.jpg
P1050083.jpg
P1050082.jpg

P1050085.jpg
P1050093.jpg

67 Cutlass

Jim, are you looking for something like this? I think the air was pulled from the headlights area by holes over & under the parking light.
I'm thinking of modifiing a filter housing and making my own set up.

Oldsguy

Pete, you definitely put some work into that thing, it looks good.
Mike, I have seen someone producing a similar "hat" with dual snorkels on the aftermarket but it looks a little bit different. That is the OE dual snorkel isn't it?

67 Cutlass

Yes Dan it was for the W30 package according to my assembly manual.

Oh yea and Pete, nice work on your air filter housing!

Olds64

Just cut a hole in the hood and put an 8" tall air cleaner on it. That is the best way to do it!

joe_padavano

VERY nicely done!

Aron Nance

Having done some metal stretching/shrinking while reworking the rear wheel well (had to hand form all pieces, and weld the seams, then weld into the car) that always rusts on a LongTop, I most certainly appreciate the work/time that you put into your air cleaner assembly. Looks great! Ironic thing about the rear wheel well area, after all that work, we decided to mount an 80's AstroVan rear A/C unit there, with duct work plumbed to blow out the side forward of that area. Used a rear speaker cover for air inlet back by the tailgate. Will try and post a picture at some point when I have the Silver Bullet out of the garage. After all that work, cannot get the A6 compressor to "stay alive". Need to add a larger condensor unit as original just wouldn't dissipate the heat from two units. Sorry to go off on a tirade, just figured all this out yesterday at the shop where she is worked on - all the time! He loves me, what with the SB, Big Red, and the Custom Cruiser.

Boldsmobile

Thanks to everyone for the comments.

In my 'spare time' i work on an open wheel asphalt modified. The modern day version of the open wheel pintos and vegas you guys might remember. 2500 pounds, ~650hp small block and 15" wide tires. We build all of our own chassis' and hand form all of the body work except for the roof. For that reason i have lots of tools at my disposal.

It certainly was a fun project to do. If and when i build another i think i would not use a drop base so i can get the air filter a little higher and it would also allow me to make the side wall of the airbox a little shorter.

Aron, dont you just love when you need just a little more shrink to get the piece round and you realize its now oval and you need to go back and stretch only to have to shrink again. Slow and steady is the way to go but its hard to resist making the perfect circle !!!!!

joe_padavano

We digress from the topic, but interesting idea, Aron. I may have to do that with my Custom Cruiser. As for the A6 compressor, that's the same compressor used on Suburbans with the rear A/C unit, so it should be adequate. I assume there's sufficient oil being added to the system?

The Stickman

I was considering using the one out of my wrecked minivan. If you want it you can have it.

The Stickman

Now back on topic. I think the new style cold air kits would work great if they actually put the filter say under the bumper. I plan on using an airhat on my carb(hopefully soon to be Throttlebody) then run the tube over and down thru where the battery is presently(will be moved to the rear) and then have a filter that is inside the drivers front fender. I will enclose that area and lead a scoop from under the bumper to that area. Should work out nice.

Phantom455

Got to agree-- fantastic job on the air cleaner, Pete!
Have you had an opportunity to see if you're making
more power and/or getting better mileage?

And Joe P.-- good to see you're still among us-- kinda miss
seeing you on the old Olds list!

ttyl-- Phantom455

'72 Delta/455--deceased 14Mar'06 ((
'95 RoadMaster wagons (2) /350 LT1
'73 Bu!ck Century/350

jimjr

Hello everybody- I haven't checked back on this post for a long time. Been trying to catch up on stuff at work after being out for a couple months (hernia/abdominal fix-up). I've read the posts and have found alot of great input to my original questions regarding cold air intakes. This website is sure loaded with a ton of talented people who are generous enough to share such ideas. Thanks and take care. Oh, and Happy Motoring!!!

captjim

You can save some time by using an 18" cake pan,
http://www.montecarloss.com/communit...534#Post491534

I have a RmAirBox set up, works great but the finish isn't fabulous considering the price.

69CutlassAlex

It looks like you know quite a bit about Ram Air. I am interested in making my own as well. Im not sure if you do or not but How does the ram air fair in the rain? I would assume that if yout driving in the rain the water might travel up the hood scoops and right into the car seeing as how now there is a great big funnel for it. Please get back to me thanks.
-69CutlassAlex

Boldsmobile

Not sure how it would make out in the rain. I have not driven the car in the rain since 1987. It got rained on at Sturbridge this year but it was under cover. It also got sprinkled on when i flat bedded it home from my parents house after its 10 year hibernation several years ago.

Its no trailer queen but i choose not to drive in the rain. I have often thought about what would happen if i did get caught in a storm. I think if i carried a reg top plate in my car show kit, i could swap out the open top for a closed top and i believe the water would accumulate at the base.

I believe its possible to put a flange in the hood opening to dam the water up and than just add some drain holes.

snowballs442

You did a very good job on that and saved money. It does look like you have done sheetmetal work before.

TripDeuces

Having seen Pete's ram air in person it does look nice. Real nice work Pete

455man

So ram air is not really ram air? Is the air moving too slow? Can anyone explain how ram air does not work?

joe_padavano

Scroll up and read post #2 in this thread.

455man

Yeah i seen that. That's where I'm assuming the air speed at 60mph is too slow. What speeds is the air entering the carb? Or is it the volume of air not enough? Or both?
I'm doing some research and some say the same as Joe others say on the ram air Trans Ams it makes a .1-.2 and 1-2 mph difference in the 1/4.

TripDeuces

Ram air is the physical act of pushing/forcing air into the inlet/carb of an engine. They are typically mounted on the hood, grill or bumper so that the forward movement of the vehicle forces the air into the engine. Cold air systems isolate the hot engine bay air from the inlet because as stated above colder denser air produces more power. I'll go out on a limb here and say that all ram air system are cold air system for the most part because they are picking up the cooler air in front of the vehicle. Cold air systems on the other hand are not always ram air systems. You may be confused because you are assuming the ram effect of the air coming in is what's producing the power but it's not. It's actually the fact that it is cooler and denser and therefore able to produce more power. Superchargers they aren't.

If you take Joe's example: Assume underhood temperature is 200 degrees (probably a low estimate) and outside air is 70 degrees. 200 - 70 = 130 degree difference = ~ 13HP. Not a bad deal.

joe_padavano

Trip has it exactly right. There just isn't enough pressure increase at the carb for any "ram" effect. Keep in mind that "Ram Air" is a Pontiac marketing term and means about as much as Oldsmobile's "Rocket" V8.

The fact remains that the twists, turns, and restrictions in any "ram air" ducting causes pressure losses. Compounding this is the fact that with the exception of cowl induction systems, Oldsmobile's O.A.I. systems, and the 69 T/A hood scoops, nearly all factory hood scoops are actually picking up LOWER pressure air than ambient. The center of the hood is a low pressure area.

Tests have repeatedly shown that any HP benefit comes from the reduction of inlet temperature, not any pressure differential.

#171Cutlassman

Another way to look at the benefit of an air box or hat, is that it helps keep the engine bay heat out of the intake. I don't have a box, but my set up sits high enough that the top of the filter lid is inside of the hood opening. I don't know if it really helps but it looks good IMO.

455man

I understand that cooler temperatures help. I did not realize there was not enough pressure at 60mph to make a difference. I also realize just like exhaust the longer and more turns decreases the speed of the air. I figured the Olds hood scoops were close enough to the front to grab some high speed air and with only one 90 degree turn it would not slow it down much. I think I need to call mythbusters

Would something like this grab enough air to make a difference?
http://www.eharwood.com/catalog/prod...?productID=499

joe_padavano

Definitely better. Note the smoothly radiused transition to the carb inlet. Of course, the specific shaping inside is still important, and since these are usually used on rear-engine dragsters, the airflow disruption from the rollcage may seriously compromise the effectiveness of the scoop. Subsonic aerodynamics are NOT intuative.

Aron Nance

Joe:
Won't digress anymore, but did want to respond to above: we didn't replace the condenser to a larger Suburban sized one, and looks as if therein lies the problem. Too much heat build up for the A6 to get rid of. That's the next step, and apologies to all for the hijack!
Aron