And....What Would Be Your Ideas For this Problem...???

[Viet Nam Vett]

This has come up before but I thought maybe I'd throw it out again...The 502 in my 65 which has a 66 BB Hood is using the supplied Holley 850 CFM Carb. I am using a GM style Deep drop base air cleaner base. Also I'm using a 3 " Tall K&N Air filter..which I have to use to get carb top clearence.

Now here's the problem..I only have 2 1/8" from the carb Flange Base to the top side of the under hood. The AC base is spaced off with base flange gaskets so that the AC Top Lid Underside.... ( Which Is a K&N Flow Thru Top Lid)....does not hit the choke plate and push it over increasing idle.

If I raise the AC Base Up to high..then the top lid hits the hood. Now..If I use a chrome flat top lid I can pick up more clearence at both ends..hood side and choke plate side. But I lose the air flow thru the top design

What I would like to see is some sort of air intake from under the hood forward of the carb or my original idea of using the 66 BB hood grills as an air intake.
The Problem with that is..Air is rushing by the grills is creating a suction rater then a postive air pressure..

Now I know I have brought this whole topic up before .so don't flame me.... I bring it up again only because time has passed and maybe some one will have a brain storm..and come up with a fresh idea.

Any takers......

 

[firstgear]

This has come up before but I thought maybe I'd throw it out again...The 502 in my 65 which has a 66 BB Hood is using the supplied Holley 850 CFM Carb. I am using a GM style Deep drop base air cleaner base. Also I'm using a 3 " Tall K&N Air filter..which I have to use to get carb top clearence.

Now here's the problem..I only have 2 1/8" from the carb Flange Base to the top side of the under hood. The AC base is spaced off with base flange gaskets so that the AC Top Lid Underside.... ( Which Is a K&N Flow Thru Top Lid)....does not hit the choke plate and push it over increasing idle.

If I raise the AC Base Up to high..then the top lid hits the hood. Now..If I use a chrome flat top lid I can pick up more clearence at both ends..hood side and choke plate side. But I lose the air flow thru the top design

What I would like to see is some sort of air intake from under the hood forward of the carb or my original idea of using the 66 BB hood grills as an air intake.
The Problem with that is..Air is rushing by the grills is creating a suction rater then a postive air pressure..

Now I know I have brought this whole topic up before .so don't flame me.... I bring it up again only because time has passed and maybe some one will have a brain storm..and come up with a fresh idea.

Any takers......

I would think about taking a pitot tube like is used on a plane or a wind tunnel and stick it in various areas in the front of the car to see where there is actually a positive pressure created.....now do you have access to such a device with remote monitoring.....that is a different matter.....I can get access to one where I work....so that is how I would go about it..... do you know anyone that works with an engineering group that takes air flow measurements?

 

[BarryK]

Mark
maybe this is bit off the wall but.........

you know how on the fuelie cars there was an air intake tube from the drivers side of the radiator support back to the FI unit?
What if you were to cut two ovals in the support, one on either side of the radiator than fabricate and fun a big hose from those cut-outs back to meet up with the air filter assembly. The increase airflow might be plenty enough that you could reduce the size of the air filter from 3" down to 2" and give you the clearance that you need.
It would kinda be like the air intake tube on the fuelies only one on each side.
You could probably utilize something like those big flexible hoses used to vent clothes dryers to the outside.

i'm not sure the best way to mate the hoses up to the air cleaner housing but I'm sure you could fabricate something that would work.

Of cource you could always go with a '67 stinger hood or even get your '66 BB hood modified slightly. To modify your existing hood I'll bet a good body guy used to working with fiberglass could do a custom job of raising the bulge up maybe an inch or an inch and a half and it wouldn't even be noticable unless it was next to another '65/'65 BB hood.

Ok, that was three ideas and i'm out of any others Beer

 

[Viet Nam Vett]

I would think about taking a pitot tube like is used on a plane or a wind tunnel and stick it in various areas in the front of the car to see where there is actually a positive pressure created.....now do you have access to such a device with remote monitoring.....that is a different matter.....I can get access to one where I work....so that is how I would go about it..... do you know anyone that works with an engineering group that takes air flow measurements?

Now that sounds like a move in the right direction... I might be able to get my hands on one here at work..I still like the idea of bringing in air from the side grills...

Thanks..

 

[Viet Nam Vett]

Mark
maybe this is bit off the wall but.........

you know how on the fuelie cars there was an air intake tube from the drivers side of the radiator support back to the FI unit?
What if you were to cut two ovals in the support, one on either side of the radiator than fabricate and fun a big hose from those cut-outs back to meet up with the air filter assembly. The increase airflow might be plenty enough that you could reduce the size of the air filter from 3" down to 2" and give you the clearance that you need.
It would kinda be like the air intake tube on the fuelies only one on each side.
You could probably utilize something like those big flexible hoses used to vent clothes dryers to the outside.

i'm not sure the best way to mate the hoses up to the air cleaner housing but I'm sure you could fabricate something that would work.

Of cource you could always go with a '67 stinger hood or even get your '66 BB hood modified slightly. To modify your existing hood I'll bet a good body guy used to working with fiberglass could do a custom job of raising the bulge up maybe an inch or an inch and a half and it wouldn't even be noticable unless it was next to another '65/'65 BB hood.

Ok, that was three ideas and i'm out of any others Beer

Thanks Bary Some good food for thought.. I did at one time consider bringing in air from the front but there are just to many things in the way like the alternator etc. The next best thing is right down the front center as I don't have a stock fan set up or shroud..

But the hood clearence is limited their.. Your idea of a hood mod is sound but requires Lotsa $$$$$$$ and the paint on the car is Laqure..Agin this seems to be the right way to go though.

But I keep coming back to those hood grills and maybe some how moding the fins to direct and or force air into the hood....maybe even building some kind of a custom grill.... Thenm I could fab a tray up to sit on the carb and seal to the hood like the L-88 air intake on the 67..

 

[firstgear]

Now that sounds like a move in the right direction... I might be able to get my hands on one here at work..I still like the idea of bringing in air from the side grills...

Thanks..

with the pitot tube you will have a good idea of airflow.....and you can move it around....it will also help in getting direction ideas....perhaps you could mount at the base of the windshield and hood where they used to get the cowl air force feed......the pitot tube will take the guess work out of it and you will know for sure....

 

[JL66REDCPE]

If the open top air cleaner is as close to the top of the big block hood as you suggest, then it is not drawing in that much air. Additionally, it is all underhood air which is HOT. Therefore, I suggest you use the flat top air cleaner which gives you more clearance and, more importantly, more overall area to draw cooler air from. I dont think the K&N filter is giving you any appreciable more power. In fact in your configuration, it may be actually hurting you.

 

[Subfixer]

Take off that hi-rise manifold and put a tri-power setup on it with the triangular air cleaner. It will clear everything, and it looks cool, too.

 

[Grizzly]

You ever give any thought to running a tube to the gills on the side of the front fenders? Rig something like a Ford Thunderbolt or 442 W30 setup. Push a big flat air filter in a box up against the gill so it can only draw from the outside.

 

[1KULC7]

How about an old trick we did in road racing...using the 66 block hood, utilize baffle sheets directing air flow rather then air suction. Small air deflectors on the hood would bank the airflow the direction it is needed.... We us to do that in the Camaro world on the 63 rear induction hoods...remember the air filter fit tight into the hood, problem was the same with air suction vice air delivery...so we remove the round hood appartus and installed small deflectors attached to the hood adjusted to the direction that baffled the air into the air intakes of the air filter/cleaner....

 

[maxphunn]

Mark, just a couple thoughts that you have probably investigated;

Does anybody make a lower profile intake manifold for the 502?

Are there any other carbs out there that are not as tall?

Any low profile fuel injection systems available?

Could any air be picked up through the wiper grills?

I like the idea of the hood bulge being raised a tad. Just enough to let the world know there is something special underneath.

Pat

But I keep coming back to those hood grills and maybe some how moding the fins to direct and or force air into the hood....maybe even building some kind of a custom grill.... Thenm I could fab a tray up to sit on the carb and seal to the hood like the L-88 air intake on the 67..

 

[Viet Nam Vett]

If the open top air cleaner is as close to the top of the big block hood as you suggest, then it is not drawing in that much air. Additionally, it is all underhood air which is HOT. Therefore, I suggest you use the flat top air cleaner which gives you more clearance and, more importantly, more overall area to draw cooler air from. I dont think the K&N filter is giving you any appreciable more power. In fact in your configuration, it may be actually hurting you.

I think you hit the nail on the head here...In fact .now that I think about it..the underside of that $80..K&N Filter has a Steel Plate with 1/8" hole's drilled all over. .You would think that the top side would be like the under side.
In fact it drops down about 1/2" to mate with the Vertical 3" filter moving it closer to the choke plate.

In fact It probably flows less air then the 3" side filter. I think I'll start here and remove the K&N Top Air Filter... and there are some other good ideas in the postsabove...Thanks John..

 

[Viet Nam Vett]

Take off that hi-rise manifold and put a tri-power setup on it with the triangular air cleaner. It will clear everything, and it looks cool, too.

Thanks for the reply Sub Boy..

Yep it would look very cool....But... Each one of those carbs in reality flows less then 250CFM using John Z's Formula even though they are rated at 250cfm. The Manifold will change the Torque range and HP Range and who knows where it'll be.

The 502's Holley flows 850 CFM and is Matched to the Intake which is matched to the cam. My point here is that I would be changing or losing HP. Since GM spent time to engineer up the Cam...Intake...Carb Flow Package. Also the Holley 850 Is made only or flowed for the 502..along with the manifold and Cam. Infact that Holley Part # if ordered states... Made for the ZZ502.

Yeah..it would look cool but.......

 

[Viet Nam Vett]

Could any air be picked up through the wiper grills?

I like the idea of the hood bulge being raised a tad. Just enough to let the world know there is something special underneath.

Pat

Thanks Pat.. Yep ..Thats food for thought.. air could be picked up their but would require some fiberglass work and special ducting...

As sid before the raising of the hood could also be done but... thats $$$$$ in Fiber glass work and lacqure paint...

 

[Viet Nam Vett]

How about an old trick we did in road racing...using the 66 block hood, utilize baffle sheets directing air flow rather then air suction. Small air deflectors on the hood would bank the airflow the direction it is needed.... We us to do that in the Camaro world on the 63 rear induction hoods...remember the air filter fit tight into the hood, problem was the same with air suction vice air delivery...so we remove the round hood appartus and installed small deflectors attached to the hood adjusted to the direction that baffled the air into the air intakes of the air filter/cleaner....

Thanks EB....
Yeah I kinda was thinking about that also.. But I'd have to mod up the grills with fins that faced a 45* angle towards the front to deflect the air in. I also thought of machining out the center area of the grill and using a air cleaner type element inside the machined out section. That in conjunction with the small fins and a tray mounted on the carb flange to seal against the hood.

 

[Viet Nam Vett]

You ever give any thought to running a tube to the gills on the side of the front fenders? Rig something like a Ford Thunderbolt or 442 W30 setup. Push a big flat air filter in a box up against the gill so it can only draw from the outside.

Thanks Grizzly...

Yeah that would be a cool set up... Only no room to route the hoses as the rad support is almost against the hood... Only other way would be to drillout some holes in the support . But again .Not enough room with the 502..

 

[67HEAVEN]

This'll work until the twin turbos.

 

[Seaside63]

I was thinking of something that ends up as sort of a hybrid of other ideas posted above.

If you got or made a closed airbox cannister that fit over the carb with one large snout, that snout could lead to the left side only where a remote K&N type filter draws incoming air through an FI type opening in the radiator support.

Picture most of the modern iductions.

It won't be as attractive with the extra plumbing but you could use some polished or anodized tubing from the filter to the air box and make it look pretty nice.

If you could find an airbox that looks like the old Paxton Supercharger boxes it would have a nice period look.

HEY, there's an idea.... why not just put a Paxton Supercharger on there ?

--- Just for fun

 

[Viet Nam Vett]

Reply to 67 Heavens Post


OK..This must be one of those invisable ink reply posts....:L You know just a picture...sorta like an international road sign.. No text...:L

Ok so lets see if we can figure out what this means...

(1)... Ok..You cheap Bast_ _rd.. Get your money out and put on a 67 L-88 Style Hood. and be done with it....

(2)...Heh.. Look at my set up...naah...naah ....naah.....:cool

(3)... Didn't we go threw this before.....:ugh

(4)... Who Gives a S_ _ T...:eyerole

(5)...My Hood is stuck up like me and I can't put it down....:cry

(6)...Red Is my favirote color....otfl

 

[JohnZ]

I don't think there's much hope for using the side vents in the '65-'66 BB hood as an air intake source; air passing by them is in the boundary layer and isn't going to divert without external deflectors. The same is true of opening the front of a '67 BB stinger hood - there's no laminar flow there either (that's why the air intake on a Pro Stocker is two feet above the surface of the hood, to get it out of the boundary layer).