# How to ID Original Ram Air tri-power air cleaner pan



## Machinest-guy (Jul 19, 2019)

Good evening, I'd like a bit of education about how to identify a 1965 NOS or original Ram Air pan. Are there part number stamps or code ? Is the pan painted ? or natural metal. What gloss level ? is there a water drain hole ? Where vs. the later or Calif AIR system breather hole. Maybe a photo of a real one ? Thank you, Ladd


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## O52 (Jan 27, 2019)

The 65 RA pan is rare since they were an over the counter option starting the last few weeks of August 65. The package, # 9841716, consisted of the hood scoop, gasket, ornament and metal pan. 
The pan is slightly bent down in the front. The center carburetor hole is bigger than the outer two.

...from the GTO restoration guide, pg 378


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## Machinest-guy (Jul 19, 2019)

Thanks, I've reviewed the restoration guide section you suggested, not finding if the pan was natural steel or painted ? Would it be a correct deduction to make, that the downward bend in the 1965 pan, negated the need to cut the hood brace ? as called out for in '66 flat pan installs. I appreciate your thoughts on this. Ladd


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## O52 (Jan 27, 2019)

from the PY forums
Wanted: 65 GTO Underhood Brace Section Ram Air Cut-Out - PY Online Forums - Bringing the Pontiac Hobby Together









PY forums





PHS question - PY Online Forums - Bringing the Pontiac Hobby Together


PHS question 64-65 GTO Tempest & LeMans TECH



forums.maxperformanceinc.com





Post #9
As far as the Ram Air, it was released August 17, '65 as a dealer installed or owner installed package.( Cold Air Induction) and was about $50.00.The scoop had to be cut out, as the regular closed hood ornament was the only part in '65. In 66 around late January, the buyer could order a factory installed Ram Air system, special engine (XS,XP),molded open scoop,(no cutting) ,pan,rubber seal (close cell sponge). Also, one could get the dealer or owner installed package, but it would be like 65 in that there was no special engine other than 3x2 WS,etc. The scoop was molded open, so, no cutting.If the owner wanted to install, there were directions, like the 65 , directing the owner where to open up the hood (cut away metal) to allow air to enter, of course.

Another regarding air flow with the pan





65 GTO Ram Air Opening - is it enuf for 455 - PY Online Forums - Bringing the Pontiac Hobby Together


65 GTO Ram Air Opening - is it enuf for 455 64-65 GTO Tempest & LeMans TECH



forums.maxperformanceinc.com





IRT painting, I didn't see anything, but Pontiac usually painted their air cleaner assemblies 60% black. I would imagine the RA pans were the same.


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## Machinest-guy (Jul 19, 2019)

I appreciate your time to post. I took my hood apart after cutting out the insulation blanket according to the outline of the pan. I removed my stock ornament, to find the opening occluded by a brace. Blueprint makes perfect sense after looking at the parts. So I cut out the most forward layer of brace then trial fit a cut out OEM ornament. Looks like a nice fit but behind that is a hood reinforcement which impends air flow. I'm setting up to cut that out now in a minimal way following the blueprint you directed me to. Looking at it from an air flow perspective, if I make minimal cuts (approxamately the size of the ornament openings) to preserve some structural benefit of the brace, there will still be edges and formed steel material which will cause turbulence, diminishing flow. I think I'll lay some filler in there to create a more aerodynamic exit path to the pan's plenum area. 

It is very gratifying how much air you can flow through a pretty small hole if the entry and exit paths are decent.

The ornament openings' area, just by eye, seem to sum to about 4 intake port sized openings.

Thanks for referring me to the old posts some fellows made wondering about air flow. Despite those threads being 8-9 years old I'll chime in there after I do some testing. I can mock up an air box pretty easy to flow test the opened up ornament. I'm estimating it will exceed the capacity of my SF600 bench so I'll fabricate the fixture to flow both sides but make a plug to do one side at a time if I have to - the results should be additive. Ladd


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## GTO Yeah (Dec 6, 2021)

I'm curious, Machinest, did you ever get a chance to flow test this set up? How did it turn out?


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## Machinest-guy (Jul 19, 2019)

Good morning, short answer is no, I became side tracked with a cracked crankshaft....... now having a hard time gathering parts to build a big inch stroker. So my car is apart and the hood is put away. 

Longer answer is I examined the air flow path finding bigger restrictions in other places. And that the replacement tri power foam sealing gasket isn't closed cell foam. The open cell foam now provided for that application will "leak" so much air the possibility of getting any pressure rise in the pan area to go down a carburetor throat from ram air passing the inlet ornament is zero. 
One big restriction is the intake manifold. I sent mine to EXTRUDE HONE to be internally enlarged and polished. It's done now but I need to get down to LA and pick it up. Then I can measure the internal volume and it's flow rates. But I'm held up waiting for SCAT to finish my rotating kit. EXTRUDE HONE and SCAT are only a few miles from each other and I want to only make one drive to pick up at both firms. SCAT is waiting to find main bearings and for the pistons to be released by Race Tech (the old J&E company) who are waiting for thermal barrier coating subcontractors to perform. 

Next air flow restriction is the pushrod tube area in the heads. I've got them fixtured in my mill to enlarge the port to max cross section at that point, but again haven't cut because I want the manifold here to measure from in case there is offset between the port and manifold I might be able to finesse a bit into a better flowing junction. 

So numbers are coming - I haven't forgotten. But I would like to know the volume of an OEM tri power manifold which hasn't been ported or modified so I can calculate how much bigger EXTRUDE HONE was able to make mine.

Thanks, Ladd


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## GTO Yeah (Dec 6, 2021)

Machinest-guy said:


> Good morning, short answer is no, I became side tracked with a cracked crankshaft....... now having a hard time gathering parts to build a big inch stroker. So my car is apart and the hood is put away.
> 
> Longer answer is I examined the air flow path finding bigger restrictions in other places. And that the replacement tri power foam sealing gasket isn't closed cell foam. The open cell foam now provided for that application will "leak" so much air the possibility of getting any pressure rise in the pan area to go down a carburetor throat from ram air passing the inlet ornament is zero.
> One big restriction is the intake manifold. I sent mine to EXTRUDE HONE to be internally enlarged and polished. It's done now but I need to get down to LA and pick it up. Then I can measure the internal volume and it's flow rates. But I'm held up waiting for SCAT to finish my rotating kit. EXTRUDE HONE and SCAT are only a few miles from each other and I want to only make one drive to pick up at both firms. SCAT is waiting to find main bearings and for the pistons to be released by Race Tech (the old J&E company) who are waiting for thermal barrier coating subcontractors to perform.
> ...


That's interesting about the open cell foam. I wonder if it was an intentional design choice to allow more airflow?

What are your thoughts on dimple technology? (like the golf ball) 

I've heard about it used in some race applications, but am curious if it would improve airflow if the inside of an intake manifold was dimpled.


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## Machinest-guy (Jul 19, 2019)

In my opinion if closed cell foam was picked as a design change to improve air flow quantity it was a poor one. You would be hoping that hot under-hood less dense air would have more oxygen content to burn fuel than cold outside of the body air. I think it was likely whoever made that decision was thinking only about sealing bugs out of the air box area and didn't understand the air cleaner base gasket was also a thermal dam - as can be the pan itself if improved by coating. 

In my opinion dimples on parts to effect air flow is at best a poor patch for a poorly designed or modified port. To be effective at making any change in flow the dimples need to be at least .030 deep. Then what they form is a localized tiny turbulent spot. If you put about 20 of these little vortexes together you can create a localized area of slower moving air. I/E air that instead of moving down the port into the valve bowl goes in circles blocking air that would otherwise flow more quickly past that area. None of that is any good by itself. However if you have a poor port with lots of areas where air or fuel / air mixture is trying to flow at various speeds the dimples can even that situation out a bit and maybe average the port flow to a slightly higher value. Maybe. It is far better to simply fix the port shape than try to correct a poor shape with a surface finish technique. 

As far as putting dimples inside an intake manifold in any meaningful way - good luck with that - how does one hit a punch inside a manifold runner to make a bunch of dots ? Cut the manifold open and re-weld it ? If you are going that far I'd just fix the internal passages and skip the dimples.

I can virtually assure you nobody in the upper levels of racing is putting dimples on anything to correct air flow. 100% of everyone are managing air flow changes track to track with specific port shapes executed on CNC equipment. At a recent engine conference with Warren Johnson guest speaking his brief comment was it takes his pro stock team about 4 hours from a track situation indicating a port change to having a fresh set of heads fully machined by a modified program ready to run. No dimples.


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## GTO Yeah (Dec 6, 2021)

The general consensus seems to be that the ram air intake does more harm that good. It sounds like the airflow restriction outweighs any benefit gained from pulling cool air from outside the engine bay, but I've only been able to find anecdotal evidence. Maybe the open cell design change is a compromise? I'm just guessing.

I just hate to see non functional hood scoops on my car, but that's just a personal irk. 

As for the dimples, my mind immediately went to a dentist's drill. If it's small enough to reach in the mouth, it's gotta work inside a manifold right? 

I suppose the air dimples thing is just for clickbait headliney stories. If it was really useful, every car would be textured like a golf ball. Thanks for entertaining my harebrained ideas!


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