I have been the proud owner of a 1988 Firebird Formula(with a 91 front clip) for about 10 year now and i recently purchased an 86 Camaro Z28 from a police auction. The car is very solid and only needs a paint job and minor small parts here and there.

I am planning this spring to make a custom fiberglass hood for this car. I have worked with fiberglass at my previous job in manufacturing making molds, plugs and parts for air strippers and blower shells. I have been wanting to make fiberglass parts for awhile but now i have the time and with this Camaro i have found some inspiration.

The question i have for everyone is this. Which in your opinion would be better or cooler to see on a Camaro.
1) A fiberglass hood with the "power bulge" of the Formulas. The bulge would be offset like those on the Firebirds.
2) A fiberglass hood with the factory 91-92 hood blisters molded into the hood. They would not be bolted on like the factory ones are.
And if one of these hoods were to be for sell, which would you buy? Which do you think would be more popular?

I know some people out there are Chevy or Pontiac purists and don't like the idea of "crossbreeding" parts(like a Ram Air style hood on a Camaro or an SS hood on a Trans Am). But I'm curious to see what everyones thoughts would be.

I have an extra Formula hood, Camaro hood, and the factory hood blisters to make exact factory replicas for my plug.

Let me know what you think.....Your ideas and opinions are welcome....Thanks

 

When I put my power bulge hood on my firebird my buddy commented he'd like to have something like that on his 86' sport coupe Camaro, I have heard that a few times from camaro owners. I've never liked the hood blisters on the 91'-92' camaros, just my opinion. I think it would be really cool to see some power bulge camaro hoods though and know of at least a few people who would probably be interested.

 

Why not combine the best of both worlds, and combine that with the functionality of the legendary "Japanese heat extractor hood"

I had the same idea a while back, just don´t quite like the hood blisters, and need additional clearance for my TBI, but consider following:

Lay up the hood blisters, as a pair of powerbulges. You can make them follow the IROC louver design, which would help when painting the hood with heritage stripes.

Smooth out the transition for both blisters, and slightly increase the profile of the blister cutout. Then open the cutout and place a mesh cover over the openings that now only need to be made functional.

 

Solitare, do you mean combining the Power bulge(formula) with the same heat extractors and front vents from the 3rd gen Trans ams? I have often wondered if you could use a Trans Am style hood and make the front vents functional. Like a "stealthy" type ram air system that would look factory.

The 91-92 blister hood could be cut out and made functional. The only concern i would have is the vent in the blister lays nealy flat(maybe 15-20 degrees) and if they were cut out water could be a problem unless some way the box below could redirect it.

Clearance has always seemed to be an issue with alot of these hoods. My Formula is a TPI and the Camaro is carbureted. I'm going to make a custom elbow coming off the carb to connect to the factory dual air cleaner inlet box.

Would it be a consideration for those that have clearance issues to have the Power Bulge located in the center to allow extra room?

 

It would not be that difficult to make the T/A hood louvers functional. The area below is just a layer of sheet metal. Doesn´t do a lot of good though.

I did not quite mean using the fender vents, but making the vents in the blisters functional. I´m not certain where exactly the openings would be situated though, so water might become a nuisance. One way to solve that would be to cut out the opening a bit wider, making the angle a bit steeper and in the second layer of the hood include an airduct that would lead any intruding water down in front of the engine rather then on top of it. The airduct could be shaped so that it widens and opens up a bit towards the radiator.

With a TPI engine that wouldn´t work because you would get in the way of your air supply, but on a carburated setup you should have some space to work with.

Another idea would be mirroring the power bulge design.
Basically like the IROC hood has a pair of these blister thingies, you can mirror the powerbulge, fitting two powerbulges on one hood, seperated by a few inches of regular hood.

Open up the back of the powerbulges to get the heat extracting effect. Here intruding water would be less of an issue.

 

I had always thought a Dual Power bulge hood would look great. The rear of the bulges could be cut out and used as heat extractors or as a type of cowl induction.

I know that making the mold off the drivers side bulge would be easy, but the passenger side would have to be made from scratch and it would have to be an exact mirror opposite. I'm not sure my sculpting techniques would be good enough for that...LOL It would be a cool hood to see although the center between the bulges would give the same clearance as a stock hood.

 

Personally I would like to see someone reproduce the blisters, but with expanded screening instead of the black plastic pieces. To make them somewhat functional as a heat extractor, all you would have to do is use a hole saw to drill a few 1/2" holes in the hood under the bulges. I know hawks and a few others make reproductions but their quality isnt the best and the price is outrageous! (Especially when new GM blisters only cost $47.00 ea when they were in production.) Wouldnt be too hard to make and stainless studs could be used instead of the factory plastic. I personally wouldnt mind paying around $150.oo or so for those.

 

Actually I have a set of fiberglass hood blisters that i bought off ebay to use on my Camaro or to use them along with the hood to make a plug for the mold(if i decide to go that route). These were made by an individual that used the originals at a template. The bad thing is they don't have any mounting studs on the bottom. I could easily weld some small plates with studs and bond them into the resin but i don't have any references to the exact location of the studs and openings on the hood.

 

What you could brobably do with them is take them, flip the blisters upside down, take a factory set of louvers and put them right side up on top of the louvers... Say, drivers side upside down with the passengers side louver on top.... Make sense?

If you dont mind my asking: What did you pay for those fiberglass ones and does he have any more?

 

If i had a factory set i could use those as a reference for the mounting studs. Actually 1 would work since like you mentioned i could make a common template and flip it for the left and right blisters.

I paid $100 which included the shipping. I'll have too look and see if can find the guys contact info to see if he has more. The bad thing besides these not having mounting studs is the fact there isn't even much of an edge to use 3M double sided tape either.

They look very similar to the Hawks Blisters that i just seen on there site. They want $129 for theres now. But there are no pics of the underside and it says you would have to drill 12 holes in the hood to mount. I'm assuming its the original holes so these can fit an existing 91-92 Z28 hood.

I know if i went with the 91-92 blister hood they would be molded into the fiberglass hood and there wouldn't be any mounting or drilling required.

 

I was thinking about possibly attempting the dual power bulge idea. I've been brainstorming on how to mirror it and what materials to use.

So what does everyone think would be best for the Camaro?

1) Offset Formula Power Bulge
2) Dual Power Bulges
3) 91-92 Z28 hood with molded Hood blisters

 

The ones on Hawks site for $129.99 are designed to be used on an RS hood and wont work with the IROC/Z-28 hood. They are a slightly different shape than the "OEM style" The cheapest I have seen the factory type was $199.99 + 17.00 shipping. The quality was questionable and then I have to butcher them to get the Grilles out of them. I would really appreciate it if you could find the info! Thats dirt cheap! Thank you!

 

IIRC, it is Showcars that makes a dual Power Bulge hood, so not exactly a new hood design.

 

I checked the Showcars site and the listings and pics didn't match up but I didn't see a Dual Power Bulge pic. I did see a sketch of a large single bulge(similar to the early stage of Stephen's custom steel hood). There are listings for several twin scoop hoods(one looked kinda close but the bulges weren't curved like the factory one) and Ram Air hoods but nothing with the a dual factory style bulge. If they are out there I'd love to see a pic of one.

 

Here ya go. Real pics of the Showcars hood.

Mine followed the hood creases already there & just enhanced the design. Those are all new lines.

 

^ that´s almost like the SS hood without the air intake in it.

I would go for the twin offset power bulge, which repeats the design of the IROC style blisters without the cutout but open at the back of the bulge, but instead of show gives you working heat extraction.

Here´s a rough sketch

 

I seen those on the site. What i'm talking about as my #2 choice would be a Dual Power bulge. The bulges would be seperated in the center of the hood so you would have a right and left bulge. I would have to mirror the driverside bulge to be an exact opposite.

 

Exactly Solitare. Your sketch is better then my MS paint pic....LOL You got the idea

 

On making my sketch I just happened to notice that the powerbulge is rather big and will probably destroy the lines of the camaro hood, that at the back of the hood has a narrower raised area then the firebird hood has (if that makes sense).

You would propably be best of taking the blisters as ruler (maybe make the final bulge 2" wider or however much you think you can get away with) and copy their footprint, then copy that on a 2" piece of styrofoam and start shaving away.

Sculpting styrofoam isn´t that diffcult if you´re willing to cheat btw.
First off, take the block of styrofoam you´re going to cut both blisters out of, and shave off the front so it tapers down towards the front of the bulge. This gives you the same height for both pieces. Use something big like a block sander used in bodywork to get this part done as even and equal as possible.

Then turn the thing around and place both hood blisters on the block of styrofoam. Outline both of them, leaving about 2" or so in between, then cut out both bulges.

Cut/sand straight and clean edges to both, then decide on an angle and make yourself a ruler of sorts to be able to verify your angle.

Now sand down the edges of both bulges to the desired angle.

For the final rounded edge on the top part of the bulge, make 2 more rulers with the desired radius and start sanding again. Verify the radius regularly, making sure it´s even.

Glue both on top of your mock-up hood and use PVA glue to seal the foam, then use bodyfiller to smooth out the positive. You can use bodyfiller to put a small radius at the base of the bulges I would advise to leave that radius fairly small however. Another ruler to pull the filler along the shape should do fine.

Way I see it that should be somewhere between 4 and 6 hours of prep work and shaping.

If you want it to be a one off, fiberglass the thing, if you want to make a mold out of it, you know where to go from here

 

Actually, that wouldn't give you heat extraction. Just a split cowl induction. I can tell you that with 110% certainty & here is why I say that.....

My hood has a cowl induction-type rise at the back, then a Japanese-style heat extractor dip forward of that, just behind the radiator "wall"

When leaves land on my hood (and i haven't bothered to do a string test after seeing this.....) any leaves at the cowl induction scoop get sucked onto the screen & do not move, due to the....cowl induction....properties of the way air flows in there.

But where the dip is for the heat extractor, any leaves that landed there get blown out quickly once I start driving & not due to the fans blowing, because the leaves blow out long before the engine gets hot enough for the fans to kick on. I can let it sit for 30 min at idles & the leaves won't move from the fans being on.

 

Even if you would end the bulge approx 12" - 14" from the end of the hood? I think that should be about enough to get out of the way of the high pressure area. Then again, I haven´t tried.

 

That would certainly help & most likely be effective. My rear rise portion is about 2"-3" forward from the windshield & still gets air pressure holding the leaves on. I woulda thought even that would help, but it works out good. Kinda like cold air pushing in the back & hot air getting sucked out the front. Probably makes for a good air circulation from back to front,m across the engine.

 

Solitare, I was thinking the same thing about the lines on the Camaro compared to the Firebird lines. The bulges might overlap the lines towards the rear of the hood. I will get some measurements once both my cars thaw out from the ice this weekend.

I was thinking of using styrofoam or modeling clay. A friend of mines mother owns a ceramic shop and they work with alot of types of clays and molds. The styrofoam would probably be easier, less messy, and much lighter to work with.

I'm not sure yet as far as working to make the hood functional yet. I know the cowl induction/ heat extractor debate would have to be tested and worked out later on. Correct me if i'm wrong, but weren't the early 82-84 Trans Ams using the power bulge hood as a cowl induction for the Crossfire fuel injection setup. I remember years ago seeing this on an 84 model. And weren't they an issue with water or was that the Camaro crossfire set-up i'm thinking.

 

Not quite sure about any water issues. This is the first thirdgen I own and I have only owned it for nearly 2 years now, so I´m still learning a lot about cowl induction and stuff. (had a 300 rwhp 1988 RX7 before this).

I think you can easily prevent any water issues by leaving a .5" ridge under the opening and a bit of gaze to prevent leaves entering the engine bay through there.

I would go with foam as modelling material since it conveniently comes in 1" thick sheets making it easy to get an exactly 2" high bulge.

From their design I believe the earlier T/A´s did intend to use the powerbulge as CAI. Too far from the end of the hood to effectively be used as a "cowl induction" as such (closer to the windshield would have given a much better induction effect at least), but definately CAI. The aircleaner assemblies had a rubber collar to seal off the aircleaner from the engine compartment and they had a solenoid opening the CAI as well.

As pointed out, that will be the main decision in the type of functionality you would want.

For heat extraction, you need a certain minimum distance to windshield. I would guestimate 12" - 14" should get you clear of the high pressure zone.

For CAI place them anywhere on the hood, preferrably closer then 12" to the windshield to benefit from the pressure zone created by the windshield and that way preventing disadvantagous air intake caused by a low pressure zone directly behind the bulge, if it were too far away from the windshield.

For cowl induction, pull the cowl all the way to the windshield. Anything else is compromising functionality of cowl induction.