Build Thread: The Roaring Season Firebird

[Steve Holmes]

Steve wrote; "The Craig Fisher Firebird, like most Trans-am cars of the era, had a basic exhaust system whereby each bank of four header pipes fed into one collector pipe, which dumped out on either side beneath the doors. There were no noise limits back then, and the cars didn’t use mufflers. They just had straight open pipes. In the modern world, however, most tracks have noise limits, and therefore I’ll need to fit my car with mufflers."
In 1969 you could just go out and let 'er "rip". Noise levels were not an issue then. No wonder my hearing is not worth a hoot right now ! ( Only old people wore ear protection in those days !) I have many regrets now but it was such a great sound. Imagine this at high speed on the speedway banking.
Attachment 41533

(Ken H)

Yes thats a great example of how the exhaust systems commonly looked in period Ken. There would be a similar pipe exiting on the drivers side. The collectors and exhaust pipes were commonly 3.5 inches in diameter. Really loud. And Trans-Am cars usually didn't have side windows. Imagine that after 4 hours!

The Historic Trans-Am group in the US still run the original style open pipes, as these cars are extremely correct to how they originally raced. These are all the original cars, no replicas. So they race at tracks where noise isn't an issue, or where the tracks have permission to run historic events where the cars are loud.

This is a great example of just how loud these cars were/are:

[khyndart in CA]

Thanks for that reminder Steve. I was at that race in 2010 and the sounds of the opening laps when they were bunched up was truly magnificent.

[Steve Holmes]

Engine:

This is one area where the FIA rules really differ from those of HMC. The engines for FIA historic cars must be completely period correct. Well, sort of. And for the car to get an HTP, an FIA inspector checks it, looking for all the correct serial numbers for each part.

In HMC, we’re allowed aftermarket engine blocks, heads etc. This isn’t the case under Appendix K. I have to use an original production car block and heads of the type that would have been used in period. My car will run a small block Chevy. The Trans-Am series rules for the period 1966 – 1972 required mostly production car parts be used on the race cars. There were some freedoms, such as wheels, tyres, engine internals etc, but for the most part, these were production-based cars. You may think production car parts wouldn’t have coped with the stresses placed on them in a competition environment. But in fact, they held up extremely well. Most Trans-Am races were around 3 or 4 hours long. Added to that events such as the Daytona 24 Hour and Sebring 12 Hour races were part of the championship in the late 1960s. The engines were producing less horsepower than we see today, and they were far from bullet-proof, but if prepared properly, would go the distance.

Pictured below is the engine bay from one of the 1968 Penske Camaros. This was Mark Donohue's main race car for 1968, which he used from Round 3 of the series, and in which he dominated the championship. This car has been owned by Tom McIntyre for many years, and is a great example of how a period correct engine bay should look. There is no bling. The engine bay features nothing that isn't serving a purpose.

Penske, like any good race team, didn't want any parts coming along for the ride if they didn't serve a purpose. So too, although the team took great pride in the appearance of their cars, they generally didn't leave the hood open for prying eyes. Unlike in todays historic racing, the engine bay usually wasn't on display. So there was no need for adding chrome, or polished aluminium, or anything else that wasn't purely functional.

Note the grey paint on the engine. I'll talk about this towards the end of the engine chapter.

[khyndart in CA]

Steve,
I know you will give a much better explanation but I had entered this piece of information a few years ago.
(05-30-2014,*09:50 PM
#102
khyndart in CA

"Grant, Thanks to your comment I remembered my first visit to Riverside in October 1974.
It was to see the IROC race that was now consisting of (Identical) 1974 Camaros powered by 350 Chev engines prepared by Traco Engineering that produced 440 horsepower and also had to be identical.
(The engines were painted gray so as to show any oil leaks. )"

Was that the reason in 1968 ?
It does make sense compared to the Black, Cherry red, Ford blue, Green etc engines that were out there.

[Steve Holmes]

Steve,
I know you will give a much better explanation but I had entered this piece of information a few years ago.
(05-30-2014,*09:50 PM
#102
khyndart in CA

"Grant, Thanks to your comment I remembered my first visit to Riverside in October 1974.
It was to see the IROC race that was now consisting of (Identical) 1974 Camaros powered by 350 Chev engines prepared by Traco Engineering that produced 440 horsepower and also had to be identical.
(The engines were painted gray so as to show any oil leaks. )"

Was that the reason in 1968 ?
It does make sense compared to the Black, Cherry red, Ford blue, Green etc engines that were out there.

Hi Ken, that may very well have been the reason for TRACO painting their engines grey. Much like how most Trans-Am and A/Sedan cars back then had a grey interior. Its thought the lighter colour allowed for spotting oil a little easier. Also, many of the teams acid dipped their cars very heavily, and the grey paint was thought to help spot the cracks easier from where they'd broken apart.

But as for the grey paint on the TRACO motors, while I'm sure the grey paint would have helped spot oil leaks, the various engine builders would paint their engines in their own chosen colour, which often differed to that of other engine builders. It was almost like a signature, so you'd know who the engine builder was from the colour of the engine.

[Steve Holmes]

Engine Block:

The SCCA Trans-Am series had a strict maximum engine limit size of 5000cc (305ci). Chevrolet produced the Z28 Camaro specifically to compete in the Trans-Am. By mating a 3 inch crank with the blocks standard 4 inch bore, they achieved an almost perfect 302ci. The Z28 was the only model in which the 302 motor was available. Likewise, the only engine option available in the Z28 was the 302.

When the Z28 Camaro was first homologated for the Trans-Am series in 1967, the Chevy engine block used was casting #3892657. For 1968, the production part number for the engine block was 3914678. But these were only 2-bolt mains blocks. For racing, a 4-bolt mains block is preferable. However, for 1969 onwards, the more familiar 3970010 block was used, which first went into production in late 1968. The ‘010’ block was used in numerous applications, and was available in both 2-bolt mains and 4-bolt mains. The 2-bolt mains blocks were used in low-stress applications including passenger cars and trucks etc. But the 4-bolt mains blocks were used in high performance applications, and were the basis for the 302ci motor found in 1969 Z28 Camaros.

Now, I should be using a ‘678’ block in my car, being that this is the correct block for 1968. However, as explained earlier, the Appendix K rules have what they call “Date Classifications And Definitions”. This is, as the name suggests, date classifications, ie, the classification into which each make and model of vehicle falls based on its year of manufacturer. This is described as such: “A car will be dated by the specification of that car and not necessarily by the date of build”. My 1968 Firebird is classified under Appendix K G1; “1/1/1966 to 31/12/1969 for homologated Touring and GT cars”. What this means is that I can use parts that were in production prior to 31/12/1969.

To that end, for my car, I’ll be able to use an ‘010’ 4-bolt mains block. This is the block many of the Camaros use in the Historic Trans-Am group in the US, as well as those racing in Europe and the UK under FIA Appendix K rules. I can use a ‘678’ block, but an FIA inspector will green light me having an ‘010’ block also. What I absolutely can’t do, is use a modern aftermarket block, such as a Dart or similar. It must be an original Chevy production block with the correct production part number on it.

So I spent some time searching the internet, and eventually found a good block in Las Vegas that had been bored 020 over, magnafluxed, cleaned, and fitted with new frost plugs. I think from memory it cost me about US$600. Decoding the factory stamping, the block dates to 1976. I don’t know if this will work against me if/when inspected by an FIA officer, but I feel I might keep a look out for a 1969 block, just as a back-up.





I’d been collecting parts in the US, and needed to get them to New Zealand. So I bought an old 1964 Ford Galaxie in Arizona with which to ship home some of my parts in the boot (these things have a HUGE boot!), and by the time the engine block reached New Zealand it had developed a layer of surface rust, so I’ll need to have it cleaned again. But in the spots where surface rust hasn’t formed, its possible to see the cross-hatching from where it was recently bored.



Technically, the engine internals need to be as used in period, but from asking various people who race historic cars in the UK and Europe, this area provides relative freedom. What is important, however, is that the engine size is correct. The Trans-Am series had a strict 5 litre (305 cu.in) limit, and my Firebird will need to have the correct engine size.

[seaqnmac27]

[Steve Holmes]

Thanks Sean, that was awesome!

[Steve Holmes]

Heads:

The heads on The Roaring Season Firebird must be original Chevy items, and period Chevy race heads were based on what we refer to as ‘camel hump’, or ‘double hump’ heads. Some people also refer to them as ‘fuelie’ heads, a name picked up from the fact early versions were fitted to Corvettes running fuel-injection. However, they were also fitted to Corvettes running carbureted motors as well. These were in production for several years, from 1961, and included various minor changes along the way. Casting numbers for me to look out for were: 3782461, 3890462, 3917291, 3917040, 3927186, 3947041, and 3991492. The term ‘camel hump’, or ‘double hump’ refers to the casting shape on the ends which look like the humps on a camels back. This is the case for all the castings above, except 3917040 and 3947041, which have a triangle shape on them.



Intake and exhaust port sizes were either 1.94 and 1.50, or 2.02 and 1.60. Obviously the larger option is preferred.

I searched for some time to find some nice heads. The key with these heads is in finding a set that have been crack tested. After hitting a few dead-ends, on an off-chance I emailed my good buddy Tony Garmey (TRS member Horizon) of Horizon Racing. Tony is an ex-pat Kiwi who has lived and worked in the US for many years, race preparing, restoring, and racing historic cars. He runs his very successful and very busy company out of Washington State, and despite being insanely busy all the time, to my mind is living the dream. He is also an awesome guy, and very, very talented.

I emailed Tony and asked if he had a set of camel hump heads he’d be interested in selling. He replied saying that indeed he did, a nice set that had been crack tested and lightly ported. He said he had both Roger Williams’ and Graeme Cameron’s race cars in his shop that would soon be sent back to New Zealand, and that he’d put the heads into the container with the cars. I asked how much he wanted for them, and in an amazing gesture, he said he didn’t want any money. He said he gets so much enjoyment from The Roaring Season, he wanted to gift them to me. I was blown away by this generosity! Thank you Tony. I really appreciate it. You are an absolute champion.

Please visit Tony’s website at: http://www.horizonracing.com/

Thanks also to Graeme Cameron for delivering the heads to Tony Roberts, and to Tony for bringing them down to Manfeild for me.

The heads Tony sent me are the original camel hump items, 3782461, and they’re in beautiful shape. These were produced from 1961 through 1966, so I definitely don’t have to worry about them being too new for the FIA inspector.





In the Trans-Am series, roller rockers really didn’t appear until at least 1970, which therefore means I can’t run them on my engine. However, I’ve also been told that the FIA inspectors often don’t check such things, so I’ll make a decision on whether or not to use include roller rockers once I get to that stage in the build.

[khyndart in CA]

Steve,
I might have found an engine for you !
Tuck this one away under the hood and you could find yourself up on the podium ahead of all the "big boys "


http://www.msn.com/en-us/autos/enthu...cid=spartandhp

( Ken H )

[Paul B]

The Firebird will be a very cool build, You are right they are aesthetically very nicely balanced design.
I did not start racing until I was 49 ... don't let anything hold you back.
I am looking forward to lining up together in the Sprint.
Cheers

[Steve Holmes]

Steve,
I might have found an engine for you !
Tuck this one away under the hood and you could find yourself up on the podium ahead of all the "big boys "


http://www.msn.com/en-us/autos/enthu...cid=spartandhp

( Ken H )

Hi Ken, wow, that is really cool! I can't even begin to imagine what that must be worth.

[Steve Holmes]

The Firebird will be a very cool build, You are right they are aesthetically very nicely balanced design.
I did not start racing until I was 49 ... don't let anything hold you back.
I am looking forward to lining up together in the Sprint.
Cheers

Hi Paul, hey thanks so much for the awesome encouragement. I really appreciate it. I'm looking forward to getting out on the track with you and your Falcon Sprint. I hope you'll create a build thread here for it? This is really going to be an amazing car.

[khyndart in CA]

Steve,
Here is another engine option even though it may not meet the rules for your class.
This would have kept the lads at Repco busy if this had gone into production !

It was John DeLorean's desire to give the Firebird a racing image with this Brabham 400 version. The fuel injected OHC Brabham-Pontiac V-8 proved disappointing in early tests and very expensive to produce in 1967 so the project was terminated after only one prototype was produced.




(Ken H )

[khyndart in CA]

Steve.
I got this 1988 book regarding the Firebird from the library and it is very interesting reading. You may have read it but if there is anything you might be interested in please let me know.






( Ken Hyndman )

[Steve Holmes]

Steve,
Here is another engine option even though it may not meet the rules for your class.
This would have kept the lads at Repco busy if this had gone into production !

It was John DeLorean's desire to give the Firebird a racing image with this Brabham 400 version. The fuel injected OHC Brabham-Pontiac V-8 proved disappointing in early tests and very expensive to produce in 1967 so the project was terminated after only one prototype was produced.




(Ken H )

Hi Ken, hey wow, this is so cool! I wasn't aware Pontiac ever looked into such a project. Must have sounded amazing! Out of interest, what size was the Repco Brabham engine?

[khyndart in CA]

Steve,
It was a 5 liter SOHC Repco / Pontiac fuel injected engine.



You can read more about it at this site.

http://musclecarfilms.com/1969_Fireb...ng_Cars_1.html



( Ken Hyndman )

[Kevin Hirst]

Steve,
It was a 5 liter SOHC Repco / Pontiac fuel injected engine.



You can read more about it at this site.

http://musclecarfilms.com/1969_Fireb...ng_Cars_1.html



( Ken Hyndman )

Did you see Gas monkey garage last where they have Firebird #1&2 to restore.

[Greg Stokes]

Looks great Steve and very inspiring for others to build something. I sure love the Penske Donahugue car too

[Steve Holmes]

Steve,
It was a 5 liter SOHC Repco / Pontiac fuel injected engine.



You can read more about it at this site.

http://musclecarfilms.com/1969_Fireb...ng_Cars_1.html



( Ken Hyndman )

That would be so cool!