273, the good points

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105 mad

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Hi Folks, I'm throwing this out there & will hopefully get some sensible answers. I was on another similar Mopar forum & was pretty much told I didn't talk the "same language" so they couldn't help & go away.

I'm in the UK & compete in vintage road racing for pre 66 cars. We have a great mixture of European cars entering including Ford Lotus Cortinas, Mini Coopers, Alfa Romeos etc. There is also a small but strong contingent of guys running 289 Mustangs & Falcons.

Now, the thing is I've always liked Mopar muscle cars & I'd really love to build a 273 Barracuda but as with all the other cars it has to be built to FIA racing regulations so no big blocks, 8 3/4s or massive brakes etc. The regulations basically mean I have to use parts fitted to the car back in 65, some limited mods are allowed.

I don't even have a car yet but am trying to put a plan together which makes sense.

Brakes, transmission etc I think I can work out, but I have questions about the engine.

I know the early 273 is basically a good strong engine with the forged crank etc & mech cam. I can't do a lot with the engine except clean up the heads, put in a slightly better cam & headers are allowed. I can also use all the "Formula S" spec parts. The engine will be properly built but bear in mind it could be spinning between 4000-7000RPM for anything up to an hour, do you think the rest of it will stand up ok & what kind of power do you think I could get out of it? For your info, the Ford 289s get 350-400hp with the same build restrictions.

Any help with this would be really useful, I want to try & make this work but if it's too hard I may go down the Mustang route.

I look forward to your replies.
 
Good luck flying the Mopar flag over there!
Someone correct me if I'm wrong but an 8-3/4 rear was used behind 273 4 barrels in 65 A-bodies with 4 speed manuals.
The discs were 4 piston Kelsey-Hayes SAME as the early Mustangs.
Forged crank and rods were stock.
7000 rpms's will definitely require a cam change.
Less reciprocating weight (pistons) would help.
I'd try to find a vintage aluminum Edelbrock intake, grind or fill the Edelbrock name and numbers, and paint it engine color (red)
How strict are the rules on originality?

Oh yeah, the 318 looks the same as a 273 on the outside.

The first American Trans Am race was won by a 273 dart. You can look it up. Bob Tullius.
 
The edelbrock ld4b (273s from 1966 forward - with d4b for 1964/65s) intake manifold can be found the Chrysler part number

A formula S would be a huge help in racing
 

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I believe the 8 3/4 could be found behind some of the later 1965 273's, including the 2bbl, 4 speed cars, but it was a optional.
I have seen factory 4 speeds with the 7 1/4 and have been told they started adding the 8 3/4 later in the production run because of the weakness of the 7 1/4.
KosmicKuda said:
Good luck flying the Mopar flag over there!
Someone correct me if I'm wrong but an 8-3/4 rear was used behind 273 4 barrels in 65 A-bodies with 4 speed manuals.
The discs were 4 piston Kelsey-Hayes SAME as the early Mustangs.
Forged crank and rods were stock.
7000 rpms's will definitely require a cam change.
Less reciprocating weight (pistons) would help.
I'd try to find a vintage aluminum Edelbrock intake, grind or fill the Edelbrock name and numbers, and paint it engine color (red)
How strict are the rules on originality?

Oh yeah, the 318 looks the same as a 273 on the outside.

The first American Trans Am race was won by a 273 dart. You can look it up. Bob Tullius.
Click to expand...
 
B-onefan said:
I believe the 8 3/4 could be found behind some of the later 1965 273's, including the 2bbl, 4 speed cars, but it was a optional.
I have seen factory 4 speeds with the 7 1/4 and have been told they started adding the 8 3/4 later in the production run because of the weakness of the 7 1/4.
Click to expand...

My April build date of my 273 2 barrel 4 speed car still has the 7.25. I parted out a 65 Dart GT 273/235 motor with a 4 speed and it had an 8.75 with 3.23 open in it. Build date of the Dart was Jul23, 65 (really late build date) and the 8.75 was dated something like 3 weeks before the build date of the car.
 
The '65 Barracuda has potential to be a good vintage racer. The 273 has a nice stiff valve train with solid lifters so it should rev up well. Adding headers solves the biggest issue with the '65 273 and that's the restrictive left side'exhaust manifold. I think someone had a '65 at the Goodwood revival & it was up to 2nd place amidst the Mustangs, you might be able to track that down & get a lot of insight.
Although not FIA here's a good start to another vintage early Barracuda http://www.teamstarfish.com/index.html
As others have said you should be able to use the 8.75" rear axle since it was available in '65 model year.

Now to answer your question; yes you can make a car competivemwith the other cars and with a bit of research you'll be able to determine if its worth it to do something different.
 
The thing with ford 289's is they have a 4" bore
where 273 have 3.625" bore hard to get decent flow
 
Team Starfish runs a 1966 Barracuda Formula S in Vintage FIA racing. Check out their web site.
 
The little motor will work well for what you want. The biggest thing IMO at those engine speeds is the oiling system. Search "Oiling mods I did" by Guitar Jones. Although you probably don't need to do everything he did, it will be a good guide to what it takes to live at those high sustained RPMs.
 
Welcome to FABO and I'm sure you will be able to get any answers you need here. Keep us posted on your progress.
 
cutVintage Road Racing

Tough to compete with those 65' Mustangs. They are about 200 lbs.
lighter with the 'Hardtop Coupe'.

The 65' Barracuda {Shipping Weight; #2940 lbs.} has to work at
a weight disadvantage.

Checkout the Limerock, Connecticut site.

I've been there more than a few times. The Mopars running in those
Vintage Classes are 'far-and-few' between.
 
Thanks for all your positive replies folks.

I feel a little more comfortable about the engine now, I thought is was good & strong but previously other people said stay away from 273 & get a 340. At least you guys seem to understand what I'm up against when building an FIA car.

Interesting about the 8 3/4, I didn't think they were availble in a pre 66 a body.

To the guy who mentioned weights. I have a set of FIA papers for the Barracuda & the minimum weight is 1200kg / 2640lbs, the Mustang minimum weight is the same give or take 20lbs. The question is can I realistically get down to that weight, I have to keep all steel panels but can replace all the glass except the windshield with plastic. They do get Mustangs down to the min weights.

Something else I was thinking, checking on the internet, I can't find anyone who seems to sell sheet metal for Barracudas. Unfortunately, a reality of road racing is you may pick up some body damage.

Man, I have so many questions, maybe I shouldn't to excited until I actually have a car.
 
theres a piece of steel under the back window that you can loose 20 lbs make the steel seat fold down bar and hardware alium I bet you could loose 20more lbs just in screws and bolts an 8 1/4 rear end sure would like to take a drive in that road car
 
Try Googling "Scott Harvey" -- he campaigned a Barracuda back in the day. There used to be some good info about it on the web.
 
Just a thought,

The OP doesn't have a 1965 Barracuda yet, and no one is racing them
on the UK circuit.

There is a reason for that.
 
hi, the 8 3/4 rear end came out at very last of 1965. mopar sent a letter to NHRA in august of 1965 stating the 8 3/4 was accepted. only behind 235/273! mopar paid out lot of money in warranties on the 7 1/4 behind 235 /274 cars. it was a move to save mopar money.
 
For 400hp you'll need 200-220 cfms, more cfms eases the burden of running more duration and compression.
273/318 heads are good for 300-325 hp stock maybe 350 with lots of duration and compression.
The problem there's no data on small block heads in anything other than a 4" bore. So it's a guess to how much flow loss the 273 bore will eat up. I've seen flow comparison between chevy's 4" bore compared to 305's 3.75" bore and the 1.94 valve heads were down 5-10 cfms across the board. Mopar has better valve placement but is a smaller bore.

My plan was to run ford 1.85/1.55 valves not that I wanted bigger valves, I think even with stock valve the block should be notch to reduce shrouding. But the Ford valves would make the valve job on fresh meat so the won't be sunken in plus there thinner stemmed and you can get hollow and under cut ones. Your gonna want your heads to flow between 220-240 cfms in a 4" bore and probably end up in the 200-220 range in the 273 bore. Plus your gonna want to start with the close chamber ones since compression hard to build in smaller displacement engines.
 
69 Cuda 440 said:
Just a thought,

The OP doesn't have a 1965 Barracuda yet, and no one is racing them
on the UK circuit.

There is a reason for that.
Click to expand...

There is two Barracuda's racing the UK, a 64 and a 66. The 64 has been raced for many years and has had some big names drive it at the Goodwood Revival.

Im building a 66 Road Racer with a 273. My engine isn't built to a class and it's making around 480hp.
 

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If you're worried about weight, why not go to a '64-'66 Dart 2dr? The '64 GT V8 had a shipping weight of 2638lbs!
 
Does the engine have to be an actual 273 block, or just 273cid?
I wonder if the block would survive an overbore to say; 3.91? or 4.00?
I wonder what the shortest stroke crank a guy could find/ build.
I wonder if its possible to build a 273 with a bigger bore/ shorter stroke
Lets see, I seem to remember a short stroke crank from back in the TA haydays.And lemme see,I wonder if the machine shop cold find me some appropriate bigger bore sleeves. Hmmmm
 
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