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Badart
Badart New Reader
11/30/12 6:39 p.m.
slantvaliant wrote: I think I read that Mopar used destroked 340's for Trans Am, coming out to around 303. You can do that when you have cubic money.

No kidding. You don't happen to have one of those cranks laying around do you?

I was going to roll the car outside today and get some pics of the stance, but it has been raining all day here.

Badart
Badart New Reader
11/30/12 7:21 p.m.

I will fill in this little bit of down time with pics from my other project. 71 Dart, 408 stroked small block <img

sethmeister4
sethmeister4 Reader
11/30/12 7:49 p.m.

This is sweet! I'm itching to see what a 15 series tire looks like! (I'm assuming it was a typo)

Badart
Badart New Reader
11/30/12 8:56 p.m.
sethmeister4 wrote: This is sweet! I'm itching to see what a 15 series tire looks like! (I'm assuming it was a typo)

LOL yep, good catch

Rob_Mopar
Rob_Mopar SuperDork
11/30/12 9:15 p.m.

Welcome aboard!

Just saw the thread and wanted to let you know you aren't the only Mopar guy here, and not the only one with an A-body Barracuda. Or the only one with a business dealing with these Mopars.

On the 360 crank in the 273, there is an aftermarket forged crank with the 3.58" (360) stroke and the 273/318/340 mains. A .030" over 273 with that crank gets you to 301 CID. Going to need custom pistons to get you there. It's still only a 3.66" diameter bore so shrouding will still be an issue.

The Trans Am cars used custom destroked cranks in 340 blocks. They had something like a 2.95" stroke. I'm pretty sure nobody has one of those cranks sitting around.

Badart
Badart New Reader
11/30/12 10:19 p.m.
Rob_Mopar wrote: Welcome aboard! Just saw the thread and wanted to let you know you aren't the only Mopar guy here, and not the only one with an A-body Barracuda. Or the only one with a business dealing with these Mopars. On the 360 crank in the 273, there is an aftermarket forged crank with the 3.58" (360) stroke and the 273/318/340 mains. A .030" over 273 with that crank gets you to 301 CID. Going to need custom pistons to get you there. It's still only a 3.66" diameter bore so shrouding will still be an issue. The Trans Am cars used custom destroked cranks in 340 blocks. They had something like a 2.95" stroke. I'm pretty sure nobody has one of those cranks sitting around.

Very nice Barracuda you have there. Is that a formula car? I thought it would be possible to put a 3.58" stroke crank in a 273. I know guys have done it with 318s to get 349 and have done it in 340s to get like around 379 cubes. I have found the MP crank at summit racing and the price is not that bad. Like you said finding pistons that will work without custom machining might be a challenge. It's only money to my machinist right? LOL I have heard about the destroked crank for TA racing in the past, but have never seen one.

Badart
Badart New Reader
11/30/12 10:33 p.m.

Well I snapped a couple of pic anyway of how it sits right now. I need to drop the rear about 1.25", but will wait and see what I have with the interior gutted. I am happy with the drop on the front. Under full compression I should still clear the fender no problem. I never understood guys who are happy to drive cars that are in the weeds, but can't turn the wheel more then a 20 degrees to make a turn. LOL I will be ordering the Wilwood calipers this week and picking up the larger cordoba rotors to get them mocked up.

mblommel
mblommel Reader
12/1/12 8:02 a.m.

In reply to Badart:

Looks supercool! Great work.

Badart
Badart New Reader
12/1/12 7:39 p.m.

Here are a set of seats that I picked up a while back. They are light and cheap and will work for now.

wlkelley3
wlkelley3 SuperDork
12/1/12 9:24 p.m.

Wow! I'm really enjoying this thread. Keep up keeping us posted please.

Badart
Badart New Reader
12/2/12 6:19 a.m.
wlkelley3 wrote: Wow! I'm really enjoying this thread. Keep up keeping us posted please.

Thanks.

Badart
Badart New Reader
12/2/12 6:35 a.m.

I have been doing a ton of thinking about which motor to eventually run. I have checked with many engine builders on other forums about stroking the 273 to get a 301, but it doesn't seem feasable. It is possible to get over 400hp from a 273, but how streetable will it be.
If I did it I will sell off my stroker parts to fund this.
Really the only reason why I wanted to start with an early A body is because of size and weight. If I build a monter small block then I will be defeating the purpose of what I started with. I will be running some desktop dyno numbers shortly.

.030 over 273 block

Not sure about pistons yet may look at Egge (I have heard they make a .030 over 10.5 dome piston that is 68 grams lighter than factory pistons)

Will try to keep compression around 10:1

Engine Quest Magnum heads with 1.92 intakes 1.60 exhaust 62 cc

Racer Brown 1.6 roller rockers

Solid Roller around 265-275 degrees

RPM airgap

Doug's Headers

I would love to rev this thing to 7K

Rob_Mopar
Rob_Mopar SuperDork
12/2/12 8:54 a.m.

Personally I like the RHS/Indy heads for the small blocks. I'd go with the LA rocker shaft version for something that's going to spin to 7K.

I'm curious to see how well the Maggie valves do in the 273 bore. Please take some pics when you mock it up.

You are going to need custom pistons. Might be able to get away with a stock 2bbl spec replacement piston, but I believe the EGGE's are only available in cast. There's not much available off the shelf for the 273. The Commando spec domed ones will want to occupy the same space as the closed Maggie chambers.

The stock wrist pin in the 273 is heavy. They did that because the crank was the same as the Poly 318 with much heavier pistons. Look into substituting wrist pins from a 318/340/360. Sorry, I don't have the weight specs handy. Plan on having the machine shop re-balance everything.

The 273 and early LA 318 rods are supposed to be lighter than the later rods. This might be an area where I'd trade the light weight for longevity and upgrade to at least the later LA rods with ARP hardware or if your budget allows aftermarket rods. With the aftermarket rods check the clearances. I haven't met anyone running them in a 273. At least not yet.

I'm running the RPM Air Gap on my Barracuda. Check your hood clearance on the early A. Depending on your carb and air cleaner combo it will be tight if you want it all to fit under the stock hood.

Are the Doug's under chassis headers or the old school fenderwells? TTI offers under chassis headers for the early A's now. I've been running their system on my stuff for years. And in the interest of full disclosure I am a dealer for them, but I had their stuff for a decade before I started my shop.

Oh, to answer your question from earlier, no my '68 isn't an S. It started life as a 318 car. It's well beyond what a Formula S had now.

DILYSI Dave
DILYSI Dave MegaDork
12/2/12 9:17 a.m.

Nice work. My only concern is if you want to stuff monster meats under the car, that those fender braces are going to be the first thing that gets in the way.

If that's not in the car's future, no sweat, but since I'm currently obsessing about how to get 345 wide Hoosiers under the stock fenders on my CP project, I figured I'd chime in.

Badart
Badart New Reader
12/2/12 6:20 p.m.
Rob_Mopar wrote: Personally I like the RHS/Indy heads for the small blocks. I'd go with the LA rocker shaft version for something that's going to spin to 7K. I'm curious to see how well the Maggie valves do in the 273 bore. Please take some pics when you mock it up. You are going to need custom pistons. Might be able to get away with a stock 2bbl spec replacement piston, but I believe the EGGE's are only available in cast. There's not much available off the shelf for the 273. The Commando spec domed ones will want to occupy the same space as the closed Maggie chambers. The stock wrist pin in the 273 is heavy. They did that because the crank was the same as the Poly 318 with much heavier pistons. Look into substituting wrist pins from a 318/340/360. Sorry, I don't have the weight specs handy. Plan on having the machine shop re-balance everything. The 273 and early LA 318 rods are supposed to be lighter than the later rods. This might be an area where I'd trade the light weight for longevity and upgrade to at least the later LA rods with ARP hardware or if your budget allows aftermarket rods. With the aftermarket rods check the clearances. I haven't met anyone running them in a 273. At least not yet. I'm running the RPM Air Gap on my Barracuda. Check your hood clearance on the early A. Depending on your carb and air cleaner combo it will be tight if you want it all to fit under the stock hood. Are the Doug's under chassis headers or the old school fenderwells? TTI offers under chassis headers for the early A's now. I've been running their system on my stuff for years. And in the interest of full disclosure I am a dealer for them, but I had their stuff for a decade before I started my shop. Oh, to answer your question from earlier, no my '68 isn't an S. It started life as a 318 car. It's well beyond what a Formula S had now.

Well last night I was just kind of throwing around ideas and will have quite a while to make my decision because this little 273 is already together. I do like the RHS heads and am a big fan of the bang for the buck, but the EQ Magnums are cheap and I think that I was a little optimistic on the solid roller LOL.

Here is a quote from a mopar engine builder buddy of mine last night "To get the best balance between flow and shrouding the intake valve should not exceed 51% of bore... so 3.628 bore means nothing larger than 1.8ish... I think if I were building it I'd use EQ Magnums milled down to 52ccs and the 1.92 valve. A custom forged piston to get me zero deck and have decent valve reliefs that gives 10:1 static with a .028 Cometic gasket. That leaves .028" quench, and with a solid lifter cam around 240-250° @ .050 it's around 8.25 dynamic so it's good for pump fuel. That's what I'd do. No pistons on the shelf will work with the cam you need to run. No head gaskets on the shelf will give decent static compression because they're thick and the bore's almost 1/2" larger than a 273s. No open chamber head will work for the same reason as the gasket (way too much volume). Porting a set of 302s to work will be cost prohibitive when the EQ heads are 1/2 the money and will feed it well enough in as-cast form. Unfortunately 273s are the small block 383... It's afflicted with not much solid support by the aftermarket."

The Doug's headers are spendy, but are really the only option for the early cars. They are 1 5/8 under chassis and will support the kind of power that I am looking for. Does TTI make a header for the early cars?

I figure that hood clearance will be an issue, but I will worry about that down the road. LOL Thanks for your input and keep it coming.

Badart
Badart New Reader
12/2/12 6:23 p.m.
DILYSI Dave wrote: Nice work. My only concern is if you want to stuff monster meats under the car, that those fender braces are going to be the first thing that gets in the way. If that's not in the car's future, no sweat, but since I'm currently obsessing about how to get 345 wide Hoosiers under the stock fenders on my CP project, I figured I'd chime in.

Trust me, if I decide to go to wide sticky tires under this car I will do a cage and tie in the shock mounts directly to the snout bars.

Rob_Mopar
Rob_Mopar SuperDork
12/2/12 8:33 p.m.

There's a whole lot more support for a 383 than a 273. Now if you said a 361...

FYI, the LA 360 used a 1.88" intake valve. They are typically a good upgrade on a 318. Not sure how close it gets to the cylinder walls on a 273. Finding a used valve to mess with should be easy enough.

I need to go back to the beginning of your build thread to see why you are keeping the 273. I know CPDave here petitioned the SCCA to allow 318's to be substituted for 273's, but I can't remember for what classes. IIRC, they allowed it. He's built a pretty stout '66 Dart with that 318. If you've seen pics of a zebra striped '66 Dart, that's his.

Yep, TTI has 1 3/4" step under chassis headers for the '63-66 A's. Look for part number TTI636A. They are spendy too. The good Doug's tend to run within a few bucks of the TTI's.

Badart
Badart New Reader
12/2/12 9:22 p.m.
Rob_Mopar wrote: There's a whole lot more support for a 383 than a 273. Now if you said a 361... FYI, the LA 360 used a 1.88" intake valve. They are typically a good upgrade on a 318. Not sure how close it gets to the cylinder walls on a 273. Finding a used valve to mess with should be easy enough. I need to go back to the beginning of your build thread to see why you are keeping the 273. I know CPDave here petitioned the SCCA to allow 318's to be substituted for 273's, but I can't remember for what classes. IIRC, they allowed it. He's built a pretty stout '66 Dart with that 318. If you've seen pics of a zebra striped '66 Dart, that's his. Yep, TTI has 1 3/4" step under chassis headers for the '63-66 A's. Look for part number TTI636A. They are spendy too. The good Doug's tend to run within a few bucks of the TTI's.

Good info on the TTI's Thanks. I will look you up when it's time to order. That would be awesome if they allowed 318 into the CP class, because I can build a stout 318 and have a couple of blocks laying around as well as a set of 302 castings and a couple of sets of J heads with 1.88's. One of the teen blocks is a magnum that has already had all of the machine work done and I already have the dog bones and roller lifters. If I use the magnum block then I would have to go to a magnum style head correct for oiling reasons correct? If you are correct about the rules then I would upgrade Eddys or EQ Magnums. How can I find out more info about the 318 thing????????? That would be awesome and a whole different ball game.

Rob_Mopar
Rob_Mopar SuperDork
12/2/12 10:26 p.m.

I'll ping Dave and tell him to take a look at your build thread.

If you use a Maggie 318, then yes you need to use the Magnum heads or figure out a way to get oiling to the rocker shafts. The passages from the cam journals to the heads that the LA blocks have is not drilled on the Magnum blocks.

Badart
Badart New Reader
12/2/12 10:40 p.m.

In reply to Rob_Mopar:

I sent cpdave a pm, but looking at one his thread I think he was referring SVRA and not SCCA rules. I hope not anyway. Thanks for your help.

Sky_Render
Sky_Render HalfDork
12/3/12 2:16 p.m.

This is a sweet project!

Badart
Badart New Reader
12/6/12 8:38 p.m.

Not much really to report to the barracuda. I have been talking to a couple engine builders about a stock stroke 360 that will pull hard down low and have good mid range. And will most likely be building an 8 3/4 rear and run 3.73 gears and a suregrip eventually. But for now the 8.25 will do.

I did mock up some cheap gauges and fabbed an aluminum plate to fit where someone already hacked a spot for a head unit. I media blasted the factory gauge cluster and will be painting it later. I removed the factory gauges from the aluminum frame and the 3 3/8" tach and speedo will fit perfect in there and look decent. There is no gas gauge, because I will just be running a fuel cell with no sending unit.

Rob_Mopar
Rob_Mopar SuperDork
12/6/12 9:09 p.m.

Nothing wrong with a stock stroke 360. Plenty torquey. That's what I'm running in mine with a .030 overbore. Run low to mid 12's in the quarter with 3.55 gears and a suspension setup for turning not straight line weight transfer.

And I forgot to send Dave a note. Sorry. Just sent him one now.

Badart
Badart New Reader
12/6/12 10:40 p.m.

In reply to Rob_Mopar:

Yeah I love the 360. I have been communicating with Dave over the past couple of days. Very helpful. The SCCA does not allow a 318 to compete in 5,100 cc class. So I'm building something bigger.

Badart
Badart New Reader
12/6/12 11:13 p.m.

Sorry for all of the changing of engine plans, but I think this is the best option.

So I just got off the phone with a mopar head buddy of mine who raced circle track for years can get these factory heads to flow. I am sending him my J heads (I never had them on a flow bench) and he will work them over, flow them and call his buddy at Engle Cams and come up with a custom solid lifter grind that will make the most down low torque to pull out of the corners and good mid range. My elevation at 5,000ft plays a big part too. The short block is one I have had in plastic for a couple of years, saving it for a project (You can never have too many small blocks LOL). It's .030" over 360, KB107's zero decked. Here is what they look like now.

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