FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: countrysquire on November 08, 2017, 01:48:59 PM
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Hi all, I'm in the planning and parts gathering stage of building an FE engine for an ERA Cobra that I have on order. My last FE build was about 12 years ago, and came out great thanks to all the advice offered by the FE community, so I figure I will ask for the same help again. The car will be configured as a street car, and I want to have it look reasonably stock under the hood. This means undercar exhaust as opposed to side pipes, and I think 2.5" will be the largest that I can hope to use. I have a complete '66 428 Q code engine that will be my starting point, and I plan on using a 4.25" stroker rotating assembly from one of our vendors here. While I don't see the car ever taking a trip to the drag strip, I do want it to be really fierce from a rolling start and up to 6,000 RPMs or so. The transmission will be a TKO600 5 speed and I have not decided on a rear gear ratio yet.
These are my goals:
Reasonably reliable
Cool running in the Texas heat
Decent idle - not so much cam that it can't idle under 1,000 RPMs
Decent vacuum - I plan on running a throttle body FI, and I understand they like 10" or more vacuum
Pump gas friendly - has to run well on 93 octane
Low profile - No hood scoop, so I will have to run one of the lower profile intakes, but I can figure that out from Jay's book
Has to make more power than the 213 cubic inch V6 Ecoboost engine in my F-150 - 375hp/470tq
So, I guess depending on how much it takes to clean up the bores, we will be 462-465 cubic inches with the 4.25 stroker kit. I do plan on a hydraulic roller cam, and probably a BT CJ style intake. I'm at a loss as to what to do on the heads. My concern is that the restrictive exhaust would make spending a lot of money on heads with a lot of work a waste, but I simply don't know enough about that or a cam profile that will fit this application.
Anyway, I appreciate any advice that y'all can give.
Thanks,
Bobby
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Hi Bobby aka countrysquire
First, welcome. Second, does this Q code 428 have anything to do with your handle (countrysquire)?
As a recent entrant into the Squire club my little ears are perked up for anything.
Fill us in a little on the countrysquire name.
As far as the cobra build goes, light car, lotsa cubes, all good. Would think you don't have to get to crazy (read reliable) to have lots o' fun.
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While I've been a lifelong Ford guy, I've never owned a Countrysquire, though I did have a '41 Woodie for a while. One day about 15 years ago, I showed up at work driving an old BMW station wagon and a co-worker immediately gave me that name, which stuck.
My last FE build was for another ERA Cobra, and it was fairly stock with a stock 1964 LR 2X4 intake and new BJ/BK carburetors from Carl's. It ran well, but I'd like to do a little more with this one.
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Ah ok
Since there is a Q code Country Squire I had visions of you ripping the heart out of a great car for the cobra. Would've hurt my soul.
I wish I could fit my big ole arse into a cobra. I guess its a good thing though, that's one car I can't bring home. ;)
Ok I'll get outta the way and let the motor guru's grill you :)
Good luck with your build.
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I was looking at going this route with my own Cobra.
Look into ovalized tubing for the exhaust. It will give you better flow over the golf-ball sized exhaust that usually comes on the street cars.
You're probably going to be stuck with a LR intake if you're not going to run a scoop.
I think I'd be tempted to just rebuild that 428, with a custom hydraulic roller and a good set of aftermarket heads.
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Thanks Brent. The oval exhaust pipe sounds like a good option and I have been planning on looking into that, and to see if there's a shop in the area that installs it. Quick, rough math looks like I would save about $12-1500 by reusing & renewing the stock crank and rods, so that's worth considering. Assuming that I can run an exhaust that will breathe decently, are you suggesting that I use one of the available heads with a basic bit of port work?
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What intakes originally came on 427 Cobra's? Low riser or Medium riser?
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A BBM head or a Survival head out of the box would be more than sufficient.
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Bobby,
I must be a little bit ahead of you in line at ERA. They were supposed to start my frame the last week of September, but they're pretty backed up. I'm also building a street car, and chose to focus on cubes and reliability over compression ratio and HP.
I chose a BBM cast iron block 4.250 x 4.250 Scat rotating assembly with forged pistons (482). Edelbrock heads (10.5:1 CR) with stock springs and rockers. Blue Thunder MR intake. I'm hoping for ~500 HP and 550 ft-lbs of torque.
AC
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What intakes originally came on 427 Cobra's? Low riser or Medium riser?
The 427 Cobra roadsters originally were produced with a variety of 427's and for a period with 428's in some of the street cars. Just generalizing here, but due to their nature the full competition cars came with High Riser 427's or Medium Riser 427's, usually 1-4V's, depending on how the buyer intended to use it, what race series, etc. The S/C cars tended to have 427 Medium Risers, most 2-4V's, some 1-4V's. The street cars came first with 427 Low Risers with 2-4V's, then 428's, then Medium Riser 427's. Again, this is just generalizing since the cars weren't necessarily built in strict order either. It also depended too on the engines Ford had available to supply.
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I worked for two different Cobra companys in the 90's and free lanced as well for a few years.The second Cobra I put together had a over the counter 427HR crate engine in it.Did a couple with 427 dual quad MR's.Air cleaner choice is paramount...
Most fun in a 427 Cobra for general driving were the cars with 351C 4V's.Burned a tank of fuel up in one in Toronto powered by a 500+ SVO 460..Saddly it was a auto but it was fricken powerfull.
ERA builds nice cars...
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AC,
Sounds like we like the same thing! I'm wondering if for my purpose the FElony or BBM heads are worth the extra ~$1,000 over the Edelbrocks, which I guess would be a little more than having my stock heads reworked and ported.
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You're gaining 30-40 cfm with either one of those heads over an out of the box edelbrock. It's worth it. Both of those heads both have modern combustion chamber shapes as well, along with smaller stemmed valves.
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Dammit Brent, you ain't helping my bank account! 30-40 cfm is not trivial though, so I guess I will figure in a set of Barry's heads.
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Guess it depends on the end use. In my case, breathing will be limited by the air filter under a hood without a scoop. Combine that with restrictive under car exhaust and I'm not sure how much extra CFM of heads matter. In my case it's all about torque, not HP. Intake and head velocity is important, volume less so.
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The head flow would be a benefit, even with the choke point. Pretty much every engine that comes off the engine dyno gets choked down in one way or the other. We spend time tweaking the combo on the engine dyno, then get the engine in the car and spend time curbing the restrictions.
I built a 510hp/510 lb-ft 427 that utilized ported factory C3 LR heads that flowed about 280-290 cfm. It had a factory C3 2x4 intake that was ported as well. With some creative exhaust and underhood work, you could take full advantage of it. IMO, if you found some guys that knew what they were doing with the exhaust, you could end up in a better situation than the guys with the sidepipe cars. The sidepipes in a lot of replicas are so restrictive that you can't roll a golf-ball through them and I've seen guys gain 100 hp on a chassis dyno by pulling the sidepipes off between pulls.
Torque is good on a street engine, but you don't want to end up with a truck engine either. ;)
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Thanks Brent. I do know that others have managed to fit 2.5” round exhaust under these cars, so I should have at least that to work with, even if I don’t elect to use the oval pipe.