Upcoming FE build: plan coming together

[vector1]

excaliber

a well known cam maker mentioned getting the avg. piston speed up to the "magical 4500fpm" range, which would put a 4.10 stroke at around 6600 rpms. i don't know if this has any merit as i don't know what he was basing this on, probably experience as he does a lot of higher performance race stuff. take the cup cars which are turning 8k+ at 3.48 stroke and they are into the 4600fpm range.

also look at the emc winner who has done well the last few years and what they build, longer stroke smaller bore seems to be the tendency i'm thinking, smaller bore also produces less friction.

if you can make a bigger stroke live and breath at higher rpm it will always make more hp, rpm being a mulitplier of tq.

i'm only wrong 50% of the time, so i'm batting .500.

[Excaliber]

Short stroke, builds rpm faster, but it's less filling...

[patrickt]

Originally Posted by Excaliber

Short stroke, builds rpm faster, but it's less filling...

Perhaps you should caution him on the importance of putting the correct flywheel on his build....

[rustyBob]

aks801 if you already have a 390 block USE IT put webbers on it and ENJOY IT...
not EVERYBODY cares about resale value on a car thats not an ORIGINAL anyway...
the only way i would spend money for a 427 is on a new block,there to many abused old blocks out there and by time you spend money on them you could have gotten a new one...

[Gunner]

If you're choosing not to pay much attention to originality etc., then it doesn't matter at all. Virtually all builders have to face losing 20-25% of the money they put into a completed car, not even counting their own labor. If you want to take the position that it's your damn car and you'll build it any way that suit you... I'll give you a snappy salute and an honest "power to ya!"

But in general, the further you get from original, the lower your resale value is going to go. We've all seen some beautifully, expensively-built cars go for a song because no one else wanted, say, the fluorescent orange car with a carbon-fiber interior, Porsche seats, a show-quality Chevy 327, Foose 22-inchers and NASCAR roll cage of YOUR dreams. A choice for something more original in each of these cases would be a choice for a higher return value... or more, a set of Trigos being cheaper than Chip Foose's latest hot design.

There's something to the argument that there are enough original replicas around already, and some variation has its place. Maybe someday it won't cost so much to go off the straight and narrow ladder frame. But I'd caution anyone against throwing some large multiple of $10k into a project car without thinking through how much they might want to eventually get back out of it. Cobras and their kin might be the one class of hobbyist car that has a potential to return all of a builder's money, with a little luck and foresight.

[patrickt]

... and don't get hung up on the horsepower numbers. If you have over 400 after you hook up the pipes and accessories then you'll have more than you can ever use on the street or mild track days.

[aks801]

Originally Posted by patrickt

... and don't get hung up on the horsepower numbers. If you have over 400 after you hook up the pipes and accessories then you'll have more than you can ever use on the street or mild track days.

Great point, Patrick and one I am certainly keeping in mind. The only real reason I am going this route, as opposed to say a 347 with Mass-Flo EFI, is personal preference. The originals had an FE engine, so I'm with that. Something about that ridiculously big engine in that car is just hilarious and is what I want to see in it. And the Webers give it that touch of exotica that I love.

I won't get too hung up on the 390 v. 428 block question.

[patrickt]

Originally Posted by aks801

The only real reason I am going this route, as opposed to say a 347 with Mass-Flo EFI, is personal preference. The originals had an FE engine, so I'm with that. Something about that ridiculously big engine in that car is just hilarious and is what I want to see in it.

Yep, exactly right. Plus one of the added benefits of putting an FE in your car is that you'll be able to put your nose up in the air and rag on all the small block engines (even if they have more power and cost half the price).

[vector1]

Originally Posted by patrickt

Yep, exactly right. Plus one of the added benefits of putting an FE in your car is that you'll be able to put your nose up in the air and rag on all the small block engines (even if they have more power and cost half the price).

head up in the air cause he can't see ahead of him that far down the road, and cussing (or ragging as you call it) cause he should have built something else

[RodKnock]

Originally Posted by aks801

The originals had an FE engine, so I'm with that. Something about that ridiculously big engine in that car is just hilarious and is what I want to see in it.

I won't get too hung up on the 390 v. 428 block question.

aks, if you would allow me to add my $0.02. I know the 390 is an FE block and I know cost is also an issue, but for the sake of resale value, as Gunner expressed earlier, and also for more cubes, I would try to "move up" to the 428 block. Additionally, a 428 was installed in many Cobras and would be higher on the "originality scale." I originally looked at several 428 and 427 blocks, but I got tired fast of looking at blocks that either were rusted, needed sleeves, cracked, etc. While I didn't want to spend big bucks on an aluminum block, I'm now very happy that I did, although now I'm hankering for a SOHC engine. Though I don't really want to carve up my footboxes and make my steering linkage look like a snake.

I'm not saying go buy an aluminum block, but try and imagine yourself in a couple or few years with the car and driving it, and ask yourself the "BACK TO THE FUTURE" question "Am I happy with the 390?"

[767Jockey]

Originally Posted by RodKnock

aks, if you would allow me to add my $0.02. I know the 390 is an FE block and I know cost is also an issue, but for the sake of resale value, as Gunner expressed earlier, and also for more cubes, I would try to "move up" to the 428 block. Additionally, a 428 was installed in many Cobras and would be higher on the "originality scale." I originally looked at several 428 and 427 blocks, but I got tired fast of looking at blocks that either were rusted, needed sleeves, cracked, etc. While I didn't want to spend big bucks on an aluminum block, I'm now very happy that I did, although now I'm hankering for a SOHC engine. Though I don't really want to carve up my footboxes and make my steering linkage look like a snake.

I'm not saying go buy an aluminum block, but try and imagine yourself in a couple or few years with the car and driving it, and ask yourself the "BACK TO THE FUTURE" question "Am I happy with the 390?"

Maybe it's just me. I'm an FE guy, I have zero interest in Windsor based engines. As far as FE's go, there is the SOHC, there is a 427 sideoiler, and the rest are all just FE's. A 390, 428, 352, etc. block with a stroker kit in it is all the same. They're FE's. A 428 engine was just a slightly bored and significantly stroked 390. That's it. Externally they're identical, internally they're almost identical. I personally see no value in a 428 block unless you're redoing an original Cobra, Mustang, etc. that originally came with one, a restoration that needs a specific block. For a replica to have any significant additional value with a 428 vs. 390 block - I just don't see it. They're just FE's. Step up to a cross-bolted, sideoiler big bore 427 block, and THAT's a significant difference. 390 vs. 428 block - there really is no difference at all, value wise. As far as power, a 428 block can be made to displace a few more cubic inches than a 390 block, assuming you take both to their max capacity, and therefore on a max effort engine it'll naturally make a few more HP. However, that is the ONLY difference. You can EASILY exceed the 500 HP mark reliably on a 445 cu. in. "Prison Break" stroker kit for a 390 block. No problem with that, and while I don't have the numbers in front of me now, you can get, what, maybe 15 more cubic inches out of a 428 block? That should work out to about 17 extra HP on a HP per Cu. In. basis. Is anyone going to pay a big premium for this? I seriously doubt it. Get the heavy web 390 block, they're all over the place, readily available for about $100. Machine it well, drop in a stroker kit, and you're complete with the short block for less than some numbers correct guru would pay for just a 428 block that'll make no more power and last no longer. That's my $.02, your mileage may vary.

[rustyBob]

there so many more 390 blocks out there than there are 427/428 blocks that to not use them just because there displacement is just wrong........
i spin my 390 to 6k whenever i feel like it and have been doing this for several years now WITHOUT any problems at all.........

[aks801]

Good stuff, thanks all. Just want to throw in a little more context:

- I will not be looking to "max out" this engine. So, while a modest increase in stroke may be in the works, boring it out for all it's worth will not.

- While I will go for a number of originality/authenticity bits throughout (more for my amusement and getting the right "look" I'm going after), this car won't fool a serious Cobra enthusiast. At this point I'm looking to go with the Factory Five product (hard to argue with the amount of support available), but once the Hurricane car is available again next year I'll be taking a close look there as well (more correct body shape being primary reason). Point being, I'd have no issues with using a 390 block as a starting point.

[patrickt]

Originally Posted by aks801

At this point I'm looking to go with the Factory Five product (hard to argue with the amount of support available), but once the Hurricane car is available again next year I'll be taking a close look there as well (more correct body shape being primary reason). Point being, I'd have no issues with using a 390 block as a starting point.

I think that's a great idea. The FFRs have a look that I particularly like and putting a 390 in it will make it run like a bat out of he11.

[olddog]

Since no one said it, many 390 blocks can be safely bored to a 428 - I think that is 4.130" bore if memory serves me. Maybe half the 390 blocks have enough meat. It requires sonic testing, but it is done quite a bit.

If your 390 block has enough meat, why not?

[lovehamr]

RK, I don't think that you are in fact in the minority here. I chose to use a 428/462 FE in mine which has caused quite a few problems for me but when it's done it'll be beautiful. The fact that there are some things that seem to separate one Cobra from another in terms of value to the majority of buyers is also indisputable. Hence my belief that you are NOT the minority on this. Some of the things that jump to mind as separators are, CSX#?, aluminum body?, 427/428 FE?, independent rear suspension?, and color (tangerine with pink flames don't cut it). Of course there are others that aren't coming to mind right now but you get the drift. There will also be exceptions to the rule as well. Right now there is a SV car with a 390 and straight axle priced at almost 65k. It's a beautiful car and I hope he gets what he wants, but I won't be taking any bets on it just because of the 390 and solid axle.

Steve

[Gunner]

Originally Posted by lovehamr

Right now there is a SV car with a 390 and straight axle priced at almost 65k. It's a beautiful car and I hope he gets what he wants, but I won't be taking any bets on it just because of the 390 and solid axle.

Probably what he put into it (down to the last tube of weatherstrip adhesive) plus a percentage for his labor. A nice thought, but...

[patrickt]

... everyone here is not building their car with resale value in mind. Some are building their car solely for the enjoyment that it will bring or to make it the way that owner wants it. For example, there are probably more people that would pass on my car, because of the dual roll bars, than would seek it out because it does indeed have them. I think by the fact that he's putting in an FE at all in his FFR that he should be applauded.

[Gunner]

Absolutely - if you're building a car, it's first and foremost for *you*. I haven't meant to harp on resale value but since most of these cars do end up sold, sometimes much sooner than planned or expected, my cautions are not to throw out all consideration for resale issues.

To which I'll add: do plan on throwing out a minimum of 20% of what you spend as builder or first buyer of a Cobra - *any* Cobra built after 1967. You might regain some in appreciation but adjusted for time and inflation, it won't be much. That pelf is the net cost of doing it your own damn way and your own damn self... and I'd be the last to say it's not worth it.

[patrickt]

"It seats two, but it's built for one."

RodKnock, have you checked your rev limiter settings yet?