514 crate vs. 393 stroked 351 in spf

[rated x]

600 h.p. vs 500h.p. please vote on which is better set up and why? same $$$

[BlueRooster]

Are you going to race? Or just bring it to shows?

[rated x]

no track racing but maybe take on viper or vette!

[Cracker]

If that's your intention I would vote for bigger is better. Just remember to keep it pointed straight when on the gas hard. Yes, I have learned why!

[OneFastRide]

Rated x,
Ahhh, big block vs. small block redux. The classic controversy. There is no right answer, but here's my take. If what you want is straight line acceleration, there is no substitute for cubic inches. The big block will out pull the small block - by a fairly small margin - ONCE IT HOOKS UP. Traction is not a small issue when considering the benefit of horspower in these cars. NO ONE makes a street tire that will come close to transfering all this horsepower to the pavement. Once you get over 500hp or so, first gear pedal to the metal produces lots of smoke. Period.
Big block = more horsepower = more smoke. Big block = more weight on the front end = less weight on the rear end = even more smoke. I would say the big block will begin to gain the advantage on the small block from about 60mph on. I have outrun 514s in the 1/4 mi with my 392 stroker. How much better than 11.89et, 120.5mph is a 514 going to run? (That's my 392's best time to date on street tires) I'd be interested in hearing some real world 514 et's - anyone?? The small block's lighter weight gains some advantage in handling if you ever decide to do some twisty/turny things - drag racing seems pretty boring once you give this a try, and spf has some great events twice a year with lots of opportunity for just such fun! Noodling on a small block - changing your own spark plugs for instance - is easy and a satisfying experience with the small block. It is major surgery and just as painful with a big block. A big block gets you bragging rights, an engine compartment stuffed to the gills, a lower frequency exhaust rumble, and all the rear tires you care to buy. A small block gives you a better balanced driving machine that is easy to work on and has more power than you can use. Take your choice. The good news is, you can't go wrong!
Happy Motoring!
Steve

[rated x]

steve , thanks for your imput said just like a poet would. anyone elseout there ready to go there?

[Goober]

OneFast Ride is correct with his statements. I too have a SPF with a RDI 392 stroker and have friends with the SPF 460's / 514's installed. Not much room in the engine bay for work. My best time is also around 11.9 / 12.0 with street tires. The big block guys don't run any faster. I guess the extra weight add up a little.
Main thing here is what ever engine you go with, you will be bad on the street. Vipers and Vettes will hide from you
The SPF is a great car and can handle anything you can throw at it. I don't think you can break one!
Be interested in what these cars can do with slicks. Anyone out there done it?
Mark

[HIQ]

Rated X,
From your recent posts you are looking for a used Cobra. If you find the "right car" either a 393 or 512 should work great for your application. I would be more concerned about the car and the build quality of the engine and less concerned about the configuration of the motor.

[rated x]

514 crate motors(early versions wereproblems) just want to know cost factor in updating before purchase. Surely there are some club members that have gone down this road? please give me some insight

[Randall Thomas]

This is something that no one can answer *for* you, but they can certainly assist you in seeing the differences you should consider when making your powerplant selection.

Recommending the level of power to someone is like recommending the type of girl you should marry. Only you can or should make that decision, because you are the only one that has to live with it. ;-)

What are *you* comfortable with? TRY it first and let your first impression be the judge. If you're not used to big power in a small car, be careuful.. If you *are* used to it, then still be careful!

Choosing a big block or small block is like shooting guns. You might have a .44 magnum and not hit a thing, but be deadly accurate with a .38. Then which would be better... for you? This might be more the reason the small blocks are said to be better on the track than their slightly larger bretheren. Less fear of the car itself, not the actual handling differences some might think. This is especially true in the very rigid and well handling SPF, which doesn't seem to differ much from small to big block any way.

However, with the big .44 magnum and you may never have to use it, which is why at car shows and on the street the Big block usually are respected as the most intimidating thing out there, and may very well keep you from HAVING to prove it, just by having it under your hood.

You can make nearly as much if not MORE horsepower with a well built small block, however, usually you can make that same power more relaibly and cheaper with a Big Block (429/460 series) because the inherent strength is already there in metallic size, not structual expense. On another note, the FE (427/428 series) Big Blocks will cost significantly more for the same results, and do not skip in this area with this series engine, ever.

But of course, if you are really not going to use all that extra power, then it can be more of a nuisance than a benefit... kind of like having a dually long box four door crew cab pickup and only tow a trailer once a year. For some it would still be worth having it. However, for many, it wouldn't... again, the personal preference is the final factor in any decision such as this.

I have both a small block Superformance car _and_ a big block Superformance car. They almost weigh the same (125 pounds difference), feel the same (in ride and street handling) and handle darn nearly identical in the turns (not hardcore racing, but spirited street and country road corneering, etc). However, that's where the similarities end.

The big block's sound is deeper, however not different enough to tell people it's different other than trained fellow cobra owners. The G-forces the big block puts out is, well, darn right scary and certainly dangerous in the wrong hands... even the right hands on occasion. The small block is a little more forgiving with throttle "mistakes", and may have an edge in short course autocrossing events where every single pound counts when racing against Miata's and the like.

The Big block I have (750hp) gets 17mpg at best, and averages 12-15. The small block I have (450hp) gets 23mpg at best and averages 13-18.

All engines will respond differently depending on their build and how racidal their cam/porting is, so these numbers can vary greatly, but usually in proportion to each other.

Niether is better or worse, but again, it's really abut what *you* want, what *you* expect and what *you* are comfortable with, and certainly, what *you* can handle. Now is not the time to use the machoness we guys all are born with... because saying, "ah, I can handle it" may be the last words you speak.

and remember when making your decision, that you may not be the only one driving your car... if your wife is not comfortable with driving it, that may take a lot of the fun out of a previously thought of "joint pruchase" into what "you bought yourself"... and you know where that can lead! Remember, you need an excuse to buy more stuff for "our" Cobra in the future, not "more crap for YOUR car"... lol... these words have been repeated by many a spouse in the past... heed these experiences.

The best advice anyone could ever give you is go to your local Superformance dealer and let them take YOU for a spin in Superformance's with several powerplant types such as a Mild SB, Radical SB, Mild BB and a Radical BB. If the dealer does not have all those variations you seek availble for driving at the time, they will certainly assist you in finding owners in your area to give you a test drive in the various options.

You shouldn't base your final decision on price, durability or fuel mileage of any of the choices, since they can be made very similar in the end result. Use them as factors, but not as the deciding one.

Unless you are hard core racing, I wouldn't use a few pounds either way as your desicive factor. First, lean towards what you "want", or have wanted all along. Then go out and prove to yourself if that's will be the right choice in the end. Sometimes just the underhood appearance is the factor all in itself. Sometimes it's the "drivability" of being able to hop in your car and take a 15,000 mile trek across the country like this guy did...

http://performanceunlimited.com/supe...e/usatour.html

Just be sure the "negatives" of your choice one way or another do not outweigh the positives. After that, there is no question that you have just made the right decision.

Please note I did not suggest which engine you should seek one way or another, because *you* should be the one making those decisions. Besides, I myself couldn't decide as well... so I got one of each! (although, I do have my favorite, but you shouldn't be making your choice on what my personal preference is!)

Hope this helps...

/Randall

[Goober]

Randall
You hit the nail right on the head.
Excellent advice for first time buyers!
It's funny you mention the gun caliber thing, I have a 357 magnum that I can't hit $hit with, but with my old 22 revolver I can bust a beer can at 50 feet!
Mark

[rated x]

THANK YOU!!!! please save that info,that was really well said. You were able to give both views and have the resources to back it. Your info could be very helpful to others with same confusion.

[Bilster]

If handling is a priority to you, I would go stroked 351. You could build one cheaper than the big block crate and with Trickflow Alum. heads, the SB would be at least 250 lbs. lighter on the nose. I autocross and wouldn't even consider a BB. I am very biased as I think the 351 Windsor is the best SB design out there. The tall deck lends for a great rod/stroke ratio and the aftermarket supports the 351 very well.

[bmalone]

The best way to decide and really the only way if you ask me is to drive and compare. I drove four cars back to back; each with a different engine. Or, I should say two engine families modied to a varying degree. Within a half-hour, I had made up my mind and never looked back.

[Doug Axelrod]

Two things.
1. I'd like to commend the commentators on this thread for extremely balanced and lucid points of view. This is the core strength of ClubCobra.
2. The advent of the aluminum 351 stroked to 427 raises a third option. Mike Stenhouse might with to comment further.

[BANDIT 1]

The difference between the 600 horsepower 514 (most 514 ci. engines make even more than that straight from the factory) and the 500 horsepower 392 is that with the 514 you will "smoke" the Viper and with the 392 you will be giving excuses as to why you lost (small block owners are good at this...).

[Excaliber]

Small block, been there done that. Now looking forward to the Big Block thing.

Maybe I'll like the small block better? Don't know yet!

Ernie

[HIQ]

Ernie,
Did you ever get to drive your Classic Roadster? What motor did you use?

It seems your new ERA will be a big step up in horsepower.

[Ant]

Here is my opinion and I am not trying to criticise any of the well balanced posts.

1. Without getting into a discussion of firearms, a Model 29 S&W loaded right will put all its lead into a less than 2" group at 25metres, its got nothing to do with calibre where a grouping it, this speaking from a regular pistol shooter in NZ. I can wave my H&K USP Expert .45auto past the bianci plates at 25-50 and blow every one, it shoots less than 2" group at 50metres! Also using a Model 41 .22 same thing, but they dont go over sometimes due to less grunt, maybe from a newcomers angle it would be better to start out smaller! SW.44 Magnums are very very accurate!!!

2. Big blocks V Small blocks, I have raced two big blocks one with 650+ bhp BB Chev LS7 Injected and if I could I would fit a BB 427 Chev to my present car far cheaper power more revs (availability in NZ that is) but it would not be correct for my application. The first car had a FE406, and a very good engine, but heavy. Now....Handling around corners, I would forget the BB unless its all alloy, if you are talking run of the mill alloy headed 392/408 and 427/460 I would go for the small block, and from what I can gather going down to all alloy for a 351 block only saves 60LBS. If you want to have grunt/tire smoke on the street/strip the big block would be great, and only marginally over a similar small block, build an angry small block and I doubt there is any different.

This can go on for ages discussions on engine size, but if you want handling LIGHT WEIGHT -period!!! How you achieve this is a compromise.

Can-am cars still go well with 850bhp BB Chevs in them. On shorter tracks here the small block is more pleasant to drive, sounds nicer in my opinion, of course then you could get carried away and do a full house 347 all alloy 700bhp race engine and your big block aint going to see it off on a tight track or maybe even on a bigger track!?!?!?

Just a novices opinion