robzr

Jenny, make sure you take things like bore:stroke and rod length:stroke ratios with a big grain of salt. Remember we are not designing engines from scratch, nor are we building high dollar competitive race engines. In other words, it is silly to spend another couple hundred to get a slightly more "ideal" rod:stroke ratio, then skimp that cash on your heads where it really counts. Sure you may lose that 2 horsepower that the less ideal rod:stroke ratio gives you, but you'll gain far more with the money spent elsewhere. Same with bore:stroke. I don't understand why anyone would destroke a 400 unless they are building a very high revving motor (ie not-streetable). Part of bore:stroke debate goes back to the "old days" when metal alloys were not as good, and aftermarket parts were not as plentiful/didn't exist. If all you had to work with was a low quality 1053 forged crank and pink rods, then you'd really want to pay attention to piston speed and therefore stroke length / rpm. But today you can go out and buy a generic 4340 or 4130 crank and some 4340, 4130 or even 5130 rods for cheap. The bottom end is no longer the limiting factor in revving, realistically it's going to be the valve train, heads, cam profile. And for a street motor, it's usually more practical to be making your 500 hp closer to your cruise RPM, which allows for more efficient cruising (gas mileage). So in other words - forget about bore:stroke, any additional cubes you can get will make FAR more of a difference, rendering your "bore:stroke" and even "rod:stroke" insignificant. Gkull's a great example of this, he loves revvin' high and making big power with a stroker. As does Monty with his huge stroke 434.

Rob

Tominator

427 sb, I don't know any stats for it but it sounds so :cool:. I see kits for it and company selling them as crates motors as well.

rambler323

http://www.ryanscarpage.fiftymegs.com/combos.html

that might be of interest to you...my .02

Jenny

Link doesn't work. It sends me to "Domain name for sale" But i think i've seen it. It has a bunch of different motor/head combo's and dyno numbers. I take those numbers with a grain of salt. I don't know the validity of those numbers, especially since a lot are put out by the corporations.

The Dude- You definitely take the sarcasm award of the day. Seriously though, i've heard the old "Overheating" folklore. I've also talked to some real world 400block owners and drivers.. none of whom have had any sort of problems at all. If it is built correctly, and complemented by a nice cooling setup i doubt that you will have any problems. Overheating occurs when you try to heat a 500hp 406 with a stock Vette radiator meant to cool 180hp. Now let me go to the marina... i hear they have blocks-a plenty tied to boats.




[Modified by Jenny, 8:25 PM 4/22/2002]

SmokedTires

Jen I realize that you must have done some research on the AF heads, but have you seen their 383 package? They claim to make 517 ft. lbs. of torque and 503 hp with their 190cc Street Heads. The dynoflow shows a really nice flat torque curve with just over 450 ft. lbs. at 2500 rpms, and the peak hp is reached at 5500 rpms. This looks like it could be a really nice combo for the street :yesnod: . I agree with the displacement comments above, but this is a combo that I'll be seriously considering for myself in the future being that I can save a bit with some of the things I currently have on my 355 ;) .


[Modified by SmokedTires, 4:43 PM 4/22/2002]

Kingt

Remember one other difference between the standard SB and the 400 is the 400 is externally balanced. Different harmonic balance and flexplate/flywheel.

jackson

Kingt makes a a good point about balancers/flywheels/flexplates ... one to not forget. I've also found there are nice forged aftermarket 383/400-type cranks that are internally balanced ... for use with 350-type balancers/flexplates/flywheels. I won't build another stroker with a 350 block ... next time I'll use a 400 block.
JACKSON

Golden80

I'm also looking at stuffing a 400 instead of a ZZ4 in my 80. There's a guy here who says he can build one that will pass an E-test better than the ZZ4. We'll see. Hopefully by this fall I'll have the new motor in my car.

Matt

joe73vette

Don't sweat the external balance. Use the 400 crank and stock damper and if you need a flywheel, there are balance plates that you put under the flywheel to allow using a standard one. It also works with a flex plate. You should have the complete rotating assembly balanced anyway, and it should be done with your damper and flywheel or flexplate, not the shop's.

One more thing to keep in mind, if you have the 400 block align honed, you have to use a special rear main seal with a slighty larger OD, because of the big main journals. It's not hard to get, just have to specify.

Also, if you use the stock rods, get ARP bolts. I suggest you go with the 400, no reason not to get the added displacement.
Joe

vettedan

Jenny- If you ever want to do a engine conversion, go with a late model engine like a L98, LT1 or LS1. There's plenty of expertise on the forum.
Dan

93Polo

Dan very clean looking swap. I do love my LT1 the only 2 things I don't like is packaging of a blower in a C4, and limited cubic iinches. You can take the LT1 out to 383 or 396 with no problems. :yesnod: Also the later motors give you factory hydraulic roller cams. I have heard of some problems with roller retro fit kits in older flat tappet blocks. I keep thinking about building a stroker for mine with some nitrous. You can do some :cool: things with nitrous on an electronically injected car. A friend is building direct port NX system for his LT1 I can't wait to see results.

Guru_4_hire

I read in a couple of books on making high performance small blocks -- one of which I believe is lingenfelter's book. He talks about 400s being prone to overheating not necessarily that they did but the siamesed center cylinders removed the water jackets between them, and affected cooling. Now if U are gonna be running a good super cooling system, it probably isn't an issue. Just a thought, If people alot smarter than me say something about it, there is probably something to it. Anyway just my .02

Have fun either way

Jake :flag

The Dude

Didn't mean to be all that sarcastic, but good, rebuildable 400 SBC blocks are getting scarce. They are neither plentiful nor cheap. You might luck out and the first one you look at will be perfect. You may have to look at a dozen or more pieces of junk before you find one to build.

As for the overheating thing people seem to be hung up on. <sigh> This is only my personal experience here, but I ran a 10:1 compression 415 for a while. I had the proper steam holes drilled in the heads. I used the proper 400 head gaskets. I drove it on the street. It ran 12.60s at 110 all day long at the drag strip. (3.08 gears, TH350). It also used the SAME RADIATOR as the L-48 it replaced. It was boiled out and checked for leaks and that was that. It did not run one single degree hotter than the engine it replaced.

As I have advanced in this hobby through the years I have learned, just because somebody's name is Lingenfelter or Shelby or whatever, that their word isn't carved-in-stone gospel all the time. A cautionary note in the form of a blanket generalization from guys like this to get you thinking and aware is one thing. But, really. Let's all let the "400s are prone to overheating" thing go. They're no more prone to overheating than any other correctly built SBC.