I'm having a tough decision on what to do about my motor...so I'm looking for some advice. In Jan. 2010 I'm getting a little money and want to upgrade my engine. I know some will say....just upgrade the whole car to an LSXX car but I've done so much to this car I think imo it would be to costly to buy a whole new car and start over so I think just working on the engine would be the best choice. What I have now is a jasper crate engine but it is only based on factory specs 285hp other then some upgrades jasper does like moly rings and Teflon seals and some engineering modifications its basically a stock LT1. My original thought was to just buy an LS7, which at 12k is really not a bad way to go but the problem with that is by time you change everything needed to make the LS7 work in in a 97 Z28 I'll probably be near 20k which is a bit more then I want to pay. I've been looking at like LT4 crates....383 stroker's etc...that boast 425hp but by time you get to the wheels your really only looking at around 330rwhp. I'd like to be around a minimum of 400rwhp realistically 450 would be where I would like to be but 400 and my nos kit would be efficient. The next curve ball is the car is my DD and I'd like to keep it that way, I have friends that I run 100mph with on the highway from Tampa to Orlando so It needs to be able to withstand that kind of running, that's also why I haven't changed the gear ratio. I don't really want to go turbo or supercharged because that's just another problem to worry about going wrong or are superchargers reliable for long term daily drivers? If they are, then a 383 stroker with a sc would certainly have the hp I'm looking for. I really want to stay with the LT1/LT4 style intake and throttle body. I'm sure This should be able to be accomplished for 10k or less but I've been looking all over the web for a while and can't find the exact answers I'm looking for. Should I just build off of this Jasper crate? Should I upgrade to a 383 block because obviously there's no replacement for displacement? I think finding someone to custom build me a motor is going to be my best guess. Just trying to get some opinions....advice....options.....etc.

Thanks for any input.

 

heads/cam with supporting mods and you'll be right at 400rwhp

 

yeah man you don't need to build a 383 to get to 400rwhp. you can build a 383 with a solid heads and cam package from lloyd elliott or advanced induction and put down those numbers rather easily

 

Keep one thing in mind, he's got an automatic w/2.73's that he doesn't want to change.

A: The more cam you go, the more stall you'll need. The more stall you go, the looser it is, and the worse your dyno # 's will be. 1/4 mile time will be good though.

B: The more cam, the more gear you will need to make it streetable and to get it into it's power band.

Most that are making 400 rwhp with these packages are 6 speed cars. Where you don't want to change your gear ratio, I would build something boosted with a lot of torque, you'll need it to keep those gears and to hit your goals without going big cam w/big stall.

Jut my opinion though.

 

First things first, F the LSX idea. LT all the way.

Next build a 383 with AI's 200cc top end or LE's Le3, if you dont skimp out anywhere and buy all the supporting mods it should put down 425-450rwhp depending on trans/rearend.

Than hit that motor with a 125/150 shot. You should be good than.

What speed shops are you close to? Where exactly in FL do you live? There are lots of good shops down there.

 

I'm In Tampa.

 

keep in mind that with his auto, to make it streetable he's going to have to get a higher stall and gears. i would think if he went with say a 3000 stall and 3:42 gears that he would still get decent gas mileage

 

All good ideas....I don't mind changing the gear if it doesn't affect the highway rpm to much. I think 3.73's would be to much. How would 3.42 work? I don't want to kill the motor if I go for an hour drive at 100mph. I'm not a 1/4 person more of a street person and long long runs are common, that's really why I would like to stay with the 2.73's but I'm open if its not gonna hamper that fact. Speed stalls don't seem to me to be for street cars but for 1/4 cars. I bought the car when it was 2 years old, its a 97 and just rolled 100k to give you an idea of how much I drive it, a little less then average but its not a weekend car. I've upgraded the brakes, suspension, trans, interior, the engine just hit 25k, the paint is only a couple years old, so not much of the car is 100k. I love the car, just want to be faster then the average street racer and keep up with a new vette and go back and forth to work everyday. Keeping in mind some of these damn srt's around here with there turbo's are doing 12.9's, I need nos just to keep up...lol. And the main reason why I don't want to change the gear is because after 135 an SI can't hang. The 383 with the a good top end sounds good, maybe a ported intake and a 58mm tb on top to finish it off with a good tune sounds like it would do the trick. I'm sure that will keep the stock trans mount happy...lmao(useless pos)thanks to those 10.5s on the rear, but them damn performance mounts make you feel like your in a jeep, but i have an idea to create my on flex stop(is what im going to call it) so the factory mount can only stretch so far, but that's a whole different subject. Thanks for the input. Keep it comin

 

can you even move in traffic with a 3000 stall?

 

Of coarse you can move in traffic with a 3000 stall. I had my 3600 vig with my stock motor and it was fine. And to comment on the above about the stall converter being mainly for 1/4, yes, but try getting a big cammed motor to idle in gear without a stall, it's going to jerk hard into gear because it's going to idle higher and it's not going to want to idle in gear anyway.

 

ahhhh....that makes sense. I did not realize that. Maybe I am better off just trying to convert it to a stock motor like the ls7, 500hp and a normal idle.

 

Well that's the life of an automatic car. If it was a 6 speed car, it would be easy to do everything you want to do and keep the streetability and gas milage and high speeds even with 4.10's. Ultimately, it's your car, so make it what you want it to be. LS7 would be a lot of work, but would be cool. Even though you don't want to supercharge, it would be cheaper.

 

correct me if i'm wrong, but wouldn't he need a new tranny with the LS7?

ps, i have a yank ss3600 on my bolt on engine and it is nice to drive still. the engine i'm building might even require a bigger one for me

 

Whats your budget?
Honestly, if you want something tame, good power, great drivability, i would look into a blower or turbo setup.
Turbo can be done slightly cheaper but is more of a PITA. blower is easier but costs a little more

I went FI on my car, and i love it.
Advantages: Drives stock, make over 500RWHP, and maintain decent gas mileage
Disadvantages: costs, crowds the engine bay

Honestly, I would look at a 355, Speed pro 21.10 dish pistons, eagle h-beams with ARP bolts, and a stock crank. That'll get you good to 600ish RWHP reliably using a D1SC

Then, you can use stock heads, and a stock cam, run 12PSI or so, and be past your 400RWHP goal, and it'll drive like completely stock.

 

I 100% agree with the above statement. It just fits what you're trying to do.