bahlorm

I just got a hold of my first z28. Here within the next few months I will be doing a rebuild on the engine, so during that period I plan to do as much research as I can to find out exactly what route I should go with this. My goal is to get around 500 prefer whp. So I figure I will come on here and ask the people who probably know the in's and out's of these engines well.
It is a 94, lt1. timing chain broke on it.
What route would you go to achieve this number? n/a or forced induction? Nitrous may be after I achieve this number.
While I have the engine torn down is it worth having anything forged bottom end? From what I understand the bottom end can handle quite a bit. When it comes to the heads, should they be replaced by something off the shelf, or taken to a machine shop?
Also I'm not too sure how well the transmission would hold up to this (kind of doubt it would) or the rear end, so any info on what you would suggest about those will be appreciated also.

Injuneer

"Drivetrain" forum cover everything from fhe flywheel on back. For help.on building a 500rwHP LT1 engine you will get better results on the "LT1 Based Engine Tech" forum. I'll move your post there.

nicks94_redz28

Upgrade to a 12 bolt rear end. With the kind of power you're aiming for if you put stickies of the rear and run it there is a very high chance you will grenade your stock 10 bolt. Save yourself the trouble and do it right.

bahlorm

Thanks for the move and the info so far. I will have to look to see what all needs to be done to get that 12 bolt rear. I would also like to add it does have the automatic and it needs to be a street driven car run on pump gas

97WS6SCharged

500 whp on pump gas with an auto is going to take nitrous or forced induction unless you have a ridiculous budget for heads and such. Could always go with an LSx conversion, my 408 puts out around 470 rwhp and is tame as can be. Will run 50 in 5th gear with no real cam surge and that's running 95 lb/hr injectors.

MachinistOne

500 to the wheels is a lot, and cost a lot as well....much easier and cheaper to do 500 at the crank.

As was said, the LS is easier and cheaper to make that kind of power out of, 500 at the tires is easy to do and still pas CA smog. The most common setup I do is a Darton sleeved block for a 4.125" bore, 4.0" stroke crank, custom cam, LS3 heads and intake with some minor bowl work and you've got an honest 500 at the tires with pretty affordable components.

bahlorm

What all may be needed for 500 crank? I'm not really looking forward to doing a swap. A rebuild and slowly getting it all up to par is easier for me than worrying about fit ment and wiring and finding an ecu and so on lol. Got a little burnt out on that from a 350 rx7 build

David94TA

Forged internals, good heads/headwork and power adder will get you to your goal. Upgrade to the 95 vented optispark.

MachinistOne

The reality is that 500 at the crank can be done on a stock bottom end, but if' I'm doing it from scratch and want to make sure it's bullet proof then I'll put ARP fasteners in the main caps and line hone to correct for distortion and the settling that happens to a seasoned block making the main line not straight anymore. The factory crank is a strong piece and will handle the power just fine. As for the rods I would go with a 6.0 Scat Pro I beam and then use a shorter piston to take weight out of the rotating assembly. Some 4032 forged pistons like a Mahle powerpack kit and then a head and cam package to match and you're set.

Make sure it's a performance shop that does the work, you don't want a production quality job.

bahlorm

Perfectly what I was looking for. I will write that down. I am also pretty surprised that the prices aren't as bad as I figured it would be. I am sure that the head work will be where the costly part will come in though.

97WS6SCharged

You'll spend around a grand for good head work not counting parts. With cam and all figure around $1500-1800 depending on what needs to be done and/or replaced. My advice would be to go with someone who knows these heads like Lloyd Elliot or A.I. and tell them exactly what you want from the car. Letting Bubba at the local engine shop port your heads is just asking for poor results. Also, keep in mind what you use the car for 95% of the time and plan accordingly. A cam that pulls to 7000 rpm and idles like a race car sounds good when you're building it but sucks when you drive the car everyday.

bahlorm

What do you guys think of this camshaft here? Chevy Roller Performance LT1 LT4 270 Design Camshaft | eBay I was debating whether or not to get this or maybe the lt4 hotcam. Trying to find something that's in the 5800-6000 rpm range. The price difference between the 2 is what got me interested in the cheaper one since all the other ones are near $250-300. And like many others money comes in slow and leaves the wallet quickly lol especially when it comes to cars.
My total budget on the build engine wise I would say would fall under about $3000 category, rear end transmission and suspension ect not included in this. Currently though I only have about $800 to get the car running, with an unknown knowledge on if there's any bent valves or damaged pistons with the timing chain issue. The harmonic balancer has been giving me 1 hell of a time, and broke 3 wrenches with no success.

Injuneer

What happened to 500HP at the flywheel? You won't get close with either of those cams. You plan the entire build, and pick the cam as a matched part of the package. As mentioned above picking a heads and cam package from a highly experienced LT1 head porter is a good idea. Cutting corners with a "remanufactured" cam seems risky.

In view of the limited budget you may need to rethink your goals. The engine typically eats up 2/3 of your budget with the other 1/3 needed for the drivetrain and suspension upgrades.

97WS6SCharged

Before you spend any money rip it apart and see if you can figure out exactly what is wrong with it. No sense in buying parts until you know what you need and what you're doing.