Nitrous on stock bottom end?
#1
Nitrous on stock bottom end?
I'm currently in the middle of a budget race build. It's a 91 z28 that has had a post 87 roller 350 motor swapped. Was a 5.0 car. My goal is to do a 150 shot but from everything I have read in build books is saying that a late model bottom end is only good to about 425-450hp my goal is 500-600hp. I'm on a super strict budget so as long as everything looks ok when I tear the motor down there will be minimal machine work. Basically just a bath and bore hone if I can get away with it. Is it safe to say I'm gonna need a new rotating assembly to reach my goals and not grenade the first time down the track?
#2
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Car: 1988 Camaro
Engine: 377
Transmission: TH350; Circle D 4200 converter
Axle/Gears: Ford 9"
Re: Nitrous on stock bottom end?
I definitely wouldn't; especially on a set of hypereutectic pistons. You're asking for an expensive learning experience by doing that.
At bare minimum I strongly recommend a set of coated forged pistons.
At bare minimum I strongly recommend a set of coated forged pistons.
#3
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Car: '86 Bird, 96 ImpalaSS, 98 C1500XCab
Engine: LG4, LT1, L31
Transmission: 700R4, 4L60E, 4L60E
Axle/Gears: 3.73 Tors, 4.88 spool, 3.73 Eaton
Re: Nitrous on stock bottom end?
I'm currently in the middle of a budget race build. It's a 91 z28 that has had a post 87 roller 350 motor swapped. Was a 5.0 car. My goal is to do a 150 shot but from everything I have read in build books is saying that a late model bottom end is only good to about 425-450hp my goal is 500-600hp. I'm on a super strict budget so as long as everything looks ok when I tear the motor down there will be minimal machine work. Basically just a bath and bore hone if I can get away with it. Is it safe to say I'm gonna need a new rotating assembly to reach my goals and not grenade the first time down the track?
What IS a concern is your goal of 500-600 hp on a tired old bottom end without a thorough rebuild. It won't last for long at that level.
Like I said, nitrous alone isn't the issue. But for your target power level, you're also going to be spinning some serious R's, and that is the issue. Even if the bottom end "looks" ok, ovalized rod big ends (yes, they will not be round after high mileage at ANY power level) will lead to bearing failure......which usually fails the rod in short order. And that doesn't matter whether they're old style SBC rods or PM rods.
I'm currently making ~660 hp with a 100 shot on a PROFESSIONALLY rebuilt stock bottom end with ARP rod bolts /re-sized stock PM rods, and also revving it to the moon. But don't try anything like that on a tired old stock bottom end!
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Car: '86 Bird, 96 ImpalaSS, 98 C1500XCab
Engine: LG4, LT1, L31
Transmission: 700R4, 4L60E, 4L60E
Axle/Gears: 3.73 Tors, 4.88 spool, 3.73 Eaton
Re: Nitrous on stock bottom end?
The bottom line is: Either build the bottom end properly, or lower your target.
#5
Re: Nitrous on stock bottom end?
Ok thank you very much. Looks like I'm budgeting in a better bottom end. And I am not personally schooled in tuning a nitrous set up but my brother is and is my go to guy for this build. Appreciate the feed back helped a ton.
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