I am wanting to build a Twin Turbo'd 396ci Stroker Engine that will meet all of these limits. Can it be done? If so, what HYDRAULIC cam would I use on something like this?

*Will be an everyday driver and run on 93 octane pump gas.
*Make 700+RWHP (Before N2O)
*Has to run off of a Hydraulic Roller Cam.
*Cannot overheat during stop and go traffic.
*Engine has to last at least 75,000 miles before MAJOR overhaul. Reliability is the MOST important thing. Can't afford to rebuild once a year.
*ALL forged internals (8.5:1 compression ratio so I can handle high boost #'s.)
*Again something that will LAST LAST LAST!

P.S. I know that I will have to replace the valve springs every so often but I do not concider that overhauling. I call that typical stroker maintaince.

 

If you cant afford a rebuild once a year, how are you going to afford a motor that will last 75k mi at 700rwhp? Not to mention the fact that you want to add N2O.

I just don't see this realisticly meeting all your requirements.

 

Yes
Yes
Yes
Yes
Probably not
Yes
Again, no.

When I think of twin-turbo and nitrous, "longevity" isn't the first thing to come to mind.

 

Yes, it's quite possible in the general sense. Some caveats though. Boost plus N2O is not compatible with 93 octane. The main caveat though is when you start talking about needing 75K miles, it makes me wonder if you have thought this through. Don't get me wrong, it's possible to build a 700rwhp daily driver, but it will be extremely expensive. So the whole concept is inconsistent with someone who cannot afford a yearly rebuild. I don't consider doing rings and bearings once a year a major rebuild but "freshening it up". Anyway, the need for freshening is a function of how you use it. If you didn't use the nitrous and didn't spend a lot of time at WOT, it will last longer. Beat it hard, and it won't last as long.

Rich Krause

 

i hate to say this ............but stock supra internals have been shown time and time again to handle 600-700rwhp in a daily drivable car, without ever needing a rebuild (other than valves that were a defect).


why is it that a properly built, fully forged, aftermarket 396 would not be able to do the same thing reliably (sp?)

assuming you can turn the boost way down for reliable daily driving, and turn it up for racing.

 

Why not stop at 600 RWHP? Then I'm sure your other goals could be met. And correct me if I'm wrong ... but 600 RWP in one of these F cars is about all you want anyway, chassis/driveline limitations and all.

It's that last 100 HP that costs all the money and heart ache.

When my stock engine lets go, I'm going with a good 383 build and let the dyno gods deliver what they see fit as its final output ...

Hope this helps

LWM

 

The way the question is phrased begs the question, have you ever driven a 700rwhp car, even a 500hp car? You’re talking about 900hp at the flywheel.

To start with, even assuming that you built it so that it is very street able, you’ll find that it is in no way a daily driver. It’s dangerous, most of the power is unusable on the street and in a lot of cases, approaching insane in bad weather. Insurance companies don’t usually appreciate the value of the ‘mods’ and work that you’ve put into it, you start worrying about driving it on the street in case some jackass runs into you, because you can almost never justify what it’s worth to you to get it fixed to the other guy’s insurance co. And you probably wouldn’t even consider telling your own co if it was your fault. The cost of “freshening” and maintenance becomes a minor thing, compared to the cost of replacing the driveline parts that you’re now capable of breaking or the outlay to put parts that you won’t break in the car. You’ll welcome spending only a few hundred for fresh rings, bearings, gaskets… and a much better chance that you won’t be carrying pieces of your high $$$ parts home in a bucket. If it’s ever to see track time, you’re talking a minimum of a 10pt cage (possibly more if you want a really stiff, reliable chassis), suddenly getting in and out goes from a 2 second thing to a 30second thing. You learn neat tricks like getting in head first (feels awkward, but MUCH easier, especially if you’re a big guy and your knees won’t clear the steering wheel going feet first).

Heh, my brother’s car is probably making a little over half of your goal and is already having all those little problems. Hell, it’s easily street able, it even saw snow over the winter. And then it got hit by a snow plow while it was parked. He got an estimate of just over $5K to repair the damage, produced over $30K worth of receipts and they valued the car at $2925. That was after a 3rd appeal, initially they looked up the book value and said, “Ok, it’s worth $475” (it’s an older car but was spotless, we just finished putting a cage in it, lots of custom interior goodies…). My brother is actually happy to finally get their check for $2925 (just got it 2 days ago), since that’s enough that between the spare parts that he’s got, we can buy new parts, disassemble it ourselves, do most of the bitch work ourselves and then get a GOOD body shop to do some minor custom work and put a good paint job on it.

If you build a decent, 700rwhp car I’ll be shocked if it actually sees 25000 miles on the street in 5 years. I’ve built a few high hp cars over the last 10 years, all very street able, even passing emissions and none of which saw more miles then that, even if I (or whoever owned them) loved driving them.

 

Mark make excellent points. I see ~4,000m/y in my smog-equipped, very streetable (working AC and all) 700rwhp car. Like he said, I think I am lucky when all the motor needs is rings and bearings.

The chassis in these cars, with typical mods, can use ~600rwhp with street tires. More is a waste on the street. That said, I am upping the hp this year, but not 'cause I think it will improve street performance.


Rich Krause

 

Forgive me if I'm wrong, or missing something here, but I'm confused as to why you want a 396 when you're going to be running that much boost.

A 6" rod 355 will have a lower piston velocity and will place less stress on the cylinder walls. If you're going to be running turbos with a lot of boost, you'll have plenty of torque without needing those extra 46 cubes anyhow.

It just seems like a higher rod-to-stroke ratio would be worth more than extra cubes given your reliabilty concerns.

- Chris

 

A 6" rod doen't leave much room for the ring package or a deep dish in the piston crown.

I agree about the 396 though.

Rich Krause

 

Small point but where are you guys getting 93 octane anymore? Are you mixing it? We've (California) been without 93 for over a year now! 91 is the top. So, even if I had the stupidity to activate the nitrous on the street with 93 (which is pretty insane and totally unnecessary), I never do it anymore unless I'm at the track running 103.

And, just to confirm some other comments, even my little 462 rwhp does not get daily driven. It's reserved for fun and driving in stop and go traffic with a clutch that can hold 600 ft lbs of torque is not fun in traffic. Could I do it? Absolutely, it never over heats and is generally speaking extremely drivable but getting in it on weekends makes it all the more enjoyable. You know ... absence makes the heart grow fonder

 

florida always has 93

theres also a chain here that has a race gas pump...like 104 oct or something

 

My first concern would be the daily driver aspect of it. To me, daily driver means just that...driving it daily, regardless of weather. I shudder at the thought of running a 500hp car in the rain, let alone a 700hp car in icy weather. You'll be replacing more than bearings and springs then.

What I'm wondering is why do you want a 700hp daily driver? If you're looking for something to dominate on the street, you don't need 700hp to do that.

I also agree with the statement about cubic inches. I'd stick with a 355 or a 383 for a turbo motor and use a 5.7" rod. If you're dead set on a 396, a 5.875" rod would be the best bet.

Good luck regardless.

 

Freaking cali, i buy 104 at the pump down the street. 396 and 75000 miles with no boost sounds like a dream motor. I hope to get 50,000 miles out of my combo now, and i drive very nice. I might get flamed but 700 hp on a daily driver is not smart or reliable. Im sure those who have 700hp+ will tell you they cant even floor there car on street tires till 110mph. Hell i cant floor my car till 60, and i can play with most sport bikes and any factory car. I think you would be better off with a well built 355 anyway!