Max HP for stock 5.0L internals?

[N2O-SHARK]

Does anyone have a guestamit on the max HP stock internals can support, assuming the engine is in good order?

I had initially thought I cracked my block from too much N2O. I had run +175RWHP for about a year, then +200 for 4 months and +250HP for a couple weeks prior to grenading the engine. Upon taking the heads off, I found a nitrous jet in the cylinder!! Yes, I am a major dumbass! Apparently the jet fell in the last time I had the intake off to change to the 250hp jets. It must have rattled around for a couple weeks prior to getting sucked in to the number 2 piston. The jet is tiny..but big enough. When the piston went up it sandwiched the jet to 1/2 it's size. But in doing so it cracked the cylinder. No damage to the head or valves, thank God, but the piston has a small chunk taken out of it.

Soooo, it wasn't the HP that killed the block. How far is up? Just curious what the max HP someone has gotten on a SC or turbo 5.0L with stock internals. If I can add 300RWHP jets, I will be almost doubling the power. Although I'm hungry for more power like a heroin junky, I really am tiring of rebuilds.

[lizard928s]

My goal is to try for 650+ RWHP on stock 5.0L internals (85/86)

[Danglerb]

Apart from the 2/6 bearing thing and 93 GTS rods, I haven't read about anything breaking relative to power in the motor. You will be out of traction long before internal trouble is my guess.

[N2O-SHARK]

That's right where I want to be as well. Just enough to take some of the mod'd EVO's and STI's around here.

With my 250RWHP shot I figure was just over 550RWHP. I want to crack 600RWHP. When I get the Hybrid back together I'm off to the Dyno for some hard numbers. So far I've only been using the G-Tech and I'm not convinced of it's accuracy.

DanglerB, what is the 2/6 bearing thing?

[lizard928s]

2/6 bearing failure is when the #2 and #6 (same crank journal) bearings get starved for oil and spin, this causes crank and rod failure and depending on the severity of it can destroy many other things.

To fix this you need to drysump and have a "chevy like" drilled crank, this can be done through Taylor iirc, but a search will turn up more.

[Fabio421]

High HP 928 engines have been known to crack through the center crank journals. There have been a couple of threads about it. Maybe Dangler can get the lowdown from Greg Brown. He seems to know alot about it.

[rhjames]

Originally Posted by lizard928s

2/6 bearing failure is when the #2 and #6 (same crank journal) bearings get starved for oil and spin, this causes crank and rod failure and depending on the severity of it can destroy many other things.

To fix this you need to drysump and have a "chevy like" drilled crank, this can be done through Taylor iirc, but a search will turn up more.

the 2/6 rod journal fix requires the crank mod as lizard says, including fully grooved main bearings. then you're also looking at dry sump, pan baffles, crank scraper, etc.....

if you're serious about changing out the crank, I've got drilled Taylor--new, never used--it's for sale. In fact, I'll cut you a heck of a deal on a 5.0L hybrid rotating assembly---ready to go. PM me if you're interested.

Originally Posted by Fabio421

High HP 928 engines have been known to crack through the center crank journals. There have been a couple of threads about it. Maybe Dangler can get the lowdown from Greg Brown. He seems to know alot about it.

haven't heard of this one yet, but not surprised it could happen....

then there's the dropping valves, liners floating--causing all kinds of issues, and head gasket problems....to name a few.


John Kuhn has near 600hp at the rear wheels, on a well seasoned S4 motor. Zipped the clutch out of it on the first pull....as I remember.


As Mike said...the breakage issues start to come up in other areas besides the motor when the hp gets turned way up.



--Russ

[Herr-Kuhn]

This depends on compression ratio. With the stock compression the practical upper limit for an S4 on pump gas is around 14 psig...any more and you'll be into detonation. If I put race gas in my car and ran 16 psig, then put some timing in I am sure the car can make 650-700 HP on the wheels. I had one pull with 16 psig which made 640 ft-lbs on the tire with 93 pump gas. We pulled the throttle at 3,800 RPM because there was not enough fuel to begin to feed that upstairs.

It also depends on the dyno you use. Many of the dynos with user defined correction factors seem to magically give larger numbers. Go figure. I would caution people on comparing dyno pulls on different machines. When in doubt, back-calculate based on injector size, fuel pressure and duty cycle to see if what you were told makes sense.

Food for thought...remember it isn't all about a peak HP number on the tire. Powerband width is very important for a street or track car. If you look at the sheets on my car you can see there is a large amount of power in the performance band range (3,500 to 6000 RPM). This is how I sized and matched the turbos...not to lazy and not too jumpy. I'd rather drive a car with 500 RWHP with an ultra-wide powerband than one with tons of turbo lag with 600 HP and a tiny powerband. Consider where you run the car in the RPM range and then size and match accordingly. This is the same reason a 750 RWHP supra is just as fast in the real world as one with 1100 RWHP.

Leave the nitrous on the shelf...it has no business on these engines.

[Fabio421]

http://forums.rennlist.com/rennforums/showthread.php?t=332018&highlight=block+crack

[N2O-SHARK]

Originally Posted by Herr-Kuhn

Leave the nitrous on the shelf...it has no business on these engines.

As always you are a wealth of knowledge. I will eventually go turbo in the future and will use much of the knowledge you have shared. I do however have to disagree with your comment on Nitrous.

Generally speaking how you get power into the engine does not matter. Turbo, SC or Nitrous, the end result is the same. Stresses on the engine are the same. If an engine cannot handle 600hp on N2O it won't handle it on boost either. Nitrous can be aided with timing adjustments and even methonal injection just like tubos and SC's. In fact nitrous could be deemed just a tad safer as it has a natural cushioning effect.

If done correctly Nitrous will safely yield as much power for far less initial investment. Now start adding a couple years of bottle fills and you close the gap. The reason I am interested in replacing the N2O is it's all or nothing. No middle ground. You're either N/A or Balls to the Wall. And for Auto X it's just flat out impractical. But light to light or 1/4 mile it's great. On a straight away, light to light or 1/4mile I can easily keep up with most built sharks on this board. I have hit mid 500's at the rear wheels and will be shooting for 600 soon. And with only about a $1200 investment and $60 a bottle. Plus my N2O system can go to my next car.

I have a pretty sophisticated set up for N2O. My timing retard ramps from 2* to 8* under spray, A/F is monitored by a safety switch that shuts down the N2O if I go lean. Progressive controller ramps the N2O based on what the engine can handle at any given RPM range, cutting off just before the rev limiter. I can change power levels with a dial in the car on the fly. It's a great system, but I would like something I don't habve to think about prior to use. I just want to stomp the pedal and get the results.

Even when I go turbo, I will use a tad bit of N2O to help with lag and then methonal to help with detonation.

[m21sniper]

Some of the guys on rennlist have used nitrous to very good effect. This is one rare instance where i DON'T agree with Mr. Kuhn.

Done properly nitrous is just like any other forced induction wrt reliability and power building.

[lizard928s]

Everyone has their own preferances, NOS is for people who like short expensive fun.

Turbos is for people who like power when they want it.

John, what do you want for that taylor crank?

[rhjames]

Originally Posted by lizard928s

John, what do you want for that taylor crank?

I have the Taylor crank, 5.0l pistons cut for 16V and 5.0L rods


--Russ

[rhjames]

Originally Posted by lizard928s

what do you want for that taylor crank?

PM sent----


--Russ

[Danglerb]

Lots of choices, hard part is to figure out what makes your boat float.

[Herr-Kuhn]

Guys...in my book the only "consumable" fluid needed to run a properly modified boosted engine is as follows:

FUEL

To bet the safety of your engine on a consumable fluid is very 1970s in my opinion.
What is one to do if a car is tuned on water/meth spray and then the bottle runs out under WOT? You just lost octane and cooling and are now headed south...FAST. To each their own, but I engineer this stuff to be reliable and the only fluid needed to keep it running is fuel, and maybe some motor oil here and there depending on how hard you run it.

I'd like to see the cost of running nitrous oxide on a daily driver that is tapped into every now and then next to a turbo system. How much a bottle and the bottle is good for like 2 mins WOT or what? It's a well known fact that the nitrous is very hard on parts.

One other thing...just because you read it on Rennlist doesn't make it true...

[rhjames]

Originally Posted by Herr-Kuhn

One other thing...just because you read it on Rennlist doesn't make it true...

Careful, John.....they'll be pounding the doors in.....again....



--Russ

[lizard928s]

Thanks for the PM and offer Russ,
However I would be simply looking for the crank.

I will be running stock 32V parts up top.

Hence asking about the crank only.

With my power goals I am doing dry sump. As well as running two Bosch 044 pumps.

[rhjames]

Originally Posted by lizard928s

Thanks for the PM and offer Russ,
However I would be simply looking for the crank.

I will be running stock 32V parts up top.

Hence asking about the crank only.

With my power goals I am doing dry sump. As well as running two Bosch 044 pumps.

no problem, just hate to separate the parts.

if I sold the crank by itself, I'd like to get what I have in it.

--Russ

[N2O-SHARK]

Originally Posted by Herr-Kuhn

It's a well known fact that the nitrous is very hard on parts.

I totally agree about the fuel. Although a good system with safety's will keep you from running south, you will still be back to N/A power levels. As for cost, I have spent maybe $900 in the last 2 years. I hit the juice maybe once a week or so, though I can run through 2 bottles on a track day. If someone uses it as often as I would hit the turbo...it would be much, much more expensive after a couple years. That's why I am looking at other options at this point.

As for Nitrous being well know to be hard on parts...Sorry but that's just garbage IMO...
HP is HP. IN fact the cushioning effect of the free nitrogen creates less wear and stress on internals. Nitrous also has the benefit of cleaning valves as it goes. In smaller amounts, 75hp or so, it actually prevents detonation, again safer for your engine. Above 150hp or so you do need to start retarding timing to prevent detonation, but still less than an equivalent turbo. There is nothing in the processing of N2O that causes more wear over a turbo. Especially with a progressive system. Adding 300hp at 1500rpm in 4th gear would be fatal. Then again if you had a turbo that could generate 300hp extra at 1500rpm in 4th gear it would also be fatal. It's not the N2O it's the user and delivery.

I'm not saying N2O over Turbo or SC. They all work and have benefits and disadvantages over each other. I've already said I want to go turbo in the near future. Nitrous if done wrong can very, very quickly cause issues. I think with the cost of Turbo's and SCs, folks tend to do more homework and design safer systems, with N2O, every wahoo with $500 can explode their Honda and then give Nitrous a bad name.

I think the bigest issue folks have with nitrous is it's too easy and too cheap. That's why NOS brand systems are even called "Cheater" systems. It's such easy HP, it must be cheating. Real HP has to take work and lot's of $$$.