Offroad engine selection. 1200-1300HP, reliable.

[viper]

Looking for a platform (not an engine builder or supplier) we can work with to hit our target needs as an offroad race engine. I have made the decision not to push too hard for an Al block since it will likely only save 100lbs and we can save that elsewhere. Engine will be pos displacement supercharger.

Here are some basic guidelines. Broad high torque engine like what a V8 delivers, pump fuel 91oct but may custom blend if needed, approx 300-500hrs between rebuilds, cast iron or Al block, deliver 1200-1300hp, economical solution!, common enough that parts availability is very good, as compact as feasible.

We will build several and need to keep a diet on the budget. I was looking at an LS7 setup with SC which will get us close but likely only 900hp reliably on pump fuels. I am not looking to break the bank building radical custom LSX engines or something. I really need something fairly compact so trying not to go to a bigblock configuration but I realize that to get the target power reliably on pump fuels, more displacement is needed.

So, to all you well rounded engine builders, I have purposely left the barn door open for ideas here. I realize some will want WAY more information but I don't think it is required here. It may be that the LS platform is the best bang for the buck and a good way to go but I can't leave a rock unturned. Not brand loyal here, and not even loyal to the V8. I actually really like the performance of direct drive DOHC heads on an I6 but not sure we want to get into that on a blower engine. A little more boost and charge temp management seems easier so we can run more standard parts.

[lada ok]

how about a RR merlin or even a Packard merlin ... compact water cooled reliable hp ... best option I can see

[PackardV8]

Broad high torque engine like what a V8 delivers, pump fuel 91oct but may custom blend if needed, approx 300-500hrs between rebuilds, cast iron or Al block, deliver 1200-1300hp, economical solution!, common enough that parts availability is very good, as compact as feasible.

X2 on the Merlin or Allison, but you're about forty years too late for economical or parts availability. Otherwise, nothing I know will fit inside your dreamship envelope.

[MadBill]

From a weight, HP and 500 hr. service interval standpoint I think it will need a military helicopter turbine, but broad torque curve? Not so much, absent a killer CVT transmission...

[viper]

Let me try to better explain. The 300-500hr may only end up being design fatigue life in components but may be much more practical at 100hr service intervals.

Regarding broad torque, I am simply stating a good lower end grunt engine like a V8. I only say that because I know of several 2JZ engines singing over 1000HP but no grunt whatsoever. Need decent torque at 3000RPM. Power curve of a V8 is just fine. We can tailor the engine specs from a certain point to make the throttle man happy.

The LS7 and even some custom LS2 setups have been well over 1000HP, I don't think I am asking for the moon here. Massage a 572 with a roots and it will go there but that is a BIG engine and I am trying to avoid the size issues there.

When i say "economical", I realize these won't get built for 2K each! The budget right now is targeting 15K each.

[user-17438]

twin turbo R07.. shouldn't need much boost.

[Bos's5.0]

Oh... so 1200-1300 hp on pump gas in a reliable and preferable small block setup.....while providing good torque at 3000 rpm.. with a $15k limit?

[wyrmrider]

My customer has blown up more than my share of Blown BBC's in offshore boats trying to do what you are trying to do and we went surplus turbines
1200 HP and reliable does not compute on gas-- could be done on Methanol
The high buck European turbo V and W 12s do not come close
Allison or Packard Merlin would work- my first thought too
E85 or Alcohol OK?
if so a Top Alcohol combo could work with big intercooler and other durability tricks but not cheap
Al Teague showed the way to that much horsepower with Blown Stage 5 Hemi on around 35% with excellent reliability
Anyone else remember the pass of the Sadd Teague and Bentley High boy roadster? (before aero rules changes)
I see no way on single engine V8 gas
The monster trucks don't do it
We made a 500 mile reliable 1,000 hp on 210 inches twin turbo AMC 6 cyl over 40 years ago- on methanol with no intercooler (an error IMHO)
488 Viper based? the extra main and spreading the load out over 10 cylinders might help
The problem I see with a big V8 is that one blower will not feed it without big overdrive and lot's of heating
In a boat a air to water intercooler is easy with a supercharger
so it would be easier with a turbo
small block and reliable at that HP level????

[viper]

I think Kenny Bell kicked out a big girl twin screw a while back but will still need to do some spinning!

I would VERY much invite E85 if I could find a way to stay tuned on it. Problems I see are the need to vary boost relative to gasoline/Ethanol ratio. maybe I could get away with timing changes.

I love Methanol and I suppose I might be able to make it work but in past small engines I use it in, I have not seen much over 20% gains with it and hard to warrant the gain. I have not done alky on a blown V8.

Nelson is pulling over 1000hp out of LS7s on pump. These engines will NOT be required to run at 100% performance at 100% duty cycle. This is offroad, a lot of on and off but when you need the "go", you need it now.

EDIT: pump fuels certainly have appeal here but I should be able to get denatured 99% Ethanol and blend my own if needed. I believe E85 is cut with a very low grade gasoline.

[Rizzle]

as wyrmrider said, the viper v10 is one to consider. Decently large displacement, modern design and there has been plenty of work in boosting them. Helps its somewhat common and aluminum as well.

[PackardV8]

1200 HP and reliable does not compute on gas

For true

Nelson is pulling over 1000hp out of LS7s on pump.

On a twin turbo. Duty cycle, minutes at that level. Tom builds very good, at a price.

twin turbo R07.. shouldn't need much boost.

Again, lifespan of minutes

I know of several 2JZ engines singing over 1000HP but no grunt whatsoever. Need decent torque at 3000RPM

Maybe less than a minute

This is offroad, a lot of on and off but when you need the "go", you need it now.

So low RPM grunt, 1200 top end horsepower, 500-hour durability, $15k low cost, easily available parts. Yeah, right.

[Bos's5.0]

Did any of you guys replying see the budget? He didn't ask if it was just possible, but he wants a $15k budget.

Call up Nelson racing and ask how much for a turn key 1000+ hp LS7... Oh wait.. here's a price right here

http://www.nelsonracingengines.com/asse ... tt-cdd.pdf


Almost $40k... I'm sure you could shave $25k off that and still make the same hp.

http://www.nelsonracingengines.com/pric ... lsx_tt.pdf

Little cheaper.. only $36k

[John Wallace]

Diesel power?

Need decent torque at 3000RPM.

Sounds like you need torque at that low RPM?

How about 1200 or more ft/lbs of torque to deliver the low end?

[Cubic_Cleveland]

Diesel power?

Need decent torque at 3000RPM.

Sounds like you need torque at that low RPM?

How about 1200 or more ft/lbs of torque to deliver the low end?

That's his answer. Big turbo diesel. Not light, small, or cheap. Plus throttle response will be terrible.

[ap72]

Twin supercharged LS engines. That may be the she's pest way to hit your goals.