Wildman_grafix

I may have been the one talking about buying gas on the water, the reason is that we often go father in a day then the tanks will hold. It's not that unusual to have a 130-200 mile day.

Brad Christy

Wildman,

Same. Although, we typically don't run that far in a day, I also rarely top off the tank. I just don't feel the need to lug around that much extra weight if we don't have to. It has bitten me in the azz a few times, though, and I've had to grit my teeth and pay marina prices. But it makes sense to build engines around the idea of occasionally having to live with the fuel you can find unless that's just outside the parameters of the build directives.

Thanks. Brad.

offshorexcursion

So how can your 427cu/in 4.5 whipple LS make 1350hp on 91 octane? (Obviously reliably marine)

I've never seen a 4.5 whipple on a BBC make that kind of power let alone any belt driven supercharger.

Just trying to learn along with help you so you don't blow er up. Having a realatively smaller, efficient, cat will help it live cause no way you will be able to hold it WOT for long like some bigger, heavier, slower offshore boats.

Can you post dyno sheets just for fun

LakeBoat4

You are correct that a 4.5 Whipple can not make these numbers on a BBC. They can on a 427 LS though. It has to do with filling the cylinders with the air available. It is a lot easier to fill 7 liters (LS) than say 9.4 liters (BBC). Then add Boost. The sheets say 22.5lbs to get the LS numbers. My original 565, 1400's now 572 did those numbers on 14psi but with (2) 3.3 Whipples. Look at Teague's website. Both engine are on 91, gas available on the lakes I will be going to. The 4.5 is Max'ed out on the LS spinning 18,000rpm with engine at 7200rpm. Have to get more air with a quad-rotor or Twin Turbos to get more out of it.

The dual graph is the difference between running Meth injection and not. Its good for about 50hp and 30tq. Not bad for a little spray, cheap HP!

If it Blows up it is Ken's problem, 1 year warranty came with it in writing. He knows exactly what I am doing and what its going to be use in. They set it up with Marine Specs, they had done it before.
Showing my age, remember NASCAR in the early 70's, 427cu/in max? Now think 358cu/in Max and have to run restrictor plates to keep hp and speed down. What is up with that? Think smaller engines are more reliable than the 427's of the past and not finish a full race.
I love big displacement but more can be had with the smaller stuff. Lets talk it out.

hogie roll

A really good LS3, LS7 or big aftermarket LS head can flow similar to a decent 24* BBC head. So if you’re willing to spin the LS about 20% faster they could make similar numbers.

The BBC still has the edge though.

1350hp is spicy on a 427 for a boat.

Teague does 1580hp on a 565 BBC with 5.0 whipple (1400 package) for boats, for comparison.

The 13-15* chamber of an LS will be more efficient than a 24* BBC chamber, so they could theoretically take a little more boost or timing.

The skirted block of the LS is a disadvantage in oil control compared to a really good big pan on an SBC or BBC.

Tartilla

Interesting on the deeper LS skirts and oil control factors.

One Achilles Heel for BBC seems to be the lifters. Roller or flat.

LS seems to have a better lifter reliability with easier valvetrain dynamics. Larger base circle etc.

hogie roll

Im not sure if “oil control” or “pumping losses” is the correct term and phenomenon, maybe both.

I know in discussions on building the ultimate small block, the conclusion was that a non skirted sbc would be preferable. Assuming on a really extreme build the heads and valvetrain end up looking the same on an sbc or LS.

Good point on the valvetrain. BBC also has identical cam and lifter diameter to an SBC! so it’s usually the limiting factor on a BBC. Of course all of those things can be changed with enough money.

Wildman_grafix

Didn’t know that the block skirting would cause issues.

I thought that was to help stabilize the bottom end.

like the old cross bolted main ford FE.

pretty sure that they also use that type of design on the overhead cam motors and the new 7.3 truck motor.

why is it a issue?

LakeBoat4

I like Spicy Just because it has 1325hp doesn't mean it has to be used all the time, moderation has to come into play.

Brought up the Teague 1400's, yes got 2 of those in the machine shop now. 1580hp is on Race Gas. That 5.0L Whipple is Max'ed out on a 565, it can not spin any faster and makes around 11psi, the reason for the Quad-Rotor. Two smaller 3.3L Superchargers can spin faster with more boost. This LS can do that as well on Race Gas. For reference the 1400 Teague's have a 7200rpm redline the same as this LS. Actually if both Dyno charts as overlayed they are very close to one another. LS vs BBC at that power and torque level.

This LS is ALL aftermarket stuff. I would not try this on a stock block, heads or anything Chevy for that matter. The Dart block has extended cylinder bores, for piston skirt control, added head studs and a full lower pan skirt. The skirt is the reason for the dry sump, to get that oil out of there and not worry about a big pan with a kickout and baffling. Heads are AllPro with Full CNC porting. The Teague is all aftermarket as well. The ones I have have Teague wet 14qt pans. New 1400's are dry sump.

I hear and know there are advantages to the LS but there is a lot of saying a BBC is better. At one time that was True. If still True why doesn't GM put it in anything anymore. Available only in crate engine form as far as I know these days.

There is one huge difference here that I should bring up $$$. One of the reasons for doing an LS, Price, I called Teague to get a price on a new 1400. It is $120k, Yes $120k, that is almost in line with Mercury's outrageous pricing. Rebuilds are a lot less than Mercury sending it back to Teague but with a 4-6 month wait to get it back.

The LS new is around $50K from Borowski plus $10k for headers, that is a $60k difference from Teague. Just saying that I am not one to just write a big check if it can be done more economically.

Tartilla

At GM the Duramax diesel pretty much sealed the fate of the BBC.

The LS engines have no trouble providing the required HP for the auto/light truck needs.

Total costs for that level of power will definitely contribute to overall LS use. With the big push for high output multiple outboards, we need a good reliable mill to keep the traditional offshore sport going.

M8 Mercury drive can take 1650hp @ $55k

So theres some serious capacity to put the power to the water.

Why not larger superchargers used for LS? 8/71 size etc.

One large factor for me and LS use is the short bore skirts. 4" stroke is an issue. L8T 402CI truck block really helps with that.