Look at this six cylinder engine table from '90'.

In 1990, when the Jeep 4.0 still had 177 hp,
the GM 4.3L V6 only made 160 hp,
the Ford 4.9L I6 (used in the F150 and Econoline) only made 145 hp,
the Ford 4.0 V6 made 155 hp,
the Chrysler 5.2L made 170 hp,
the Jeep/AMC 2bbl 360 V8 made 144 hp, and
the Nissan 3.0 V6 (used in the Pathfinder) made 153 hp.

I've been thinking about a Boat engine with a Slow turning 300 Six banger. A gas engine with lots of torque.
What if we put a longer stroke crank in the 300 six?
Can that be done?
Does anybody make one for it?

If we had EFi, water injection and a Watercooled Turbo, could we then get a lot more HP at a lower Rpm?
Do you think this combination might get 300 Ft Lbs of Torque out of the Six banger at 3000 Rpm or less?

 

supercharge it and you could run it up over 500 lb-ft. of torque

 

Well...this is for a boat. We just might be in for some trouble if we put a Supercharger on it.
Why will a Super chager get 500 Ft Lbs of Torque, when a Turbo Charger wont?
And thats 500 Ft Lbs of torque at WHAT Rpm?
I want to stay down low in Rpm.
And what are you doing up at this time of the morning?

 

what are you doing up LOL its only 1:30 here im half cut and dont feel like sleep

if you used a screw style turbo it would keep pretty much constant boost through all rpms and depending what max boost you set it at you could run that much torque any day probably hit 450hp too

i cant remember where the link is but this guy has a 66? ford with a 300 carb'd in it and a super charger, 450hp engine

a turbo requires the exhaust velocity to build boost, higher exhaust velocity higher boost, to get the higher velocity you need higher rpm and a good turbo setup could probably get you up there but not as efficiently and like i said it would be more suited to higher rpm on top of that you get the inevitable turbo lag where there isnt enough exhaust velocity to build any sort of boost in the compression side of the turbo

 

ah HA http://www.cardomain.com/ride/451198

there ya go...i lied its a 67!...yeah 450hp with leaves me roughly estimating at 500lf-ft. of torque at least

 

WOW! 500 Ft Lbs of Torque. That's almost 150 more than the 7.3 L Diesel.

A boat engine runs at a steady state most of the time. It idles for long periods, and when docking, its in Fwd, then Rev, then Fwd again, repeat repeat.
It needs tremendious amounts of Torque right at Throttle up. Not much difference in Torqued between Throttle up, and full Throttle.

Higher Rpms means shorter life.
I'm wondering if there is such an engine, in Gasoline, built for that kind of torque.
This 67 is a hand made super producer. I wonder about reliablity and longevity.
Maybe I can contact him?

 

It wouldn't be your average boat engine. The gearing would have to be weird to keep low RPM and spin the propeller fast.

 

x2

thats why most boats use v6 engines...litte ricer high rpm things...and sadly mine is a 292 ch**y ...i should slap a big ole 351W in there

 

supercharged 460, nuff said

the 300 six is a love it or hate it motor, it does great when in the power band, but is a slouch when over or under it. i have a 262 chevy inline in my boat and it hauls ***! when in the power band around 2500. needless to say it is a marine motor with a better head than an over the road 262.

might wanna try a 240 and shoot for some mid range power. you can spin a 240 higher without running out of breathing space. Turbos will ALWAYS lag, but you can get that lag down with maybe a 6.2 diesel turbo, small diesel turbo designed for low end, top rpm is 3000 rpm.

if set on using an inline, try either a CTD 6 or 4BT or a 240 block and do the regular upgrades to the head and use a diesel turbo to get added power. there is always the easy route too, a big block v8

my 2 cents

 

I always appreciate the .02 worth.
My idea was to make a long stroke six that would use less fuel to do the same work a big block V-8 would. Half the weight, one manifold to deal with etc.

I want a low Rpm unit! I'd like to have the Torque curve and Power curve peak at 2500 Rpm. The Engine should last forever with no maint problems at that rate.

I like EFI. No carb in the world can equal the efficiency of an EFI unit.
I like the idea of Multi-port as opposed to Throttle body, however both have proven very efficient.
I had a Turbo Diesel that came on pretty strong about 1800. I put 205,000 miles on that little 2.3 without any problems from the fuel or turbo.
From that experience I thought a Turbo on the 300 six would help out tremendiously at the low Rpm's so I could limit the Cruise Rpm to 2200-2500.
A boat engine needs torque from the moment its put into gear.
Thats what I'm really looking for.
I dont have any experience with the Chevvy 292, but it cant be much different than the 300 Ford. The old 235's were OK. Nothing to write home about though.

I know somewhere in this world, some speed shop or some other kind of shop has come uup with a long strok crank for the I-6's.
Then a Cam, like an RV cam or Truck cam, and the Turbo, efi, and a guy should have a power house with a low Rpm working range.
Better fuel milage, and longer lasting than any V-6 or V-8.

 

The 300 is already a stroked 240...not much left that will do any good. ROI is just about non-existent.

 

What harte3 said. The 4 inch stroke is longer even than a 460's. Minor port work and valve work on the head, EFI manifolds, a good hot spark, and a small aftermarket cam would get you a very good, long running, 2.5K rpm torque peaking motor. Trying to stroke it is barking up the wrong tree.

 

Thanks for that stroke information guys, I didnt know.
I remember reading about somebody in CA who came up with a different crank for the 460 and made it a 502. I thought maybe there was something for the 300 too.

I really wasnt looking for more cubes, but more torque.

Maybe you remember reading about some of the old Pump motors, or Sawmill motors.
One-lunger's they were called. Single cylinder, with an exposed ignition source, a link from a lever that was moved by somthing attatched to the cam.
The valves were in a cage that screwed into the top of the cylinder.
There was no head, but just a big cast steel tube, the top was enclosed, with a piston in it.
Low compression, 300-800 Rpm and huge amounts of Torque.

I doubt the industry will ever see anything like that again, but I'm thinking there might be a use for the engine I'm daydreaming about in the near future.

 

if you want more torque in the 300 you can bore it out that will give you more cubes but with bigger cylinder bore comes bigger pistons, bigger pistons have a larger surface area for the explosion to contact...if you remember 3rd grade math you know that if you have a piston setup with an area of say 60cm. squared vs. one with an area of 30cm squared the larger one will go slower and have much more power and potential to do greater amounts of work. the smaller will do less work but it will do it faster (with the same amount of force acting on the pistons, per squared cm). this is the difference between v8s and I6s...an I6 will have much larger pistons which is why they like low rpm and put out so much torque with less HP, a v8 has 2 more cylinders which gives it more cubic inch displacement but they are smaller and there for produce less torque but they move faster which is why they have higher rpm power bands and pretty well suck below 3000rpm

sorry for the long winded post...

 

Dont be sorry. I enjoy the reading.
I'm of the opinion that Gasoline Fuel/air mix (14.2:1) expands at a given rate.
Small amount or large amount, the burn rate will be the same.

A longer stroke, means the Expanding gasses put pressure on the piston for a longer time.
In the interest of "diminishing returns" the faster turning American V-8's will give up the last half of the burn, by using a shorter stroke.
It means the exhaust will be hotter.
By using the hottest or most active part of the expansion, they get more RPM's and use those RPM's to get the more active production out of the engine.

Those old "one Lungers" used nearly all the expanding gasses in a stroke. The emissions were a lot cooler and the fuel usage/Hp was a lot less. Slower by far, and more useful in certain applications by far.

We all know all this stuff. It's pretty elementary, but I still feel Im missing something. Else we'd have what I'm daydreaming about in a lot of applications. Including heavy trucks.