It's finally running!

Got the Ford 3.8L V6 running Sunday. Finally.

I got back from taking a friend flying at noon and finished up
buttoning it up.

Here's the background: This is a modified 3.8L V6 with a Northwest
Aero PSRU. The engine was completely rebuilt with the block baked,
bead blasted and scoured, then bored and honed to fit new 9 to 1
compression ration pistons from Wiseco. The crank was sent out to be
turned and new bearings were installed for the crank and con rods.

The heads were planed and I needed four new intake valves. New seals,
new guides, valves lapped in and 1 to 8 ratio roller rockers with new
lifters.

New cam per David Blanton's original specs. Regardless his
strangeness with horsepower claims, no one found fault with the
camshaft specs. No reason to, the design was spec'd out to one of the
premier camshaft engineers in Detroit and he got it right.

The cam was milled from a solid billet rather than regrinding the
original so the original, standard length pushrods could be re-used.

New stock Ford valve springs were used. I fabricated a test stand on
casters that I can drag into my Tacoma and drive it up into the woods
for testing away from civilization. I built it tall enough so that
the engine could run with the prop installed.

But it wouldn't run. I spent three weeks fooling with it trying to
get it running with no success. Finally someone asked if I had any
intake suction. That's the one test I had not done. Carb removed,
hand over intake opening, crank the engine and nothing. No vacuum at
all.

I used to be a certified auto mechanic and never misstimed an engine
in my life, but I'd misstimed this one. I pulled the timing chain
cover off and stared in disbelief. The camshaft was at least 5 teeth
away from where it should be.

So I reset it and double and triple checked that it REALLY was correct
now, scraped off the old gaskets, installed new and buttoned things
up. Cranked it with my hand across the intake manifold opening and it
tried to suck my hand through the opening. Even after I'd stopped
cranking, the suction remained. That was an encouraging sign.

By Sunday afternoon I was pouring in hot water (to make the engine a
little easier turning over) and ready to try it.

Starter switch to on, ignition on, fuel pump on, instruments on and
start! Row row row row row... nothing.

Flip the throttle in and out a few times: Row row row row... nothing.

Recheck timing by cranking the engine with the ignition off and finger
in the no. 1 spark plug hole till it blows my finger out indicating
it's on compression and then hand turn the engine to TDC and check
where the rotor in the distributer is pointing. Hmmm, it's actually
off some so I twist the distributer to align it better.

Try checking the timing using the timing light and no flashing. Could
that be the problem, no ignition? Recheck everything with a test
light, all is functioning properly, what's going on here? Oooops,
timing light clip has fallen off the battery. I re-attach it and
crank the engine and now the timing light is flashing properly. I can
now fine tune the distributer to get the timing at 8 degrees BTDC.
Obviously, the ignition is working.

Ready again, hearing protection on: Row row row... nothing, not a pop.

Ok, time for auxiliary starting fuel. Grab the acetylene torch and
crank up the acetylene and stick the tip into the carburator with the
butterfly valve half open to allow the gas in to the intake manifold.

Row row row row... **BAAAARRRRROOOOOOMMMMMM**BRAP BRAP BRAP, it's
running. I pulled the tip out and slammed the throttle shut and
darned if it didn't continue to run, albeit somewhat roughly, and very
VERY loudly.

I spent the next half hour fiddling with various adjustments and
finally got it running reasnably smoothly, at least at idle and up to
2,000 rpm. But man that thing is *L*O*U*D* loud, and mean sounding.
It sure doesn't sound like grandma's Plymouth.

I need to quiet that down or I won't be able to take it into the woods
and run it without upsetting folks for miles around.

Perhaps "Supertrapp" mufflers?

Anyway, it's running, the psru is tracking smoothly and this is a
milestone. It has a little leak of oil from the front crankshaft oil
seal, not sure what's going on with that yet but it isn't severe.

I also runs a bit rough when revved up past 3,000 but I'm not sure
what's happening there either, I haven't check to see if the timing is
advancing. That's another test yet to do.

So I'm fairly pleased right now. Next step is to bolt on the prop and
run the engine in and then do some long term testing at various power
settings. I spent a lot of time modifying the intake manifold per
Ford V6 STOL suggestions and specifications to have an engine that
will run smoothly at 4,800 rpm but that's with the prop installed. I
also custom fabricated the exhaust headers, making each tube exactly
40 inches long precisely to prevent a rough running hard to tune
engine. More testing to follow.

These tests need to be carefully documented so that the DAR can verify
that the engine has been tested. It's important for me too. ;-)

Corky Scott

On Mon, 18 Apr 2005 17:19:32 -0800, "Ron Webb"
wrote:

Congrats!

It sure feels good when a project that you have been working on for a long
time finally comes to life!

If you decide to do dyno testing, I'd be interested in the results. My
Dyno2000 desktop dyno program says Blanton's claims of 260+ HP are right on
the money. It also fits well with known performance of the 5.0L Ford. This
thing is not far from a 5.0l with one bank lopped off. A 5.0L will put out
350 HP without any tricks much at all. (6/8)*350hp=262.5hp.

The others here claiming that it won't do over 200 HP must be using stock
heads, stock cam and manifolds. Dyno2000 says that will get about 200hp.

The engine cubic inch displacement is 232. The piston compression
ratio is 9 to 1. The camshaft is what amounts to a 3/4 race cam and
I'm using the typical two barrel holley carburetor. The most
outrageously modified 3.8 I've ever heard of had higher compression
ratio pistons, special connecting rods and the guy was willing to rev
it to 5300 rpm. He dynoed out at 235 horsepower and I for sure would
not want to be standing near the engine when it was doing that. I
think he may have had a different carb on it too.

Blanton was missusing the formula when he dynoed his engines. It's
simply not possible to get that much power from 232 cubic inches and a
two barrel carburetor without supercharging or revving it to 8,000
rpm.

We don't do that, we limit rpm normally to around 4,800.

All the Blanton engines that have flown have not demonstrated that
they are producing anywhere near 260 horsepower. If they were, we'd
be seeing some very high fuel consumption figures because you cannot
make 260 horsepower and yet burn only 8 gallons per hour.

The actual figures just do not add up. Most guys are getting from 180
to 200 horsepower, with most of those closer to 180.

I'd be happy to report 180 horsepower but I cannot run the engine
without the psru attached, and I don't think the engine will fit on a
dyno with it installed.

Corky Scott

Corky

The engine cubic inch displacement is 232. The piston compression
ratio is 9 to 1. The camshaft is what amounts to a 3/4 race cam and
I'm using the typical two barrel holley carburetor. The most
outrageously modified 3.8 I've ever heard of had higher compression
ratio pistons, special connecting rods and the guy was willing to rev
it to 5300 rpm. He dynoed out at 235 horsepower and I for sure would
not want to be standing near the engine when it was doing that. I
think he may have had a different carb on it too.

Thanks for those specs. I'll plug'em into dyno2000 and email you the
predicted torque and HP curves if you're interested...(do you know the CFM
rating on the carb?)


Blanton was missusing the formula when he dynoed his engines.


I've heard this said before, but it's not likely. Even if he was using the
most primative dyno imaginable. The formula is HP=(torque * RPM)/5252. The
dyno would provide torque directly. I have Blantons engineering package, and
I can't believe that someone capable of that impressive package literally
can't count (which is what he is being accused of here)

But none of that matters much. If a 302 cubic inches (5.0l Ford) can produce
350 hp - Which it can if every hot rod dyno test for the last 20 years is to
be believed) then 232 cubic inches can produce 262 by simple ratios.

Even normally aspirated with no nitrous the 3.8 liter should produce over
260 HP if you get the intake, carb, heads, cam, and exhaust flowing
correctly. At least so says 3 different sources.

One thing though. You mention "special rods". I definately would not fly
behind any engine using powdered metal or cast rods. A set of good forged
rods would be my minimum for internal mods.

The above has been a theory of mine for quite a while. I know that a lot of
folks do not agree. That's why I wanted you to let me know if you dyno.

Thanks
Ron Webb




It's
simply not possible to get that much power from 232 cubic inches and a
two barrel carburetor without supercharging or revving it to 8,000
rpm.

We don't do that, we limit rpm normally to around 4,800.

All the Blanton engines that have flown have not demonstrated that
they are producing anywhere near 260 horsepower. If they were, we'd
be seeing some very high fuel consumption figures because you cannot
make 260 horsepower and yet burn only 8 gallons per hour.

The actual figures just do not add up. Most guys are getting from 180
to 200 horsepower, with most of those closer to 180.

I'd be happy to report 180 horsepower but I cannot run the engine
without the psru attached, and I don't think the engine will fit on a
dyno with it installed.

Corky Scott

"Richard Riley" wrote in message

Assuming what RPM and compression ratio? Are you using numbers that
are perfectly reasonable for a street rod, but are higher than the
airplane guys are willing to fly behind?


Richard

Good question. Since RPM is in the equation, I should certainly specify.

Blanton used a self imposed limit of 4800 RPM, so that is what I used as
well. It is very close to the HP peak when using the Blanton cam. A the
standard street/race cam that is used on dyno2000 yields 302 HP at 6000. A
bit high for our purposes even with forged internals. But at 4800 it shows
262 HP. Blanton's plans derate this a bit and only claim 230 hp.

As for compression ratios, I have run the simulation assuming compression
ranging from 9:1 to 10.5:1 - At 5000RPM, 9:1 yields 261 HP, while 10.5
yields 296 (both at the flywheel). Needless to say, I'll stay with the lower
ranges.

Note that I can make it show 160 HP just as easily. A 2 barrel 300 cfm carb
and stock low heads, cam and shorty headers are all it takes.

This desktop dynamometer program- if it can be trusted - is a wonderful way
to know what to upgrade and what to leave alone. I have references to a
couple of engine building competitions in the past couple of years where it
helped new guys compete with people who have been around for a long time,
and hit the HP figures dead on.

On Tue, 19 Apr 2005 22:38:24 -0800, "Ron Webb"
wrote:

Note that I can make it show 160 HP just as easily. A 2 barrel 300 cfm carb
and stock low heads, cam and shorty headers are all it takes.

But Ron, you just described what V6 STOL owners **DO** use for the
engine. The 500 CFM two barrel carburetor was tried but was found
unsuitable for the engine because it's too much carb. If you use the
usual carburetor air flow formula which is: CFM = (engine size in
cubic inches) x (maximum RPM) / 3456.

Plug in the figures without taking into consideration the pressure
drop inside the carburetor and the answer is 322.22 CFM.

Be realistic, how can an unsupercharged 232 cid engine, limited to
4800 rpm and choked by a carb flowing only 300 CFM make 260
horsepower? Oh I forgot, factor in the altitude too, which as you
know has a negative effect on power as you get higher.

I'm the only builder I know of who has fabricated headers designed to
enhance the power of the engine. All others have "shorty" exhaust
stacks which, as you mentioned, have a detrimental affect on power.
I've heard of only one builder who spent the money to have his heads
professionally modified. My recollection is that he spent a lot of
money and didn't gain much power.

Corky Scott

In article ,
Corky Scott wrote:

unsupercharged 232 cid engine, limited to
4800 rpm and choked by a carb flowing only 300 CFM make 260
horsepower? Oh I forgot, factor in the altitude too, which as you
know has a negative effect on power as you get higher.

What are you doing for mixture control?

Note that I can make it show 160 HP just as easily. A 2 barrel 300 cfm
carb
and stock low heads, cam and shorty headers are all it takes.

But Ron, you just described what V6 STOL owners **DO** use for the
engine. The 500 CFM two barrel carburetor was tried but was found
unsuitable for the engine because it's too much carb. If you use the
usual carburetor air flow formula which is: CFM = (engine size in
cubic inches) x (maximum RPM) / 3456.

I had a copy of Desktop Dyno for a while. (In other words, I forgot to look
for the installation disk after the latest HDD rebuild) And was dazzled by
the horsepower predictions for a number of engines--provided that you were
willing to run them hard and fast, use big pipes and a very big carb (or
throttle body), and also use a cam that was optomized for a fairly high rpm.
I really had my doudts about the engine pulling from idle; as I suspect that
a propeller load is vaguely similar to a torque converted. I also admit
that I am chicken and not willing to run a small-block continuously much
above about 4000 rpm, and would feel more comfortable around 3600 to 3800.
That, a conservative cam, a lower compression ratio, and a small enough
intake to idle smoothly would probably give me around 160 hp.

In article ,
Corky Scott wrote:


"It is finally running"
Snip.

Have you notified "The Barnyard Thing"?

"Corky Scott" wrote in message
...
On Tue, 19 Apr 2005 22:38:24 -0800, "Ron Webb"
wrote:

Note that I can make it show 160 HP just as easily. A 2 barrel 300 cfm
carb
and stock low performance heads, cam and shorty headers are all it takes.



But Ron, you just described what V6 STOL owners **DO** use for the
engine.


Yea, I know. That's why I threw that in there.

It's not what Blanton did though. He ported his own heads, and had his own
cam custom ground. I don't remember what he used for a carb, but I'll bet it
was bigger than a 300 CFM 2 barrel. He also made his own headers (parts are
available now from northwest aero).

All that adds up to substantiating Blanton's claims, and simultaneously
explaining why others have not done as well.

ower wrote:

"It is finally running"

Have you notified "The Barnyard Thing"?

He said "running" not flying...