12 ENGINEBUILDERmag.com | AUGUST 2020
ENGINE DEVELOPMENT
factor were the turbos,” Moran says.
“We had been lobbying Garrett for the
prior three years about having a bigger
turbo that owed close to 300 lbs. per
minute worth of air. Of course, it took
them three or four years to do that
because nobody was asking for those.”
In the meantime, Moran tested the
engine using Garrett’s Gen I turbos as
well as their Gen II turbos, which were
smaller than the Gen I versions. Using
the Gen II turbos, the Motor City Billet
Bullet picked up power and went over
4,000 hp.
“We knew the engine would be
capable of more,” he says. “But the
turbos really weren’t there. Eventually
we got a surprise package from Garrett
and they had sent us the new Gen II
106mm turbos. We threw them on for
what ended up being the last day we
could dyno before I had to do a bunch
of NHRA engines, and we made two
di erent pulls over 5,000 horse with
those. e rest is history.”
When Moran started this engine
design in 2009, his goal of 4,400 hp
was based o of the current turbotechnology at the time. e more
e cient they keep making the turbos,
the more pounds per minute they
keep putting out. With Garrett’s new
turbos becoming available, Moran’s
horsepower goal had changed, and the
engine made 5,295 hp at 7,300 rpm.
“Somebody might be thinking,
‘Why can’t you take those 106mm
turbos and put them on a smaller
motor?’” he says. “Well, you could,
but then you’re at the limit of the
architecture of that engine. ey’ll blow
the mains out or they’ll start pushing
gaskets and moving stu around. at’s
why I built this engine so it could do
what it did. When you try and push
that much air through some of that
other stu you’re going to be replacing
parts or xing stu because it doesn’t
have the bigger port volume and the
camshaft that we do.”
e two pulls over 5,000 hp
were made in July 2018. Moran has
since made some adjustments to
the valvetrain and changed out the
camshaft.
“We had Danny Jesel make us thenew valvetrain that we wanted and we
did a slightly di erent cam,” he says.
“We ran it on only 28 lbs. of boost and
it made 3,370 horse like that, which
was up probably 150 hp from where
it was before at that point. en, we
looked at some of the valvetrain stu
and wanted to make one more change
on the cam before we ran it hard up to
9,000 rpm and 70 lbs. of boost.
“We changed to a low-pro le cam
and changed ramp speed. From there,
we’re just working on valve spring life.
In the past, the motor could run up
past 8,000 rpm with no problem. Once
you’re done with the pull, however, the
springs are down 150 lbs. It’s a little
abusive on springs.
“What we’ve done is worked on
smoothing out ramps and we changed
some ratios around so it wasn’t so
violent and then we re-ran it. Since
then, now the thing will go to 9,
rpm two or three times at the same
boost level it used to without killing the
springs. ey’re just slightly fading, so
we saw room for improvement.
“We’re hoping this last iteration
is going to be a home run. What I’m
looking for – and I know it sounds
crazy – is an almost 6,000 horsepower
engine that you don’t have to change
valve springs on or do any work on. I
don’t know if I’m going to achieve it,
but I’m in the right direction.”
Years in the making, many barriers
broken and still possibly more to come,
Moran describes the Motor City Billet
Bullet build as a fairy tale the way it
came together.
“I knew it’d be a long road,” he says.
“I jumped in with both feet before I
realized I was going to be designing
dynos. I never thought I was going to
have to wait for turbos to come out. I
guess it’s better I didn’t look. I just leapt
into what would be the best architecture
and engineered engine, but it was worth
doing for a rst!” EBSince running the engine in excess of 5,200 hp back in July 2018, Moran
Motorsports has made changes to the valvetrain and the camshaft profile in
hopes of picking up even more power.
08-12 eb.aug20 Engine Development.indd 12 8/7/20 8:37 AM
Naresh Jariwala