Paul and all,

I have waited 3 months for machine work on a std. 4 port 13b intake and
am now contemplating the P-port as a quicker and less expensive intake
to build . I have tried to follow this topic closely but I have a couple
of questions.

#1 Original dyno run on Marks P-port you ended up using carb. What
problems do you expect with EC2.

#2 Is the water jacket jb weld the only seal other than machining to
prevent water in combustion chamber . If so would  o-rings at or near
the liner add  little cheap insurance.

#3 Is 600 ci. rad required for additional heat load ( I have 13by19xby2
installed)

#4 Any idea on endurance /TBO

         As always thanks in advance for your time and wisdom.

         Geir,       598JW Murphy Elite


I would not say we "ended up" using carbs. I would say it was a can
of worms trying to get the mixture right on the dyno using
Tracy's EFI system. Tracy EFI system was designed for prop
load. A huge difference when it comes to ease of tuning.
I was running over my budget on dyno time.

Mark has run the P-port engine with Tracy's EFI default mixture
settings so far and no real problems as far as I can tell.
He did say it misses once or twice at 3600 RPM but that
is still a long way from 5000 RPM cruise or 7500 take off RPM.
That may go away when the mixture is finally tuned
properly.

Yes the JB Weld does an excellent job of sealing the
tubes into the rotor housing. You need not worry about
that. No O-rings required. Despite an improper mixing
on the first go around leaving the epoxy soft there still
was no water leakage from this source.

There was water left in the
water jacket and the engine was stored in an un heated
hangar over the winter while the air temperature dropped  to
-30 degrees F as I recall. If it were a piston engine
it would have a cracked block. With the rotary however
the tension bolts merely stretched a bit more and water got
by the water O-rings into the combustion chamber.

495 cubes for the rad is a bit on the marginal side
however you are in a rather cool climate area so
you may be fine. A lot depends on how well you fabricate
the cooling scoop, the duct connecting it to the rad
and how well the duct is sealed. It is best to bond the duct
directly to the rads so there is no possibility of air
leaks. You also need to shield the rads from exhaust
heat and feed them with cold air.

Read http://www.rotaryeng.net/how-to-cool12.html

I know you know all this but we always have new subscribers.

The Lemans P-port engine was hardly worn after running
24 hours wide open at mostly 8500 RPM and winning the race
outright. I expect no difference in wear between the side
port and the p-port both running at the same cruise RPM.
The rotary is very easy to overhaul once you do it once.

If you need more than about 2000 hours TBO go with the $1200
ceramic apex seals that nobody has been able to measure
the wear on yet. Other wise stick with the high tech stock
Mazda apex seals. Use two cycle oil mixed with the fuel
at one ounce per gallon and Idemitsu rotary engine oil
or Mobile One in  the oil pan. Both are synthetics.

BTW the car racing organizations have either outlawed the
P-port or handicapped rotaries in general. If they had not done
that nobody in their right mind would race a piston engine.
The rotary is that good.