dowelling
 

how much boost can you run before you have to think of dowelling the housings and plates??

In a 13B over 1000bhp...you will not crack the plate.

If detonation occurs you will break anything.


The BMEP can go to around 3 to 4.5Mpa all day, when you have detonation there is a spike in BMEP which can send the pressure in the chamber from the peak of about 20 to 26 Mpa to well over 80 to 100 Mpa !!!

This will break anything, seals/Dowels/rotors.

Correct fuel, right tunning and stay within normal operating conditions of the engine and you will never need to dowel your engine....

This is the hard data, no guesses, or opinions...I have run dowelled and run non dowled. I worked as a machinist and know how hard it is to make these things accuratley (it is near impossible!) half the extra ones you put in end up doing nothing because they take no load due to incorrect clearances and infact all you end up doing is weakining the endplates and rotor housings. I have seen these crack in the "extra" dowel area.

Repeat after me, there is no need for extra dowles...unless of course you like to waste money on mods you do not need. If this is the case then I can do that machining job for you :)
Drop me an email.

Regards.

This info just made my day. I have always been a little bit concerned that my engine was not dowelled and I have heard so many conflicting views on it. Now I can forget about ever getting it done. That is if RICE RACING knows what he is talking about. ;)

Same goes for me. It's always nice to have someone else to the hard research work to make you look smart in front of your friends when your car makes 500 HP and doesn't blow up.:rolleyes:

Rice just saved me a few hundred bucks:D

Thanks mate

Luis

apparently you do not understand the benefits of doweling

It has nothing to do with the strength of the "plates"

It's to prevent the rotorhousing from "walking" out (warping) due to extreme pressures from the combustion, this occurs around 18-19psi and has been observed, tested, and documented since the 80's- its not new

It would never happen at a manifold pressure point it would happen at a HP / TQ point. Different turbos are making different power at the same boost levels.

What kind of documentation do you have that dowelling is needed?

it would happen at a specific cylinder pressure....has nothing to do with power, has everything to do with intake pressure, temperature, and ignition timing

Many rotary engine builders have been figuring this out over time, for a street car running 93 octane, stock (conservative) timing, and 18-19psi with 115-120F intake temps, this will be the type of cylinder pressure that will cause some distortion

i would go the extra mile and dowel the engine

My friend,
I have "stopped" trying to convince ( educate ) people on this subject.
It is to no avail.
I have been witness to stories told, in full testimony and even proclamations of actually seeing the phenominum of a Turbocharged Rotary engine having "TWISTED" IN THEIR OWN PRESENCE" while at full power IN A CAR, and actually seeing this, before craking a steel plate. And that they "solved" the problem by Dowling the engine.
WOW, there is no end to the human mind and it's imagination... Analysi, Experience, Testing and Reasoning, will not overcome RUMORS & HEERSAY of fanatic worshipers of Local Rotary Drag Gods. !!
I totaly and analyticaly agree with You. ........
But, better You than me.
I have actually lost contact & friendships of coligues over this issue.
NO USE TRYING, You'll live better by taking their $$, and keeping you're knowledge private.
You can take a horse to a river of water, BUT You CAN'T make him drink it !!!

I used to ask people that experienced this problem 2 questions ?
1) Did the engine STILL run after cracking the steel plate ? ans. YES........
2) Where the ApeX Seals still good, in one piece after the oil mess ? ans. Yes....

Then how do You explain the twisting of an engine, by severe cobustion presure, literally forcing the Rotor Housing to "walk" and distort to the point of braking a THICK CAST IRON plate, and not damaging the weakest part of the engine which is the Apex seal. ??
I don't know, maybe those guys posses a "higher" level of mechanical knowhow than the education I paid for while going through Mech. engeneering school.
If the "TUNING" is NOT correct, no amount of Dowling or Super advanced, Extraterrestial metalurgy, or elements, will live under the BMEP of "Un-Controled Detonation" from an internal cobustion engine... Rotary or Otherwise... PERIOD.

Better results (Documented) have been achieved by Pros. by allowing a little "give" in areas where BMEP is Hi, resulting in less breackage of parts than w/ Pinning or Dowling.
But then again,
What do I know ????????????

GT1-20b

Avenge 13B 8.15 @ 164MPH............. How much HP you think he's making?

http://users.tpg.com.au/users/bsmc/PFtop20drag.htm

Read his post

http://ausrotary.dntinternet.com/for...=16792&start=0

Grant Williams 13B 7.81 @ 175mph "NON" Dowelled!!!!!

http://ausrotary.dntinternet.com/for...grant+dowelled

[QUOTE=RICE RACING]In a 13B over 1000bhp...you will not crack the plate.

If detonation occurs you will break anything.


Sorry for the repeat, Don't know what happened.

Oh, and one last thought, a 700+ Hp 4 Rotor LeMans engine block which is literally "3 FEET" long, actually 34 inches long does NOT use extra Doewels.

3 Feet long, that's twice as long as a 13b. with 4 extra structural parts, 8 more Original Dowels, 16 inches longer, and not to mention, 2 extra pieces of Ecentric shaft for good measure.
Lets not forget the 2 extra "Twisting" Rotors and ALL the associated seals...

I don't know ?? ...How many extra Dowels did Mazda NOT tell us about while in route to winning Le Mans ?

^ you win, and your my hero

As it was explained to me by a friend, who is making close to 700rwhp in his car, that dowell pinning is not necessary if you have excellent tuning skills. It is all in the tuning. But for those of us that don't have great tuning skills the extra dowels do offer a slight margin of error so to say. But a very harsh misfire, preignition or detonation wil blow anything up. Whether it be dowelled or have a full stud kit it is going to blow. If the housings don't give then your rotors will collapse. My motor is pinned simply because I wanted extra security, that and it was done for free for me, but once I figure out the tuning aspect of these motors I won't have to pin them. Take it with a grain of salt but I'm with RICERACING on this one.

okay, just to clarify, the dowel pins are NOT a structural element in the form of preventing the "stack" from flexing

it has been observed and documented that the rotor housing will warp away from the combustion area, only in the specific spot below the leading plug and the next dowel pin....this is the area that is reinforced......

if you are under the impression the use of dowel pins is to prevent flexing, you are wrong, and that scares me

and n/a motors are not under the same cylinder pressures as forced induction, which is what I am describing necessitates dowel pinning- and yes the dowel pin count on the R26B and the 13G are both higher

I just did this!
Running 23 PSI on a T72 with 11.4:1 AFR and meth injection.
Cracked my rear iron and continued to pull hard until I realized I was losing oil.
Came to a stop and the car continued to run. A sure sign I still had good compression.

so if you dowel pin a motor and you ruin a housing do you need the rest of the motor to prep a new housing to handle the dowel pins? with such tight clearances it seems you would.