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-   -   F and R housing Question... (https://www.rx7club.com/general-rotary-tech-support-11/f-r-housing-question-858438/)

J's fc 08-19-09 06:49 PM

F and R housing Question...
 
Will the engine be affected if you got the housing irons backwards? Would it affect the Psi?

djseven 08-20-09 08:34 AM

You mean if you swapped the front and rear ROTOR housings? No, compression would not be effected.

J's fc 08-21-09 03:53 PM

Would incorrectly installed apsex seal springs cause low psi numbers?

FelixIsGod29X 08-21-09 05:38 PM


Originally Posted by J's fc (Post 9443375)
Would incorrectly installed apsex seal springs cause low psi numbers?

I would assume so....

kenn_chan 08-21-09 06:40 PM


Originally Posted by J's fc (Post 9443375)
Would incorrectly installed apsex seal springs cause low psi numbers?

define incorrectly installed..options are
improper clearance of any of the seals especially corner to side causes low cranking compression. not such a big deal if you get it running, but hard to start

after that correct springs for given apex seal? thats about all you can fuck up on it.

kenn

J's fc 08-22-09 01:28 AM


Originally Posted by kenn_chan (Post 9443742)
define incorrectly installed..options are
improper clearance of any of the seals especially corner to side causes low cranking compression. not such a big deal if you get it running, but hard to start

after that correct springs for given apex seal? thats about all you can fuck up on it.

kenn

these are my psi numbers Front #1 rotor on the leading 75psi using 5w30 and on the rear rotor #2 leading 65psi... i rebuild my engine cuz i got a blown rear oil seal and it was smoking...(note im using the same apex seal springs i just changed the oils seals and the coolant seals, and i ported the exhaust)

would the apex seal springs be incorrectly installed even tho i get these psi numbers?

yea i was having problems starting it.... i

WaachBack 08-28-09 04:59 PM


Originally Posted by kenn_chan (Post 9443742)
define incorrectly installed..options are
improper clearance of any of the seals especially corner to side causes low cranking compression. not such a big deal if you get it running, but hard to start

after that correct springs for given apex seal? thats about all you can fuck up on it.

kenn


So as long as you can get it started, there should not be a significant horsepower loss as comparded to a motor with 110psi starting compression?

kenn_chan 08-30-09 05:27 AM


Originally Posted by J's fc (Post 9444331)
these are my psi numbers Front #1 rotor on the leading 75psi using 5w30 and on the rear rotor #2 leading 65psi... i rebuild my engine cuz i got a blown rear oil seal and it was smoking...(note im using the same apex seal springs i just changed the oils seals and the coolant seals, and i ported the exhaust)

would the apex seal springs be incorrectly installed even tho i get these psi numbers?

yea i was having problems starting it.... i

Yes this can casue issues, since you did not replace them, only resue they are individually clearanced for each position so if you reinstalled them in the inccorect location your cranking compression is going to be low possibly enought to keep it from starting.

65 or 70 psi WITH oil added into combusitn chamber is extrememly low and doubtful if it will make any real HP. how are you getting a compression reading? with a piston compression guage? do you have the gas pedal depressed fully? what is your cranking RPM.

try this, do the test with a
1. fully charged battery,
2. no extra oil in the houseings,
3. gas pedal depressed
schrader valve removed from the end of the compressin guage (the one in the hose end that hold the compressed air in the guage)(not the release one on the outside)

and this:
video tape the compresion gauge
and the tach

I know its not exact but you might be able to see the cranking rpm and you can see the actual compression by watching the compression gauge in slo mo or still frame. PM me the numbers after you do this.


Originally Posted by WaachBack (Post 9459106)
So as long as you can get it started, there should not be a significant horsepower loss as comparded to a motor with 110psi starting compression?

no the amount of leak down you get is dependant upon the clearancing of the seals, just like the rings in a piston motor so it will ultimately affect your horsepower, how much depends on a lot of things.

for example (I have not measured this, just making numbers up so that I can explain this) on a NA 12a that stock makes 100 hp with clearancing issues you might only lose 10 or hp now that is about 10% of your total 10 hp quite a bit.

But when compared to a 13b thats turbocharged, ported, and running 1.4 bar of boost it might lose 40 hp now is that a lot? it depends upon your application either is enough of a loss that I would be concerned but for the guy who is only making 100 hp and useing it as a daily driver that 10% is a big deal as thing only makes a 100 hp to start with, the guy who is maing 350is (vice the 400ish he should be making) might not even notice (unless he had had it running properly at 400 before) even then unless he dyno's it or is running it every day at WOT he might not even notice.

so its does make a differance, just how much is applicatin dependant.

kenn


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