Efini

I keep hearing quotes of 800cc from people about the size of the dark blue 12a turbo injectors. They are part number 195500-0610, now according to what I have read, this is the part number for the Denso 660cc injector. I understand that there are a number of factors that can affect the cc rating of an injector like duty cycle and fuel pressure but that difference seems a little crazy, or perhaps the 12aT were running some insane fuel pressure? Does anyone have any info that may shed any light on this anomally, also has anyone ever compared their flow to the injectors of a 13B NA Cosmo, these are quoted between 680-720cc and according to the 195500-0830 part number they are the 720cc injector. I am about to compare some tomorrow but I will not know the flow in cc terms, just which one fills faster at a given setting. Now, if I am right the 12aT injectors will flow less than the 13B Cosmo injectors. Any ideas?

hondah8er

The 12at are 800 cc and will flow more than the cosmo injectors.

Efini

Flowed the 0830 and 0610 together, surprisingly there was only a few percent difference.

hondah8er, what experience have you had with them? Have you flowed them or are you quoting a figure from somewhere and if so where? If you've flowed them what pressure and duty was it at?

I looked at a table and it says 195500-0610 is the part number for the 660cc injector, I have also seen another reference to the same part number being for 660cc. I have only ever heard that the 195500-0610 injector is 800cc from rotary owners, could this be because the 12aT ran high fuel pressure? Does anyone know what fuel pressure they ran?

hondah8er

Just stating what I know. BTW I've never heard of 660 injectors in rx7's. The closest would be 680 out of an 85 SE.

Efini

Yes they are the 195500-0830 injector. They were rated at only 680cc in the Mazda application because of the lower fuel pressure. That's why I am wondering if the 12aT ran high fuel pressure, it could account for the 800cc depending on what the fuel pressure is. As soon as I know the fuel pressures I can put some light into the picture. Does anyone know what pressure the 12aT ran?

kuhlrx7

from what I understand there were two differant injectors ran in the 12a turbo rx7s the first or early turbo ones were 800cc and the latter ones were 880cc injectors there are several sits that call out both these sizes. I have also heard that the part numbers you mention were crosed at nippon and there is a differant # for the ones that are for the 12at. they are deff 800cc or more I had some a while back tested at rc and at 45lbs they flowed close to 860cc

Efini

Are you sure it was 45lb?

I finally got the injector cc rated, it rated 720cc at 3 bar, it is out of a Cosmo and has the part number 195500-0830.

As for the 12aT injectors, I had some of these too and they flowed about 2-3% less than those 720cc injectors, that means they are the 660cc injector.

720/660 = 3% ??? here's why...on the charts:

660cc injector is 660cc at 2.5 bar
720cc is 720cc at 2.85 bar BUT 680cc at 2.5 bar
680cc/660cc is +3%

2-3% is about what we got when comparing relative flows too, so the charts support our testing AND the part numbers support the testing.

How on earth anyone got anything else at 3 bar is completely beyond me.

Now, in case anyone is wondering if these calculations were wrong, other injectors were tested the exact same same way and they gave the expected results for their part numbers too. I think someone just read the 0830 number and decided it meant cc.

kuhlrx7

look at hitmans site. I also found several sites from aussy and nz and also japan that have info on 12at injectors and its 800 cc for the small ones and 850cc not 880cc for the large ones the mazda part # is the one you have not the nipon # call them they should be able to get you the corect one. and I am sure that the ones I sent out where tested at 45lbs and flowed 860cc. I do not know what presure the fuel was set at on the 12at rx7. if you go to the aussy forum some one there should be able to anser your questions or use a translater and go to some of the sites from japan. theres also a site from england that has a complete write up on the 12at rx7s including specs and differances between the 83-85 model years last time I found the site was a week ago so I will try to find it agin and send you the link.

Efini

The problem is many of these sites could easily be relying on numbers from other sites. Most the info for injectors I have found on the web is copied and pasted from the same source.

195500-0830 (12aT) and 195500-0610 (Cosmo) are both NipponDenso part numbers for 660cc and 720cc respectively, those part numbers are written on the injectors themselves. The flow test results I got are in line with documentation on these NipponDenso part numbers.

The differences could easily be due to a combination of different test duty cycles, test voltages or even fluid viscousities. The test settings my injectors were done at gives correct results for other injectors when cross checking with other sized injectors and their documentation, so the test procedure was correct.

What was the part number on your injectors? They may have been a different part number.

Let me know when you find those links.

RotorMotorDriver

iTrader: (1)

Just to throw another number in the mix, Ive heard of 1000cc 12AT injectors... The place in Austrailia that Ive been talking to about getting a 13BT engine setup from said they use the 1000cc 12AT injectors. I dont know if those are modified 12AT injectors, or stock, but I just thought Id throw it out there.

~T.J.

kuhlrx7

tj the 1000cc injectors are modded. I know the place you are talking about. efini I don't know if its the black outs but I cant get hardly any sites to come up from aussy or japan. as for the part # that was on my injectors I dont have it. I sent all the documents out with the injectors when I sold them. I know the number did not match the one nipon denzo had on their site at the time. thats why I sent them out and had them tested. there was a link from 3 rotor.com that had the complete story about the size of the injectors and the part # cross refferanced from someone restoring a 12at rx7 I will keep tring though. anybody know why hitmans site and 3rotor.com is down right now? as well as most of the rotary sites downunder? and a lot of the sites are done the cut and past way. makes misinformation a bitch to get to true facts. it sucks

RotorMotorDriver

iTrader: (1)

Well, good to know that it didnt confuse you too much then . And its also good to know that theyre modded .

~T.J.

Efini

I think that virus that's going around may have something to do with it, power cut wouldn't have helped either. Yeah, look forward to getting that info, thanks.

hornbm

When you find the link could you post it? I'd be interested in seeing this site as well.

laundryhamperman

iTrader: (3)

Has there been any resolution to this?

I bought a 12aT and I'm looking for as much reference material as possible.

steve84GS TII

12AT injectors would definately be the ones to mod,if you had a need for 1000cc injectors.Never heard of them being 1000cc stock,up until now Id only heard about them being 800's in the 12AT.But since we never got that engine here,Im sure only a select few are truely experts on the 12AT.

In my secondaries,Im running S5 TII injectors that are modded to flow 800cc. RC Engineering did them for me a few years ago.I believe they said that most injectors can be opened up to flow 30-40% more fuel than stock.Of course thats also dependant on pressure.....