satch

iTrader: (1)

Sorry to hear about your mishap. At least we know you are an animal lover (the best kind). W/respect to the RX7, try adding some oil into the housings to build compression to see if that helps things along.

driftxsequence

iTrader: (8)

Are you using the proper injectors impedance / relay pack?

alritzer

Yes, the 7 started up the first time I tried after the rebuild. It ran pretty good and was idling at about 2000 rpms for about 35 minutes and then just shut off. It didn't sound like it had run out of gas but more like the key had been turned off.

Its pretty cold here today, about 25 right now, but we plan on starting to look for the correct voltages at the ecu.

alritzer

We haven't worked on the 7 much lately. We don't think there is anything else to check. Must have been something internal although both rotors have compression.
I was about to give up on it and part her out but I found an S4 NA engine complete with 85K on it for $100. Really, complete engine (that runs)and auto transmission for $100. There is a story with it but I don't want to bore anybody.
We have spent so much time and money on this 7 that everybody now calls her project "Angie". The current engine is an S5 T2 but I think some things swap over from S4 NA. YES / NO?

As soon as it warms up a bit (it's 6 degrees here), we are going to pull the engine again, slowly disassemble it and look for mechanical failure.


ashley

SpikeDerailed

iTrader: (7)

If you're going to throw in a s4 engine into your car you're going to need a S4 tii flywheel to keep everything balanced.

alritzer

Hi guys, I finally made time to get the compression check on the 7. The first video is the front rotor and the second is the rear.
This engine ran for 35 minutes after being rebuilt, The rebuilt was done with all new soft parts and the rotors and housing were used.

Take a look at the videos and let me know what you think.

ashley

SpikeDerailed

iTrader: (7)

On both housings youre getting two weak and one strong pulse, apex or corner seal sealing issue i would think. Only soft seals replaced not hard seals or springs? Maybe flattened/worn springs were reused.

alritzer

Thanks for the input. The only things not replaced were the iron, rotors and housings. All seals and springs were replaced.
Wonder why both rotors have about the same compression after 35 minutes?
Center housing maybe????

lduley

iTrader: (1)

Doubtful, unless no measuring was done of the irons and housings?

arad99

iTrader: (2)

All irons and housings were within specs.

I'm not sure how both rotors would fail at the same time at idle.

lduley

iTrader: (1)

Stranger things have happened

SpikeDerailed

iTrader: (7)

The fact that you have 1 considerably stronger pulse on each rotor would make me think the irons and housings are in ok shape.

arad99

iTrader: (2)

Both of the rotors were pinched by an unknown object. All 6 apex seals are intact and I think only 1 housing was damaged and it might be reusable.
I didn't find anything in the housings that should not have been there.
I'll get a pic of the housing to see what you guys think about its condition.

lduley

iTrader: (1)

Those rotors look trashed

arad99

iTrader: (2)

Your right, I'll have to replace them.

Any ideas what could have damaged both rotors? The last rebuild we did last spring, one rotor was damaged similar to these two but everybody pretty much thought the same thing: that a washer had been dropped into the LIM during final assembly.
How do both rotors get damaged? Plus, the engine ran really good for 35 minutes.

rx7racerca

iTrader: (1)

It's a pretty good bet the lost washer got ingested - that would easily account for the damage to either rotor; the second is harder, unless there was a second foreign object, or if it somehow managed to exit the first, and possible get sucked back in the second. I'm not sure how plausible that is, in terms of port timing and there being any negative pressure at the exhaust port somewhere during the cycle, but doesn't seem impossible based on what I know of piston engines - early 2.5L Nissans in the SE-Rs were prone to valve and cylinder damage through the upstream cat core breaking up, and bits being sucked back into the engine. Your "large street port" from your sig makes me think that could be more likely, since that would increase the intake/exhaust overlap.

arad99

iTrader: (2)

The LIM has only 1 open water port but the housing has two open water ports.
The pictures might show what I mean.
Is this correct?

cone_crushr

iTrader: (18)

Yeah, looks fine, thats the turbo coolant supply port, check on the outside of the LIM to see the coolant line. Optionally, you can install a freeze plug in the front rotor housing (using RTV), that way the oring at the LIM flange won't leak over time.

arad99

iTrader: (2)

Thanks for the input. I wasn't sure.
Both ports had an o-ring installed. Should the front port have an o-ring installed?

SpikeDerailed

iTrader: (7)

Yes there should be an o-ring for both rotor housings.

RXSpeed16

iTrader: (41)

I just pulled my intake because it was leaking from that front coolant passage. It was a lot of work to fix something that doesn't really have a purpose.
I opted to install the freeze plug in the front housing instead of another oem o-ring. And the freeze plug was cheaper.

SpikeDerailed

iTrader: (7)

Do you remember what sized freeze plug you used? Im going to be pulling my intake off in a month or so and I would like to do the same.

RXSpeed16

iTrader: (41)

20mm. NAPA #381-2151 for under $2.
https://www.rx7club.com/1st-generati...intake-990704/