Justa bought a 89 rx7 vert. The car has got 170k miles on it, and its hard to say how much the engine has got, or if it has ever been rebuilt or changed, but it feels a bit "tired"

Last night we did a compression test, and we got 7.0bar (101.5 psi) on each side of the front rotor, and 6.5bar (94,25 psi) on each side of the rear.(meassured with modified piston comp gauge)

We tested it with both the leading plugs removed, warmed up engine and with full throttle.The engine rpm during cranking was 200-230rpm.

The engine is a s5 na with 9.7:1 comp btw.

What compression pressure can be expected on an fresh rebuilt engine after its broken in?

and what is the minimum recomanded pressure (time to rebuild pressure)?

I have been searching every where, but I cant find any numbers for the s5 9.7:1 comp engine.

I have only found for the turbo2...

What do you think, time for a master rebuild or not?

There is a tiny coolant leak,so during 1 month daily use it "drinks" just under 1 liter coolant. have to top up the coolant every 3-4day.

I suspect its in the early stages of waterseal failure,

Any help appreciate



Cheers

Ronny

 

Sounds like it's quite healthy for the mileage. If it's feeling weak, I'd look towards other things, like auxiliary port actuation, clogged exhaust, dirty air filter, or just the fact that it's a heavy-*** convertible.

 

@170k i'm sure it could use fresh side seals, and stuff.



i had one that had a mystery water leak like that, it turned out to be the water pump, it didnt leak when the car wasn't running, i had to run it in the garage for a while and leave it sitting before i could find a water leak. it was a lot harder to finger out than you'd think a water pump would be...

 

Call me at 253-735-9590 to better access your issues and what options to get them fixed.

 

Well,my suspicion was right.

I pressurised my coolant system with 0.6bar over the night, and when I started it up, it only ran on the front chamber for 15-20 sec. before the rear chamber started to ignite..

I have decided to get a "master rebuild kit" from Rotary Aviation and do a full rebuild,

Anyone got any experience with the new "RA 2mm Super Seals",or know if they are softer on the rotorhousings than the old RA seal?

I am going to streetport the ex. ports, and use T2 exhaust inserts,It will also get a garrett gt3540 with a/r0.84 ex. housing.

I will keep the stock na rotors, and set it up for running E85.

My goal is to get around 300-400rwhp without sacrifiseing to much "user friendlines" and fuel milage.

Any toughts or ideas that could help me get there, is appreciated.

Anyone got a clue how high the comp. pressure on a fresh S5 na should be, or the highest pressure that is messured?



Cheers

Ronny