Jump to content
SAU Community

Rb26 Compression

Don Dada

By Don Dada,
in Engines & Forced Induction

 Share

Recommended Posts

Don Dada Mentor

Don Dada

Posted
Posted

Started a rb26 (R33) today "on the ground" from Japan.... Engine sounded good,revved out good, oil pressure was about 65psi when now started and went to 95psi or so when revved. Also was able to see about 10-11psi boost when revved hard,Is this too high for a stand still rev?

My main concern tho is after running the engine for about 5 mins i did a compression test with results as follows:

1--- 175

2--- 174

3--- 176

4--- 171

5--- 160

6--- 161

Now the R33 manual said the standard value is 170 psi and minimum vale was 128 psi with a variance between cylinders of 14psi

Are cylinders 1 2 3 too high? thus givin me a variance of 16psi across 3 & 5?

Probably with some running it will work in a little?

Don't know how long the engine was parked up for.

Also did a test on a running R33 RB26 (25 000km) as follows:

1--- 162

2--- 165

3--- 170

4--- 166

5--- 170

6--- 162

This looks a little more normal to me :)

What do u guys think about the first set of results?!?

Thanks.

Link to comment
https://www.sau.com.au/forums/topic/266524-rb26-compression/
Share on other sites
The Dan Grand Master

The Dan

Posted
Posted
Started a rb26 (R33) today "on the ground" from Japan.... Engine sounded good,revved out good, oil pressure was about 65psi when now started and went to 95psi or so when revved. Also was able to see about 10-11psi boost when revved hard,Is this too high for a stand still rev?

My main concern tho is after running the engine for about 5 mins i did a compression test with results as follows:

1--- 175

2--- 174

3--- 176

4--- 171

5--- 160

6--- 161

Now the R33 manual said the standard value is 170 psi and minimum vale was 128 psi with a variance between cylinders of 14psi

Are cylinders 1 2 3 too high? thus givin me a variance of 16psi across 3 & 5?

Probably with some running it will work in a little?

Don't know how long the engine was parked up for.

Also did a test on a running R33 RB26 (25 000km) as follows:

1--- 162

2--- 165

3--- 170

4--- 166

5--- 170

6--- 162

This looks a little more normal to me :)

What do u guys think about the first set of results?!?

Thanks.

I'd make a few suggestions.

1. You are worrying about it too much

2. Your compression gauge is not that acurate to tell you 176 it would be 175.

3. If it's straight off the boat and has made the trip over, chances are the battery is not too crash hot, and if you didn't use a really good jump pack for the test then the battery is likely to be getting tired by 5 and 6 anyway.

4. Did you keep the throttle open while cranking during the test?

Don Dada Mentor

Don Dada

Posted
  • Author
Posted

If u know the price we pay 4 a Rb26 on this side of globe u would worry too!

Its the same gauge i used 4 all 6 cylinders so i would expect some kind of consistency.

The engine was started outside of a car "on the ground" using a battery from a working vehicle and i actually thought it was getting tired too, so replaced it with another batt from another vehicle to test 5 & 6 and got the same results.

Yes had the throttle open.

Don Dada Mentor

Don Dada

Posted
  • Author
Posted
i would not worry about it. the engine is fine. make sure you use GOOD oil. Motul 300v chrono if you want the engine to last.

btw make sure you dont ping this one :)

I use Redline oils engine/gearbox/diff so i should be good to go.

Don"t think i'll be experimenting too much with this one tho....just 14psi and drive :)

On that note what do u think about using a SAFC2 to "tune" it a little at the 14psi??? since i already have it.

Guilt-Toy Grand Master

Guilt-Toy

Posted
Posted
I use Redline oils engine/gearbox/diff so i should be good to go.

Don"t think i'll be experimenting too much with this one tho....just 14psi and drive :)

On that note what do u think about using a SAFC2 to "tune" it a little at the 14psi??? since i already have it.

DO NOT TOUCH IT. chuck the safc2 in the bin. the rb26 computer will be more then capable of running the engine with heaps more power then what you were used to.

enjoy the motor, it will be good. don't destroy it like our 300kw stagea kid in the other thread lol

90% of engine failures are from the user.

Guilt-Toy Grand Master

Guilt-Toy

Posted
Posted
Geeze.... just askin :)

Never seen anyone here use a SAFC2 on a Rb26 and i sure was'nt going to be the first!......

So 14psi good?

put the engine in and run it on no more then 10psi to start with. make sure everything is running fine. run no more then 13psi and you should be fine.

i also suggest putting a afr meter on it and checking the afr's

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • dbm7
      R34 Skyline climate control unit transistor

      By dbm7 · Posted

      That's not a transistor --- it's marked ZD1 which makes it a zener diode. As to what the breakdown voltage is, not enough there to divine.
    • bilbo117
      R34 GTR Seats / No longer reclining

      By bilbo117 · Posted

      Hi all, Long time since I've posted here. Looking for some advice on what I can remove to further identify the cause of my issues.  I can move the passenger seat forward and back but the knob used to adjust the seat angle is pretty much free spinning, there's very little resistance.  Removing the side cover I can see that the chain is intact but the shaft for the adjustment spins without the gear attached to it moving.  What's my next step for disassembly here? Is this a common fault? Just being a little cautious as I didn't want to start removing bolts for a spring to fly out or something equally as stupid.  Cheers
    • joshuaho96
      Ethanol Content Sensor - Always at 11%?

      By joshuaho96 · Posted

      The incentives are mostly the same, yes. Ethanol is cheap compared to the cost of doing 98-100 RON with crude oil alone. 87 to 93-94 AKI all with E10. In 2020 Canada mandated E10 as a part of their "renewable fuel standard" and is supposedly going to go to E15 in 2030. In California where there are only 8 refineries with two threatening to shut down next year it's been over 20 years now of E10 and 91 AKI maximum because there's just not enough refinery capacity or crude oil supply relative to the demand for premium unleaded fuel. And CARB's low carbon fuel standard means functionally none of the diesel available at the pump is made from crude oil anymore. It's almost all entirely 20% biodiesel blended with 80% renewable diesel (hydrotreated vegetable oil) now. The number of gasoline vehicles that support E15 or higher ethanol concentrations is surprisingly low, I can't imagine it being wise to play tricks like this without flex fuel sensors in most of the fleet.
    • GTSBoy
      R34 Skyline climate control unit transistor

      By GTSBoy · Posted

      It's almost certainly the same as the one next to it. Have a fish around amongst these hits https://www.google.com/search?q=surface+mount+transistor+m33&sca_esv=9cb49794e0b2005d&source=hp&ei=2vJ5aNjTB7Kw0PEPldnS8QM&iflsig=AOw8s4IAAAAAaHoA6qkfmF6XcygtrZ4Vu9f92NXF_RFd&ved=0ahUKEwjYqIPP7MWOAxUyGDQIHZWsND4Q4dUDCA8&uact=5&oq=surface+mount+transistor+m33&gs_lp=Egdnd3Mtd2l6IhxzdXJmYWNlIG1vdW50IHRyYW5zaXN0b3IgbTMzMgUQIRigATIFECEYoAEyBRAhGKABMgUQIRigAUjKCFAAWABwAHgAkAEAmAHfAaAB3wGqAQMyLTG4AQPIAQD4AQL4AQGYAgGgAuYBmAMAkgcDMi0xoAfMBLIHAzItMbgH5gHCBwMyLTHIBwU&sclient=gws-wiz
    • GTSBoy
      Blue slip

      By GTSBoy · Posted

      South Australia, which is hardly as far behind as the rest pf Oz makes out, and who is also not a paragon of progressiveness (read that as over-legislation) in the area of vehicle standards, has this to say on the subject: Adjustable coil-over suspension Aftermarket adjustable coil-over suspension components are suspension units that incorporate an external thread on the main body and corresponding threaded spring saddle that allows the vehicle's suspension height to be varied. If fitting aftermarket or coil-over suspension components you must submit an Application to modify a light motor vehicle form and a report from a light vehicle engineering signatory (LVES).
×
×
  • Create New...