Jump to content
SAU Community

Recommended Posts

hey guys my sr20det had a compression test done.... now apparently it dropped 50psi between cylindrs 1 & 2 im not sure of figures but assuming 150 to 100!

now my engine is in perfect running order, doesnt loose one drop of oil in 5000ks, doesnt blow any other smoke out the exhaust, other then black fuel! she drives like a dream and pulls really good power for its mods! iv never had an idle problem, starting problem or anything meachanically really, i was assuming the compression would come up trumps as i knew it was an a1 engine!!

now what the hell could be wrong with it, im sure its not piston rings at 50 psi loss!! is there anything else that would give me compression loss of that severity with no symptoms whats so ever!!!! any operator error taht could have caused this? i.s. mechanic was a nuffnuff???

help would REALLY be appreciated! and i will get a second opinion asap!!

danny

yeah i know but im still worried that there is a problem now, should i take it easy, should i not run 1 bar etc? i just dont want it to go "bang" what other problems could it be... valve seals? (is there still oil loss with these?

and i wlways thought that with a 50 psi difference there woyld be some serious symptoms?? is this right?

UPDATED

i got the compression test re-done this afternoon, now the results are much better but i thnk thier all a little low!

cyld 1 128

cyld 2 125 *took a little longer to reach this figure, compared to the other ones**

cyld 3 128

cyld 4 128

these seem quite low to me, the car was at temp, and the throttle was fully open, cylinder 2 took a little longer to get to its figure to!! and i didnt disconnect the ignition either, would this give me low figures, and battery was struggling??? i dont know if these low figures are of a concern? anyone, im just now glad that there isnt a 50 psi diff betw 1&2

cheers guys

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


  • Similar Content

  • Latest Posts

    • From my youth: GTi-R clutch change is a massive pain. The gearboxes are fragile? But the car is super cool and I want one 😢 
    • Remember this is 1988 tech.
    • Driveline vibration is resolved. I ended up loosening all my engine mount and trans mount bolts, giving it a good shake then retightening everything and it's gone... Let's just say I was surprised that fixed it.  I've been happily driving it around again but unfortunately put zero time into my direct port/constant pressure WMI setup. I'm on vacation next week, so I'll try and finalize it then.  On a different note, I spent all week fuel/ignition mapping 2x 216L V16 engines. Turbo's were burning glycol and we swapped them out for larger units. We also had planned emissions testing on site, so I figured I'd be there the same week to use their instrumentation and massage any emissions issues out if needed. This was a first for me. Fuel management is similar in certain ways to automotive (i.e air density as load variable) but very different in others. It's all PLC based and AFR's are controlled by air and not fuel. They use a control valve between the turbo and air manifold to control pressure which in turn controls AFR's. Due to this, target AFR tables supplied by the OEM are in pressures and not mass which really through me off. They use air pressure vs fuel pressure tables. I also relied on an O2 concentration sensor the emissions team had in the exhaust. Ignition timing was also all over the place and we were losing a fair bit of power. They're now happily sitting at 16-40BTDC depending on load. We were making about 1600kw at 900rpm at 90% load. Engines were running a lot smoother as well.    
    • heh, aint no R32 ever meeting modern targa cage rules unless the driver is veeeery short OP, good luck with the sale, since its already in the land of freedom I'm sure you will find a good buyer.
    • meh, it was a good video, clear about the issue and how he dealt with it. A bit heavy on the RTV and very brave to put an RB in anything without rebuilding it first, but otherwise I thought it was good Dose, I'm not sure that having the pickup forward is a big issue; yes of course the oil could shift under brakes but the sump should never be empty enough for that to be a problem (unless you also have a higher volume oil pump, and that oil can't return from the head to the sump quickly enough)
×
×
  • Create New...