Jump to content
SAU Community

Recommended Posts

  • Replies 68
  • Created
  • Last Reply

Top Posters In This Topic

Due to the absolute precision manufacture of rings these days, most of them are almost bed in before you even start the engine. Bearings will knock off the high spots but apart from that your run in can be done in as little as 10 minutes just to put the engine under load and cut the rings in. The varying revs is usually a good idea too but not always necessary. Every engine is different and every ring is different.

If the tuner is competent, he should hear detonation before it becomes a problem and should see things much sooner.

  On 26/09/2012 at 6:56 AM, bubbabooga said:

Okay first up I previously had a built 25/30 running 356kw using the same head and custom intake manifold.

Only changes this build were to the oiling system, 0.5 higher comp ratio, total seal rings, cam change from 232 duration 6.5mm lift cams to 262/9.1mm with appropriate springs and port tidy up and match the intake manifold ports.

Now I had discussed with the tuner I only wanted it ran off spring pressure in the wastegate so I can learn to drive it at that power level First, made it very clear I wanted a super safe tune and wasn't to concerened with the power level.

So he apparently he had it up and running, bedded the rings In on the dyno for around 10kays, changed out the mineral oil to redline oil ready to get into tunning.

Then he tells me he's ran it up for a power run without touching anything with the tune or boost, where it pulled only 320wkw on 21psi. Down considerably on the old setup and boosted well past where I wanted.

Now apparently Afr's were safe the whole time.

After fixing a small coolant leak the car wasn't idling right and had smoke pluming out of the catch can. Comp test revealed front 2 cylinders down around 50psi and the rest were at about 110psi (which I feel is extremely low for a brand new engine).

Now the engine builder and tuner are unsure of why this has happened but only suspects are the custom intake manifold which kinda points the throttle body towards cylinders 1-2.

I would post a pic of intake manifold but I'm posting from iPhone away at work.

But it's the intake manifold off dahtone racings old 2GUUp candy red r32 skyline.

Now I'm curious if anyone has had similar issues due to a plenum? And who should kind of be at fault here?

I'm far from happy so far!

Specs of the build as follows: rb25/30

Custom je pistons with total seal rings and spool rods, usual block and crank prep, nitto oil pump, lewis engines race sump, r32 rb25de non vct head, ported, springs, cam tech 264/9mm cams, custom intake manifold, sard 700cc injectors, twin entry rail, walbro lift pump, 044 feed pump, haltech e11v2 ecu with boost control. Twin scroll t04z, 0.8 rear housing, turbo smart 50mm gate.

Sorry about big post! Cheers all

The second line in your post explains it pretty obviously IMO.... 0.5 : 1 up in comp ratio, bigger/different cams and he does a FULL power run without even atleast putting 15-20% fuel trim into tune is asking for trouble!!! Surely they checked ignition timing before even starting the run-in....(but i bet they didnt) Also what was the comp in previous set-up? Engine builder must know...If i was you id do as Elite says about not being to raggy...But if they start trying to baffle you with BS i would be going for them to repair at they're expense..

  On 01/10/2012 at 7:46 PM, NoFigJamHere said:

The second line in your post explains it pretty obviously IMO.... 0.5 : 1 up in comp ratio, bigger/different cams and he does a FULL power run without even atleast putting 15-20% fuel trim into tune is asking for trouble!!! Surely they checked ignition timing before even starting the run-in....(but i bet they didnt) Also what was the comp in previous set-up? Engine builder must know...If i was you id do as Elite says about not being to raggy...But if they start trying to baffle you with BS i would be going for them to repair at they're expense..

This was my explanation for the failure as well.

Yeah was also just about the mention the same thing.

Especially with more comp how could you not wind things back a little before trying to squeeze numbers out of it??? If thats what really did happen then its careless on the tuners behalf. Would have most likely knocked its face off! Didnt you say they found signs of detonation?

Sucks dude I know your feeling.

Called up the tuner today but their still waiting on flow benching of the intake manifold which is with the engine builder, who unfortunately had his workshop broken into over the weekend with a shitload of tools and parts stolen.

That's what I would have thought the tuner would have done straight up to. Not too happy with his approach to it especially after I clearly specified I wanted to run no more than 16-17psi.

Previous cr was 8.2, this time around its up at 8.8 to 1.

I asked the tuner about wether a knock monitoring device was used on the run, he said yes of course and no worrying amount of knock was seen.

The waiting game continues..

Unrelated but I bought myself a turbo gsxr1000 to keep me occupied till this damn rb is sorted :D

Cheers guys! Appreciate the wise words.

  On 02/10/2012 at 7:57 PM, DVS JEZ said:

I love those words "no worrying amounts of knock". No knock is good knock

Even better is that he was actually looking for it!!! He couldn't "see" it????....... So how could it have been knocking... Must have had the head phones over his eyes!!! I dont want this comment to encourage you into confronting your tuner/builder guys but whats the point of flow bench testing the intake??? From what you have said ALL the cylinders have some degree of damage!!! As with just about any engine, 1 cylinder (rarely 2 go if your paying attention to what your doing) goes bad before the others... Your engine has low comp in ALL cylinders just because 2 are worse than the others just means those 2 were always going to be the ones to keep monitering when tuning... Just about every engine bar an F1 engine would have the excact same type of problem. Being a particular clyinder is most likely to be the 1 to fail...

  On 03/10/2012 at 2:59 AM, Dahtone Racing said:

There were no worrying levels of knock yet 1 and 2 had detonation damage??????

Scary to think what they classify as worrying knock.

Flow testing the intake is just the builder/tuner postponing the inevitable, which they both know is finding the real cause of the failure and deciding who's going to pick up the tab. It's not going to tell you anything, and it won't be the plennum at fault.

I would be asking to view the det damage personally through the scope, it's pretty easy to see as the crown of the piston will show signs straight away. If there's no det damage then the ring clearances were probably wrong, and you need to do a leak down on all cylinders. If it's a fairly well known tuner, then I doubt there to blame.

You need to get personally involved in finding the cause, otherwise your just going to get fed BS like flowing this intake.

  On 03/10/2012 at 5:13 AM, James_03 said:

Flow testing the intake is just the builder/tuner postponing the inevitable, which they both know is finding the real cause of the failure and deciding who's going to pick up the tab. It's not going to tell you anything, and it won't be the plennum at fault.

I would be asking to view the det damage personally through the scope, it's pretty easy to see as the crown of the piston will show signs straight away. If there's no det damage then the ring clearances were probably wrong, and you need to do a leak down on all cylinders. If it's a fairly well known tuner, then I doubt there to blame.

You need to get personally involved in finding the cause, otherwise your just going to get fed BS like flowing this intake.

That's a pretty bold statement. Have you seen the intake manifold to make that conclusion. Generally unless you've overheated the crown you won't notice detonation via a borescope. If you dont know what your looking for then get an independent failure report.

  On 03/10/2012 at 5:13 AM, James_03 said:

I would be asking to view the det damage personally through the scope, it's pretty easy to see as the crown of the piston will show signs straight away. If there's no det damage then the ring clearances were probably wrong.

How so?

  Quote
That's a pretty bold statement. Have you seen the intake manifold to make that conclusion. Generally unless you've overheated the crown you won't notice detonation via a borescope. If you dont know what your looking for then get an independent failure report.

Cmon dude, flowing the intake? It's a motor that now has low comp due to an internal failure. It's pointless, and even if it was the manifold, how would you link it to a failure like low comp? Doesn't make sense.

You should be able to see signs of det with a bore scope. Even if the crown has nothing, it has low comp which means rings, which means the bore will have drag marks all over it where the rings lands have failed.

When I said clearances I said probably, which means it may or may not be that. Just about every second failure I have seen has been either:

1. Incorrect ring clearances

2. Incorrect bearing clearances

I would put money on it being either of the above, pending it's a well known tuner, who of course ran it up himself.

  On 03/10/2012 at 9:07 AM, James_03 said:

Cmon dude, flowing the intake? It's a motor that now has low comp due to an internal failure. It's pointless, and even if it was the manifold, how would you link it to a failure like low comp? Doesn't make sense.

You should be able to see signs of det with a bore scope. Even if the crown has nothing, it has low comp which means rings, which means the bore will have drag marks all over it where the rings lands have failed.

When I said clearances I said probably, which means it may or may not be that. Just about every second failure I have seen has been either:

1. Incorrect ring clearances

2. Incorrect bearing clearances

I would put money on it being either of the above, pending it's a well known tuner, who of course ran it up himself.

If the manifold favors cylinders 1 and 2 then it is likely that these are the lean cylinders - which most likely means you've overheated(melted) a couple of pistons. Hence the comp will be low.

Has anybody noticed that he said the engine used to run fine with the old setup which had the same plenum?

Which IMO would mean the plenum is not the problem because obviously it was fine on the old engine nor was it a problem with my old engine.

So how could it all of a sudden be the cause of the failure?

You need to look at the things that have changed since the last build.

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



  • Latest Posts

    • From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
    • Place the new daughterboard in the case and mount it using the 3 small black rivets provided, and reconnect the 3 factory ribbon cables to the new board Then, use the 3 piggyback cables from the daughterboard into the factory board on top (there are stand offs in the case to keep them apart. and remember to reconnect the antenna and rear cover fan wires. 1 screw to hold the motherboard in place. Before closing the case, make a hole in the sticker covering a hole in the case and run the cable for the android unit into the plug there. The video forgot this step, so did I, so will you probably. Then redo the 4 screws on back, 2 each top and bottom, 3 each side and put the 2 brackets back on.....all ready to go and not that tricky really.      
    • Onto the android unit. You need to remove the top screen because there is a daughterboard to put inside the case. Each side vent pops out from clips; start at the bottom and carefully remove upwards (use a trim remover tool to avoid breaking anything). Then the lower screen and controls come out, 4 screws, a couple of clips (including 3 flimsy ones at the top) and 3 plugs on the rear. Then the upper screen, 4 screws and a bunch of plugs and she is out. From there, remove the mounting brackets (2 screws each), 4 screws on the rear, 2 screws top and bottom and 3 screws holding in the small plates on each side. When you remove the back cover (tight fit), watch out for the power cable for the fan, I removed it so I could put the back aside. The mainboard is held in by 1 screw in the middle, 1 aerial at the top and 3 ribbon cables. If you've ever done any laptop stuff the ribbon cables are OK to work with, just pop up the retainer and they slide out. If you are not familiar just grab a 12 year old from an iphone factory, they will know how it works The case should now look like this:
    • Switching the console was tricky. First there were 6 screws to remove, and also the little adapter loom and its screws had to come out. Also don't forget to remove the 2 screws holding the central locking receiver. Then there are 4 clips on either side....these were very tight in this case and needed careful persuading with a long flat screw driver....some force required but not enough to break them...this was probably the fiddliest part of the whole job. In my case I needed both the wiring loom and the central locking receiver module to swap across to the new one. That was it for the console, so "assembly is the reverse of disassembly"
    • But first....while I was there, I also swapped across the centre console box for the other style where the AV inputs don't intrude into the (very limited !) space.  Part# was 96926-4GA0A, 284H3-4GA0B, 284H3-4GA0A. (I've already swapped the top 12v socket for a USB bulkhead in this pic, it fit the hole without modification:) Comparison of the 2: Basically to do the console you need to remove the DS and PS side console trim (they slide up and back, held in by clips only) Then remove the back half of the console top trim with the cupholders, pops up, all clips again but be careful at the front as it is pretty flimsy. Then slide the shifter boot down, remove the spring clip, loose it forever somewhere in the car the pull the shift knob off. Remove the tiny plastic piece on DS near "P" and use something thin and long (most screwdrivers won't fit) to push down the interlock and put the shifter down in D for space. There is one screw at the front, then the shifter surround and ashtray lift up. There are 3 or 4 plugs underneath and it is off. Next is the rear cover of the centre console; you need to open the console lid, pop off the trim covering the lid hinge and undo the 2rd screw from the driver's side (the rest all need to come out later so you can do them all now and remove the lid) Then the rear cover unclips (6 clips), start at the top with a trim tool pulling backwards. Once it is off there are 2 screws facing rearwards to remove (need a short phillips for these) and you are done with the rear of the console. There are 4 plugs at the A/V box to unclip Then there are 2 screws at the front of the console, and 2 clips (pull up and back) and the console will come out.
×
×
  • Create New...