Fresh Twin Cam 30 Gone Pop During Run In :(

[bubbabooga]

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

[sky30]

I doubt manifold would lean out 1and 2 if its a front facing plenum the usually lean the rear cylinders.

Post Pic of plenum

[bubbabooga]

https://m.facebook.com/dahtoneracing?refid=9#!/photo.php?fbid=1174491395851&id=1035030725&set=a.1174487315749.26782.1035030725&__user=553976899

I can't post a direct pic from iPhone sorry. Here is a link tho.

I have that entire top end, head plenum injectors rail throttle body.

[Kenna802]

Mate This will be a story with no happy ending. Workshops are very forward stating if the motor pops on the dyno they not at fault. If they monitored the runs right they could show you that the AFRs where safe but i suspect they wont.

[abr33]

Im not 100% sure but doesnt the dyno computer usually save every run's afr's, boost, revs, power etc? They should be able to show you??

[bubbabooga]

I'm away at work at the moment which makes this whole situation shit, I'm back on Monday morning and going straight to the tuners to demand to see the dyno read outs

[bubbabooga]

I'm away at work at the moment which makes this whole situation shit, I'm back on Monday morning and going straight to the tuners to demand to see the dyno read outs

[SilverECR33]

that really sucks, sorry to hear.

[The Dan]

I'm away at work at the moment which makes this whole situation shit, I'm back on Monday morning and going straight to the tuners to demand to see the dyno read outs

You'll get a MUCH better result if you go there and ask nicely to see them. Don't assume they are at fault, it will only make things much harder for you.

Instead, go there with your objective thinking cap on and listen to what they say, take all the information on board and then ask some other experts about what has been said. Try to take someone with you who might know a lot more about these things.

Think about trying to find out WHY rather than WHO and the WHO will work itself out in the end.

[R31Nismoid]

^ +1

Without even knowing where the failure(s) are, its nothing but pointless speculation that will do nobody any favours.

[SilverECR33]

+2.

[bubbabooga]

Okay I worded that very Wrong saying demand.

I entirely understand the power of respect and level headedness in a situation like this, i know the finger cannot be pointed at anyone just yet untill we figure out what caused this failure.

Last I spoke with tuner and engine builder they were pulling off the intake manifold to have it put on a flow bench.

But if the needle does land on this intake manifold after flow bench testing and the engine builder had to weld up a small tab on the intake manifold and checked the port matching on the manifold, said it looked like a good unit.

shouldn't perhaps some concern have been expressed if it didn't look up to the task?

[brad 110]

Forget looking at the cause until you have fully accessed the outcome. Get it apart and with careful inspection you will be able to pin point what and how this has happened . The dyno runs showing afr means little as it shows an average tailpipe mixture not individual cylinder mixture and shows nothing regarding detonation, which if it's drilled something would be the cause wether a lean mixture concentration promoted the detonation in the first instance.

[The Dan]

Forget looking at the cause until you have fully accessed the outcome. Get it apart and with careful inspection you will be able to pin point what and how this has happened . The dyno runs showing afr means little as it shows an average tailpipe mixture not individual cylinder mixture and shows nothing regarding detonation, which if it's drilled something would be the cause wether a lean mixture concentration promoted the detonation in the first instance.

Zachary.

Pull the engine down and assess the damage. Only then can you begin to unwrap the puzzle pieces in reverse

[rob82]

If the volume of the plenum (volume between tb and runner division) is large enough it won't be an issue.

[JustinP]

Think about trying to find out WHY rather than WHO and the WHO will work itself out in the end.

Thats a great way to put it!

And sorry to hear about your engine, that must really suck

Edited September 26, 2012 by JustinP

[SiR_RB]

10kays to bed engine in before making decent power??

[JonnoHR31]

10kays to bed engine in before making decent power??

More than enough if you do it properly.

[bubbabooga]

They informed me they put a borescope down the low comp cylinders and they had signs of Det and damaged bores on my already 87mm bored block.

I have heavily researched hard running in methods etc.

Now the tuners run in method was

Fire engine, free rev and blipping throttle under 50% till at temp, shut off engine check leaks etc, let it cool down, load it on the dyno and sit it at about 90kmh in 4th gear under medium load lowish boost for the 10kays.

I was under the impresion a good ring bed in required vartied loads, revs and engine braking?

On a fresh as fresh engine with good ring bed in what kind of cylinder pressures should be expected?

110psi for cylinders 3-6 seems low to me.

[WMDC35]

whichever run in method if the engine gives out this way it was doomed from the start