Motor Blew Last Night

[SoCal80six]

Originally Posted by John Rambo

I was running a FBM base kit @ 10psi on 91 octane for about 15k miles (Car is almost at 29k miles, turbo went in around 14k)... until last night, when the car decided it would be better off with another window.

I'm posting because I'm wondering what my options are from here on out in terms of cost. I've done some looking around the forums and a lot of people would build the motor for boost, and others say they would just fix it and maybe part out their FI kit and other mods. Others still would take this as an opportunity to do an engine swap? Shop said they can't take a look at the car until the 23rd so I've got some time to decide.

How much am I looking at to replace the block? How much am I looking at to get a built motor? And is it worth it considering so many people have posted about transmission issues with high power output? What about an engine swap? How much money am I looking at for a dope swap? Looking for any and all advice.

Thanks in advance.

Sucks man I know the feeling just blew mine not even 2 days ago smh. Had about 2k of boosted miles and decided to switch map to same exact map with less boost on e85 worked perfect the whole day put e85 in and boost started to spike. Was only set to 7.5 psi ended up hitting around 18 and 19psi around 17 when car gave out smh. Looking for best way to go about this also no visible damage don't to block what so ever though no oil, doesn't look like rod knocked out of block either still hoping for the best on it. Good luck though man let me know what you come up with definitely looking for some opinions on best route to go with it also.

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[John Rambo]

Originally Posted by GsxrMe

What were you tapping oil for next to the AC? Did you install a different oil feed for the turbo? Fullblown doesn't tab oil there; they use a T fitting on the oil pressure barb.

I also see a catch can, do you have both left and right PCV valves venting to atmosphere to prevent crack case being boosted? Fullblown recommends vent to atmosphere on the kit no matter what.

I used this



I'm not sure how the catch can was installed. I can take a look at it later today. I had evasive do it.

[Rampage]

Going with a built short block won't necessarily cause more power than the transmission can handle. Get a short block with forged components that is built for boost with a lower compression ratio. The power output is controlled by the amount of boost you chose to push through the engine.

The problem with these engines are they are not built for boost and the high compression does not play nice with boost so you are walking a knifes edge when trying to get a proper and safe tune. Then what happens in a lot of cases is the owner gets use to and bored with the power and decides to turn the boost up "just a bit". Sooner or later they will all blow.

If you are going to go boosted again then get a block that is built to handle it, get a good tune that is just a bit on the conservative side and then practice self restraint by leaving it alone outside of proper maintenance and periodic inspection..

[FRS Johnny]

Originally Posted by GsxrMe

What were you tapping oil for next to the AC? Did you install a different oil feed for the turbo? Fullblown doesn't tab oil there; they use a T fitting on the oil pressure barb.

I also see a catch can, do you have both left and right PCV valves venting to atmosphere to prevent crack case being boosted? Fullblown recommends vent to atmosphere on the kit no matter what.

I bought the jdl catch can for the fbm kit. That still okay right?
https://jdlautodesign.net/shop/ft86-...ted-catch-can/
Is it necessary for another one for the crank case?

[Sportsguy83]

Originally Posted by FRS Johnny

I bought the jdl catch can for the fbm kit. That still okay right?
https://jdlautodesign.net/shop/ft86-...ted-catch-can/
Is it necessary for another one for the crank case?

That catch can has two inlet ports, it is connected to both the PCV and the breather sides, so you're fine with that one, don't need anything else.

[JDLAutoDesign]

Correct both rear and front engine ports connect to the can and the upper can port connects to the turbo intake or OEM intake port.

[GsxrMe]

I'm only obsessed with the PCV to atmosphere/Turbo inlet because of pervious turbo hayabusa hickups. I was having so many damn issues with the crankcase not releasing boost and it cost me, rods, je pistons, case and head work.

[wparsons]

Originally Posted by Rampage

Going with a built short block won't necessarily cause more power than the transmission can handle. Get a short block with forged components that is built for boost with a lower compression ratio. The power output is controlled by the amount of boost you chose to push through the engine.

The problem with these engines are they are not built for boost and the high compression does not play nice with boost so you are walking a knifes edge when trying to get a proper and safe tune. Then what happens in a lot of cases is the owner gets use to and bored with the power and decides to turn the boost up "just a bit". Sooner or later they will all blow.

If you are going to go boosted again then get a block that is built to handle it, get a good tune that is just a bit on the conservative side and then practice self restraint by leaving it alone outside of proper maintenance and periodic inspection..

High compression isn't the problem, not at all.

You're right that the issue is people turning up the boost, but it's because they're doing so without adjusting the rest of the tune for it.

The same thing will happen with a built block, it's just stronger so the threshold is higher.

With a lower c/r you need to run a lot more boost to make the same power, you get more lag and less off boost power. More boost = more heat, so you might need better intercooling.

[Rampage]

Originally Posted by wparsons

High compression isn't the problem, not at all.

I disagree with this in at least one sense although I will refrain from entering into a long winded debate with you or anyone else on the subject. High compression increases the likelihood of detonation therefore the need for higher octane fuel, direct injection (in part) and tuning measures that must be used to control it. It definitely lowers your margin for error when going forced induction.

Yes, heat is also a factor (and a factor related to high compression).

[John Rambo]

Trying to weigh the costs of a brand new shortblock from toyota/subaru or a junkyard complete motor. With labor for each respective option, anyone wanna chime in here?

[Scott@HKSUSA]

Originally Posted by Rampage

I disagree with this in at least one sense although I will refrain from entering into a long winded debate with you or anyone else on the subject. High compression increases the likelihood of detonation therefore the need for higher octane fuel, direct injection (in part) and tuning measures that must be used to control it. It definitely lowers your margin for error when going forced induction.

Yes, heat is also a factor (and a factor related to high compression).

Static compression ratio vs. dynamic compression ratio.

Variable cam timing plays a huge role in this as it allows one to control cylinder pressure throughout the rev range. You could run a 15:1 engine on pump gas with 12 psi of boost if you allow the cams to bleed off enough cylinder pressure. Which is why it's not hard to find a boosted 12:1 Honda K, or Toyota 2ZZ, or FA20.

But without variable cams, you'd have to degree your cams for the minimum amount of overlap that keeps the engine from detonating. And that takes a lot of time and testing. Which is why you don't see a lot of boosted 12:1 Honda B's. Or KA24's. Or 4G63's. Or SBC's. Etc.

But to your point, if I was starting a FA20 build for boost from scratch I'd certainly pick a lower than stock C/R. The window for MBT is simply a lot wider and easier to find the lower you go.

[Dr Speed]

Do you monitor your active A/F ratio's on a guage with regular driving??

[John Rambo]

Originally Posted by Dr Speed

Do you monitor your active A/F ratio's on a guage with regular driving??

I have a p3 gauge so either I'd usually switch it between afr, boost, and coolant/oil temps on an average drive.

[stugray]

Originally Posted by wparsons

High compression isn't the problem, not at all.
...
With a lower c/r you need to run a lot more boost to make the same power, you get more lag and less off boost power. ...

But with low CR and boost, you have a greater margin for error.
If it quits running right, you lose hp.

With high static CR and boost, you have very little margin for error.
If it quits running right, it blows up.

Similar to that old racing tuning adage: 'You can run rich all day long, but you can only run lean once.'