JohnBoy's Turbo Build

[lpcapital]

Originally Posted by xxxJohnBoyxxx

Forget the brakes I just had a bad issue where the turbo ran away on me and boosted over 32psi and blew the hose off the MAF sensor. I need a boost controller before I get brakes...

New aluminum hose caused this the old boot to the TB was leaking bad. Now I got the manual controller hooked up right so this doesn't happen again. Car started breaking loose the tires at over 50mph, it was pulling so hard I was waiting for it to blow up....Very addictive


I wonder if I can just start running 35psi boost from now on

There's several electronic boost controller out there, but if you get one, I would make sure it gives you the safety feature that is whatever reason boost goes above a certain level (that you set) it cuts off the injectors. That would avoid you blowing the motor...

[xxxJohnBoyxxx]

Originally Posted by nuvolarossa

what MetricMechanic do to the M44 head? you have the M44 head, right?

I remember someone boosting that high years ago in M4x and he ended craking heads always in the same spot...

I have the M44 head ported with the small light weight valve gear. I've not heard about the head cracking issue, but you've perked my ears.

I do use the head gasket that Metric has used for years with no failures on their FI motors and special M3 head bolts that are cut shorter so I can torque them much tighter and they don't bottom out. The head has larger exhaust studs for the heavy turbo manifolds.

Let me know more about these cracking heads. Is it overheating issues? Were is the crack at?

I bet it is in the exhaust port around a valve seal

[xxxJohnBoyxxx]

Originally Posted by lpcapital

There's several electronic boost controller out there, but if you get one, I would make sure it gives you the safety feature that is whatever reason boost goes above a certain level (that you set) it cuts off the injectors. That would avoid you blowing the motor...

JohnBoy is non edumacated on electronic boost controllers and what options are important. Can anyone help me pick a good one with blue display?

[lpcapital]

Originally Posted by xxxJohnBoyxxx

JohnBoy is non edumacated on electronic boost controllers and what options are important. Can anyone help me pick a good one with blue display?

I'll check with my neighbor tonight: he has one on his IS300....

[xxxJohnBoyxxx]

ENGINE GO BOOM


Yep ran 32psi this morning by accident. Installed the mechanical boost controller and put about 75 miles on the car at 25psi. Pulled over about 2 miles from my house and turned down the boost. Pulled out and max boost was 17psi 1st and 2nd gear pull. Let off and coasting to the light the engine stalls. I restart it and it won't hold a idle...No proble a hose is off before the MAF so I pull in a parking lot and open the hood. All hoses are good, everything is clean. Check the oil and it looks perfect like honey. Start it up and drive it home 1 mile on three cylinders. Pull all plugs and they all look great light tan no metal so I'm feeling real good now. Do a compression test just to be sure before I look for fuel electrical issues and guess what. 1, 3, 4 all 120psi. #2 0psi.

So number 2 has 0 compression no metal on plug, oils good, coolant is clean. I'm praying it's a broken valve spring. I've melted a bunch of pistons and still drove them to finish a race and the car always over heats and the oil is a mess. Also with that f'ed up piston in a jacked up cylinder you still can get 5-10psi compression so I'm praying it's just a valve open since that's the only thing I've ever run accross that give a 0psi reading on a compression test

[pnosker]

Sounds like a broken valve spring to me... I thought those honeycomb springs are good for a while? I hope your valve didn't hit the piston...

[lpcapital]

Wouldn't spring go is you over rev it? I mean, at least normally, also you should hear it hit the pisotn... but maybe lower comperssion avoids it... Overboosting shouldn't cause that. How about a crack in the head around #2? I would try a leakdown and see where the leak is...

[xxxJohnBoyxxx]

Originally Posted by pnosker

Sounds like a broken valve spring to me... I thought those honeycomb springs are good for a while? I hope your valve didn't hit the piston...

No odd noises at all I'm praying and I'm not religious. Got fans on the car now so I can pull the valve cover

[xxxJohnBoyxxx]

Originally Posted by lpcapital

Wouldn't spring go is you over rev it? I mean, at least normally, also you should hear it hit the pisotn... but maybe lower comperssion avoids it... Overboosting shouldn't cause that. How about a crack in the head around #2? I would try a leakdown and see where the leak is...

I want to get into the valve train first. If I put my leak-down on it and the valve slams shut it might fall in the cylinder when I release pressure. I'm hoping to find a collaped spring with the keepers still on it. Will know soon.

[lpcapital]

Originally Posted by xxxJohnBoyxxx

I want to get into the valve train first. If I put my leak-down on it and the valve slams shut it might fall in the cylinder when I release pressure. I'm hoping to find a collaped spring with the keepers still on it. Will know soon.

Yea, you don't want that to happen...

[pnosker]

Hopefully since your engine is lower compression, the piston won't be able to interfere with the valves.

[xxxJohnBoyxxx]

Pistons is good. Took off the valve cover and there was a rocker arm anging in the bottom on #2. Did a leak-down and that valve is leaking real bad. It's the intake second valve on #2. Spring looks ok . Wonder if a piece of aluminum from al the intercooling work had a stray burr that made it's way to the combustion chamber and is wedged in that valve seat? Worst case I pull the head and have Metric send me another one as long as the core is not damaged.

This is going to be a pain in the butt. Engine has to be pulled to get the exhaust turbo etc off the head for removal from the car. I'm going to pull the intake and see if I can go down the intake runner and see the damage.

I got luck it could have been a big window in the side of the block with many other parts destroyed in the mayham. Still interested to figure out what caused this. I don't think it was the boost I think I missed a small burr with all the pipe cutting and welding and it got wedged in the valve seat... Only my guess

[yoda]

Damn!
I hope it's nothing bad and it's a simple fix...

[xxxJohnBoyxxx]

Pulled intake and looked down the intake runners at the back side of the valves. They look normal for what I can see. I don't have a mini mirror so I had to feel around the inside radius with my pinky but I don't feel anything holdig the intake valve open.

just started to rain hard so I'm inside until it lets up. Talked to Jim at Metric and he agreed something got caught in the intake valve seat jamed the valve and the rocker poped off since the spring never completely shut the valve. valve looks straight and back side of both look the same.

Hoping just a piece of intercooling aluminum slag or burr got caught and I can get it out of there without removing the motor to get the head off it.

Complete idiot issue caused by the user (Me) and most would blame this on the builder...Man I will be pissed if i find a turbo impeller blade in there

Yoda sure you want that free install...I do make mistakes but never twice, always back them up and fix what I've damaged

[pnosker]

Just run 15 psi on his motor... with the t3/t4 hybrid and he won't have any issues... and make sure to keep all the aluminum clean around edges and it should be good!