I've been working on a turbo project on a VG33 Nissan truck engine, finally got it together

Yesterday I set up the AEM FIC , added enough fuel to be nice and rich under boost, and retarded 1 degree of timing per lb of boost. Checked to see that the retard was working with my timing light.

Then I slapped the turbo etc on and took it out for a test run to watch AFR. She was nice and rich under low boost, spooling and boosting at low rpm, BOV was working. Great.

I got a little ahead of myself and did a WOT pull. Unbelievable power. I was at the top of 3th and she wouldn't stop gaining power, super excited. Unfortunately my wastegate didn't open. Last I saw I was going on 20lbs, it happened extremely fast from vacuum to 20lbs.

I was too excited, Should have felt it out a little more and stopped right when she went over 10psi. I only put an 8psi spring in there lol.

Then I smelled coolant
Pulled over, upper rad hose popped right off the rad. Clamp was tight. Uh-oh, Cooling system must be getting pressurized with cylinder pressures. Opened cap, refilled her.

With cap off, I went to crank and got a hydrolock sound. She was almost completely hydrolocked after 1 WOT pull. For every revolution the starter could turn the engine, the radiator was shooting water like a geyser. Stopped everything, hooked up the chain and towed her home. It was late so that was that.

I've never had this happen before so this is new to me, and I would appreciate some input so that it's not all guess work when I pull the heads off to see if I can slap new head gaskets in and put it back together after fixing the wastegate issue

I'm thinking before I buy any new head gaskets I need to pull the heads and inspect.

Best case scenario I blew the head gasket, next best the head floated and the threads in the block are still good. Maybe the bolts stretched. I can work with that with new head bolts

I doubt the head cracked but it's possible. If the the water jackets in the block have any damage I'm screwed.

Now while I was fabricating all the turbo parts during the last few months I also regasketed the engine top to bottom. I used felpro head gaskets. Now if I can salvage this I'll go with MLS gaskets.
Any input as to what I should look for and what you think happened? Thanks.

 

you probable lifted the head and blew the head gasket. That's an inny , internal leak. Hope you didn't bend rods when it hydro locked. It might be a good idea to do a complete tear down

 

Pull heads and inspect. Check deck height on all the pistons to make sure you didn't bend a rod. Be more careful next time.

 

This is where a unit from J and S would save you. If you detonated t would pull out timing and shut the motor down. I agree for now take her down check deck heights. Then go with studa and good head gaskets

 

All the feedback I've read says that system is too finicky and, for example, pulls timing on motors with forged pistons misinterpretting the slap for detonation amongst other reasons.

 

Have you seen the pulls on the buick boards? Check out the termnator boards. I have two. The first in my 350 silverado the second in my roush. The chevy worked fine but it did have cast pistons. Call John he runs the company he is a brilliant guy

 

I have not. I did ask around about the system and researched through google. So, at the time I might have been on those boards. I was hoping I had found a way to tune timing across the board on the street instead of on a dyno. I still have a link to the system, but was dissuaded from pulling the trigger on it.

 

Don't let a few internet posters deter you from looking into the J&S. Call John himself and talk with him directly. He'll tell you the honest truth. If your engine was detonating I would bet good $$ that it would have detected it and functioned perfectly if the J&S unit was tuned correctly. If it didn't pick it up then that would be the oddball combo and certainly not the norm.

I have it on my car and it works consistently and very reliably. I would never run a pump gas car without it.

ks

 

The J&S worked fine on my car when it was super charged. I use a Holley EFI now and don't need anything external. The Holley does everything, even boost control.

The J&S would not have saved the engine if you over boosted. Way too much pressure, especially with poor fuel and hot air, will blow gaskets and break parts no matter what the timing is at.

 

I hit 27psi on 91 octane a few days ago due to a problem with the hose to the back side of the wastegate. Fortunately, I think a couple things saved me. First and foremost, I recognized something was wrong immediately and was out of it within a second or two. 2nd, my timing table is tuned to drop to 8* above 15 psi.

I'm more interested in the potential of tuning mid-range WOT, part-throttle, and cruise conditions. WOT can be done with an accelerometer or by watching trap speeds. However, when you're not actually measuring power output, the only other thing I can imagine is watching fuel efficiency. Perhaps plugs. Problem is, with so many cells, this would take a lifetime to get right.

I'm an amateur tuner, though, just teaching myself. Perhaps, it's not that important to get every little bit out of it.

 

Tom, Which Holley EFI are you using?
Thanks,

 

Holley HP with their digital dash. I had a variety of things previously including Megasquirt.

I wish I would have bought an Holley Dominator system. Despite a number of external electronics device, like PWM controllers and bump box, I've still pretty much filled the external I/O ports.

As my car gets more and more power on small tires I need more controls.