dwashy21

So I plan on turbocharging my d16z6 this summer, and before I finish that process I need to first deal with some issues the motor has now. Right now it idles like a V8 and I did the test where you put paper over the exhaust and the paper was not blown away from the exhaust consistently it was flapping back and forth. If I'm correct this means that I have a bent valve or one that isn't seating correctly right?

Assuming this is the case, I figured the best option would be to:

• Pull the head
• Replace valves/seals and get 3 angle valve job
• Deck/resurface head for flatness
• Install new headgasket
• Install ARP Headstuds

Now assuming I go through all of this, I was wondering whether or not it would be worth it to invest in upgraded springs/retainers/valves for the head. Would this be a good idea or would the bottom end give out before the top? Also is there anything I might be forgetting? Just trying to finalize all the details of the build before I start to really dig into it. Thanks in advance for any help I might receive

OneBadTurboCRV

You could have the strength of the bottom end x2 and STILL not have more strength than the top end can withstand from the factory. I know smoking weed makes you paranoid and all but a piece of paper isn't exactly a test even worth performing. You need to do a compression and leak down test and see what's going on.

dwashy21

Ok thank you for helping to guide me, I'm still learning and we all start somewhere. No need to make childish gibes about my decision to use cannabis. I know holding a sheet of paper to an exhaust tip doesn't for sure mean anything. I asked regardless because a head rebuild is something I want to get done.

Now I know how to perform a compression test, but how do you complete a "leak-down" test? Can the tools required be rented from a local auto parts store? If not, I guess I can just pick one up from Harbor Freight or order one online.

On the comparison of a head/block's strengths then, what parts/upgrades to the motor would be necessary/suggested if I wanted a stable, daily-driveable 250 whp on a d16z6?

OneBadTurboCRV

Childish gibes? Anyways, for anything above 180 wtq / 220 whp you need to upgrade rods if you want reliability. You can do it ghetto, decent, or the "right" way. Ghetto being LS rods with ARP bolts, decent but staying cheap with cast Vitara pistons and Eagle forged rods, or forged everything would be the correct way. In any case the mods listed above will support your low power goals. The head doesn't need to be touched, nor the crankshaft... period.

Some parts stores may rent a leak-down tester and most should rent a compression tester. If you aren't worried about the numbers from the leak-down test you can just apply 100 psi or so to the compression tester whip and listen for where it is leaking out of. You want to be able to listen at exhaust, intake manifold throttle body, valve cover oil cap, and pull the radiator cap to watch for bubbles. You need to make sure the valves are closed on the cylinder you are testing.

Everything I have vaguely covered is HEAVILY discussed countless amounts of times. There are write-ups, YouTube videos, and many build threads that show how to build a D16 and test engines.

dwashy21

Perfect, so just for clarification on achieving reliablilty the main things to address would be:

• Rods
• ARP Bolts
• Pistons

If the difference in price isn't too much I'll probably go with forged, since I'll want to keep this motor for a while if I build it. I'll try later this week to see if I can do a leak-down test.
Just out of curiosity, would you happen to know at what point in power output the top end would need to be built?

Pro-SeriesFab

The poor man's leak-down tester (if you have a welder) is to take an old spark plug, break off the porcelain and get it out, take a $2 male air fitting and weld it to the leftover thread portion of your old spark plug.

Essentially screw the spark plug/air fitting into the head and run compressed air to it.

Obviously you have to make sure all of the valves are closed but it will tell you where its leaking.

JPhilBradley

A simple ignition misfire will cause a dollar bill to 'flap back and forth'. Found this out by mistakenly reversing the harness to the ignition coils on a FWD V6 one time. Had just got gone replacing all of the lash adjusters and thus has to lift the cams. Thought the motor had jumped timing at first; turns out I just had a dead ignition miss on 2 cylinders.

JPhilBradley

What about regulating the amount of air to it? Def don't want to put 130psi into a cylinder.

kyden

i wouldn't worry about 130psi, lol. combustion pressures are way more than that.

OneBadTurboCRV

ARP bolts will come with forged rods, but if stock based rods are used ARP's would be a wise investment if spinning around and above stock RPM limit. I am not that into D-series engines but if my memory serves me correct the flow of a stock D head starts being seen 450-500whp. But again, I may be wrong on this but I am about 80% sure that is right.

Vagitarian

Howd you know buddy was a stoner?

Pro-SeriesFab

What do you supposed would happen at 130psi over at 100psi which is the normal pressure for checking leak-down?

What amount of pressure do you think the valves/seats and rings see when under load?

OneBadTurboCRV

I see, hear, and know everything. MuhaHaha!

m4xwellmurd3r

Ohh somewhere around 1000-1500psi+

Considering a stock engine can compress 180-200psi+ if youre scared if breaking it at 130psi you should think again about how an engine operates

Pro-SeriesFab

I use the little air fitting I welded up for helping to get the crank pulley off occasionally. Fill the cylinder with air just prior to TDC so when you are trying to get the crank bolt off you are also trying to compress the air you are putting in #1. Usually works if you've ever had the crank bolt off previously.

m4xwellmurd3r

Thats a good idea. Safest too vs physically locking the engine with something.

I bought a new crank bolt and put a dab of silver anti sieze on it. Even with all the torque needed to rip it off at least I know it wont be stuck.


You just gave me another reason why I need an air compressor

dwashy21

Thanks everyone for the input, I've got a paper due on Friday and after that I'm done with school so I should be able to dig in more with this car. Building the lower end will probably take me a while so I might just pick up a spare block to work on during the summer

Sadly I can't weld, watched plenty of people do it but never been able to try myself... Someday I'll learn

Sometimes when trying to start the car it's unusually difficult to turn the key, or when I turn it off it's harder to turn the key counter-clockwise and pull out. Could this be a sign of a bad ignition? All I know is there used to not be any resistance and it's pretty annoying

JPhilBradley

Did you ever figure out what was going on?

VeeSykkz

Because he seemed intelligent, intuitive, polite, and then said cannabis.