Turboing an uncommon engine. A learn me thread.

Thanks for all of the input so far!

Question about ring gaps...  do you gap them all, or just the top rings?

Thanks!

Rob

You might pick up a copy of this:

Street Turbocharging, by Mark Warner

Order placed.

I had another turbo book, but I believe I gave it away in the new years eve gift exchange.

It's been years since I had a turbo car and that mostly stock.

Thanks for your patience yall!

wvumtnbkr said:

Question about ring gaps...  do you gap them all, or just the top rings?

Some make them all the same.  Some make the top gap larger by about 0.002". Some make the second gap larger by 0.002".

I chose to do the top rings on my LQ4 at 0.026" and the second rings at 0.028". Apparently this prevents pressure from building up between the rings.  Or something like that. I forgot.  It made sense at the time I was researching it four years ago.

Never never make the top gap larger. Second ring gap .002" more. 

Paul_VR6 (Forum Supporter) said:

Never never make the top gap larger. Second ring gap .002" more. 

Why not?  (This is me asking so I can learn).

Is it because it would let more pressure to the other rings?

I have a question about boost control...  I don't plan to run an aftermarket ecu.

Can't I just use a 10psi, or 12psi, or 15psi pressure switch (or have 2 installed and switch between high and low boost) that feeds a 3 port solenoid that feeds the wastegate?  

Wouldn't that give me fairly good control and if the wastegate is sized correctly, it would be fairly safe from overboosting.  

Switches are less than 30$.  A solenoid is about the same.  Just need a 12v auto relay and could control boost to whatever pressure you want based on whichever pressure sensor you are running. Put 2 of them on a common manifold and switch between high and low boost.

I have nothing to add other than I should be following this after I already added a turbo to my uncommon engine so I can fix everything I did wrong already.

So, I gapped the top ring at .024" and the 2nd ring at .026".  Should be good for 10 to 12 psi!

Yay!