Cracked Mi16 Liner

[Bally 4]

I have started to increaseboost on my mi16 turbo engine and have split a liner. The tuning was good, afrs good, timing good. Pistons are perfect, head is perfect but liner crack from top to bottom on the side. #4 Is it the boost, what are my options. I have been at 18 - 20 psi. It split omn the first pull at 20 psi in 2nd gear.

[EdCherry 34 1 Cars]

Standard Size or Oversize?

[Bally 4]

Standard ribbed mi16 liners. Its been on boost for a long time running perfect at 10 psi-12 psi. As soon as I increase liner splits. Am I wasting my time changing the liner just to split one again?

[rapidcossie 0]

cylinder pressure increases with boost so Id imagine it a good guess.

[Bally 4]

So waste of time me continuing down this path. HAve to go to iron Block?

[dee205 3]

Is there any way of going closed deck on the 1.9 Mi... Or it might be cheaper to go iron block for a few extra cc's and more reliability at higher boost.

[petert 589]

So waste of time me continuing down this path. HAve to go to iron Block?

 

Or just try 15psi........... Wouldn't that be enough anyway?

[Tom Fenton 1,542]

My guess is timing. I've been running over 20psi on my 1600 turbo for over 4k miles, and that is using the supposedly weaker 8v liners without the ribbing. Too much timing equals detonation equals something broken, on a wet liner XU the liner is the weakest link it seems. Also what CR does the engine have.

[DrSarty 90 1 Cars]

My guess is timing. I've been running over 20psi on my 1600 turbo for over 4k miles, and that is using the supposedly weaker 8v liners without the ribbing. Too much timing equals detonation equals something broken, on a wet liner XU the liner is the weakest link it seems. Also what CR does the engine have.

 

 

Slightly OT but I'm glad you've said that Tom, as I was looking for 'confirmation' that I could build an Mi using the 8v liners. If yours are standing 20psi - all other things being equal - then it seems there's no reason why not, especially running N/A.

 

Back OT: I'd speculate that the turbo-esque craving for more 'power' has caused this, as the crack didn't happen until you wound up the boost, and in conjunction with running temps, advance, fuel type and forces within the engine you broke the liner, the weakest link......'goodbye'.

[Miles 331 1 Cars]

The liners are not that often prone to cracking but they do even on std engine's, The liners are no weaker or stronger 8 or 16v as the weak point is between them (Thinest point) and not the front of backs of them,

Just get some good Quality liner's but these will cost

[cyman 1 1 Cars]

I'm running 17-21 psi with no issues.

What timing and boost retard numbers are you running.