Blew a head gasket
Thread Starter
Instructor
Joined: Oct 2008
Posts: 194
Likes: 0
From: OC, CA
Sounds to me like you may have detonated the engine due to a combination not designed for 91 octane (and the gasket failed from detonation).
Do you have notches in your pistons at all....are they OEM that were flycut or aftermarket pistons?
You might need to drop the CR of that combination some if you plan to continue to run 91 pump gas.
-Tony
Do you have notches in your pistons at all....are they OEM that were flycut or aftermarket pistons?
You might need to drop the CR of that combination some if you plan to continue to run 91 pump gas.
-Tony
Former Vendor
Joined: Mar 2004
Posts: 1,518
Likes: 7
From: Valencia CA
If they didn't your static CR is way too high for 91 octane (and if they did its only a little too high....LOL).
If your heads need refacing that shrinks the chamber even more creating more compression issues. I would encourage you to have someone pour a chamber on each head and verify its current actual volume as well.
Your juggling a host of issues that can cost you alot of money in the long run if they aren't resolved properly so if you puckering up now at the costs associated with the proper fix you most certainly wont be able to afford the consequences of not remedying the situation (a blown or seriously damaged engine).
I could port the heads and open the chamber to increase the volume as well as install lighter valves that give you more piston to valve clearance (your two big issues currently the way I see it), but thats not inexpensive. It would however add a significant increase to your power output so at least the money spent adds value as well as cure your larger problems (compression and potentially marginal P to V clearance). Of course this is just one if your options.
When you finally get this engine apart and we know exactly what you are dealing with, that would be a better time to evaluate what course of action may be best. If your pistons are shot you would be better suited investing that money in your bottom end for instance.
Good luck....PM or call me if you need some help
-Tony
Edit....Just noticed we aren't too far from one another in the event you want me to look over or rework the heads.
Last edited by Tony Mamo @ AFR; Dec 27, 2009 at 02:33 PM.
Thread Starter
Instructor
Joined: Oct 2008
Posts: 194
Likes: 0
From: OC, CA
If the pistons are stock my guess is you may see a few of them with a cracked or broken top ring land when you pull the heads. Also, do you know if anyone fly cut them because if they didnt thats a potential future disaster waiting to happen (piston to valve issues).
If they didn't your static CR is way too high for 91 octane (and if they did its only a little too high....LOL).
If your heads need refacing that shrinks the chamber even more creating more compression issues. I would encourage you to have someone pour a chamber on each head and verify its current actual volume as well.
Your juggling a host of issues that can cost you alot of money in the long run if they aren't resolved properly so if you puckering up now at the costs associated with the proper fix you most certainly wont be able to afford the consequences of not remedying the situation (a blown or seriously damaged engine).
I could port the heads and open the chamber to increase the volume as well as install lighter valves that give you more piston to valve clearance (your two big issues currently the way I see it), but thats not inexpensive. It would however add a significant increase to your power output so at least the money spent adds value as well as cure your larger problems (compression and potentially marginal P to V clearance). Of course this is just one if your options.
When you finally get this engine apart and we know exactly what you are dealing with, that would be a better time to evaluate what course of action may be best. If your pistons are shot you would be better suited investing that money in your bottom end for instance.
Good luck....PM or call me if you need some help
-Tony
Edit....Just noticed we aren't too far from one another in the event you want me to look over or rework the heads.
If they didn't your static CR is way too high for 91 octane (and if they did its only a little too high....LOL).
If your heads need refacing that shrinks the chamber even more creating more compression issues. I would encourage you to have someone pour a chamber on each head and verify its current actual volume as well.
Your juggling a host of issues that can cost you alot of money in the long run if they aren't resolved properly so if you puckering up now at the costs associated with the proper fix you most certainly wont be able to afford the consequences of not remedying the situation (a blown or seriously damaged engine).
I could port the heads and open the chamber to increase the volume as well as install lighter valves that give you more piston to valve clearance (your two big issues currently the way I see it), but thats not inexpensive. It would however add a significant increase to your power output so at least the money spent adds value as well as cure your larger problems (compression and potentially marginal P to V clearance). Of course this is just one if your options.
When you finally get this engine apart and we know exactly what you are dealing with, that would be a better time to evaluate what course of action may be best. If your pistons are shot you would be better suited investing that money in your bottom end for instance.
Good luck....PM or call me if you need some help
-Tony
Edit....Just noticed we aren't too far from one another in the event you want me to look over or rework the heads.
Thread Starter
Instructor
Joined: Oct 2008
Posts: 194
Likes: 0
From: OC, CA
I need to look up if that's what the compression is. I don't think it is because from what AFR said the compression shouldn't be that high with the parts I have. I think I may have made that number up lol. I'll look up my full mod list that I have written down somewhere tho.
Thread Starter
Instructor
Joined: Oct 2008
Posts: 194
Likes: 0
From: OC, CA
Got my car back last night. I got really lucky. He did a leakdown and said it looked great (so no bad rings). Heads were straight and good. Two cylinders on the passenger side were clean so that's where the leak was. He did an oil change while I was there too and oil still looked fine.
I think I got extremely lucky. Car started right up and temp was good. It actually feels like it's running smoother now too.
I'm selling the car for sure, but I have an MGW sitting here I bought before it broke and I'm trying to decide whether or not to put it in today. lol
I think I got extremely lucky. Car started right up and temp was good. It actually feels like it's running smoother now too.
I'm selling the car for sure, but I have an MGW sitting here I bought before it broke and I'm trying to decide whether or not to put it in today. lol
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