"Tuned" blown head gasket WHY ?

[v8killer]

Hey guys i blew my head gasket tonight on just 15-16 psi. but i do have a slight boost creep problem that will spike to 20-22 in higher gears but only for a second and i'm stumped motor barely had 500 miles on it .i have the following parts and the car was tuned to 11:1-11:3 wide open. and timing was set to 17deg from 4000 up to 7500. could that be tomuch timing to soon !

arp head studs torqued to 90 ftlbs
evergreen composite head gasket "could it be this cheap gasket, it looked like a good gasket"

 

[JDR7919]

Was it knocking?

 

[slowgsr]

strange.. probably just a install error as far as the HG goes.

Try this..

Use a OEM mitsu MLS headgasket with copper spray, and tq the ARP's to 95. Make sure you block surface is very clean, (same goes for the head). Clean it clean it and clean it, I always use a razor to get the composite gaskets off.

Goodluck. Make sure everything is straight though.

 

[v8killer]

well the thing is i have a 95 eprom and i have been having a problem with finding a logging program that works but the last few time i ran my car which is maybe twice it had a hesitation when first in boost then smoothed out, i kinda think i had to much timing to early. both # 2-3 plugs have antifreeze on them ! i'm stumped..........

the head and block was cleaned real good before install !

 

[JWoodley]

Did you use the proper torque sequence and re-check them after a few heat cycles?

 

[v8killer]

i torqued to spec then went over them but did not check after a heat cycle, never had a problem before. how do you guyd feel about felpro head gaskets ?

 

[JWoodley]

I run a Felpro 1153-1.

 

[v8killer]

well this is the tuning forum, does anyone see a problem with my tune ?

 

[v8killer]

Well guys i pulled the gasket and it blew into the water port on # 2-3. i think i had tomuch timing to early in my tune causing detonation ! but my plugs looked good ? maybe it just lifted the gasket or maybe the gasket was just weak.....

 

[jrohner]

Hey guys i blew my head gasket tonight on just 15-16 psi. but i do have a slight boost creep problem that will spike to 20-22 in higher gears but only for a second

Boost creep and boost spikes are two totally different things, they are pretty much opposite of each other. Boost creep - boost pressure goes up with RPM, usually fairly smoothly increasing. Spike - goes high for a split second when you first hit boost.

If you are hitting 22 psi and are not tuned for that or don't have the mods to support it, that's definitely a problem. If you really do just have 450 injectors, there's your problem when hitting 22psi. Why would you have all that stuff done yet be on stock injectors? 16psi is probably pushing it unless you're using pretty good fuel.

 

[v8killer]

Boost creep and boost spikes are two totally different things, they are pretty much opposite of each other. Boost creep - boost pressure goes up with RPM, usually fairly smoothly increasing. Spike - goes high for a split second when you first hit boost.

If you are hitting 22 psi and are not tuned for that or don't have the mods to support it, that's definitely a problem.

Thats true yeah it will spike for a split second then fall to what ever i set it at. i have a ebay boost controller thats i dentical to a turbo smart ! i am installing my alcohol kit in a few days so the spike wont matter then becuase i am going to max this 14b out ! as of now i have put the stock tune back in.

 

[v8killer]

If you are hitting 22 psi and are not tuned for that or don't have the mods to support it, that's definitely a problem. If you really do just have 450 injectors, there's your problem when hitting 22psi. Why would you have all that stuff done yet be on stock injectors? 16psi is probably pushing it unless you're using pretty good fuel.

well thats why my base fuel psi is around 62lbs and the widebande was right on 11.1-11.3 and the boost spiked to 22 then fell to 14-16 thrugh the run ! my whole problem is not having a good logger to log with........ DAMN 95 EPROM !!!!!!!!!

 

[JusMX141]

I'm not convinced the cheap head gaskets are of good quality, even though they may appear to be.

I recently did a complete head rebuild on a customer's car after his timing tensioner failed....a bone-stock 1990 TSi AWD. Nothing was aftermarket except the exhaust system. The guy provided his own gaskets, and they were also Evergreen just as described by the O.P.

I did everything by the book (I obviously know how to change a head gasket properly by now), and the gasket blew between cylinders 2 & 3 after just a few hundred miles. The car ran perfect when it left my shop, and obviously poor tuning wasn't to blame....it had to be the fault of the cheap gasket. Unfortunately the owner couldn't afford another head job, so he unfortunately was forced to sell the car as-is.

 

[v8killer]

I'm not convinced the cheap head gaskets are of good quality, even though they may appear to be.

I recently did a complete head rebuild on a customer's car after his timing tensioner failed....a bone-stock 1990 TSi AWD. Nothing was aftermarket except the exhaust system. The guy provided his own gaskets, and they were also Evergreen just as described by the O.P.

I did everything by the book (I obviously know how to change a head gasket properly by now), and the gasket blew between cylinders 2 & 3 after just a few hundred miles. The car ran perfect when it left my shop, and obviously poor tuning wasn't to blame....it had to be the fault of the cheap gasket. Unfortunately the owner couldn't afford another head job, so he unfortunately was forced to sell the car as-is.

Did it blow between cylinders or into the water port on both cylinders ? if it blew across 2-3 then the head could be warped. a also think it was the gasket and maybe my timing curve !

 

[JusMX141]

It blew between 2 & 3, resulting in no compression in those cylinders as well as filling both cylinders with coolant. Head was definitely not warped, unless the machine shop cut it that way.

 

[v8killer]

yeah i guess i can blame the gasket some but after looking at the gasket one cylinder is egged out so detonation must have occured !

 

[PIMking]

what do you guys think of the felpro?

 

[TurboAnything]

Everyone should just run a Mitsu MLS. I have made alot of tuning errors and just beat the snot out of the car and my 3 year old MLS is still good. I have literally seen 40+psi of boost and stayed in it.

 

[twicks69]

Everyone should just run a Mitsu MLS. I have made alot of tuning errors and just beat the snot out of the car and my 3 year old MLS is still good. I have literally seen 40+psi of boost and stayed in it.

I agree. I have been using MLS head gaskets for the last 7 years and have not failed one yet. I have totally destroyed cylinder heads, and not trashed the gasket.

The key thing to do is use a good block and cylinder head surface that is perfectly smooth and perfectly flat. You should have you cylinder head properly machined, and clean up the block deck surface with a zip wheel and a die grinder to clean/polish the surface. Be sure to use a fine grit abrasive. You do not want to "cut" the surface, you want to "polish/clean" the surface.

You should use a bit of brake cleaner and a paper towel and clean the mating surfaces of the block and head, and both surfaces of the head gasket. They should be extra clean!

Also, when using a NEW MLS head gasket on a properly surfaced and prepped block/head, you do not use any type of copper spray. It is not necessary. The key part is to properly install your head studs using ARP moly lube, torque them in sequence in 3-4 torque cycles up to the specified torque rating (most people use around 86 lb/ft with ARP 8740 head studs; I use 115 lb/ft with ARP L19 head studs, and I torqued my old ARP 8740's to around 95-98 lb/ft without issues).

After having a few heat cycles under lower boost levels, pull the valve cover and re-torque them to spec. Then again around 1000 miles, pull the valve cover again, and re-check them.

Following these instructions will definitely help prevent head gasket failures when using a MLS head gasket on a properly tuned vehicle.

IF, for some reason, you are re-using your head gasket, which you really shouldn't....THEN, use Permatex Ultra Copper Spray gasket maker on both sides of the MLS head gasket in thin layers, with curing time between each layer, until the gasket is fully covered with no thin-spots. Just remember, you are reusing a "crushed" head gasket and having the copper spray compensate, while giving a bit more surface adhesion to the block and head.

Again, be sure to re-torque your head studs after a few heat cycles, and on a regular basis to keep the car in tip-top shape. It is good preventative maintenence.

As well, for the OP, I would stay away from cheap discount composite head gaskets. They are better used on a Non-Turbo 4G63 than a Turbo 4G63. Cheap definitely doesn't mean better than OEM. Usually, the stock OEM composite head gasket and ARP head studs properly torqued and re-checked can handle around 30-35psi max on a good tune without detonation. The OEM MLS head gasket has easily supported over 50psi with no problems for years on my car.


Finally, if you aren't already running a stage colder spark plug than stock, I would recommend looking into that. Use BPR7ES at 0.028" gap. Otherwise, if you are having detonation or blowout issues, AND you already have an upgraded ignition system (COP, or decent ignition box w/ COP), then you should run NGK BR7ES from 17-35psi. If you are running higher than that, look at NGK BR8ES. Personally, I run BR7ES in my GVR4 at 22psi on pump gas all day long with a ARP/MLS setup with no problems whatsoever. My Eclipse uses BR9ES at the 40-52psi range with ARP L19/MLS setup with no problems. The reason for the BR7ES vs. BPR7ES is the change to a non-projected tip. It will help in preventing blowout or minor detonation issues.

Still, your tune is extremely important, and your timing looks like it would be decent; you may want to pull a couple degrees just for safety, and re-tune it a bit more agressively when you can watch for detonation (knock count) and AFR's on a dyno.


Good luck with your car!

 

[JusMX141]

Tim, have you ever re-used an OEM MLS gasket?

I'm not accusing you of poor mechanical workmanship or anything, but all of us have had a weekend where we have to get the car together and all we have are used gaskets. I've done it in a pinch with my motocross bikes so I could make the race- I just wondered if you had ever re-used an OEM MLS and how well it held up to high boost after it had been previously compressed.

 

[twicks69]

Tim, have you ever re-used an OEM MLS gasket?

I'm not accusing you of poor mechanical workmanship or anything, but all of us have had a weekend where we have to get the car together and all we have are used gaskets. I've done it in a pinch with my motocross bikes so I could make the race- I just wondered if you had ever re-used an OEM MLS and how well it held up to high boost after it had been previously compressed.

Oh, heck yeah I have, I just use Permatex Ultra Copper Spray then, and the next time I need the head off for a fresh resurface, etc., I replace it. I am not going through these things every week....I used 5 or 6 in 3 years on a high-boost race setup. Heck, I really only needed to do 3, but I had extra cash, and put a fresh one in when I had everything disassembled a over the winters. I used a new one in July of 2005 with the fresh engine build, then a new one in April of 2007 with the engine refresh (rings/bearings), and then 2 head gaskets due to head swaps/and blowing stuff up on the dyno in June of 2008. Even then, all of them looked brand new with the exception of the first cylinder head failure one...I stretched the crap out of the 8740 head studs I was running since July of 2005, and made my cylinder head all wavy. The gasket actually didn't fail, it was lifting the head enough to make it look like a head gasket failure (pressurizing the cooling system). This was after an entire season of running 40-50psi of boost on 8740 ARP head studs. I retorqued them and finished out the dyno day, then pulled the head (getting valve float from dying valve springs) and put on a fresh head and new valvetrain with a fresh head gasket. I ended up pulling it off again after 5 pulls due to a piece of foreign debris entering the combustion chamber, causing a misfire, and a couple tweeked valves.

The USED head gaskets never had an issue either; I just really didn't want to have to pull the darn head again just to fix a problem I could have averted beforehand. I take my stuff apart fairly regularly, so really, it isn't an issue of using a fresh gasket every time. I do the same with my intake and exhaust manifold gaskets, and replace them when I see fit to do so.

 

[JusMX141]

Awesome man. You've said exactly what I wanted to hear. It must be working for you...a 9 second timeslip and nearly 750whp on a 2G daily driver is nothing to scoff at!

What prompts you to get your head resurfaced....do you have a set amount of miles or operating time that makes you uncomfortable reinstalling a head without getting it resurfaced? How many thousandths are too many when it comes to milling the head surface before you think it's a good idea to switch to a thicker gasket or different head?

 

[twicks69]

Awesome man. You've said exactly what I wanted to hear. It must be working for you...a 9 second timeslip and nearly 750whp on a 2G daily driver is nothing to scoff at!

What prompts you to get your head resurfaced....do you have a set amount of miles or operating time that makes you uncomfortable reinstalling a head without getting it resurfaced? How many thousandths are too many when it comes to milling the head surface before you think it's a good idea to switch to a thicker gasket or different head?

I never really had a set mileage or operating time before contemplating a head resurface. If the head was in perfect shape and within .002" flat, I didn't bother, and I would put it back on. I had the last head shaved two times from virgin, the first time was .002", and the second resurface was .004" more. I believe that there is a spec out there concerning how much you can shave off the head.

Last time, the head was so out of shape, it wasn't worth salvaging, so I found a 1G virgin replacement head to build and surfaced it before install. When I ate the foriegn debris and tweeked the valves, it really only had like 5 dyno pulls on it (I literally put it on the car and had to take it off the same day after screwing it up), and it didn't need a resurface; just two fresh exhaust valves and it was ready to go again the next day. When I finally got everything back together, I hand-grenaded my transmission on low boost.

After installing a new transmission the next week, I toasted it in less than 10 pulls because I accidently put the wrong front differential ring gear on (I put on a 58-tooth gear instead of a 57-tooth), causing it to torch my 3rd/4th, and a few other parts. I was running a center diff spool, so it really was mean to my transfer case and rear end as the ring gear caused my front wheels to travel 2mph different than my rear wheels.

After that, I put in another fresh race transmission the next day, and drove the car home. The next time I drove my car up to the track to race with the new setup, I hand-grenaded the turbo before I even got to the track. After that, I trailored the car home from my friend's, and took everything apart.

I am not resurfacing the head when I reinstall it this next time, it still looks brand new. I will clean the oil and coolant passages, and inspect everything, along with a new MLS head gasket and my ARP L19 head studs, and it will be all ready to go.

 

[TurboAnything]

Well now i have to eat my words. I got overzelous and put in 10 gallons of e-85 and tryed to tune it. Well i have had some issues with my #1 cylinder for a while burning alot of oil. So i adjusted my afc to 18% more fuel and tryed 25psi and she ran like a rape date. A/F was real lean but i wanted to push it so 35psi here i come. And as you can see from the pics 35psi went!

 

[92AWDHX40]

wow never seen that before. ouch.