Jump to content
HybridZ

wow fel-pro + boost = BAD


twistex

Recommended Posts

well.. I have a customers car thats equipped with a 3.0 with forged pistons and all that jazz. Well I installed a front mount, hks bov, 3" exhaust " took off the flowmaster lol." lsd install, electric fan, removed a/c and clutch fan whatever. The 60mm ka throttle body has a hole drilled in it to make it idle im guessing ? They had the idle air motor deal capped off so I hooked it up to the intake tube on turbo. Idles great now.

 

Anyways he has a hybrid type t3 on it and a external turbonetics waste gate. Boost with flowmaster on was about 8psi when I got the car. After all the crap I did to it.. it was holding about 11 or 12. He calls me and says when he first got the car he was running 18 psi. I told him well .. I would rather see it on a dyno before I turn up the boost. He tells me to turn it up to 15. I turn it up to 14 and wow it blew the head gasket so bad compression was shooting out the side of the head between block on turbo side. Pulled spark plugs and did compression test and it was shooting water out of the 2nd and 3rd cyl across my shop! Anyways what it all boils down to is why would someone run a fel-pro? Now this is suppose to be a rebello motor built in 2000. 3.0 with forged pistons.. well I don't see a hks gasket under this head! I think he got jacked from the old shop he took it to and got charged 5500 for a rebuilt crap motor!

 

Other things I noticed while taking the head off was on the exhaust side the head bolts that travel through the cam towers had 2 washers under the turbo head bolts but all others had 1 and one of the cam towers had 1 .. thinking .. would dave do this ? also the 12mm head cam tower bolts all are nissan except one looks like a ace or osh hardware bolt... would dave do this ? Also the p90a head was converted to solid lifter and has a billet cam in side that says hks on it ;).

 

This car came equipped with a 7th hks style injector but was later swapped out for a jwt 300zx computer, 450cc injectors, cobra maf.

 

 

well I'm looking into some head gasket choices and well only gaskets I can seem to locate are the nismo .60 mm head gaskets 1mm and 2mm are no longer getting sold. What are people doing lately for headgaskets ?

Link to comment
Share on other sites

Well let me add to this.. I'm hoping it wasn't detonation that cause this head gasket failure :( . Once I do get this car up and running again I'm sure going to check base timing and toss it on dyno and check out the afr and tell customer that 12psi for now until then.

Link to comment
Share on other sites

  • Administrators

Sorry to hear this. It is always disheartening when this happens and I feel your pain and frustration.

 

With that said, why is it when a head gasket blows, everyone is quick to blame the manufacturer of the head gasket because it didn’t contain detonation???

 

Now everyone please understand this, especially if you are building/tuning Turbo cars for other people.

Regardless of the manufacturer of the head gasket, it will blow if there is detonation! (or if the gasket is old and the engine was neglected for several years or over heated). ½" inch ARP head studs, metal head gaskets etc, will NOT stop the release of combustion gasses to the atmosphere via the block-to-head interface if detonation is present and extreme enough. A blown head gasket is just your proof positive indicator that detonation was present and those detonation pressures were high enough and rose quick enough to literally lift the head, releasing the clamp on the gasket, allowing the fire ring to blow out. If you use a head gasket that is more resistant to blowing out and also increase the clamping pressure with studs or larger studs, you may have contained the detonation longer, but the next weakest link WILL let go if the gasket doesn’t and that is generally even more expensive to repair.

 

Felpro head gaskets are NOT weak in the fire ring. The Fire Ring of the Felpro L-series head gaskets will contain the pressures of NORMAL combustion, even at elevated boost. If there is any abnormal combustion, I don’t care what gasket is being used, all bets are off for the gasket maintaining its seal between the head and block. The biggest and only issue of the Felpro head gaskets for the L-series is the weeping of coolant, externally only, on the passenger side of engine on cars that tend to sit for extended periods, like over winter.

 

I do advocate the use of metal head gaskets in boosted L-series, especially if the engine has proven itself to withstand higher boost levels with no issues, but only if there are no issues. The standard head gaskets are a nice early warning indicator that something still needs attention if it blows, i.e. detonation is present. I just hate to see gasket manufacturers blamed for something the manufacturer has no control over.

 

L-series are detonation sensitive to begin with. Add boost and that sensitivity is exaggerated, as twistex just experienced. There are members here that successfully push 20-25+ PSI boost on their engines over and over for years with no issues, and there are others that have blown head gaskets at a mere 12-14 lbs the first time they reach that boost level. The main difference is attention to detail in the “tune(fuel, timing, and maintaining “safe” combustion temps). The successful just don’t crank up the boost until they are comfortable that all their bases are covered in reducing the possibility of detonation as best they can.

 

By the way, Dave does successfully use Felpro head gaskets on his N/A engines. I’m not sure what he uses on his boosted engines.

 

Again, I'm sorry to hear about this as it is not only time and money consuming, but no fun to deal with and come to terms with when it does happen. Just keep in mind that this happens to even the best of builders and tuners. That is how the good tuners become good! :wink:

 

Hope you are able to get it back up and running in short order.

Link to comment
Share on other sites

A friend of mine runs 11's and 10's with nitrous on l28 stroker engine

with fellpro gasket no problems

 

another one built a backyard high compression engine kept blowing gaskets

got a metal head gasket guess what broke the piston

 

we've blown gaskets at 10 psi of boost due to detonation... :-|

Link to comment
Share on other sites

Sorry to hear this. It is always disheartening when this happens and I feel your pain and frustration.

 

With that said, why is it when a head gasket blows, everyone is quick to blame the manufacturer of the head gasket because it didn’t contain detonation???

 

Now everyone please understand this, especially if you are building/tuning Turbo cars for other people.

Regardless of the manufacturer of the head gasket, it will blow if there is detonation! (or if the gasket is old and the engine was neglected for several years or over heated). ½" inch ARP head studs, metal head gaskets etc, will NOT stop the release of combustion gasses to the atmosphere via the block-to-head interface if detonation is present and extreme enough. A blown head gasket is just your proof positive indicator that detonation was present and those detonation pressures were high enough and rose quick enough to literally lift the head, releasing the clamp on the gasket, allowing the fire ring to blow out. If you use a head gasket that is more resistant to blowing out and also increase the clamping pressure with studs or larger studs, you may have contained the detonation longer, but the next weakest link WILL let go if the gasket doesn’t and that is generally even more expensive to repair.

 

Felpro head gaskets are NOT weak in the fire ring. The Fire Ring of the Felpro L-series head gaskets will contain the pressures of NORMAL combustion, even at elevated boost. If there is any abnormal combustion, I don’t care what gasket is being used, all bets are off for the gasket maintaining its seal between the head and block. The biggest and only issue of the Felpro head gaskets for the L-series is the weeping of coolant, externally only, on the passenger side of engine on cars that tend to sit for extended periods, like over winter.

 

I do advocate the use of metal head gaskets in boosted L-series, especially if the engine has proven itself to withstand higher boost levels with no issues, but only if there are no issues. The standard head gaskets are a nice early warning indicator that something still needs attention if it blows, i.e. detonation is present. I just hate to see gasket manufacturers blamed for something the manufacturer has no control over.

 

L-series are detonation sensitive to begin with. Add boost and that sensitivity is exaggerated, as twistex just experienced. There are members here that successfully push 20-25+ PSI boost on their engines over and over for years with no issues, and there are others that have blown head gaskets at a mere 12-14 lbs the first time they reach that boost level. The main difference is attention to detail in the “tune†(fuel, timing, and maintaining “safe†combustion temps). The successful just don’t crank up the boost until they are comfortable that all their bases are covered in reducing the possibility of detonation as best they can.

 

By the way, Dave does successfully use Felpro head gaskets on his N/A engines. I’m not sure what he uses on his boosted engines.

 

Again, I'm sorry to hear about this as it is not only time and money consuming, but no fun to deal with and come to terms with when it does happen. Just keep in mind that this happens to even the best of builders and tuners. That is how the good tuners become good! :wink:

 

Hope you are able to get it back up and running in short order.

 

+1

Link to comment
Share on other sites

Sorry to hear this. It is always disheartening when this happens and I feel your pain and frustration.

BRAAAAP, BRAAAAP, BRAAAAP....

 

As always Paul, 100% dead on...

 

I run 15psi on a stock head gasket. All out 15:1 CR race L28 GT2 motors run stock Nissan head gaskets! The problem is detonation. If you just swap in a metal one, you will break something else (pistons, rods, crank) when you turn the boost back up.

 

Verify your timing tab is accurate (#1 piston at TDC, then index the pointer on the damper), then verify your timing is correct with a timing light. Next tune it for 12:1 AFR under boost, 14-15 AFR under atmospheric pressure. If the motor has flat tops, the CR is probably around 8.5:1. At 15psi I would start at an advance of 20 degrees or less.

Link to comment
Share on other sites

I ran a felpro gasket in my motor for a couple years with absolutely no issues. I ran 18psi on a daily basis with that gasket. And that was with old stock headbolts, but they were torqued correctly. People keep bashing them but this is completely opposite to my experience.

 

I eventually went to ARP head studs and a metal gasket for higher boost, but I will be one to say there is nothing wrong with a felpro gasket... and I have NEVER blown a head gasket. I blew 3 pistons on my engine without touching the head gasket.

 

But anyway sorry to hear about you trouble!! Time to get metal!

Link to comment
Share on other sites

This is a factory installed, original, 110K mile, Nissan gasket that held for five years with the factory ECU and injectors at 15psi!!!

 

I installed Megasquirt, mis-tuned (learning process), and the gasket blew at about 13psi.

 

190081387_8ZRkg-L.jpg

 

No blaming gaskets here. :nono:

Link to comment
Share on other sites

well.. I have a customers car thats equipped with a 3.0 with forged pistons and all that jazz. Well I installed a front mount, hks bov, 3" exhaust " took off the flowmaster lol." lsd install, electric fan, removed a/c and clutch fan whatever. The 60mm ka throttle body has a hole drilled in it to make it idle im guessing ? They had the idle air motor deal capped off so I hooked it up to the intake tube on turbo. Idles great now.

 

The 300zx/Wolf ecu doesn't properly control the 280zx aac valve. Even if it did, the stock 280zx idle control system uses non intercooler air for idle control. Your source of air for idle control should come from the intercooler outlet, not the turbo compressor inlet or outlet(the stock 280zx use the compressor outlet because it was designed for low boost, non intercooled situations).

 

If the idle control is improperly hooked up, you may be causing a boost leak, allowing air to be recycled and reheated by the turbo. In another case, you may be allowing some compressed, uncooled air to bypass the intercooler. Either case is trouble for engine and the turbo. Not only could you have detonation, but you could be over spooling your turbo.

 

"Who is it? Dave's not here".

Link to comment
Share on other sites

The 300zx/Wolf ecu doesn't properly control the 280zx aac valve. Even if it did, the stock 280zx idle control system uses non intercooler air for idle control. Your source of air for idle control should come from the intercooler outlet, not the turbo compressor inlet or outlet(the stock 280zx use the compressor outlet because it was designed for low boost, non intercooled situations).

 

If the idle control is improperly hooked up, you may be causing a boost leak, allowing air to be recycled and reheated by the turbo. In another case, you may be allowing some compressed, uncooled air to bypass the intercooler. Either case is trouble for engine and the turbo. Not only could you have detonation, but you could be over spooling your turbo.

 

"Who is it? Dave's not here".

 

interesting.. well now that i think about it your correct. I know on a sr20det the idle air tube runs under intake mani and couples itself to a tube on the cold pipe going into throttle body. How should i hook it up ? I know that when tb is completely closed the tps is set at like .45 or so. And only way to get enough air into the intake manifold is using a idle air type deal.. that comes from the intercooled air that has already been metered by the maf. Should I weld a little tube coming off my cold pipe at throttle body and hook it up there ?

Link to comment
Share on other sites

Sorry to hear this. It is always disheartening when this happens and I feel your pain and frustration.

 

With that said, why is it when a head gasket blows, everyone is quick to blame the manufacturer of the head gasket because it didn’t contain detonation???

 

Now everyone please understand this, especially if you are building/tuning Turbo cars for other people.

Regardless of the manufacturer of the head gasket, it will blow if there is detonation! (or if the gasket is old and the engine was neglected for several years or over heated). ½" inch ARP head studs, metal head gaskets etc, will NOT stop the release of combustion gasses to the atmosphere via the block-to-head interface if detonation is present and extreme enough. A blown head gasket is just your proof positive indicator that detonation was present and those detonation pressures were high enough and rose quick enough to literally lift the head, releasing the clamp on the gasket, allowing the fire ring to blow out. If you use a head gasket that is more resistant to blowing out and also increase the clamping pressure with studs or larger studs, you may have contained the detonation longer, but the next weakest link WILL let go if the gasket doesn’t and that is generally even more expensive to repair.

 

Felpro head gaskets are NOT weak in the fire ring. The Fire Ring of the Felpro L-series head gaskets will contain the pressures of NORMAL combustion, even at elevated boost. If there is any abnormal combustion, I don’t care what gasket is being used, all bets are off for the gasket maintaining its seal between the head and block. The biggest and only issue of the Felpro head gaskets for the L-series is the weeping of coolant, externally only, on the passenger side of engine on cars that tend to sit for extended periods, like over winter.

 

I do advocate the use of metal head gaskets in boosted L-series, especially if the engine has proven itself to withstand higher boost levels with no issues, but only if there are no issues. The standard head gaskets are a nice early warning indicator that something still needs attention if it blows, i.e. detonation is present. I just hate to see gasket manufacturers blamed for something the manufacturer has no control over.

 

L-series are detonation sensitive to begin with. Add boost and that sensitivity is exaggerated, as twistex just experienced. There are members here that successfully push 20-25+ PSI boost on their engines over and over for years with no issues, and there are others that have blown head gaskets at a mere 12-14 lbs the first time they reach that boost level. The main difference is attention to detail in the “tune†(fuel, timing, and maintaining “safe†combustion temps). The successful just don’t crank up the boost until they are comfortable that all their bases are covered in reducing the possibility of detonation as best they can.

 

By the way, Dave does successfully use Felpro head gaskets on his N/A engines. I’m not sure what he uses on his boosted engines.

 

Again, I'm sorry to hear about this as it is not only time and money consuming, but no fun to deal with and come to terms with when it does happen. Just keep in mind that this happens to even the best of builders and tuners. That is how the good tuners become good! :wink:

 

Hope you are able to get it back up and running in short order.

 

Yes you are completely correct! I did take some time out on the search feature to read some of your posts about basing on head gasket company's and most time its just the installer not cleaning or prepping this correctly or just bad tuning. Now that I think about it I think I heard detonation.. but you know what I'm thinking.. jwt ecu blah blah blah should be fine with these injectors and maf yada yada yada. I will put this all back together and turn the hks manual boost controller completely down so its at 7psi and im going to go dyno it and see the afr. I called jwt btw and asked them if there any updates for my tune and he said there has been 2 updates. Mainly because the fuel has changed since 2000 ? You think it would be worth sending the chip in for them to re tune ? maybe send the dyno sheet back with the 28 pin chip from ecu and pay them $100 big ones. The funny part is ever since this customer has had this car from day 1 in 1999 in a 280zx chassis it has never been intercooled and he said he was running 18 psi. Blew first motor on drive home from l.a to bay area cali. This is where his nightmare started lol. So I figured wow he has the bigger injectors, the cobra maf, the 300zx ecu tuned from jwt, now a intercooler thats cooling the air it should be fine at 15. Obviously not. Thanks for your input but Your 100 percent on the detonation obviously. I know 76 fuel has to suck balls because every time I would pump 76 gasoline 91 oct into my sr20det it would run so bad!

Link to comment
Share on other sites

It sounds to me, that anyone running 18psi on a stock engine, with no fuel management upgrades, intercooler, injector upgrades, just goes to show that this person is a bit of an idiot. I've found so many threads amongst these sites about stock boost that you can run, and it sounds like without any sort of upgrades with the stock system about the most you can run is 11-12 psi, before the system can't even keep up and even at those boost levels it's still risky with no upgrades.

Link to comment
Share on other sites

interesting.. well now that i think about it your correct. I know on a sr20det the idle air tube runs under intake mani and couples itself to a tube on the cold pipe going into throttle body. How should i hook it up ? I know that when tb is completely closed the tps is set at like .45 or so. And only way to get enough air into the intake manifold is using a idle air type deal.. that comes from the intercooled air that has already been metered by the maf. Should I weld a little tube coming off my cold pipe at throttle body and hook it up there ?

 

 

I believe most people just allow more air through with the throttle plate angle adjustment screw and rotate the TPS sensor accordingly.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...