Stingray Corvette Forum banner

1 - 20 of 28 Posts

·
Registered
Joined
·
85 Posts
Discussion Starter · #1 ·
I have one of the first supercharged Stingrays, and want to give a little warning to all considering modifications, such as turbo's or blowers. These cars have a problem with excessive crankcase pressure, and front seals are blowing out on the cars. Heneessey, LMR and others are working on breather systems to help, but don't think anyone has developed a sure fire mechanism for releasing adequate crankcase pressure. The front seal seems to be the weak link on the engine, and is what is failing first. Mine is being replaced as we speak.

Just a bit of advice for those in consideration phases...or if has already been done be careful. :(
 
  • Like
Reactions: Sinner and smajicek

·
Registered
Joined
·
1,330 Posts
Also wondering what Callaway has done on their new supercharge kits to avoid this issue? or have they?
 

·
Administrator
Joined
·
16,583 Posts

·
Premium Member
Joined
·
739 Posts
You'd want to consider the beefier LSX front seal. No direct replacement as of now, but they can be slightly milled to size.

OP did you remove the ball valve in the valve covers? Client had the same thing happened and went to the open breather system and replaced seal as well. Had a pretty healthy track day on Saturday without repeat issues.
 

·
Registered
Joined
·
85 Posts
Discussion Starter · #7 ·
I am hearing removing the ball valve does not solve the issue. LMR has a crankcase breather system developed but I am hearing it only reduces partial pressure, and really does not solve the problem. Hennessey is looking at a new breather for the valve covers, but still in development...no fix as of yet. Heavier duty seal is not the answer. Pressure has to go somewhere...I personally would rather see a seal blow out rather than a engine detonating.
 

·
Registered
Joined
·
85 Posts
Discussion Starter · #8 ·

·
Registered
Joined
·
85 Posts
Discussion Starter · #9 ·
LMR is putting their breather kit on my car next week...hope it will work for me!
 

·
Registered
Joined
·
34 Posts
Also wondering what Callaway has done on their new supercharge kits to avoid this issue? or have they?
Callaway, who was the first to supercharge the new Direct Injection V8 Engines, doesn't have issues as reported in the thread.

Power, Style, and Exclusivity - Callaway is Powerfully Engineered, indeed...
 

·
Registered
Joined
·
85 Posts
Discussion Starter · #11 ·
Lol....Chris, if you haven't created a resolution to crankcase pressure, you have then simply been lucky. Supercharging the engine, and not creating a new design for the engine itself is nothing but a bolt on to a known problem. No offense, as Callaway is a good name but don't come into my thread and try to insult me by saying my car is lesser than what you are producing...plain and simple BS.
 

·
Registered
Joined
·
34 Posts
Lol....Chris, if you haven't created a resolution to crankcase pressure, you have then simply been lucky. Supercharging the engine, and not creating a new design for the engine itself is nothing but a bolt on to a known problem. No offense, as Callaway is a good name but don't come into my thread and try to insult me by saying my car is lesser than what you are producing...plain and simple BS.
No worries, as I am sure your tuner has it handled :cool:

Just responding to someone regarding the 2014 SuperCharged Callaway, I've been driving one with the new Direct Injected V8, it's now over 15,000 miles, no issues. No BS, plain and simple :cool:
 

·
Registered
Joined
·
85 Posts
Discussion Starter · #13 ·
One car?? really, and you are the expert?? Come on....tuning isn't the problem with the crankcase pressure. No other comments needed...you have your opinion, and I have mine based on more than 1 car being done...lol
 

·
Banned
Joined
·
631 Posts
Sorry I am late to this thread. The issue has nothing to do with the checkvalve as long as a proper crankcase evac system is used, and to date, not a single manufacturer of FI systems seems to understand what is needed.

And what I see out there is most are deleting the evacuation function and only venting pressure to the air filter. Then there are some systems TOTALLY deleting the PCV system and running the fresh and foul sides together in one breathered can so that zero evacuation takes place allowing all the harmful combustion byproducts to accumulate in the crankcase contaminating the engine oil. Part of the blow-by all engines experience (the better the ring seat, the less blow-by) are compounds that will cause premature wear and damage to the internal engine parts over time if NOT evacuated as soon as they enter the crankcase before they can accumulate and contaminate the engine oil. As this wear happens over time, most will never associate the wear with the lack of a proper PCV system. Now, in that blow-by there is unburnt fuel, water vapor (released from the air in the combustion process), abrasive carbon particles (many to small in micron size for the oil filter to trap) and other damaging hydrocarbons, etc. In the crankcase sulfuric acid is also produced from a combination of these compounds and if this is not constantly, and completely evacuated (flushed by fresh in and foul out) it is going to accumulate in the crankcase settling into the engine oil and onto the internal parts (anyone that tears LS engines down can attest to the corrosion on the rocker arms and the needle bearing buckets on the drivers side when the valley cover vent is used on older LS engines that left the driverside stagnant).

So, there are going to be some unhappy C7 owners miles down the road that are installing the systems that delete all evacuation and tie the fresh and foul sides together into one can to vent.

And, now with the LT1 being Direct Injection, the intake valve coking issue is a new issue never before encountered by the LS crowd.

The solution? You must have a PCV/crankcase evacuation system that will retain the constant evacuation of these compounds, and any system that pressurizes the intake manifold under boost has to be modified as the intake manifold vacuum will only provide evacuation while in non-boost operation, and all systems to date we see are defeating the evacuation process by just running a vent line to the air filter.

The OEM PCV checkvalve is not designed to operate under 12-16# boost, so you must use a properly design checkvalve on the foul side to prevent boost pressure from entering the crankcase, and if used between the IM and the PCV valve, the OEM valve will not fail and stick. Then you most have an alternate evacuation source to switch to as soon as boost is detected. For this we have for the past 12 years used the inlet of the turbo/centri blower for this alternate suction (GM just began doing the same with the Cadillac ATS 4 cyl turbo with inlet suction fitting already cast/machined in). So, if you look at the RX system for the C7 Procharged, ECS/A&A systems you see we have the PCV system remain intact. We use the intake manifold vacuum to provide evacuation when in non boost with the primary checkvalve closing as soon as it detects any boost (protecting the OEM PCV valve preventing failure). We then tap into the head units inlet side for suction to continue evacuation as soon as in boost so when the primary valve closes, the secondary valve opens providing proper and continuous evacuation no matter if in boost or not. And the RX can is the only one that stops all the detectable oil from ingestion. Then, the cleanside separator provides the fresh side air uninterrupted and also stops and traps any oil from ingestion when pressure seeks the path of least resistance during the brief transition between non-boost and boost. So, you have zero pressure issues, you have a properly evacuating PCV system, and have maintained a EPA Emissions compliant system. The oil ingestion is stopped preventing detonation and intake valve coking, and no issues with these other compounds contaminating the engine oil.

Ask any questions on any part of this not clear...this is a subject that is so full of wrong solutions and misunderstood functions all over the internet and vendors jumping into the market with catchcans not designed to deal with any of this properly.
 

·
Banned
Joined
·
631 Posts
LMR is putting their breather kit on my car next week...hope it will work for me!
You understand that this defeats all crankcase evacuation, don't you? It does a great job of releasing pressure (and is 50 state illegal on the street) but it also leaves all the damaging combustion byproducts to settle and accumulate in the engine oil and crankcase. Your sacrificing engine life for pressure relief when you can accomplish all and be pulling evacuation at all times. Don't believe this? Wait 5 k miles and do a BlackStone oil analysis and see for your self. If you want more details or wish to discuss in-depth your welcome to call direct: 941-721-1826.

LMR does such a great job on engine and power builds as well as tunes, but as most, are only considering the obvious issue of pressure and NOT evacuation. Very few shops understand this, it is not taught any more and very few old guys have kept up with it over the tears, especially on forced induction applications. I am in no way meaning to insult you....just sharing actaul fact that with the price of an engine you may want to consider.
 

·
Registered
Joined
·
85 Posts
Discussion Starter · #16 ·
Interesting information, and you sound knowledgeable about this topic....Spoke with Hennessey today, and he said the front seal is happening on stock cars as well. Said they have seen 3 recently with 100 or less miles on them completely stock, with front seals leaking. Seems to be an issue GM is now investigating according to the GM at Hennessey.
 

·
Registered
Joined
·
20 Posts
o2texceta, how's the progress on your car? What do you think of Tuner Boost's comments? I'm scheduled to have a D1 procharger installed in a few days so I'm a bit concerned :confused:
 

·
Registered
Joined
·
85 Posts
Discussion Starter · #19 ·
His comments were very lucid, and appreciated. I understand evacuation vs pressure relief...just not sure whether I am going to add anything else to the car at this point. I have had blowers on my cars for many years, and always just worked with catch cans with no other ill effect. My current Trans Am had a blower on it for 4 yrs and almost 70k miles with just a catch can with no issues, as well as other cars.

I let LMR put their breather (crankcase vent) system on the car, and also removed the valve balls that had been recommended earlier. I then added a Snow Methanol kit(different subject), but was also done while at LMR, and they are re-tuning. I was already involved with LMR, so am sticking with that. They seem to think I will be ok as well.
 

·
Registered
Joined
·
85 Posts
Discussion Starter · #20 ·
o2texceta, how's the progress on your car? What do you think of Tuner Boost's comments? I'm scheduled to have a D1 procharger installed in a few days so I'm a bit concerned :confused:
I would talk to your shop about it, and get their input. This is just what I am doing, and feel as confident as one could be based on the newness of this platform. Mine is supposed to be done today.
 
1 - 20 of 28 Posts
Top