COSPEED

In West Central FL, we have a shop with dyno willing to document base dyno runs to establish power, and then will perform manual intake valve cleaning procedure and re-dyno to show the true documented power loss from intake valve coking. All will be provided at no cost, the cleaning is worth $800-$1200, and dyno time over $100.

The more miles on your C7, the better. See exactly what is occurring inside your intake ports.

Also want a group of unbiased members present to document and witness each step to make this accurate and well witnessed/documented. Video, pics, etc. of each step.

Expect to spend app 4 plus hours at shop while all is done. Must all be completed same day for accuracy on the dyno.

IF you should choose to purchase a CoSpeed or Elite E2-X system to prevent this, that will be installed at the same time at no cost. Only purchase the system ahead of time and have with you.

So much debate on this, and so much misinformation out there this should go along way to actually document for all.

This will also be included in Vette Magazine article on these issues and how they affect the new GDI V8's from GM. Let's verify, document, and share with the World.

PM me for details,

Jason

Rooster OG

I will be very interested in seeing the results from this!

raylo

What I'd really like to see is a more scientific approach that shows what the valves on a number of cars look like at different mileages. While the vendor here might get a dirty one and show a decent before and after dyno, a sample of one is not representative and is basically meaningless. But hopefully our valves don't look like some of the BMWs I have seen in the youtube videos of the manual cleaning procedure. They were horrid.

MikeLsx

Well if one engine has nasty valves, then more can. So far everything i have seen in terms of valve deposits on new generation GDI GM v8 hasn't been as bad as the FIRST generation BMW GDI engines.

My predictions are that while carbon build up will happen over time on the LT1, its not at the rate of a 2007 BMW 335i.

I find it hard to believe that GM did nothing at all to combat this problem.

I think sooner or later the OP will find someone.

COSPEED

Mike is correct. They all have this, but none are as severe as the early BMW's as every automaker has made great strides in reducing the severity mainly by internal oil separation improvements with GM's cyclonic separator in the 2015 and up dry sumps, and the valve cover design and baffling on all LT1 based V8's including the trucks. I would say that these engines in the past 3-4 years are realizing app 1/3rd the severity of the late 2000's did/do. But the issues still remain, and it is impossible to correct/eliminate this w/out an external device designed to specifically stop the oil and other compounds from ingestion. Internally separating and retaining this is now also retaining the same damaging compounds the PCV systems of the past used to evacuate and remove back with port injection engines, so engine wear will increase and life decrease.

So, GM, and all others have been "working around the clock" to combat this (while still denying it exist's according to Tadge, yet the Camaro engineers acknowledges the great strides made contrary to Tadge's statements) and are continuing to. That is where new developments in the external separation devices not needing to be end user emptied should be showing up in the next 3-4 years (minimum time to make such changes in production).

We inspect these and most all other makes engines as much as possible and see turbo versions have a bit less than NA of the same engines, but all still are seeing worn valve guides by 20-30k miles, the degradation of power and efficiency, etc.

Until we can see valves remain in the shape and texture they come form the factory like port injection engines (example here at 140k miles):




Even BMW from 2010 to 2015 has made improvements that show app 50% as bad, but these are still alarming.

raylo

We'll see where this goes, but I am skeptical that separation devices will fix the issue compeletely. The amount of material in those deposits isn't all that much so if any oil gets through we will still see some level of gunking. I wonder if it will take some sort of active approach like Toyota's port/DI hybrid injection system to be truly effective.

COSPEED

Any move away from the shape and texture of the valves as the engineers designed them has a pretty dramatic effect on the flow rate, the amount entering each cylinder, and the velocity, or speed of that flow and all are negative.

We will always see a small very minor amount from the burnt gasses that do back-swirl during the EGR emulation of variable valve timing, but that is negligible.

Audi, Toyota, and several others have added the small port injectors back in to attempt to slow the rate, but this results in 2 things happening. One, it is far to little as it requires the full time showering of the valves as in the past with port injection to really eliminate this (port injection run several hundred thousand miles and have no deposits at all) and 2, any fuel present during the compression stroke now results in detonation again that true GDI eliminated for the most part, so timing is now pulled in greater amount and incidence negating much of the advantages of GDI. So that has turned out to have limited reduction in coking, but greatly reduces the advantages and inefficiencies of GDI.

COSPEED

The member we found w/over 30k miles to do this test has a super charger installed and we want to first do it with a basically stock LT1 for accuracy and relevance. Looks like they will do the test later w/this FI example though. We still need a higher mileage LT1 basically stock (NA) to show this in relation to the majority of GDI LT1's here.

Thanks! :thumbsup:

COSPEED

Offer is still open! Get over $1000 value of product and services for free, and help the members here see documented results.

NinjamanZ51

Wow... Nobody's jumping on this? SMH.

owc6

Well, I've got 43,000 miles, but Colorado is pretty far away.

davidtcpa

Fastoldguy

I wish I was Closer! I'm at 23k and considering looking at mine (and possibly cleaning).

COSPEED

The shop to perform this is located near Tampa, FL. Nice and warn compared to MD this time of year....minutes from the beaches and all the spring break bikini's!

Suns_PSD

Great idea and I can hardly wait to read the results.

COSPEED

Bumping this up!! Florida members, has to be someone wanting to do this. Just look at the data that will be gained and the free$$ worth of it all.

COSPEED

Bumping this up! Not only does the car owner get a high $ value of services and product, they also help this go a long way in detailed documentation of all of this.

Flame Red

Gee, I am not far away but I only have a couple of thousand miles and a catch can in it since day 1. Can't believe dozens of local folks have not filled up your PM box!

COSPEED

Looks we have a candidate! Just confirming all. Yes, needs to be a basically stock example w/no catchcan installed for the 20k miles.

COSPEED

An interesting article by consumer reports:

http://www.consumerreports.org/cro/n...ines/index.htm