barnett468

i know techron is a deposit reducer as i posted in my previous posts on this thread which i guess you missed . . this is one of my points . . he is running one of the cleanest gasolines around and he has what .looks like 150,000 miles of deposits in just 2000 miles.

from post number 3.
i typically start at the beginning of a thread and read all the posts before i reply.

i also know pretty much what his engine temps and compression and carb jetting are too from other threads whic i also considered and they asre not far from around 100 zillion other engines around my area so back to the same question . . other engines don't do this...whay does his?

i also actually know pretty much where he lives from ither threads he has posted and it is not terribly far from where i am, so i considered this variable too.

not sying your theory is completely unplausible, just saying it is unlikely imo, but unless the actual cause is determined, inquiring minds will never know.
.

67mustang302

Other engines do it. I've seen it. Even on Chevron fuel. I've even had the same issue running on various fuels, including Chevron. CA fuel is pissy and inconsistent.

Different regions can also get different fuel blends. California alone has something like 17 different blends based on the region you're in, of the same grade of fuel. The 91 octane Chevron out of a pump in LA is different than the 91 Chevron out of a pump in Fresno, because the state says it has to be.

He changed from iron heads to aluminum heads. If the seals were new, and since it's highly unlikely that all 8 intake seals would fail simultaneously and to the same degree....what is the changed variable that caused it? Going from iron to aluminum can due to heat characteristics, or the new heads required a change in tune and the fuel ratio and/or timing is off (changing valve temp). Is he cruising at the same throttle position, or is he running higher load now (which would be even more likely with a cam change)? Running higher load cruise means a higher absolute pressure in the port, which reduces the vaporization characteristics of the fuel.

A lot of variables were changed, some having a larger factor than others. But there's only a few that he can change easily. Things like AFR, ignition timing, engine operating temperature...those are easy to change. Things like compression and valve timing are not.

It is possible that all 8 valve seals failed, but that would require bad install procedure that was replicated across all the seals...and would still be very unlikely to cause every seal to fail at the same time and to the same degree. But I'd bet a lot more on engine temperature vs fuel characteristics. CA blends fuels based on emissions requirements, so it's expected they're run in emissions controlled vehicles with high vacuum, high mileage/low emission cams, high engine temperatures, and high compression. Burning a fuel intended for emissions engines in a non emission performance engine, causes issues.

In my engine running at 195-200* or higher, no deposits. Also, mileage is better. Also, throttle response is better. But, I'm also in an area where it gets below 0 in the winter (but also drive where it's over 100 in the summer). Fuels in CA cause all sorts of issues in performance engines, including deposit formation.

Gun Jam

Interesting ideas.

My gut reaction was deposits were a result of valve temps. The heads were brand new and pre-assembled by trickflow. So valve guides should have been new...but maybe they all leak equal amounts? This is why the oil via PCV seems more likely to me I know it will overtime accumulate in the breather caps and you can see small amount of oil on the valve covers under the breather caps despite the baffles in the valve covers (this could be a likely source but I have no idea how much oil it would take to stick onto valves like that...seems like the fuel would wash it off pretty well considering were talking gallons of fuel to a few drops of oil...hummm)

When you measure your engine temp its at the thermostat with say a non contact temp gun right?

How would I know what the optimal thermostat would be for my application? Im Pretty sure im running a 185... Should I make sure to stay at or below 200 Tstat wise? Throw a 195 in it and see if it changes the way it runs?

Thanks

-Gun

67mustang302

I get my temp through the sensor for the XFI, in the manifold at the front crossover near the thermostat.

I run a 195 in mine, but optimal depends on what you want. I set things up for running best for how I drive it. That's sort of true for most tuning, give the engine what it wants and not what you think it wants.

Starfury

Ok, now that we know what kind of heads you're running...

I have the same heads on my 331 and I do not have the same problem, or at least I didn't the last time I yanked the intake. I can verify again in a month or so when I get around to yanking it again to fix a blown rear coolant seal. I run a 195* t-stat and also live in CA (and yes, CA "gas" is terrible and inconsistent). The motor runs at a pretty consistent 205-215*, measured from the front intake crossover just like 67mustang302.

I still like the PCV-oil burning idea, but as mentioned, it's all theory at this point. Fill up from a different gas station than normal, run some cleaner through the top end, and see what happens.

STA-BIL®

Hi Gun Jam,

Sorry for being a little late to the game. For something like that we would recommend using a high quality complete fuel system cleaner that is aimed at specifically that purpose - cleaning the fuel system. Chevron Techron makes the best Fuel System Cleaner on the market. When buildup gets that bad, you want to attack it with a product made just for that purpose.

Moving forward, the help prevent that from happening in the future, use a high quality ethanol treatment with fuel system cleaner more often. I may be a little biased, but I would suggest trying STA-BIL® 360° Protection.

STA-BIL® 360° Protection will help keep fuel fresh, clean up the fuel system, and prevent rust & corrosion - both above and below the fuel line.

The key with additives is to be wary of those that have laundry lists of claims. Generally, when an additive has a ton of claims, the rarely perform any one of those claims well.

Have a great afternoon!

barnett468

what engines in general?

they get this much build up from gas with techron after only 2000 miles? . . i mean we are talking about driving 100 miles round trip to work everyday for 3 weeks . . at this rate, the valve would have so much junk on it it 2 months that it would block off almost all of the air flow.



i definitely agree in theory but we know nothing about hos heads . . the might not even have seals on them and the valve clearance might be .010" so unless these things are determined of course we are just best guessing.




of course but from what i remember, his timing is correct and it is not jetted rich.
.

barnett468

it is not incosistent...it is always terrible.



easy deal, just plug the pcv for 2000 miles and look again

Gun Jam

A little biased...Well thats honest I'll read up on the 360.

I had 192 Tstat installed it was old so I replaced it with a new 195...A 200f is not available. The 195 I got is a better unit it can not be opened unless heated. The old was very easy to open by hand its plausible that under load water could force it open via pressure alone but that takes us to another point. I dont think changing Tstat would make a difference I could put a 300F Tstat in there and it would probably run at the same temp on the freeway as it does now because I think water through the bypass hose is enough to totally remove the tstat from the equation. I bet it never opens on the freeway when temps are below 70f.

A 2nd temp gauge would be good at this point maybe....one that actually gives me a number. The stock gauge is very reliable and very consistent but a real number would be good in this case....I dont know where I would run a 2nd temp sender (probe) I still want to keep my stock gauge running...any ideas?

The PVC plug seems like a good idea too!

Thanks

-Gun

Gun Jam

And this looks totally bad ***...

http://www.ebay.com/itm/DIGITAL-ENGI...-/110678264837

I have an edelbrock airgap intake...now I gotta figure out how to get that to play ball.

-Gun