gmgearhead454

Thanks for the advice everyone, I'm thinking it's Definately a non - seated or completely bad ring issue. To answer the questions, the heads are 2005 Vortec 454 heads, and actually they came off of a natural gas engine used by Laclede to run their generators. So really they are from the industrial line bbc motors, as these heads have super hardened seats, no exhaust crossover, and came factory with inconnel exhaust valves. They are large oval port heads, and have 99cc heart shaped combustion chambers. After I had them surfaced, I did a substantial amount of work in the chamber to unshroud the valves (aftermarket SS large valves). After all the work was done, the heads cc'd right out to 99cc exactly, and with the standard 4.250 bore, flat top pistons with
3cc worth of valve reliefs in each one, and the measurement of the compressed gallery thickness and diameter, it came out to 9.01:1 compression, and it's never been even fitted with anything less then 93 octane. I've heard that they don't generally like a lot of timing, but every set up is different, and but the more timing I take away,
the worse it runs? Oh, and to run these heads you simply use the original mark IV head gaskets. I studied that intently, and all the cooling passages lined up really well. The puking oil into the carb may be a big contributor to it dying maybe? I really wanna just try adding a puke tank, putting a smaller carb on, move the coil away from the heat and see if that makes a substantial change. If that don't do it then I'll Definately be pulling the motor and doin the rings, check out the cylinder wall and go through the heads to figure out wtf....

donzi matt

iTrader: (1)

With 70psi compression in the cylinders there is no point in even trying to get the timing optimized. The motor needs to come out and find out what went wrong as your next step.

29 FOUNTAIN FUN

Compression test and leak down test is the first thing. As with the above post. Then remove oil filter and cut the threaded end off and pull paper out for inspection. There should be less than a teaspoon of misc. debris in there. More than that you have issues that need to be addressed before running it anymore. Feel free to call me at 989-224-9803 Kyle. Good Luck in your project.

blue thunder

If the rings are ok then it must be a cylinder issue, out of round, taper or just excessive clearance or like someone mentioned above, you already burnt pistons due to setup and/or not enough ring gap. FWIW, I've built engines with good straight bores and only did the glaze breaker hone and had good ring sealing so I dont think its rings not sealing from bore finish.

SB

iTrader: (1)

I know this sounds dumb, but have to ask. Have seen other's do this.

Assume the block is factory standard but ends up .030" or more. 'Factory Replacement Standard Bore' pistons gets installed.

Chase tune forever. Bother me forever. I suggest compression test. That gets blown off because 'no way, I just built it" disease.

Tune, tune, tune, tune,,,,,motor still a slug and pushing oil.

I do compression test - can't deal with answering bad question after bad question.

Find out it's got compression near yours.

Tear it apart. Kick person in mouth after finding something like that.

Just my crazy experiences I can't seem to hide from.

LOL.

donzi matt

iTrader: (1)

That motor must have piston slapped like a bastard.

SB

iTrader: (1)

Ran into this twice. Didn't hear either run, Thank god. I probably would have cried. LOL.

I have a customer that decided to do the brakes on his own on his Focus. He brought it in due to scraping noises. He had his pads so that the friction material faced away from the rotors.

After I cried/laughed/and puked I called him and he preceded to drill me with questions on why his other car's check engine light is on and it runs rough.

Told him not to touch it and pay me to properly fix it.

I have pics of it somwhere in my other computer.

Anyway, moral of story, is some should not touch things.

Rookie

iTrader: (4)

I can't believe we are trying to still diagnose this with those compression #'s. There is no tuning, timing setting or valve cover baffle that is going time fix this thing.

There is something wrong with the pistons/rings/bore. (I hope something inexpensive)

My 0.0002$
Carry on

ICDEDPPL

iTrader: (1)

70 psi is fiiiiine.. I~m sure its something simple, probably need to run some thinner oil or add some Slick 50

offshore312

At this point, I'm thinking Wet Roof Cement just might do the trick!