Motor needs some defined help

[RootBreaker]

OK so i haven't been around much.. but haven't touched the truck either.
I have tried to get this pig to pass emissions but just cant seem to do so.
Not even with cats on it.
so my emission number I'm failing is PPM (raw un-burnt fuel). You are allowed a max of 300 and I am at 1550!!!!!
But I do not smell the fuel so it is weird...

starting the truck it puffs white smoke (or grey or whatever) and i think it smokes some when i hit the throttle when it is warm.
A while ago we had to replace 2 pistons.. long story for another thread...
my father being a mechanic has become lazy and when we did the 2 pistons in 2004ish time frame... only wanted to do the 2 pistons, rings and bearings for those 2.

Well I am going to pull this motor and go over it. It needs a rear main seal (1 piece) so got to pull motor or trans anyway.

so on plans...
rear main seal - need to buy
rings - for 6 cylinders (still have the original box I purchased and looked at them last night. In NEW shape, no rust or anything so going to use them.
Bearings - still have box of new ones from before and they are still in NEW condition so will use them.
Heads - my uncle said we will put new valve guide seals in and pull every valve and make sure all is well and smooth. If not he has some head grinding stuff..don't know what it is...


so motor specs.
1991 Chevy Caprice Roller Police 350 2 bolt (L05 block)
1996 Chevy Tahoe Vortec Heads
Weiand Power Plus+ Vortec Dual Plane Intake
Holley Truck Avenger 670CFM
CompCams Xtreme 4x4 cam (idle-1500rpm 08-409-8) 08-409-8 - click me




so I attempted to take a compression test on this motor... the gauge i got from autozone is supposed to hold the pressure but it doesnt.. so going to buy a new one from harbor freight today.
anyway... I had my son crank the motor over so I could watch the gauge..
let it crank 4-6 times on cyl 3 and cyl 6 to do one from each side. and the gauge puffed up and dropped max of 60psi. sounds extremely low. truck runs great.. has power.. can spin 40" hawgs with 4.56's and smc465 trans... so not sure what gives.. both cyl read 60..
then i tested cyl 1 and it read 60... something doesnt seem right with this gauge as my uncle checked a cyl a few months ago and he said it was at 120....

more to come...

 

[RootBreaker]

{{{Reserved}}}
Before and After Pics and notes...

 

[British Slave]

Do it right this time. You said your Dad was lazy and only wanted to do 2 cyl and now you want to do just six? Sounds like the branch didn't fall far from the tree. Do all eight!
Don't look at the valves, do it right! Have the heads re worked.

Your emmissions issue, I would look at the carb, cam, and timing.

 

[RootBreaker]

Do it right this time. You said your Dad was lazy and only wanted to do 2 cyl and now you want to do just six? Sounds like the branch didn't fall far from the tree. Do all eight!
Don't look at the valves, do it right! Have the heads re worked.

Your emmissions issue, I would look at the carb, cam, and timing.

i understand your thoughts there..
but i have less than 500 miles on it... still do all 8? i know that i could as it wont hurt anything.. but my theory is they are not even broken in yet...



plus I was going to put a 05 6L in the truck with tax return but the wife felt a new bed was in order.. so now i have really no money to do this so need to do it as cheap but get it to pass emissions....

dont have the funds to rework the heads.. when i got the vortec heads the guy said they were dipped, shaved, etc... but will see what my uncle says.. he just retired from midget bracket racing so he will know the best route....

 

[SurfinCR]

before you buy a comp tester from hf check the schrader valve on the one you have. a lot of times they just get dirty and need to be cleaned. its located on the end of the tube where it screws into the cylinder and looks like whats in a bike stem.

 

[Jessie James]

Maybe try a leakdown tester?

I am not an expert on camshafts, but they may be staying open too long and allowing too much unburnt fuel to escape, causing your problem.

But if I were you ... Pull the crankshaft, hone the bores, resurface the crank, then new rings and bearings for all 8 cylinders. Match them up, do it right. No one else does 2 cylinders at a time, or 6 later, and there is probably a good reason.

Then have the head done. New valves might be needed. If they are burnt and not sealing it is the same issue as the cam being bad.

 

[RootBreaker]

well i got the hf tester...
and guess what..

b all end all.. my motor wont get pulled...

so here is the numbers..

1: 155
2: 160
3: 160
4: 150
5: 155
6:
7: 150
8: 160

6 was empty cuz my header was in the way... so i will get the reading... however i dont think it will matter..

so my uncle said my numbers are great... so he wants me to pull the heads then look in the cylinders and we can go from there..

he thinks my heads are the issue...
so head redo time...
more to come.. saturday im gonna pull them...

 

[snowdriver]

if you want to get by emmissions,before you pull the heads,provided all the ignition parts are in good order,retard the timing,you will lose power and run like crap,but it will bring down your hydrocarbons,and after you pass inspection put it back where it runs good

 

[RootBreaker]

if you want to get by emmissions,before you pull the heads,provided all the ignition parts are in good order,retard the timing,you will lose power and run like crap,but it will bring down your hydrocarbons,and after you pass inspection put it back where it runs good

i spun the timing sooo far down.. it wouldnt go enough to pass...

it could barely move too. .and yes i adjusted the carb..