Replaced Guide Seals... still some smoke

GEARS · Oct 5, 2011

OK, so I was up until 1:30 am yesterday and I completed the entire job in one go. All I did was replace the intake guide seals and the stem seals... I left the exhaust seals alone as GM had put in SBC viton guide seals on all the exhaust valves for warrenty work when the motor was new.

I found only 1 out of 6 seals that was good, 4 out of 6 were leaking and installed incorrectly from factory, and 1 seal was completely exploded into little bits!

It definitely burns less blue, and the pre-detonation is gone, but it still smokes a bit after idling for a while and then reving it. Should I give it some time to seat or something?? Maybe its really gummed up?? It burned an entire litre of oil last week!

michanic220 · Oct 5, 2011

why didnt you replace all of them while you were in there, you just made yourself have more work to do.. as the exhaust are the main ones that leak.

34blazer · Oct 6, 2011

ok they should not be exploding, not even one. did the other ones look flattened on top?

GEARS · Oct 6, 2011

Well one was on crooked, and another looked like it got ran over by a car before it was installed! Oh and iron head 660's never came with valve guide seals on the exhaust, they only are on the intake valves.

The wierd thing is, last night I took it for a run at like 1:30 am... a real easy low rpm no load type pf run... and it didnt burn a damn thing!! No smoke, no smell, no nothing! But today after about 30 miles of driving, it started coming back?? By the time I got home, we are all back to square one

-> It is definately not the PCV as I ran it without and got the same results.
-> I am 100% sure its not the compression rings... as it pulls 200 psi soooo...
-> I am 99.99% sure its not the oil rings... as it only smokes after idling for a while (during a period of high manifold vaccum)
-> The motor only has 13,000 miles... so I cant see the guides being shot.

This only either leaves the guide seals or the intake manifold gaskets. I have the motor with the rockers stripped out again for the second day in a row, and tomorrow I will decide if I will redo ALL the valves the cheap way with my little spring compressor with keeping the heads on.......... or rip the motor right down to the pistons and port/polish the heads, new head and intake gaskets, and viton-ize everything that moves!!

34blazer · Oct 6, 2011

what kind of cam are you using? did you ever put 1.6 rockers on there? if the umbrella seals are smashed then its probably the retainer smashing them. put a solid lifter in there and check the clearance. i have the same problem with a mild cam and 1.6 rockers. had to have the guides cut down

GEARS · Oct 6, 2011

I am running the equivilant of a Crane H260 cam, which is a fairly moderate cam. And ya, it has only been burning blue after the installation of the rockers, so I am thinking that the lift is too much for it... I dont wanna ditch the 1.6:1 rollers, so if anything the heads are getting ripped off and modified to work, along with a port/polish.

I guess not paying for gas will give me a good opportunity to save for more parts, I spend $60 dollars a week for 91 octane.

@34blazer, I guess it was easy for you to see that the seals were getting hammered with the use of solid lifters. What cam, and springs/retainer style were you using when this happened to you??? And how did you go about getting the guides cut???

BTW is there any benefit to solid lifters in these motors???

34blazer · Oct 6, 2011

sorry i should have been more specific. this was with my last 2.8, i had the 1.6 roller tips with a crane hydraulic lifter cam. the 260 and the 272 cam, and then the comp 440 lift. what is effed up is i used what crane recommended for those cams. i was way past coil bind on the springs and thats why they broke:rant:. once the lift got close to .490 i noticed high rpm flutter and it wouldnt pull any more. wiped 3 cams in that motor before i figured out what it was. and broke almost all of the valve springs too, even a few locks where exploded lol. so you are definitley smashing the seals with the retainers, wouldnt run it anymore until you get the guides cut down.

my solid cam is pretty sweet but its meant more for high rpm apps, with the shitty irons(even ported too) its stalling the port around 6K. and i have to relash it at every oil change, which doesnt bother me all that much.

using a solid lifter to check the clearances will be the most accurate way to check. the viton seals wont pop off like umbrella seals so thats why i used those. its gonna get expensive with those irons, i wish i would have went the hybrid route from the get go. and since you want to tweak the ecm yourself its very doable. a 3500 top end will probably out perform the 3.4 blower setup too. food for thought......

AND CHECK COIL BIND!!! lol

GEARS · Oct 6, 2011

Ya its parked for good, and the heads are getting ripped out today and tomorrow. I'm gonna do my own porting (cheap), reuse springs/valves/retainers/locks (still basically new... obviously I'll be inspecting everything!), cut the guides myself (I have access to all types of tools and machinery and a good machinest as a teacher), and put viton on the exhaust and intake.

I have an old set of iron heads to play with aswell so I'll use those as mock-up.

Now I gotta decide between Fel-Pro or Cometic head gaskets!!!!!!!!!!!

@34blazer, what did you use for head gaskets??

34blazer · Oct 6, 2011

test your springs for coil bind and then measure you net lift with a micrometer, forgot the actual name but it sits in the valvespring pocket. the guide needs to be cut on the diameter for the viton seals to fit, not just cut down. unless you are making extreme power the cometics are almost a waste of money. plenty of people making way into the 400's with standard felpros or graphite head gaskets. i used the graphite head gaskets. dont carve into the floor of the port or knife edge the hump, if you do that you might as well cut it out completley. just smooth it out without changing the camber of it.

GEARS · Oct 7, 2011

Well I studied the old heads all taken apart today, and I am amazed on how much meat there is to be eaten in the exhaust port! It also had a very very VERY rough finish and lots of loose cast just hanging in there.... so I see good potential in the exhaust side of things. Plus, I might look into headman headers due to the fact that all primary tubes have a equal 1.5" diameter, meaning I can port the exhuast ports all the way to 1-3/8" (leave a wall to prevent reversion!). Then I'll drive it over to a muffler shop and just get them to make a custom Y-pipe and have it connect to the current rear half of the current exhaust.... or if I learn enough by then I'll attempt to do it myself!

On the intake ports, I just want to clean it up, leave the floor, pretty much leave the hump, carve certain parts of the roof, leave it rough textured, and thats it.

Fel-Pro head gaskets and intake gaskets sound good enough for me.

In a way..... this entire procedure is just getting me one HUGE step closer to slappin' on the blower! Once I am done this, I'll drive it N/A until I have ALL the parts for the charger, and have it all installed and running within a few days.

34blazer · Oct 7, 2011

get ready to spend hours on trying to open those ports up lol. cast iron sucks to grind

. the bowls is where you are going to find the most improvement, reducing the size of the guide bosses and blending the bowls to the runners will yield the most gains. also, the backside of the guide can be strategically formed to direct airflow towards the center of the cylinder, which shouldnt be hard as the ports are already directed at the center of the cylinder. square up the ports and blend everything nice and there will be a difference.

GEARS · Oct 10, 2011

@34blazer,

So I see you used viton seals, but I cant seem to find any for a 660?? Did you retro-fit them from a certain SBC application?? If so, what was the application!!

Oh, and when modifying the guides, do you just cut them down a bit?? Or is there more to it??

Thanks for all the info, its certainly been an extremely large help!

34blazer · Oct 11, 2011

GEARS said:
@34blazer,

So I see you used viton seals, but I cant seem to find any for a 660?? Did you retro-fit them from a certain SBC application?? If so, what was the application!! Oh, and when modifying the guides, do you just cut them down a bit?? Or is there more to it??

Thanks for all the info, its certainly been an extremely large help!

not sure what app the viton seals are for, you might have to search for a dimension rather than a specific vehicle application. weber racing did the machine work on those heads back in 2007. yeah you want to cut them down but you should measure how much you have to clearance first. cutting off too much will take away from the lateral stability of the valves.

michanic220 · Oct 11, 2011

plus the shorter the valve seals, the faster they wear out due to loss of stability stated above.

Mad Max · Oct 11, 2011

Casual observation: Check the guide to valve stem clearance. If you have excessive clearance, the engine will use oil. I usually replace the guides by opening them up and installing bronze - phosphorus guides. They last longer.
BTW, I have a Mitsubishi Mighty Max that was CHOWING oil HARD. I thought it was guides, I installed a fresh head, no reduction in clouds. I checked compression, it was good. I became pissed and ordered rings and rod bearings, and a gasket set. Tore the B*tch apart, put in a set of premium rings, did a light cylinder hone = no more pollution. I mean really, no smoke at all.
Before rings, if I was doing 60 MPH and let off, no exageration - you could not see the car behind me. EMBARASSING!! :rant:
OK, moral of story - oil rings do not control compression, the 2 compression rings do.
I call oil rings are pooched.
Confucius say - man with bad oil ring smoke alot.

Hoosier Rick · Oct 11, 2011

Mad Max said:
Casual observation: Check the guide to valve stem clearance. If you have excessive clearance, the engine will use oil. I usually replace the guides by opening them up and installing bronze - phosphorus guides. They last longer.
BTW, I have a Mitsubishi Mighty Max that was CHOWING oil HARD. I thought it was guides, I installed a fresh head, no reduction in clouds. I checked compression, it was good. I became pissed and ordered rings and rod bearings, and a gasket set. Tore the B*tch apart, put in a set of premium rings, did a light cylinder hone = no more pollution. I mean really, no smoke at all.
Before rings, if I was doing 60 MPH and let off, no exageration - you could not see the car behind me. EMBARASSING!! :rant:
OK, moral of story - oil rings do not control compression, the 2 compression rings do.
I call oil rings are pooched.
Confucius say - man with bad oil ring smoke alot.

I had a 69 nova with an inline 6 that started using oil bad on one cylinder. Compression good. Did valve seals, etc. Ended up finding an oil ring expander broken. No more mosquito fogging.

GEARS · Oct 13, 2011

Well I torn the motor apart today, but before I did I installed the old 1.5:1 tappet rockers and drove the crap out of it............................... and there was not a hint of smoke!!!!!!!

This concludes the case with the 1.6:1 COMP Roller Rockers proven guilty to be smashing the valve seals with CRANE retainers and springs all on top of a CRANE H-260-2 cam.

I also had fun by running it with pure open headers LOLOLOL!! It was so loud even I was annoyed! We had like 4 teachers come down to the auto shop and complain hahaha!!

But now, she gets torn apart and the heads will recieve a full port/polish/gasket match, the valve guides will be shortened, and the guides will also be cut on the diameter to fit 0.530" VITON valve seals. Then Fel-Pro gaskets for the heads and intake, and new headers from Headman, and a new exhaust

All work to be done by me!

Replaced Guide Seals... still some smoke

GEARS

michanic220

34blazer

GEARS

34blazer

GEARS

34blazer

GEARS

34blazer

GEARS

34blazer

GEARS

34blazer

michanic220

Mad Max

Hoosier Rick

GEARS

Top Contributors this Month

Recommended Communities