Engine rough as hell......

[mrvette]

Timing in range....but VERY rough idle....all 8 seem to be firing.....the same, butttttt the fuel is good pressure, LT-1 engine with HEI up top in back....

so roller block, 1.6 roller rockers.....thought they all adjusted right but hoo nose??

SO how to adjust roller cam?? keeping an insane mess to a min.....

no unusual valve train noises....

any hints anyone???

[73sbVert]

Vacuum leak somewhere?

[mrvette]

Originally Posted by 73sbVert

Vacuum leak somewhere?

Seriously doubt it, thing is, the idle is more or less, 'normal' speed, not like 2+
it's lo enough that I can feel the weird firing and wonder about valves adjustments......one other thing, when I tore it down I did not keep the roller lifters in order, the got mixed up when cleaned......same with roller rockers 1.6 ratio.....

[DJ_Critterus]

exhaust opening = adjust intake
Intake closing = adjust exhaust

Do this for each cylinder and do it in order so you don't get anything mixed up. We've already gone over this in past threads

[mrvette]

Originally Posted by DJ_Critterus

exhaust opening = adjust intake
Intake closing = adjust exhaust

Do this for each cylinder and do it in order so you don't get anything mixed up. We've already gone over this in past threads

I followed the exact sequence shown in my '87 vette manual.....L98 cam so a roller cam same as I have I never tore down the '87 engine to dunno about roller rockers much less they were 1.5 these roller rockers are 1.6 ratio.....

thing is, I wonder about the adjustments on clearances.....

[markids77]

Originally Posted by mrvette

I followed the exact sequence shown in my '87 vette manual.....L98 cam so a roller cam same as I have I never tore down the '87 engine to dunno about roller rockers much less they were 1.5 these roller rockers are 1.6 ratio.....

thing is, I wonder about the adjustments on clearances.....

Wait... you went from 1.5 ratio rockers to 1.6 ? Same cam spec as the last engine or different? Are your pushrods the correct length for the current cam/rocker combo? Ditto the valve springs and installed height.
I wonder if you either have spring bind or have bent a valve or several because the increased lift made them kiss the pistons.
EDIT: Are the new rockers solid rollers or hydraulic, and what were the old ones?

[Oh-yaa]

Originally Posted by markids77

Wait... you went from 1.5 ratio rockers to 1.6 ? Same cam spec as the last engine or different? Are your pushrods the correct length for the current cam/rocker combo? Ditto the valve springs and installed height.
I wonder if you either have spring bind or have bent a valve or several because the increased lift made them kiss the pistons.
EDIT: Are the new rockers solid rollers or hydraulic, and what were the old ones?

Did you mean lifters? I believe setting the lash is different between the 2.

[mrvette]

Same rollers lifters and roller 1.6 rockers as before.....same cam even....they used to run smooth and well before the gasket failures....but like I said, they not all in the same spots they were before....the valve train does not make noise like it was loose.....

[DJ_Critterus]

Originally Posted by mrvette

I followed the exact sequence shown in my '87 vette manual.....L98 cam so a roller cam same as I have I never tore down the '87 engine to dunno about roller rockers much less they were 1.5 these roller rockers are 1.6 ratio.....

thing is, I wonder about the adjustments on clearances.....

Your specs are obviously not stock so the manual is of little help. Do it the way I suggested and it works every time.

[mrvette]

Originally Posted by DJ_Critterus

Your specs are obviously not stock so the manual is of little help. Do it the way I suggested and it works every time.

Well, my '87 vette service manual I have had since '91 or so, sez to #1 TDC and do a bunch of intakes and exhausts on both banks, then set engine for #6 TDC and so the rest on both banks.....so I set them up but thinking that the lifters were washed out with brake cleaner, and blown out with air jet to make damn sure no rust....let them dry in the sun, then tossed into a can kept indoors with a lid on it.....same sort of treatment for the 1.6 ratio rockers and pushrods.....

so the only trick is, now that the lifters are full of oil, I wonder if they forcing the valves too much open,....in other words....back off the adjustments say 1/2 a turn lovely....pull all the crap outta the way to get the damn covers off....

GRRRRR.....at least I got some arthrongus pills to kill the worst of my pains in the shoulders and hands....

[DJ_Critterus]

Originally Posted by mrvette

Well, my '87 vette service manual I have had since '91 or so, sez to #1 TDC and do a bunch of intakes and exhausts on both banks, then set engine for #6 TDC and so the rest on both banks.....so I set them up but thinking that the lifters were washed out with brake cleaner, and blown out with air jet to make damn sure no rust....let them dry in the sun, then tossed into a can kept indoors with a lid on it.....same sort of treatment for the 1.6 ratio rockers and pushrods.....

so the only trick is, now that the lifters are full of oil, I wonder if they forcing the valves too much open,....in other words....back off the adjustments say 1/2 a turn lovely....pull all the crap outta the way to get the damn covers off....

GRRRRR.....at least I got some arthrongus pills to kill the worst of my pains in the shoulders and hands....

You lost me at the first sentence. Do it the way I explained and you will get it right....and more accurately right....it'll be more righter.

[mrvette]

Originally Posted by DJ_Critterus

You lost me at the first sentence. Do it the way I explained and you will get it right....and more accurately right....it'll be more righter.

I followed the procedure in the book, and the engine has NO misfire, just a rough idle and much smoke out the exhaust much less burning off the headers in the garage,....so to back it out into the drive, and put a temp fix on the right exhaust pipe I cut to get the head off....Ricky can weld it back when I get it all dun......I suspect NOW that the engine is burning off lots of assy oils short block to heads/etc.....so to pick up on it again......maybe this afternoon, as RAIN is tmrw....according to the weather squidgy board anyway.....

[DJ_Critterus]

Originally Posted by mrvette

I followed the procedure in the book, and the engine has NO misfire, just a rough idle and much smoke out the exhaust much less burning off the headers in the garage,....so to back it out into the drive, and put a temp fix on the right exhaust pipe I cut to get the head off....Ricky can weld it back when I get it all dun......I suspect NOW that the engine is burning off lots of assy oils short block to heads/etc.....so to pick up on it again......maybe this afternoon, as RAIN is tmrw....according to the weather squidgy board anyway.....

I thought rick retired. He has the same stuff as Michael J Fox and couldn't weld anymore.

[mrvette]

Originally Posted by DJ_Critterus

I thought rick retired. He has the same stuff as Michael J Fox and couldn't weld anymore.

I called Rick some 2? months ago, he working with his brothers in their shop.....seems from him talking he was in welding shape....

but I put a hose clamp over the pipe to limit the leaking/noise and drove a few blocks ......now to handle the ignition system.....engine smoothed out a LOT from burning off all the oil from machine/assy.....but I note the temp is normal, in spite of the silly gauge on the dash....going by my IR gun.....which is super accurate over the years.....proven.....


NOT that the engine runs really gross or anything, just not PURRfect, yet....

need trace out some dizzy wiring yet......HATE my memory.....PITA....