Smoke

[Dave999]

Just need to garner some views

Help!

Engine built.
in for last years Nats
fine for 6 runs
last run down the strip i was followed by cloud of smoke (blue/white)

limped home. oiling the plugs regularly
compression was low on a couple
pulled it
stripped it
honed it
new rings
checked head
checked MLS gasket looked good the black was worn slightly on the embossed rings . pulled it to bits cleaned it spray Hylomar re rivet used iit again


back in

all good
50 miles into run in started smoking
smokes intermittently to start off with
plugs on 2 and 3 oily
smokes like a trouper now
runs fine at 1000 misses and farts at anything under load above 2500 rpm


so far

1) Compression test shows 185 on 1,2 and 3 195 on 4,5,6 that to me says not rings and no problem with valves
it shows 180 if i forget to open the throttle. oil down the hole makes little difference probably becasue its all oily anyway

2) busted my leak down set up so no figures for that (regulator at wrong end popped guage)

3) new valve seals on inlets. applied rest of set to exhausts. none on exhaust valves previously still smokes

4) replaced igntion (coil/module/plugs cleaned rotor checked cap) and cleaned all connections going back to dash. to see if i could revive above 2500 rpm performance. No luck


SO.....


head was skimmed by well known company and surfaced for MLS gasket, no compolaints.
block was done by well known geezer... did an good align bore for me when asked if he had remebred about MLS gasket when doing the deck he said yeah...it'll be alright.....

head was smooth....
deck you could still see some cutting marks.


attached pics of
plugs

and a new stanard head gasket

Big holes in middle for pistons
small holes at bottom are for dowels and water between head and block
water return each end as well

no presurised oiol feed through gasket, engine oils through the pushrods

medium holes up top outlined in blue pushrods and oil return
medium holes up top no blue outline dead ended at block. casting sand holes from head, water can get to deck but no further.


Head gasket issues???

normally expect to see water coming out the side
water getting into cylinder
bubbles in the radiator
compression issues on 1 or more

I see none of this
i see no loss of compression

all i can think of is that oil is slowly percolating through the layers or under the the gasket across too rough deck at some RPM and getting into at least no.2 cylinder and possibly no.3

or the head is lifting???? ARP studs torqued to spec...!


note even though plugs look orrible decent band on the earth of 1,4,5,6

2 was black and 3 was wet with oil

when 2 came out the hole for compression test it was followed by smoke
and that smoke continued out of the plug hole for a few minutes.


So

do you think its head gasket
if it is
i'm going to use a standard one.

got me baffled


PS didn't over fill oil. do have a sump baffle do not have enough power/ compression or forced induction so can't think head is lifting.

Dave

[MilesnMiles]

Dave, is it oily smoke or black fuel smoke? Just hoping you might have a fuel/carb issue instead of a motor issue.

[Pete]

Did you compare the Cometic against a Stock Head gasket to ensure all the hole locations / sizes stack up?

Readings would not point to rings / head gasket, but you never know....

It certainly seems a puzzler - I would have gone for guides but it seems you have checked everything...

[Dave999]

Deffo not black smoke...
that would be a prime contender. if you can't get the thing to idle properly now way can you tune 6 barrels of weber...this is why the plugs don't look great.... idles, you tune 2or 3 for lean best idle and then suddenly it stops. or it surges off based on how well all cylinders are fireing/ battling through the oilyness.
new plugs and they are filthy within 3 miles

so its set at 1/2 turn on the throttle stops and 1.5 on the idle mix i.e standard baseline + idle mix 1/4 turn either way to smooth it off.

rest of set up in the webers is genrally recognised as the Chrylser original set up with a nod to modern fuel. slight tweak on the idle jet slightly smaller on the main and its air corrector to take into account higher vacuum casued by 38 mm rather than 40 mm chokes (i'd have to look it up but its a well worn path to weber happines on a hemi 6)

Gasket has slightly bigger bore on the cylinders and needed the dowel holes rounding out slightly other than that perfect fit but lacking the embossing around the dead end water holes. its a cometic so the quality in theory should not be an issue

guides are new
seats are new
valves are new
seals are new...
springs collets rockers retainers etc etc

as in less than 500 miles or newer

hence my frustration.
i've been suffering in silence pretty damn sure i'd made a school boy error

if i have i can't work out what

even with no seals i'd tend to expect oil down the guides when under vacuum only. puffs of it

this smokes even when running at 3000 under no load i.e low vacuum.

but occasionally clears for no apparent reason

smoke screen at the lights after a squirt up the road escpecially after it was working ok then decends into popping farting and misfire under load as the plugs get wet

but slow poottle at just off idle with all cylinders singing the same tune it occaionally clears. suppose i burn the crap off and am not doing enough to pull any more oil in

cracked head?? don't think so no oil under pressure in anything, there is water between the combustion chamber and the oil. i'd excpect presuriesed radiator and bubbles.

oil exposed to vacuum i guess so and the only place would be towards the top side of that gasket between a cylinder and a hole ringed in blue??

but what comes in on induction must also blow out on igntion???

arrrgh

Dave

[charger01]

If you're running a mechanical fuel pump check that it isnt pinholed blockside. I had that, baffled me for a while.

[Dave999]

i'll check that

i guess it destroys the oil and allows it to get whipped up. haven't checked oil level for a week or so it was lower last time. (burnt a fair bit i guess)


Dave

[charger01]

Pull the fuel pipe to carbs see if there is any trace of oil Dave.

[Dave999]

I will indeed

[Mick]

Leaky intake gasket or pcv not working correctly ?

[MilesnMiles]

Dave, how many miles? I've read that until rings bed in blow by can ensue and that the PCV can exaggerate that.
Had it with a 360 I built. Went away as the rings bedded in. Never had clouds of smoke though but it was noticeable for a while.

[Dave999]

Hi Mick

intake and exhaust all on one side no oil near either its a 6, same design for inlet and exhaust as the slanter but with wider spacing.

PCV. have issue with or without it connected up. have choice of 3 valves have tried 2. has appropriate baffle in rocker tin to stop pushrod/rocker spray fireing directly at the valve (basically sits in a tube that stops down between 2 rockers out of the way of the oil being slung

Miles yeah i know thats why version 1 was torn down. it may or may not have been the problem

but i thought i'd see ring seal problems in the Compression test
and the figures seem eminently reasonable...

can you have 2 rings good and 3rd expander one bad? dunno

i'll get a new leak down guage for my set up. and try that



Dave

[Roger]

I take it that with the breather disconnected there isn't excessive smoke from the crankcase?

Assuming not, and the smoke is blue, then obviously oil is getting into the combustion chamber. You know that but how?

If youre convinced its not valve guide guides, how sure are you your piston rings are the right way up?

[Scooby]

Interesting enough Dave someone else was discussing a smoke issue at the weekend and the mech pump also came up in conversation so deff worth a look before the major strip down .
Rich

[Carl]

Dave, have you put a high pressure/volume oil pump in? It could possible your over oiling the heads and as the engine heats up some oil is running down the valve stem?

[Dave999]

OK

took off fuel pump blocked off inlet and out let and give it a gentle pump

no obvious flow of fuel out the lever hole. any other way to check? its a modern carter like 2 pillar sealed pump off a slant 6.

Rings Federal/sealed power/speedpro basic rings nout special apart from moly top ring. confusing instructions focus on other styles but have a small note on the back which basically says if you are a cheap skate and have our basic rings do it like this .....dot up profile down

smoke from the breathers, some, minor, but nothing i haven't seen before on engines that didn't do this

i'm 97.345% happy i got them in the right way up

top ring shiny edge dot on top
second ring not shiny edge profile to inner lower side biases ring down a bit i guess

expanded 3rd ring follows same as any other style or make put on expander latch it so the join jooks like all other sections and put the thin rings round

place gap of all rings round the piston to avoid lining up. avoid a gap above the pin 10 o'clock 2 o'clock 4 o'clock 8 o'clock

Nobody has made an oil pump for a hemi 6 since 1982..... this is a good body with a new spring releif piston and impellor. and its just as rubbish as they were when new 8-10LB at idle when hot and 40-50 lb at 5000 rpm. never gets any better. you can try but you tend to snap the pump housing or wind the cog off the shaft

have solid lifters with metering valve and through pushrod oiling
lots gets up there but no more than standard.


the 3 cylinders with lower compression are the 3 cylinders that had worst plugs

one of them smoked when plug pulled out.


Looked into oil migration through or under MLS gaskets on the tinternet

about 14 of an inch distance w

50:50 on opinion as usual

some say yes if the surface is not smooth to 4-5 microinch i think my head is can't vouch for the block
some say yes only if pre igntion has occured

and this is the 3rd time the gasket has been used........ (even if nout much happend in between)

there is 1/4 of an inch between pushrod hole and combustion chamber.

Dave