hi guys heres the run down. i have a 1970 355 with stock heads worked over and probably just over 3k miles since rebuilt was 2/3 years ago. all new electronics with msd module under cap with rev control. spark is good out the end of all wires. intake is edel 7104 rpm. twice now in the last 600 miles the car starts missing. limp it home and pulled the plugs and all are fine except for no 1. its jammed pack full of oil but it has compresion. it has 183 and all others are about 175-185 on the other holes. my local machinists suggest that the intake mani gasket may be leaking but wtf? only 1 hole would be affected? i put it together myself and i'm sure the dam thing didn't move but i dunno i guess its possible but other possibilities are flogging my mind as of late. the heads are old 441's that we tossed in 2.02 and 1.6's and i bowled blended and ported but there were looked over before being assembled so its not like athere a hole in them but i had the guides machined to accept the viton thimble type valve seals like what come on vortec heads instead of the tin shields with umbrella o rings. is it possible that the no 1 cylinder seals could have come loose and would it be able to suck this much oil through the new guides anyway? that last thing i was pondering is that i guess the oil ring is low tension or so and i'm told that if a cylinder isn't firing then the rings will not have compresion to force the rings to seal and then it will suck oil into the chamber. i am currently messing the gov on kmy trans and every so often i am bouncing on the rev limiter and wonder about how it works? like is the msd module cutting spark intermitintly to all or random cylinders when it comes into play or just a single one like maybe no. 1 cylinder. i dunno, got so many dam little things to finish i didn't wanna rip out the intake to inspect. anyone run across this? thanks.
fresh 355 and oil is in no.1 cylinder fouling the plug
- Thread starter 79malibu
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use some silicone at the bottom of you're intake gaskets on the manfold side it sounds like you're sucking up a lil oil from the valley, I had to put thicker gaskets on my motor to stop it from sucking up oil (.120 thick fel-pro), shouldn't be a hard problem to fix
easy one : your no1 valve seal is broken from bad install
change no1 spark pug : never know , cheap try
not easy one ; ring problem , overlapping gap or else .....
the fact that you get a bit more compression on this cylinder is the fact that you are building carbon ....
change no1 spark pug : never know , cheap try
not easy one ; ring problem , overlapping gap or else .....
the fact that you get a bit more compression on this cylinder is the fact that you are building carbon ....
yea'll i have to pop the valve cover off this weekend and check the seals out. i asking around to see if anyone locally to me has an inspection camera or video device i can go into the intake runner and look for oil at the gasket area. did not want the hassle of taking off the intake. if i have to take the intake off them i will most likely want to switch it out for an air gap type intake. last saturday it was 91* with humididty and the car was hot and not really wanting to cool even in the shade(yes i know its was hot out) i am thinking more of a electric fan and the air gap type intakes. except for the temp difference is there much of a power difference between the edebrock perf and perf rpm intakes in the air gap? besides their intakes i have been eyeballing on the net some ones that are identical but made by pro comp or competion products iirc. anyone run them or here much about them? they are priced cheap on KMJ in iowa.
i'm interested in what the leak down test would show though? like i have heard of it and know of the general idea but that wouldn't really tell me why im getting oil in thought would it?
i'm interested in what the leak down test would show though? like i have heard of it and know of the general idea but that wouldn't really tell me why im getting oil in thought would it?
a buddy of mine lent me his snap on video camera with about a 3 ft line and we probed around the car for a bit. in cylinder 1 and 2 ( never checked others yet)there is quite a bit of scuffing on the cylinder wall on the top interior side. he says it looks like piston skirt rubing. well sh*t. i can still see all of the cross hatching and there it is, north and south. black streaks like smears but in lines like scratches going veretical with the piston where the skirt indeed would be. well **** me side ways wtf?! that can't be normal for i have never seen anything like that before or what a scored cylinder would look like. no gouges or grooves that the camera could see but its there just like burnouts on a road.
inside the intake runner for no.1 i can't tell between the gas or the oil down through untill you get to the intake valve bowl and oh yea there is oil caked lightly on top of the intake valve. inside the chamber there is a blob of carbon all over the piston nearly covering all of it looking like tar putty. when i took the valve cover off and checked the seals they all looked the same to me. seated and not messed up from what i could see through the little gaps of the springs. so............ sh*t. looks like having to do intake gaskets.
on a side note, i'm running a speced out q jet carb with an edelbrock rpm q jet intake. but the rpm air gap i want isn't made for a spreadbore carb only squarebore. anyone know if a guy could moddify one out to work? dremel, drill, and tap? lol
inside the intake runner for no.1 i can't tell between the gas or the oil down through untill you get to the intake valve bowl and oh yea there is oil caked lightly on top of the intake valve. inside the chamber there is a blob of carbon all over the piston nearly covering all of it looking like tar putty. when i took the valve cover off and checked the seals they all looked the same to me. seated and not messed up from what i could see through the little gaps of the springs. so............ sh*t. looks like having to do intake gaskets.
on a side note, i'm running a speced out q jet carb with an edelbrock rpm q jet intake. but the rpm air gap i want isn't made for a spreadbore carb only squarebore. anyone know if a guy could moddify one out to work? dremel, drill, and tap? lol
Here you go http://www.summitracing.com/parts/EDL-2604/, try using fel-pro 1206 intake gaskets there are .120 thick
first thing i'd do is get that cylinder working again. pull the plug, disable the ignition and crank the motor to try and blow any oil build up out. you can also spray a little ATF of kerosene on the hole to break the gunk free. do NOT use a cleaner as anything you spray in can get into the oil. kero and ATF will thin it out a hair but not enough to damage things (it's safe to put a full qt in the oil--all it does is clean things out but i wouldn't go that far! 
) then reconnect the ignition and put a new plug in #1. fire it up and let it run for 5-10min. pull #1 and clean it. then you should be able to run it for an hour or so--driving--before pulling the plug for evaluation. you may be able to use a MAPP or propane gas torch to burn the crud off of the plug instead of using a new one--but only for testing.
) then reconnect the ignition and put a new plug in #1. fire it up and let it run for 5-10min. pull #1 and clean it. then you should be able to run it for an hour or so--driving--before pulling the plug for evaluation. you may be able to use a MAPP or propane gas torch to burn the crud off of the plug instead of using a new one--but only for testing.summit link doesn't work correctly. those 1206 felpro gaskets are huge in the ports. i think its too tall for my stockish heads. i know the 1204 and 1205 size up perfectly to my heads that i have opened up when i ported them but the 1206 seems a bit big. would it matter? i thought the intake gasket should match the port exactly or you get you could get turbulence interfering with the flow. or so i have read. i do think that i must have a block off for the heat risers though otherwise i think the exhaust gas will burn right through the intake gasket. a local guy thats builds derby and low budget$$$$ engines around he gimme some tin sheet metal flashing thats super thin(.010-.018?) to put on the under side of the intake so it faces the heat riser directly. we'll, on sunday when i pulled the intake off the tin had a hole in it cut exactly the shape as the heat riser port 
and he told me it would never melt for he's done it for years 
i'll show it to him and see what he comes up with for an excusse. so i called the people that did my short block and says to use stainless steel for it wont melt or burnout(i hope) or use old steel shim bbc head gaskets and cut a piece out to block the heat riser since its better steel than tin anyway. but........? i have seen factory steel shim sbc gaskets burnout between cylinders when they get old and tired. so..... i dunno. what have any of you done to block off the heat risers?
oh yea, in case i forgot to mention earlier. the reason i am blocking the risers is to try and keep the intake cool as possible for there is no rpm air gap type intake availible with a spreadbore carb in all the aftermarket crap i have looked at. it seems that when you get more into performance 90% of companys out there market their sh*t towards holley type squarebores and then go haten on the q jet. i can't fit a adapter plate unless i run a 2'' tall air filter cause of clearance with my stock hood which would be same as pissing into the wind. no i will not run a performer air gap. profesional products and edelbrock both said to use an adapter plate for they had no plans at the time making an rpm air gap spread bore. so to keep things cool im looking into getting the bottom of the intake ceramiced coated and maybe run a lifter vally tray.
back to business, so when i pulled the intake off. i seen the driver side gasket had slide forward and down a bit but looked like it should have sealed. is it normal to have carbon crud caked on the top side on new valves or is it just sh*t splashing back up from cam overlap or etc.? how wet does the intake mani usually run because the car was hot when i parked it a week before i worked on it and all the intake valves that are closed have about half a tea spoon or more green/yellow(oily?) gas sitting there. checked again today and it hasn't evaporated. would this carb be pouring the cobbs to her at idle? another thing i have noticed it that the no.1 intake runner on the intake mani is clean where the port to head runner is while all others are yellow/brown. looking oilly unless its gas turning into varnish or whatever. i sprayed wd-40 into no.1 to soften up the buffalo chip of carbon in there for maybe this weekened we'll blow it out. :lol: thanks for reading my long short story.
and he told me it would never melt for he's done it for years i'll show it to him and see what he comes up with for an excusse. so i called the people that did my short block and says to use stainless steel for it wont melt or burnout(i hope) or use old steel shim bbc head gaskets and cut a piece out to block the heat riser since its better steel than tin anyway. but........? i have seen factory steel shim sbc gaskets burnout between cylinders when they get old and tired. so..... i dunno. what have any of you done to block off the heat risers?oh yea, in case i forgot to mention earlier. the reason i am blocking the risers is to try and keep the intake cool as possible for there is no rpm air gap type intake availible with a spreadbore carb in all the aftermarket crap i have looked at. it seems that when you get more into performance 90% of companys out there market their sh*t towards holley type squarebores and then go haten on the q jet. i can't fit a adapter plate unless i run a 2'' tall air filter cause of clearance with my stock hood which would be same as pissing into the wind. no i will not run a performer air gap. profesional products and edelbrock both said to use an adapter plate for they had no plans at the time making an rpm air gap spread bore. so to keep things cool im looking into getting the bottom of the intake ceramiced coated and maybe run a lifter vally tray.
back to business, so when i pulled the intake off. i seen the driver side gasket had slide forward and down a bit but looked like it should have sealed. is it normal to have carbon crud caked on the top side on new valves or is it just sh*t splashing back up from cam overlap or etc.? how wet does the intake mani usually run because the car was hot when i parked it a week before i worked on it and all the intake valves that are closed have about half a tea spoon or more green/yellow(oily?) gas sitting there. checked again today and it hasn't evaporated. would this carb be pouring the cobbs to her at idle? another thing i have noticed it that the no.1 intake runner on the intake mani is clean where the port to head runner is while all others are yellow/brown. looking oilly unless its gas turning into varnish or whatever. i sprayed wd-40 into no.1 to soften up the buffalo chip of carbon in there for maybe this weekened we'll blow it out. :lol: thanks for reading my long short story.
lets put aside the air riser , air gap or anything else for now .....
we have to find your oil contamination problem , then we `ll discuss those ....
there is normaly 3 reasons for your problem :
faulty seal ,faulty valve guide , faulty oil ring .....
because if there is no combustion, it will case similar problem of yours,
first change the plug , no change , change the wire ,no change
lift the head , yesssss, youll have to do so ......at the same time youll see your cylinder walls if scoured .005 deep on a vertical line you definitely have a ring problem $$$$$$$$$$
we have to find your oil contamination problem , then we `ll discuss those ....
there is normaly 3 reasons for your problem :
faulty seal ,faulty valve guide , faulty oil ring .....
because if there is no combustion, it will case similar problem of yours,
first change the plug , no change , change the wire ,no change
lift the head , yesssss, youll have to do so ......at the same time youll see your cylinder walls if scoured .005 deep on a vertical line you definitely have a ring problem $$$$$$$$$$
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