Was that the head gasket problem IIRC?
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Was that the head gasket problem IIRC?
70NPORT
Old Man with a Hat
Yes I'm kind of thinking something like that also. The odo is at 93K maybe a bit less. It mostly sat under cover for 9 or 10 yrs or so before I bought it.
Put a stroked 400 in it.....451 cubes when you are done or you can go all the way to 512 cubes.
Their are 8 million story's in the naked city, this has been just one of them! Too many possible scenarios to speculate Gary. Pull the rocker cover on that side and see what there iz to see. and turn the engine over while you're looking.Those cute little gadgets that you clamp on to the starter relay and squeeze the lever are cheap and oh so handy rite there at your local Harbor Freight. You already know the dead hole so you know where you're looking. If you find nothing on the top end the next step iz to pull the intake and then that passenger side head. The summerz not over yet and even a completely redone 906 can be completed pretty quick. Try having 8 bronze guides, and 8 over sized hardened seats installed and every thing swapped over and have the whole deal R+R'd, done and running on ah Cross Ramed 440 in ah little under 72 hourz. And you wanna know why what little hair I got left iz somewhere 'tween gray and white? Now go forth and slay that dragon, Jer
commando1
Old Man with a Hat
Yep.
It wasn't the thermostat.........
70NPORT
Old Man with a Hat
Yep, got one or two of those in the "bin" somewhere left over from the starter motor episode. Cross rammed 440 would be mighty fine, and thus the rest of the car would have to be brought up to 440 cross ram capable,lol.. but for now its gonna stay a warmed up 383 4bbl...definitely with hardened valve seats for the shitty ethanol gas. I need to get moving I was hoping I wouldn't have to take anything apart, but the comp test utterly squashed that. Is what it is.
I'd do a wet test to see if 3,5 and 6 come up.
I'm betting bad valve in #4, and bad head gasket for 3 and 5, but you really need to eliminate the rings as a problem in cylinders 3, 5 and 6. If you don't, you'll be putting a set of good heads on a worn engine and wasting your time.
You could also do a leak down test and figure out from there where the air is leaking to.
I'd also pull the valve cover on the right side and make sure the valve train is working as Barney said.
That being said... IMHO, if the heads are shot, the engine is ready to be rebuilt. Do it once and do it right.
I'm betting bad valve in #4, and bad head gasket for 3 and 5, but you really need to eliminate the rings as a problem in cylinders 3, 5 and 6. If you don't, you'll be putting a set of good heads on a worn engine and wasting your time.
You could also do a leak down test and figure out from there where the air is leaking to.
I'd also pull the valve cover on the right side and make sure the valve train is working as Barney said.
That being said... IMHO, if the heads are shot, the engine is ready to be rebuilt. Do it once and do it right.
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I was going to suggest the leak down test, that'll tell you where your compression went.
moper
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I'd say your compression testing WAS all over the place...lol. Neverminding the "0", you've got variences in the 25% range. They should be within 5% at worst. I'd do the wet test. the actual compression test will test the sealing of the heads and valves - it has to be included by virtue of pressurizing the chamber. The leakdown will be able to tell you which is leaking. The "0" to me indicates a mchanical problem. might be gasket, might be valvetrain, might be valves and seats, might be piston, might be rings. I would suggest before you buy the Aerohead product - make sure the heads are the issue. Pull the head with the "0" reading and snoop a little.
commando1
Old Man with a Hat
Pull one, might as well pull both.......
70NPORT
Old Man with a Hat
Yeh, I'm not laying out any cash until the problem is diagnosed. Once it is then I've got to think about what I wanna do. I'm probably going to go ahead and do the wet test since its easy to do and may tell me more.
bajajoaquin
Senior Member
This decision tree seems pretty simple to me. Do the wet test. It's essentially no extra labor over what you would do if you pulled the heads. Do a leak-down if you have the tools or can borrow them, otherwise just see what the wet test tells you.
The heads are coming off no matter what. The only questions are: what's replacing them? Is the rest of the engine coming out?
If you're planning on keeping the car, I'd rebuild the engine. It's not that difficult, just takes patience and a bit of time. But even if you don't the heads are still coming off. The spark plugs are still coming out. The valve covers are still coming off. Do a wet test and see what you find.
The heads are coming off no matter what. The only questions are: what's replacing them? Is the rest of the engine coming out?
If you're planning on keeping the car, I'd rebuild the engine. It's not that difficult, just takes patience and a bit of time. But even if you don't the heads are still coming off. The spark plugs are still coming out. The valve covers are still coming off. Do a wet test and see what you find.
70NPORT
Old Man with a Hat
I'm bringing this thread back to life with more up to date goings on......
Did the wet compression test. Cranked it five or six revolutions, no compression whatsoever....no change from the dry test. So I'm betting the issues reside within the cylinder head...maybe burnt or cracked valve....someone mentioned perhaps the seat has recessed due to the unleaded crap in today's fuel pumps..the exhaust valve gets hot & when it closes it welds itself to the seat, then when it reopens it breaks the weld & removes material from the head/seat...and destroying the head. I also think the head gasket on the other side might be compromised between cyl #3 & #5. They both have low comp while the adjacent cylinders (#1 & #7) do not. I'm not doing a full out rebuild because I'm unconvinced it's needed...so dead issue. I'm aware of a subsidiary of "Indy Cylinder Heads" sells a complete set of 906 heads w/hardware for around 500 bucks which is a pretty good deal I think. I can get those with hardened seats already inserted also. So, after I get the work space and my bench cleaned up properly pulling cylinder heads in my garage should be pretty straight forward, although I know they are heavy. I don't have air powered tools, is there a decent runner up for those? I thought about getting a compressor but space is at a premium.
Did the wet compression test. Cranked it five or six revolutions, no compression whatsoever....no change from the dry test. So I'm betting the issues reside within the cylinder head...maybe burnt or cracked valve....someone mentioned perhaps the seat has recessed due to the unleaded crap in today's fuel pumps..the exhaust valve gets hot & when it closes it welds itself to the seat, then when it reopens it breaks the weld & removes material from the head/seat...and destroying the head. I also think the head gasket on the other side might be compromised between cyl #3 & #5. They both have low comp while the adjacent cylinders (#1 & #7) do not. I'm not doing a full out rebuild because I'm unconvinced it's needed...so dead issue. I'm aware of a subsidiary of "Indy Cylinder Heads" sells a complete set of 906 heads w/hardware for around 500 bucks which is a pretty good deal I think. I can get those with hardened seats already inserted also. So, after I get the work space and my bench cleaned up properly pulling cylinder heads in my garage should be pretty straight forward, although I know they are heavy. I don't have air powered tools, is there a decent runner up for those? I thought about getting a compressor but space is at a premium.
You don't need air tools for that job. In fact, I wouldn't use them for this myself. It's sometimes best to know if there is an issue with any of the head bolts... especially since the rest of the engine isn't going to be touched.
I also would have a local shop do the heads. Just me, but ordering a set from a vendor that is doing them on a "production" rebuilding line doesn't strike me as the way to go. Let's face it, they probably have some minimum wage guy grinding valves on a stack of heads.. not the same guy that builds racing heads.
At a local shop, you walk in with the heads you walk out with... No cracks in the castings or rocker stands etc. No shipping costs and not just a voice on the phone if you have an issue.
I also would have a local shop do the heads. Just me, but ordering a set from a vendor that is doing them on a "production" rebuilding line doesn't strike me as the way to go. Let's face it, they probably have some minimum wage guy grinding valves on a stack of heads.. not the same guy that builds racing heads.
At a local shop, you walk in with the heads you walk out with... No cracks in the castings or rocker stands etc. No shipping costs and not just a voice on the phone if you have an issue.
Also... My thoughts on hardened valve seats.
The valve seats in a Chrysler engine are already pretty hard. The cast iron used is better quality than other engines.
On a car that sees a lot of mileage or hard service like towing, doing hardened seat inserts is a good idea. On a limited use vehicle that might only see a few thousand miles a year, I'm not convinced that the hardened seats are really necessary. I'm not saying they are a bad thing, but it is one more thing that you are depending on someone to put in correctly and may not really be needed.
The problem is this... Guys started putting hardened valve seats in their soft Chevy heads because they needed them and the shops realized this is another money maker for them and an easy up sell. So now every car needs them... Even though a popular gas back in the day when these cars were new was Ammoco... because it was lead free!!
The valve seats in a Chrysler engine are already pretty hard. The cast iron used is better quality than other engines.
On a car that sees a lot of mileage or hard service like towing, doing hardened seat inserts is a good idea. On a limited use vehicle that might only see a few thousand miles a year, I'm not convinced that the hardened seats are really necessary. I'm not saying they are a bad thing, but it is one more thing that you are depending on someone to put in correctly and may not really be needed.
The problem is this... Guys started putting hardened valve seats in their soft Chevy heads because they needed them and the shops realized this is another money maker for them and an easy up sell. So now every car needs them... Even though a popular gas back in the day when these cars were new was Ammoco... because it was lead free!!
commando1
Old Man with a Hat
Don't use the copper head gaskets............
70bigblockdodge
Old Man with a Hat
I kind of have to agree with BJ on that there has got to be a good machine shop in NJ /Philly area that speaks a little Mopar just insist on new one piece valves all the way around. My 2 cents.
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I'd still do the leak down test which you would need a compressor for but other than that I don't use air tools on an engine either.
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