70bigblockdodge
Old Man with a Hat
Score, and excellent advise, from Big John.
67 383 rebuild suggestions
- Thread starter swisherred
- Start date
swisherred
Senior Member
I hear you on all of that...and its probably sound advice...only question i have then is how will I know when i need to do the seats if I dont take them off? leak down test? measurements? I read so many things about the valves sinking into the heads and destroying them. I just want to make it runs nice with maybe a bit more power. It seems sluggish right now compared to my past 383 in my coronet...but then again...smaller car and different gear ratio too...but it only had a 2bbl.
Valves can only sink so far before either the lifters bottom out or the exhaust valves get burned. If a burned exhaust valve stays in the effected engine long enough, the seat will burn out as well, although not usually enough to make the insertion of a hard seat impossible. You have good compression, so you are no where near having to worry about that. If the compression on one or more cylinders drops a lot, that is the time to pull the heads.
Dave
70bigblockdodge
Old Man with a Hat
Your compression is even so, most likely not a issue.
You will have a noticeable problem way before this happenes.
At this point you have low cylinder pressure due to compression ratio and cam timing. A new timing chain and some more initial timing will wake it up and give some throttle response.
swisherred
Senior Member
ok....will get into the more timing stuff later...going to replace the timing chain because even if it wasnt abused, it still has 105k on it. I was also getting floating vacuum readings when doing the timing before...a sign of a worn chain i believe. may still go to electronic ignition just to eliminate distributor wear from my current equation.
I whole heartedly agree.
FWIW, I replaced the 2bbl and intake on my convertible shortly after I bought it, 15 years ago.
I bought a package from Mancini Racing that consisted of the Edelbrock 1406, Edelbrock intake, and a crappy air cleaner. Upgraded the air cleaner to an Edelbrock w/K&N filter. Added dual exhaust as well.
This was a standard 383/2bbl and 2.76 non-SG rear end. About 123k then, 145k miles now.
Just those upgrades woke the car up enough for me, I'm a boulevard cruiser, not a racer. And it surprises a lot of smaller modern cars on the highway.
In one of your other threads you mention some carb issues/cobbling. If it were my car, I would start with replacing the existing 1806 or whatever it is with a new 1406 and all of the proper linkages and restore the electric choke as Edelbrock intended.
My 'vert has started and run reliably since the upgrade. The electric choke is dead reliable as well. I've never had to adjust anything in all this time either.
Like Big John suggests, don't dive in until you know how deep it is.
Hope the input helps.
John
swisherred
Senior Member
from what i understand, the 1806 and 1406 are similar...the 1806 was tuned for performance and the 1406 for fuel economy. I know I have several gremlins running around, but i will get it straight eventually. I just have to verify the linkages and the missing choke/parts. It runs much better right now since blocking off the open port I found....I might look into a new intake but I honestly dont know if it is worth doing it. maybe when I can do the exhaust I will add that then. Driving style.....I like the slow meandering cruise through the mountains, but love torque and hard acceleration from time to time...one thing at a time....
swisherred
Senior Member
Ok...so I've decided not to rebuild the motor right now. I do need to change the timing chain and remove the oil pan for repair. I've decided to pull the engine completely in order to be able to get the oil pan out, pop the freeze plugs and flush the block, clean and decrease it for paint.
What other things should I look at addressing while the block is out? I'm not looking to break the heads loose right now....unless there is a benefit to raving the head gaskets now while it is out.
What other things should I look at addressing while the block is out? I'm not looking to break the heads loose right now....unless there is a benefit to raving the head gaskets now while it is out.
Ripinator
Old Man with a Hat
Well. . . If yer gonna remove the engine, you should go ahead and replace the front pump seal in the transmission (behind the torque converter), the front seal (of course), the water pump, thermostat, etc., and you should remove the water jacket plugs in the heads, so you can flush the heads too. Its also a good time to replace the plugs and plug wires, because its easier to route them through their brackets, etc.
It’s 52 years old so all new freeze plugs is a great thing to do. And rinse out the block, there will be crud and scale in there. Look in the oil pan and pickup for remnants of valve stem seals. They get old hard and break into pieces.
It pretty easy to change the valve stem seals with the engine out. Put a rope or vacuum hose in spark plug hole, turn engine till it gently stops. This holds valves from falling down. Remove rocker arm shafts completely. Use a socket and hammer and whack every retainer to break free the keepers. Install a dummy shaft in the saddle. Use a lever tool under the shaft to depress the valve spring retainer and remove the two keepers. Remove valve spring and clean out old seals and install new seals. After you do a few it will go really fast.
Also a good time to replace the motor mounts. They are hard to do with the engine in the car.
The head gaskets really don’t need to be replaced, they don’t fail like 1980’s aluminum head front wheel drive cars.
It pretty easy to change the valve stem seals with the engine out. Put a rope or vacuum hose in spark plug hole, turn engine till it gently stops. This holds valves from falling down. Remove rocker arm shafts completely. Use a socket and hammer and whack every retainer to break free the keepers. Install a dummy shaft in the saddle. Use a lever tool under the shaft to depress the valve spring retainer and remove the two keepers. Remove valve spring and clean out old seals and install new seals. After you do a few it will go really fast.
Also a good time to replace the motor mounts. They are hard to do with the engine in the car.
The head gaskets really don’t need to be replaced, they don’t fail like 1980’s aluminum head front wheel drive cars.
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marty koirtyohann
Well-Known Member
marty koirtyohann
Well-Known Member
this is what I did to my 440 I had the block checked for trueness (not out of round)then I had them break the glaze I had the heads cut to get into fresh steel . then I used clvite bearings a double row timing set (I put in a mopar performance resteration camshaft ) I used hastings molly steel rings & I put a new oil pump in herr she runs great! thats what I did the block was still in spec so I dint bore it I just rebuilt it to stock now when I changed the cam I had to change the springs cause the stock springs didnt match the cam (450/458/60* over lap & a 115* centerline
Thank you for not using that texting gibberish, us old farts can actually read what you said without getting a headache.
marty koirtyohann
Well-Known Member
thank u for yur reply good luck.i have a old school machinist that did my heads & block work. one think I forgot to add was when u wipe out the bores use 10 wt oil on a shop towel to make sure u get all the grit out of the bore or it may stop up te oil filter ,just a word of warning if u do it yur self if u have it done they would know this
70bigblockdodge
Old Man with a Hat
Now you jinks him.
They fail very slowly as the rust gives way.
70bigblockdodge
Old Man with a Hat
Good thing I broke you guys in on bad grammar. Now your ready for anything, all you have to do is ask.
marty koirtyohann
Well-Known Member
if u r going to rebuild the motor any way Y would u try to reuse head gaskets? i wouldn't u run too big of chance of them not sealing .I dont know of anyone that would reuse a head gasket they r not that expencive recondition the heads but install them with new gaskets I got a over hawl set from jegs or summit I dont remmber who I got it from I had to call them & tell them what I wanted in the seats . that way I could get the molly steel rings & I bought victor reins valve cover gaskets .they r the only ones I have ever had good luck with to get them to seal right. some guys use RTV but we only use it as a glue to hold them into the covers but do as u like
marty koirtyohann
Well-Known Member
what ever I guess I will have to leave a group thats full of perfick folks
swisherred
Senior Member
I have no intention of reusing the head gaskets. I'm not taking the heads off right now. It has good compression and the valves are seating fine...just doing the timing chain and a few other things right now like the front Tranny seals and mounts. The core of the engine is in good shape so I'm not going to break into the block right now as I already started earlier.
marty koirtyohann
Well-Known Member
question 4 u ?u plan to change the timing set? I wish I had when I put a water pump on it as a result I had to rebuild it 6 months later when it through the timing chain just a thought.
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