67 383 rebuild suggestions

[marty koirtyohann]

u may want drop the pan & check the bearings if u r going to going to replace the front seal of the trany or did I understand u wrong ?

 

[swisherred]

checking the FSM says I should have 125 to 155 psi on the compression test. My low/high/ was 123/130....does this require new rings now? Anyone ever just hone and re-ring rather than overbore?

 

[detmatt]

Is the rear main leaking?

 

[swisherred]

Is the rear main leaking?

I don't believe so...I have oil back there but it might be from the valve cover leak. I will know more when I get the engine out and separated from the trans. I don't have oil on the ground.

 

[swisherred]

I'm trying not to rebuild the engine right now but I want it to last too.

 

[marty koirtyohann]

OK Now u may want to check the bore for wear if its under 10 thousandths(the rings will take up the 10 thousandths wear u can just re-ring it if its close to the 10 thousandths then u may want to over bore it .it depends on what condition the bore is in . Now that it what I did with my 440 I had my machinist check the block for trueness (make sure it wasn't out of round .Mine was fine so I just re-ringed it ). Now that is what I would do . The choose is yours .If I was you I would go through it now rebuild it . That is what I did with my 440 I used Hastings Molly Steel rings ( they seat faster ) but its your call. I hope this has helped u .

 

[swisherred]

I have replaced rings before with no trouble in my cb750...but when I changed the main bearings they gave me the wrong ones and it seized my engine at the crank. I gave them the measurements I needed and they gave me the wrong color...I assumed they knew what they were doing. I'd rather not screw this up. I have basic tools but not sure I have what I need to do it correctly. I know I can't afford to send it out to be done.

 

[Big_John]

checking the FSM says I should have 125 to 155 psi on the compression test. My low/high/ was 123/130....does this require new rings now? Anyone ever just hone and re-ring rather than overbore?

It's really more important that the cylinders are about the same.

The other thing is accuracy of the compression tester and how the test was done. If you want to really check the rings, do the test again, this time do it dry, then do it again with a little oil in the cylinders. If it comes up drastically, (it will come up some) then you might have an issue.

IMHO, just go drive the car for a while and have some fun with it. There's no big issues with it as it sits, so if it ain't broke....

Watch the oil consumption etc. and then decide if you want to spend the $$$ to rebuild it.

 

[Big_John]

I don't believe so...I have oil back there but it might be from the valve cover leak. I will know more when I get the engine out and separated from the trans. I don't have oil on the ground.

The oil pressure sender can leak too.

 

[marty koirtyohann]

Didnt u check them with a plastic gauge ? we did that before we rebuilt it .Its allways a good idea to check the bearings before u close it up. did u buy a rebuilding kit ?Or did u buy them separately? just wandering .

 

[swisherred]

I did not use a plastiguage. I measured the crank and case and went by the factory recommendations on bearings. I looked up the color code they gave me later to find out they werent the ones I had specified...it was my mistake for not double checking they gave me the correct ones.

 

[marty koirtyohann]

Yep .Its allways a good idea to check the parts . we have seen this in parts before .New parts in the wrong boxes .I guess u did the wrenching your self? .I know I do with my cozens help (he has been rebuilding motors in a dealership for years everything I know I learned from him )

 

[swisherred]

I do everything for my bikes...I've never paid anyone to do work except boring out the cylinders....but those are a world apart from a chrysler big block.

The parts were in the right bags, but I went by measurements while they went by color code. My fault for not verifying.

 

[marty koirtyohann]

ok I have never worked on a bike motor I have only worked on mopars I built big blocks (the first was a 73 400 .I built it up for street & track .the my 440 in the new Yorker .I have also put a few 318's together over the years) . now on bikes dont they check the bearing? I dont know .

 

[marty koirtyohann]

Hey if u want to private message me u can.

 

[swisherred]

Well, I have some different opinions vs. many of the posts above.
1. The gear ratio change to something like 3.23 (& corresponding speedometer gear in transmission) would probably help the most for more "pep".....but you asked about the engine.
2. I think your cam choice is just fine, even with 2.76 gears.
3. Install hardened exhaust valve seats (for unleaded gas) and new valve guides (so you don't burn oil) and keep those closed chamber heads. If you have some extra cash, maybe have the exhaust valve throats enlarged and go to the larger '68+ exhaust valves.
4. Replace timing chain & oil pump while you're in there + inspect the oil pump drive gear.
5. Your stock valve spring retainers (steel) should be fine, but install a new set of valve springs as recommended by your cam manufacturer.
6. I like electronic ignition, but you don't "need" it. Do check your distributor bushing "wobble". Your point dwell can fluctuate A LOT once the distributor housing bushings start to wear out allowing the center shaft to move back/forth.
7. You will likely need to bore the cylinders & get new pistons, so go with flat top pistons (not dished 383 2-barrel pistons)...but MAKE SURE they don't stick up too far & make contact with your closed-chamber heads.
8. Definitely add dual exhaust when you have the time/money.
9. Lastly, if you don't mind a little under hood noise, install an "open element" air cleaner with a K&N air filter, or just find a 1" taller-than-stock K&N so your air cleaner lid doesn't seal to the base (basically making it an open element air cleaner)
HOPE THIS HELPS!

how do I determine which speedometer gear would be appropriate for 3.23 gears? I do intend to install 3.23...I believe it will bring the way my car responds up to where I want it to be. I really liked my 66 coronet with the 2.94 gears...looking at the power bands/rpm/speed/weight...I think 3.23 will be comparable to it then.

 

[marty koirtyohann]

there r places that make adaptors for that it has to be with the number of teeth , now u can also ge a gps (I run one in my car it has a speed indicator in it) aflter a while u can tell yur speed by the tack .

 

[Big_John]

how do I determine which speedometer gear would be appropriate for 3.23 gears? I do intend to install 3.23...I believe it will bring the way my car responds up to where I want it to be. I really liked my 66 coronet with the 2.94 gears...looking at the power bands/rpm/speed/weight...I think 3.23 will be comparable to it then.

Pretty easy, there's a few charts out there.

Here's one. Mopar Speedometer Gear Selection Guide - MyMopar.com

These may get you closer. In my experience, sometimes you have to find one that looks good and try it. Then go up or down a tooth or two to allow for inaccuracy in the speedometer, rounding off and the tire size. Sometimes that's being fussier than you need to be, but I tend to do that.

 

[marty koirtyohann]

there u go

 

[swisherred]

Cup and a half of sludge with the oil pickup tube buried in it. Don't know how it even pumped oil. 3/4" slop in the chain...but no bad teeth. Changing everything.