383 Engine Teardown - Need Advice

[Meangene83]

I am so glad I have this place to turn to for a second opinion.
I know enough about these cars to be dangerous.

My mechanic, whom I trust, called me down to take a look at my 1968 383 Engine in my 1973 Roadrunner. It was not good news.

Pictures are fun, so I took a shitload.



What was told to me is the following.

The engine looks to probably never had a rebuild. Or if it had it was not anytime recently. My mechanic said due to the Lack of Honing marks on the cylinder walls. He stated the honing marks take years to vanish, of which there are none visibile on any cylinder wall.
Also if you look at the black carbon and sludge, there are 'hot spots' and none are marked evenly.

The Heads seem to be from a 1971-2 383, based on the casting numbers.

He also stated the Cam shaft looks to be in almost perfect shape. He did not recommend swapping that.

He did suggest I do some performance upgrades, as the 383 Engine is a good engine to squeeze some extra horse power from.

==
What I was hoping to gain from you guys is the following...

1. Does this engine look to need a proper rebuild? Why am I seeing this amount of carbon buildup?

2. What are some performance upgrades we can do, in terms of Pistons etc...???

3. Any Idea what a rebuild would cost me? He quoted me off the hip around $5000 for a rebuild and about 2500$ for a Rebuilt Crate 383. Does this sound right?

(this car is currently a 727 auto, after the engine is pulled we are going to strap on a 4 spd manual)
I appreciate the help as always. Thank you for your time.

 

[Banzaiii67]

What prompted your mechanic to remove the heads?

Head gaskets look amateur hour.

 

[IQ52]

Yep it needs a complete rebuild. This is the first time in my life I ever actually saw anyone use silicone to seal a 8519PT1 head gasket. The cylinder heads are 906 and the correct ones for a 1968-70 big block.

I'm sure you will get many suggestions on ways and parts to rebuild this engine for more horsepower.

I removed a lot of snarky comments and bad words before I posted this.

 

[Meangene83]

The mechanic decided to remove the cylinder heads due to stripped and incorrect tapped holes. 1 Header bolt only had two threads of grab. That and I believe he needed extra clearance to get my headers out of the engine bay to take out the steering box.

My mechanic also was very surprised at the heavy use of RTV. He explained to me, occasionally someone may use a small dab to help hold the gasket in place while mounting the heads. But never this much. He said it basically ran thru the entire engine, globs of it were present in all the areas you don't want it.

Believe me when I say I have been using a lot of bad words and snarky comments, in relation to the back yard mechanic who goofed all this up. Very nice guy, but he tried to spend ZERO dollars on this car. And as a result used whatever he had around to patch it together.

In the spirit of Spinal Tap. How Blacker could these cylinders get? None, The answer is none more black.


Seriously, any resources to help educate me on the rebuild options? send them my way!
I am about to drop serious coin into this. And with the birth of my first child Dec 1st, I need to make sure I spend wisely.

 

[69Bee]

Complete rebuild is in order. I would do it for about $3500 to $3800 here in AZ. Your location can obviously be different. Price will depend on your performance upgrades, and the guys here can make suggestions. As far as the cam, if you are going to rebuild it, I would not reuse a cam, and ESPECIALLY the one in this motor judging by the extremely scary head sealing job. make sure your machine shop gets all of the "Orange Death" out of the heads.

1) Complete cleaning of all components
2) Grind crank. Going to manual, make sure rear of crank is drilled for the pilot bushing
3) Align hone block
4) Square block (decking)
5) Measure cylinders, if stock, Bore & Hone 0.030" OS. If already 0.030", hone only to 0.040" (as long a taper and out of round is acceptable)
6) Resize rods, and use ARP rod bolts. 145-6002
7) Replace valve guides
8) Install hard exhaust seats
9) 3 angle Valve job
10) Mill heads
11) Replace cam bearings and freeze plugs
12) Replace intermediate shaft bushing. Dura-Bond AD584 (has groove)
13) Replace the 46 year old valves
14) Replace the valve springs to match the cam you use
15) Main bearings need to be the early style narrow thrust (Sealed Power 4094M or Clevite MS-876P)
16) NEW oil pickup is mandatory!
17) Replace pushrods PR-321
18) New OE rockers would be a plus
19) might need a harmonic balancer repair sleeve, or a rebuilt balancer (Damper Doctor)

Can't think of anything else, but I might edit list when I get to work tomorrow.

Dave
Precision Machine Service
Huachuca City, AZ

 

[bigmanjbmopar]

That looks like my 383 block and heads that is If I were you, I would put it back to stock using new cam and lifters new valves retainers springs etc, have the block cleaned and honed and unless your crank needs to be replaced just have it checked and re balanced. tear it down have the block sonic checked and magnaflux to see if you have any thin spots on the cylinder walls and if there are any cracks in the block. Replace the cam bearings and of course the main bearings. Get new pistons and rings and have it all put back together making sure they degree the cam and pre oil everything before they give it back to you. If you do all of the basics that 383 will tear up the highway and give you many more years of pure mopar joy!

For as many as they made the 383 is one of my favorites motors durable plenty of them around and can make great power on just a rebuild. Save your money for a crazy 440 or 400 build keep the 383 stock.

 

[mopar 3 B]

Factory head gaskets would have been steel and from looks of gaskets have heads checked to make sure they are flat. Engine block casting date can be found on starter side of block. Heads look like 906 but can not confirm from given casting number. Answer to question 1 lack of regular oil changes or cheap oil doesn't look that bad by pictures and have seen worse. Would use the pistons if not worn out as 383 piston are expensive also will depend on condition of cylinder's need to be checked for tapper and roundness. If you have to replace the pistons my preference is to only go large enough to correct cylinder's and size bores to pistons. $5000 doesn't sound out of line for a complete rebuild but would get it in writing ( machine work and parts list). Also have the block checked. No sense spending money on a block that should have been scraped. If you are serious about the 4-spd plan on having the crank drilled for the transmission input shaft. 5/8" deeper and sized for pilot bushing. Automatic cranks are not set up for manual transmissions. Also unless you already have to parts for the swap figure another $4000. Post the rebuild quote and we can advise farther.
A

 

[Xp29h]

Having a 383 that I have been chasing all kinds of crazy things that the previous owner did. My 2 cents, I would opt for the complete rebuild so you know exactly what you got.

Good luck!

 

[Meangene83]

Magnaflux? Sonic Checked?

What are these specifically? and how would I go about googling a shop that can do this?


Also, I was looking at CME crate motors website, looks like you can ship your engine to them for a complete rebuild? Maybe this is an option...

 

[khryslerkid]

First thing I would do is check the cylinder walls for wear and taper. If one or more are beyond machining, you might as well stop there. If the cylinders check out ok, then completely strip the block of parts, then have it cooked, cleaned and magnafluxed. You have to make sure you have a block in good shape before you can go any further.

I'm hoping those cracks at the frost plug are just in the paint. That's the area where my 413 block failed. There were frost cracks from not having proper antifreeze in it at one point. A good cleaning by hand might show them if you look real good...

 

[Meangene83]

Complete rebuild is in order. I would do it for about $3500 to $3800 here in AZ. Your location can obviously be different. Price will depend on your performance upgrades, and the guys here can make suggestions. As far as the cam, if you are going to rebuild it, I would not reuse a cam, and ESPECIALLY the one in this motor judging by the extremely scary head sealing job. make sure your machine shop gets all of the "Orange Death" out of the heads.

1) Complete cleaning of all components
2) Grind crank. Going to manual, make sure rear of crank is drilled for the pilot bushing
3) Align hone block
4) Square block (decking)
5) Measure cylinders, if stock, Bore & Hone 0.030" OS. If already 0.030", hone only to 0.040" (as long a taper and out of round is acceptable)
6) Resize rods, and use ARP rod bolts. 145-6002
7) Replace valve guides
8) Install hard exhaust seats
9) 3 angle Valve job
10) Mill heads
11) Replace cam bearings and freeze plugs
12) Replace intermediate shaft bushing. Dura-Bond AD584 (has groove)
13) Replace the 46 year old valves
14) Replace the valve springs to match the cam you use
15) Main bearings need to be the early style narrow thrust (Sealed Power 4094M or Clevite MS-876P)
16) NEW oil pickup is mandatory!
17) Replace pushrods PR-321
18) New OE rockers would be a plus
19) might need a harmonic balancer repair sleeve, or a rebuilt balancer (Damper Doctor)

Can't think of anything else, but I might edit list when I get to work tomorrow.

Dave
Precision Machine Service
Huachuca City, AZ

Thank you very much, I will use this with my mechanic! Too bad we didn't live on opposite sides of the continent. Otherwise I would be dumping this block in your lap to rebuild for me.

Any East Cost - New England recommendations?????

 

[miller]

All good info. Even just a good basic complete overhaul on the motor will make it go.

For a low block, a 383 with the right parts can put out plenty of HP, and is one of the best 'B' motors around.
Just be sure, as already said, crack-check both block and heads! Should be first on your list.

On your 4-speed...I'll get racked on this one...there's no 4-speed on this earth that can out shift a 727.

Your motor was simply mis-treated. Pat it on the butt, make it right, and go for it. Not a fan of crate motors...never know what your gonna get. Either way, have fun with it. Yeah, that's 2 cents worth.

 

[Xp29h]

Just to add that I didn't mention... On any fresh rebuild one should alway start with mag and sonic check and then always check what you have for dimensions etc. so you know exactly what your starting with. For example, Did the block get decked, the heads etc. all will make things go back together correctly nearly impossible without that knowledge.

youre on the right path. As far as anyone to do all of this, don't jump at the first one you find. Good machinists are hard to find, key word good..get references if you can, word of mouth, etc.. I do have a guy here in Maine who I trust completely but that would be a 5 hour one way trip for you.. Pm me if you want more info..

Good luck.

 

[Xp29h]

Meangene.... Return info on your pm.. But not showing up in my messages ??
Just checking to see if you got the info?

 

[Bigal75]

Time for a 440 stroker?

 

[The Horvaths]

I'll chime in and spout that those *look* like some wicked cracks in the photo. I agree with check bore/taper and then see if it is cracked. First photo looks like crack in deck. Looks can be deceiving. Best wishes!

 

[Meangene83]

I'll chime in and spout that those *look* like some wicked cracks in the photo. I agree with check bore/taper and then see if it is cracked. First photo looks like crack in deck. Looks can be deceiving. Best wishes!

My mechanic said the same thing to me. When he saw the cracking around the freeze plug he thought we were doomed. He did some picking at that area with his finger and it LOOKED as though it was just the paint.
The paint used was not proper for the engine and was chipping all over the place.

My hope is that it is just the paint. But it has been pointed out before that around the Freeze plug is a common cracking area. Which is exactly where this is located.

My mechanic is pulling the engine this week, a down payment has been made to the machine shop and they will begin cleaning and inspecting the block.

** Fingers crossed **

 

[1966satellite]

Yep it needs a complete rebuild. This is the first time in my life I ever actually saw anyone use silicone to seal a 8519PT1 head gasket. The cylinder heads are 906 and the correct ones for a 1968-70 big block.

I'm sure you will get many suggestions on ways and parts to rebuild this engine for more horsepower.

I removed a lot of snarky comments and bad words before I posted this.

The heads look like 346's to me which is Correct for 71/72

 

[Meangene83]

So, more bad news. This car is kicking my ***.


The engine has two different heads on it!

One has numbers that read 3462346 - 1971/1972 383 & 440
the second has 2843906 - 1968-1970 383 & 440.

I visually inspected them after noticing the numbers. I could not see a visible different to my untrained eye.

It seems obvious to me that I am going to need to get a set of Matching heads. And that having two different is not a smart move...

Can anyone advise?

 

[bigmanjbmopar]

Aluminum!