67 383 Dart

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brian6pac

brian6pac

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Did the 67 Dart have the HP heads with the 1.74 exhaust valve or just the std 915 with 1.60 exhaust valve. The reason I ask is I have a 67 Dart coming to me and It has no power, has 6 - 7 in vacuum at idle I turned up the timing and made no difference. the guy claims after a engine rebuild some 10 years ago it never made any power and it just sits in the garage. I was thinking maybe the guy who rebuilt it put 906 heads on it and kept the 915's or and has the cam timing off. It has a ruff idle but you can floor it and it just drives off wont even spin the tires.

or did they have 516 heads, I wasn't thinking about 915 were 440 only?
 
brian6pac said:
Did the 67 Dart have the HP heads with the 1.74 exhaust valve or just the std 915 with 1.60 exhaust valve. The reason I ask is I have a 67 Dart coming to me and It has no power, has 6 - 7 in vacuum at idle I turned up the timing and made no difference. the guy claims after a engine rebuild some 10 years ago it never made any power and it just sits in the garage. I was thinking maybe the guy who rebuilt it put 906 heads on it and kept the 915's or and has the cam timing off. It has a ruff idle but you can floor it and it just drives off wont even spin the tires.

or did they have 516 heads, I wasn't thinking about 915 were 440 only?
Click to expand...


Hey Brian6pac,

Couple of questions... Is this an original 383 car? , what exhaust manifolds? What transmission? A slant 6 will get you rubber in a Dart!!
 
AAndrews said:
Hey Brian6pac,

Couple of questions... Is this an original 383 car? , what exhaust manifolds? What transmission? A slant 6 will get you rubber in a Dart!!
Click to expand...

It is an original 383 Dart GTS, stock big block a body manifolds

727 trans with a shift kit 2500 stall
 
First I was thinking 915 then it came to me that was a 440 only head and the 383 had 516 but then looking at the chart it had another head I never seen 158? so now I'm not sure. I have 3 sets of 516 heads and 1 set of 915 with the 1.60 exhaust Saturday I will get the car and I will do a comp test, leak down test, and pull the valve covers and check where overlap is and look at the casting #
 
Imho. If a 383 (any variant) can't spin a dart''s tires than the heads are the least of the problem.

Areas to look at:
Rear gear ratio
Tall tires
Trans slipping
Carb issue
Ignition timing
Engine timing
Flat cam
Lifters bleeding too quickly

Probably 50 more issues that it could be

Again just my opinion...
 
Yes, all 67 A-Body's with the 383 came with 516 heads. Got pics of the car? I have owned 1/2 dozen 67 383 Darts GTS's, currently only have one 67 Barracuda Formula S 383 4-speed.
 
I will have some pictures of it this weekend, It has 3:55 gears, I have some diag to do for sure but I think it's the cam and possibly the heads also.
Like I said the car ran like this after he got the engine rebuilt so someone didn't do something right. I think the cam is off enough that it runs but barely. If the guy put on open chamber heads 88cc that is enough to drop 1 point or more of compression ratio, like 8.7:1
 
you say engine was rebuilt, was it bored & got new pistons ? I'm not sure, but I think aftermarket replacement pistons are even lower compression than the original, meaning even less compression.
 
So I got the car and pulled the left valve cover and found a 915 casting # so today I'm going to check to see if overlap is close to TDC, It is original car I decoded the fender tag.

IMG_4779.JPG


IMG_4797.JPG


IMG_4800.JPG
 
HemiSSDart said:
Yes, all 67 A-Body's with the 383 came with 516 heads. Got pics of the car? I have owned 1/2 dozen 67 383 Darts GTS's, currently only have one 67 Barracuda Formula S 383 4-speed.
Click to expand...

Yes, 67 383 4 bbl engine came with 516 closed chamber heads and flat top pistons sitting high in the hole. 10:1 factory compression ratio.

1101161727a.jpg


1104161453.jpg
 
So I'm trying to figure out what cam is in it, he said it was a purple shaft but that tells me nothing. I made a piece that goes over the push rod and has a center drilled end so the indicator stays in place, It worked great. .308 at the cam, so .462 at the valve. not what he was expecting. I'm thinking somewhere around .500, .509.

IMG_4821.JPG
 
Thanks George Jets, do you know how far down the pistons are a TDC,

Does any one know the cam specs for a 67 383 Dart can't seem to find it anywhere.
 
.431/.443 256/260 32* overlap. 1968
.425/.437 256/260 32* overlap. 1967
.425/.437 264/268 40* overlap 1968 A body.
 
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brian6pac said:
Thanks George Jets, do you know how far down the pistons are a TDC,

Does any one know the cam specs for a 67 383 Dart can't seem to find it anywhere.
Click to expand...

I am thinking my 67 383 pistons are .040" below deck at TDC. Wish now I would have measured this when I had it opened up. Take your best guess from this photo, it's right up there. Some are saying a lot of the 383s were at .025" below deck ???

1104161452a.jpg


20190410_105309.jpg


Next cam specs for the 67 383 4 bbl. I like to go by what the books say, but I wanted to measure mine just so I would know roughly where it is at. My thing was I wanted to keep this engine as close to original stock as possible with the original camshaft and lifters. Just doing a valve job and adding the hardened exhaust seats, new valves, new springs.

Granted this is a 50 year old engine with at least 60,000 miles on it, so there is going to be some decline in the lift and duration numbers compared to a brand new stock cam.

I ran across some information 3 years ago about this camshaft as it was set up to work well with the small 516's exhaust valves of this 383. From the information I gathered, Ma Mopar set this cam up with a split grind, the difference between the intake and exhaust profiles. Giving the exhaust valves more duration and more lift to hold them open longer and higher than the larger intake valves, providing better exhaust scavenging with the smaller exhaust valves.

Right or wrong this sounds good to me. Here is what I came up with when measuring this 50 year old 383 camshaft and 516 Closed Chambered Head combination:

Intake/Exhaust .387"/.420" Lift
Intake/Exhaust 245*/330* Degrees Duration

110* Degree Lobe Centers

20190410_100950.jpg


You can form your own opinions, I enjoy looking into all of this and the history behind it.

If you want to see how nice this 67 383 runs, you can search it out on youtube:

Mopar 1967 383 Original Engine

Here is the actual YouTube Link:


Enjoy . . .
 
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Just thinking here about your no power issue, I am inclined to think it is camshaft timing in relationship to the crank shaft.

You should bring up #1 cylinder to compression stroke TDC and check to see where the distributor rotor is pointing. Set up correctly it should point to the #1 spark plug wire in the distrubutor cap. They could also have the distributor set to fire TDC on #1 but the cam is so far retarded that it is not making any power.

Cam Gear Dot should be at 12 O'clock and Crank Gear Dot should be at 12 O'clock. (not dot to dot, cam gear 6 o'clock and crank gear 12 o'clock)

But anyhow besides this basic setup that most people know, some people want to advance the cam 4 degrees advance ahead of the stock setting. I have opened up engines that did not run right and found that they were trying to do this, they got it backwards and retarded the cam as much as 10 degrees by jumping the teeth on the cam gear.

Badly retarded cam opens and closes the valves too late and as such no power, not to mention where the ignition timing is set and what that is doing.

Try the basics and see what you can find out.
 
brian6pac said:
So I'm trying to figure out what cam is in it, he said it was a purple shaft but that tells me nothing. I made a piece that goes over the push rod and has a center drilled end so the indicator stays in place, It worked great. .308 at the cam, so .462 at the valve. not what he was expecting. I'm thinking somewhere around .500, .509.

View attachment 1715316878
Click to expand...

Silly question.

Are you sure the lifter plunger isn’t moving while your doing the testing?
 
George Jets said:
Just thinking here about your no power issue, I am inclined to think it is camshaft timing in relationship to the crank shaft.

You should bring up #1 cylinder to compression stroke TDC and check to see where the distributor rotor is pointing. Set up correctly it should point to the #1 spark plug wire in the distrubutor cap. They could also have the distributor set to fire TDC on #1 but the cam is so far retarded that it is not making any power.

Cam Gear Dot should be at 12 O'clock and Crank Gear Dot should be at 12 O'clock. (not dot to dot, cam gear 6 o'clock and crank gear 12 o'clock)

But anyhow besides this basic setup that most people know, some people want to advance the cam 4 degrees advance ahead of the stock setting. I have opened up engines that did not run right and found that they were trying to do this, they got it backwards and retarded the cam as much as 10 degrees by jumping the teeth on the cam gear.

Badly retarded cam opens and closes the valves too late and as such no power, not to mention where the ignition timing is set and what that is doing.

Try the basics and see what you can find out.
Click to expand...

I have already found 2 major problems, now this engine was rebuilt by a local mopar guy 10 years ago, 10.000 mile on it and it has always ran the same. 1st thing I noticed is that I can turn the crank about 15* and the cam doesn't even move and I can hear the chain banging clanking under the cover? 10.000 miles? 2nd problem is the reluctor is up side down (for a small block) and the shaft is loose and wobbles around. He was wanting to know what cam was in it he said it was a .500 lift purple shaft and as we found out it's not, so it might get a cam
 
prorac1 said:
Silly question.

Are you sure the lifter plunger isn’t moving while your doing the testing?
Click to expand...

I think the lifter plunger is a lot harder to move than my dial indicator, just my thought on this
 
brian6pac said:
I think the lifter plunger is a lot harder to move than my dial indicator, just my thought on this
Click to expand...

Usually they are. And I would suspect your probably correct. But a variable is a variable no matter how small.
 
brian6pac said:
I have already found 2 major problems, now this engine was rebuilt by a local mopar guy 10 years ago, 10.000 mile on it and it has always ran the same. 1st thing I noticed is that I can turn the crank about 15* and the cam doesn't even move and I can hear the chain banging clanking under the cover? 10.000 miles? 2nd problem is the reluctor is up side down (for a small block) and the shaft is loose and wobbles around. He was wanting to know what cam was in it he said it was a .500 lift purple shaft and as we found out it's not, so it might get a cam
Click to expand...

Reminds me of some of the original Plastic Geared cam gears and the stretched steel timing chains. The plastic gear wears down easily, looses teeth then the timing chain jumps on the sprocket throwing it way out of time. Can see the plastic chunks in the oil when you drain it. Also the plastic chunks get sucked up into the oil pickup screen and the oil pressure drops, you shut off the engine they fall off then start it up again and they get sucked back up in the pickup screen.

You are on the right track for getting it fixed. New steel timing gear set with new chain set to the factory install setting positions.
 
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