PRH
Well-Known Member
Good on him for not getting caught up in all the internet blather.
Nicks Garage 383 build
- Thread starter RAMM
- Start date
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I know this is kind of tangential to the 383 question, but the video claims the 59 413 wedge Chrysler 300 engine was a full second quicker in the quarter than the 58 392 Hemi Chrysler 300 engine. This comes from a ridiculous Motor Trend test of a 58 Chrysler 300 that had it running a 17.9 quarter mile which is slower than its own test of a 55 Chrysler 300 with 61 fewer cubes, 75 less horsepower and a 2-speed Powerflite automatic vs the 3-speed Torqueflite of the 58. Makes zero sense. Other mags had a 57-58 Chrysler 300 running 16 flat. And yeah, that's not especially fast today either, but its a heckuva lot better than 17.9.
The 1961 Dart 4 door [ sold here as a Dodge Phoenix ] came with a 318 Poly & 2bbl, 3.23 diff open centre. Cast iron TF, car was very heavy. The quoted weight is wrong. I had one of these cars & had it weighed at a weighbridge. It weighed 1.8 tonnes, which is 3960 lbs. My mate had a 62 Phoenix, the first year of the alum TF & the beginning of a a substantial weight reducing process; mate went onto the w/bridge same day, his car weighed 1.6 tonnes, 440 lbs lighter than my 61.
As you can see, 17.2 sec for the heavy 61. How good was the Poly!!!
As you can see, 17.2 sec for the heavy 61. How good was the Poly!!!
Episode #3 (short) >
Full episode Monday on YouTube.
☆☆☆☆☆
Full episode Monday on YouTube.
☆☆☆☆☆
Charlie_es_cool
Well-Known Member
PRH
Well-Known Member
I don’t recall seeing the specs for the original Comp cam, but they showed the cam card for the Bullet in part 2 iirc.
Quick question bout the sunken valves thing.... is it just a matter of higher CC in the chamber or another issue if they are slightly sunk.. i can't see 2-3CC that a sunk valve would cause being a lost of 30+hp/tq but i am no expert.. that's why i'm asking 
Newbomb Turk
Well-Known Member
Quick question bout the sunken valves thing.... is it just a matter of higher CC in the chamber or another issue if they are slightly sunk.. i can't see 2-3CC that a sunk valve would cause being a lost of 30+hp/tq but i am no expert.. that's why i'm asking
It depends on what you call sinking a valve.
To drop 30 hp you’d have to sink it a mile.
yeah, i was thinking you would basically have to suck the valve almost into the head.. I am not getting why he is talking bout sunk valves costing that much power
I watch(short stints), but never really thought about it until someone mentioned it here. The most I ever see him actually do is change/tweak carbs/timing and run the dyno. Never actually doing any building, unless I'm missing something? Like I said I don't watch a lot.
PRH
Well-Known Member
Thru the years I’ve had heads come into the shop where the exhaust valves were literally sunk into the head about a 1/4”.
The engines were skipping from cylinders that had nearly zero compression………because the valve had receded into the head far enough to bottom the plunger into the lifter.
When you see the ex valve valve buried down into a hole that deep, you have to realize there is very little flow happening until the valve head clears the chamber roof, which greatly reduces the amount of effective duration available to get rid of the spent gasses.
Not only that, but the new shape of the seat & port can flow way less than they did prior to the seat recession took place.
Basically, the farther the valves sink, the lower the port flow, and you effectively have less exhaust duration.
So, the spent gasses have to go somewhere……..and if they can’t get out of the exhaust port, there’s an intake valve opening up a hole, and they’re gonna shoot right up in there.
Letting spent exhaust gasses up into the intake port is a big time power killer.
The engines were skipping from cylinders that had nearly zero compression………because the valve had receded into the head far enough to bottom the plunger into the lifter.
When you see the ex valve valve buried down into a hole that deep, you have to realize there is very little flow happening until the valve head clears the chamber roof, which greatly reduces the amount of effective duration available to get rid of the spent gasses.
Not only that, but the new shape of the seat & port can flow way less than they did prior to the seat recession took place.
Basically, the farther the valves sink, the lower the port flow, and you effectively have less exhaust duration.
So, the spent gasses have to go somewhere……..and if they can’t get out of the exhaust port, there’s an intake valve opening up a hole, and they’re gonna shoot right up in there.
Letting spent exhaust gasses up into the intake port is a big time power killer.
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PRH
Well-Known Member
Whenever they’re “seriously sunk”, you can just look across the valve tips.
When the exhaust are sunk a lot in the chamber side…….they’re just as misaligned on top.
The tip heights showing .020-.030 off on a motor making solidly under 1hp/ci isn’t going to be a major player imo.
Of course……..that assumes they were pretty close to begin with…….which isn’t always the case.
When the exhaust are sunk a lot in the chamber side…….they’re just as misaligned on top.
The tip heights showing .020-.030 off on a motor making solidly under 1hp/ci isn’t going to be a major player imo.
Of course……..that assumes they were pretty close to begin with…….which isn’t always the case.
Newbomb Turk
Well-Known Member
I just watched 2/3’s of part 3.
It’s clear he’s not a machinist. If he wants more torque he needs to look at his timing curve.
Does he ever even look at the plugs?
Two cams, four carbs and all that time.
Glad I’m not writing the checks for that.
It’s clear he’s not a machinist. If he wants more torque he needs to look at his timing curve.
Does he ever even look at the plugs?
Two cams, four carbs and all that time.
Glad I’m not writing the checks for that.
Up here in Canuckistan dynos aren't very common and very costly. I'll bet a half day of 2-3 pulls, tinkering etc would be close to $1k if not more.
PRH
Well-Known Member
Spoiler alert!!!
If you don’t want to know anything in part 3 before you watch……scroll on past this post……
1- I wouldn’t consider any of the valves in the old heads to be “sunken”.
Imo, it’s a non-issue.
That being said, almost any 906 heads that come into my shop get hardened exhaust seats installed.
So, put in some seats, do a nice valve job, and a mild bowl blend.
No one can tell if the ports of the heads have been touched by a grinder after they’re installed on the engine. But the seat of your pants can.
2- fly cut the pistons while still in the block.
I did it to my 383, which had negative .010” intake clearance on the intake side.
Not a big deal. Aluminum chips? That’s what the vacuum cleaner is for.
3- I wouldn’t be surprised if the 346’s end up making more TQ. Not so much because of the less sunken valves or the cr increase, but also because ootb, the intake runners are about 8cc smaller(which could be helpful on a mild 383 with exhaust manifolds).
That was a test I always thought would be fun(but never found the time).
906’s vs either 346/902/452’s………equally prepped.
4- while he was messing around off camera with the aluminum intake, he shoulda bolted on some small-ish headers.
I bet they would have been worth more than the intake was.
Especially with the Bullet cam.
5- it’s his channel, so agree or disagree with the plan of attack…….he gets to decide how to proceed.
If you don’t want to know anything in part 3 before you watch……scroll on past this post……
1- I wouldn’t consider any of the valves in the old heads to be “sunken”.
Imo, it’s a non-issue.
That being said, almost any 906 heads that come into my shop get hardened exhaust seats installed.
So, put in some seats, do a nice valve job, and a mild bowl blend.
No one can tell if the ports of the heads have been touched by a grinder after they’re installed on the engine. But the seat of your pants can.
2- fly cut the pistons while still in the block.
I did it to my 383, which had negative .010” intake clearance on the intake side.
Not a big deal. Aluminum chips? That’s what the vacuum cleaner is for.
3- I wouldn’t be surprised if the 346’s end up making more TQ. Not so much because of the less sunken valves or the cr increase, but also because ootb, the intake runners are about 8cc smaller(which could be helpful on a mild 383 with exhaust manifolds).
That was a test I always thought would be fun(but never found the time).
906’s vs either 346/902/452’s………equally prepped.
4- while he was messing around off camera with the aluminum intake, he shoulda bolted on some small-ish headers.
I bet they would have been worth more than the intake was.
Especially with the Bullet cam.
5- it’s his channel, so agree or disagree with the plan of attack…….he gets to decide how to proceed.
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Some places down here charge that. Screw all that noise. I'll super tune myself for that kinda dough. lol
I've never priced it out, so I'm probably waaay low. I'm with you, I don't need a dyno. I'm hoping to take 1 trip down the track is all.
TT5.9mag
Two atmospheres are better than one
You don’t “think” you need a dyno and you may not, but if you’re hunting for perfect it’s a huge shortcut. A full day here (6 hours and +-20 pulls plus breakin) at a world class shop cost me $1200 and it’s been well worth it every time Ive done it.
The length of time it takes me to get **** done you would think I'm hunting for perfect, but that ain't the case, just stupid is all. Like I said 1 trip down the track for me, if I'm lucky.
RAMM
Well-Known Member
So...? The new valves caused no valve clearance? I find that weird. The pistons don't seem to be anywhere near zero deck and the cam doesn't seem to be anywhere near .500" . Not there to measure it so....Must be.
This is a great opportunity and I'm glad Nick is taking this approach with even making another video....Now we really see the dilemma an engine builder can go through. If we do this it costs X but makes power do this, If we do this it takes more time and $$$ and it does this, and so on and so forth. I see Nick asked for feedback no less than three times in the video, so lets hear it. How would you "FIX" this 383? And NO I'm not involved, I 've already said I don't do stock 383's, but then again this one is not turning out to be very stock is it? J.Rob
Original Heads:
Looks like the intake valves were sunk more than the exhaust valves.
Maybe that was intentional to get piston to valve clearance with those flat top non relief pistons???
Replacement Heads
With New Valves
New intake valves standing up higher, now causing valve to piston clearance issues?
☆☆☆☆☆
Looks like the intake valves were sunk more than the exhaust valves.
Maybe that was intentional to get piston to valve clearance with those flat top non relief pistons???
Replacement Heads
With New Valves
New intake valves standing up higher, now causing valve to piston clearance issues?
☆☆☆☆☆
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