340 cam specs?

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last post which I cribbed from an earlier post I do think plugging the above timing data into Dynomation would be interesting
as posted above
at .004 or SAE Jones is 264 and DC 260 is 284 @.004
That's about a 10 degree earlier intake close- IC is really important for low compression motors
I need to mention that this is the early DC 260

SWITICHING TO .006
.430 269 212 115 DC 260 early from cam doc
.430 269 221 DC 260 late 2001 catalog so same lift and duration but a Fatter lobe
.454 254@.006 202@.050 120@.200 Jones special
so @.006 Jones 254 and DC 260 is 269 degrees

so at .004 DC is 20 degrees longer on the seat 284-264 = 20
and @.006 DC is 15 degrees longer 269-254 = 15

@.275 lobe lift Jones is 64 @.275 when DC 260 is 42
about a 50 % difference
you can also notice that jones takes 10 degrees to move from .004 to .006 cam lift
and DC takes 15 degrees to rise .002

If you want to compare 269 @.006 duration of DC 260 (and shorter) These are in DESCENDING .006 order
.494 268 226 VD 60303 AMC 0703 1800-6200 Lunati
.506 267 220 140 Howards 721141-08 1600-5400 ( HM2203372A intake lobe) howards describes single pattern off the shelf grind
{ 506/506 267/267 220/220 108/104 smallest .904 shelf cam 1500-5400 wants headers }

.488 266 221 138 . X4X4 5904 MI 23.5 (11.3/12.2) Comp cams
.502 265 218 138 HM2183345A also used for AMC Howard
.475 262 220 VD 60302 1400-5800 Lunati
.494 261 214 134 HM2143294A Howard
.483 257 210 130 HM2103219
.454 256 213 VD 60301 also AMC 0701 1000-5000 Lunati voodoo
.447 256 212 124 XE 5441 XE256H 22 54 20 68 Comp universal lobe snuck in here
.479 255 208 128 HM2083190 Used for AMC Howard
.454 254@.006 202@.050 120@.200 Jones special
.473 252 206 126 HM2063164A Howard
.454 250 208 VD 60300 also used for AMC Lunati

But as with using .050 to estimate seat to seat .006 really does not tell the whole story
compare the .006 to .004 Jones vs DC
My cam doc goes all the way down to .001 and jones gets the door closed earlier than any other cam on this list
The shortness seat to seat with jones also shows a shorter .050 but this is gone by .100 lift
If you are looking for a cam in this range also check out Bullet and Racer Brown, Engle, Crower
Just showing what you can do for a low compression motor- or a tow vehicle- lots of coices
 
Wyrmrider said:
last post which I cribbed from an earlier post I do think plugging the above timing data into Dynomation would be interesting
Click to expand...

I can attempt a few different things, but will have to experiment as the 'cam manager' is very basic. While the it can accept several file formats from more sophisticated cam profile software, there's not much to work with when trying to just plug in timing numbers other than valve at .006 and .050.
I've not seen any MP/DC cams in the cam library that came with the program and as we now know, who ever entered the WG-1118 cam info did not know it was not SAE.
 
Wyrmrider said:
THANKS
I take it "cam manager" is part of dynomation?
Click to expand...
Yes. In fact its been a while so lets look at what I did before I read your posts on Speedtalk about this.
upload_2019-6-30_11-32-8.png


I wanted to enter the '68 'manual transmission' cam, 2899205.
All I had was the info from the FSM, which I incorrectly assumed was measured the same.
upload_2019-6-30_11-42-59.png


I don't recall where I got the 214 and 221* durations at .050"
upload_2019-6-30_11-45-17.png


Someone must have posted .050 timing events on the internet, Paul C ? here, Victory Library? maybe I have notes somewhere. I knew I was working in uncertain terratory - that's about the only thing I'm certain about!
upload_2019-6-30_11-49-55.png


So next post I'll do a little experimenting with what changes can be made in Cam Manager using the 'automatic transmission' cam we have more info about.
 
This is based on the WG-1114 and the '68 Plymouth FSM timing events incorrectly applied as if they were .006 events. (just repeating that because search spiders copy and link stuff and then people assume its correct).
upload_2019-6-30_12-9-8.png


Changing just the intake/exhaust events to the .004 numbers.
upload_2019-6-30_12-12-44.png

and it recalculates the ramp and the following as well.
Notice the seat to seat durations are just what you (wyrmrider) posted earlier for the .004
upload_2019-6-30_12-16-0.png



Oddly enough, the ramp rate can be increased back to 2.30 and the .050 numbers don't change.
It's not clear at all how the program works. It may be that it only uses the .050 valve events when autocalculating lifter acceleration. When it comes to calculating power etc, my guess is the .050 numbers are not used. Will have to do a bunch of experimentation or ask someone who knows the program better to figure that out.

upload_2019-6-30_12-31-48.png


It bothers me that the intake centerline is now so far off.
 
And because people probably want to know what the software says even though we know input is wrong..
upload_2019-6-30_12-48-23.png


The model used for the above is Fill and Empty simulations.
Sea level. Air Temp 68* F, RH 0%
340 std bore, 10:1 CR, 77 cc chambers, Open Wedge Head, Flow numbers X heads posted by Shady Dell
Carb flow 660 cfm, Dual Plane Std flow intake, H.P. Manifolds with Mufflers.

And for further comparison here is how the modeling stacked up against two real dyno tests done in the magazines. Not that I fully trust the magazine reports but I think the trends and shapes are correct. Not sure of the full details on the Mopar Muscle build (compression for example but assume its 1970 based), or how the dyno was run(600 ?)
HR = Hot Rod Magazine 1969
MM = Mupar Muscle 2001

340-basic-hr1969-mm-dyno-png.1715344981
 
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ICL 112 excl 116 lca 114
where did the numbers on the form come from 119.5?
gotta love the intake close at 79 @004 (and it gets even worse lower than that- takes forever to get the exhaust closed
note that if you advance 4 degrees the EX open moves to 83 BBDC
and folks wonder where the mileage went
 
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Wyrmrider said:
where did the numbers on the form come from 119.5?
Click to expand...
that's what happened when I changed the valve timing events.
see the second and third screenshots in this post
340 cam specs?
If we change the LCA and Intake Centerline back to where they ought to be, then the software shifts the valve events like this.

upload_2019-7-1_7-42-18.png
 
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so software is not adjusting for asymmetrical lobes
good to know
looks like it messes with the .050 also on the exhaust which would throw off that ramp rate but the ramp rate may just be for the intake
wonder if manual has something to do with it
or did you input 214 for the ex?
did you catch that asthe lca changes from 119 to the correct 114 the overlap changes by 6 as it should
Interesting and still useful
 
And I don't get how guys get all hyped-up to bolt-in/on the factory 340 automatic cam in a smogger-318, with X heads.
I did that and it was a disaster, with the only saving grace being gears and TC, which took it straight out of the realm of DD. It was a terrible idea in 1977 when I did it, and without a boost in compression, I expect it would be just as terrible today.
So riddle me this; why do guys keep saying that it's such a great idea?
BTW; I got 4 slightly used 340 cams, from back in the day, I could sell.........lol.
 
Same hereAJ/Form S. Slapped a stock 340 cam with 340 intake and AVS and exhaust on my 69 silverfish. Took a swap from the 2.94 gear to the 3.23 gear till it felt ok to drive. Sounded tough but was sluggish and definitely not a 340. Those stock cams are big. Sound good but there is a reason 318s did not come with them. Nitrous made it run good in 1979.
Tom Hand
 
Tom you got .006 or .004 info on that cam?
VOETOM said:
Here is what the 2899205 68 manual cam sounds like:

Please note my mufflers are closed, in other words, in the quiet mode.
Click to expand...
 
Wyrmrider said:
so software is not adjusting for asymmetrical lobes
good to know
looks like it messes with the .050 also on the exhaust which would throw off that ramp rate but the ramp rate may just be for the intake
wonder if manual has something to do with it
or did you input 214 for the ex?
did you catch that asthe lca changes from 119 to the correct 114 the overlap changes by 6 as it should
Interesting and still useful
Click to expand...
That's my guess - it doesnt seem to accept asymetrical lobes. We can ask on ST or I can e-mail Larry. But first I want to read through the manual because its supposed to handle lobes from cam doctor files etc. So it must have some way to convert asymetrical lobe files to a 10 point cam file???
You're right, the .050 durations did change - I missed that.
 
Mattax, I have nothing on it. I had it ground in 1981 or so by CamCraft, the guys that were doing Chrysler cams for engineering folks. Told them the part number and they went to work. Never even asked for data either unfortunately.
Tom
 
Cam Craft did all the old school masters and maybe even the OEM cams I know they did the 413 long ram and an early Max Wedge
before Racer Brown
(Isky also had an excellent .904 Max Wedge grind which we beta tested early sixties) great work without even the old computer Harold Berkshire used.
They could have done the original 340 cam, early Direct Connection Cams
 
it could work in an early 9.5 Scr engine but by the time you get to 1000 ft elevation, and using the advertised numbers; you are down to this .........
Static compression ratio of 9.5:1.
Ica of 64*, elevation 1000ft
Effective stroke is 2.57 inches.
Your dynamic compression ratio is 7.59:1 .
Your dynamic cranking pressure is 147.37 PSI.
V/P (Volume to Pressure Index) is 109

But if the actual Ica doesn't come until 12* later as previous posts seem to indicate then
Static compression ratio of 9.5:1.
Ica of 76*, elevation 1000ft
Effective stroke is 2.27 inches.
Your dynamic compression ratio is 6.82:1 .
Your dynamic cranking pressure is 127.32 PSI..
V/P (Volume to Pressure Index) is 83

but if in a smogger-teen
Static compression ratio of 8.0:1.
Ica of 76*@1000ft
Effective stroke is 2.27 inches.
Your dynamic compression ratio is 5.79:1 .
Your dynamic cranking pressure is 101.23 PSI.
V/P (Volume to Pressure Index) is 66

But changing the elevation to 100ft
Static compression ratio of 8.0:1.
Effective stroke is 2.27 inches.
Your dynamic compression ratio is 5.79:1 .
Your dynamic cranking pressure is 105.73 PSI.
V/P (Volume to Pressure Index) is 69

but with new pistons
Static compression ratio of 11:1
Ica of 76*@100ft
Effective stroke is 2.27 inches.
Your dynamic compression ratio is 7.85:1 .
Your dynamic cranking pressure is 159.01 PSI.
V/P (Volume to Pressure Index) is 104

Oh gee; VP of 104, I'm so excited......... not
So now you got a teener, about as sharp as it can be namely 159psi, that sucks gas bigtime, is gutless to 3000rpm or more, and doesn't really want to wake up until 4000rpm, which with the 4.10s yur gonna need, is around 30mph. Not my favorite way to spend a wad of cash.

As to VPs. for comparison, using advertised numbers;A stock slanty makes around 87, a smogger-teen about 118, a 5.2Magnum 124, a stock LA360 about same 124..... so as you can see numbers below 120 pretty much suck.
If you have a 3000 TC,or a clutch; you pretty much don't care about VP.
But for the clutch guy, getting stuck at off-idle to maybe 2500, with a small engine, low VPs STILL SUCK!! and now you don't have a TC to multiply your torque, so yur gonna need more gear than an automatic.
Even with a 360, you can find 50 ways in 5 city miles to get cranky about sucky VP. Whereas you will never be cranky with 155VP.. ever.

Fun VPs for streeters begin at 140, and tire fryers might be 150, By 160 you can't tame the tires no-how, and if you get to 170,well IDK what you were thinking,lol.

So the question is why would Alpar endorse this?
 
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AJ/FormS said:
So the question is why would Alpar endorse this?
Click to expand...
Same way stuff ends up in publication. The editors are not experts. They count on writers who have checked their sources, and in magazines like this they generally don't dig too deep.

The good news is the person who suggested using the 340 cam (and 360 heads) in this thread, did so back in 2011. So hopefully you guys have put the final nails in the coffin.

Now how 'bout running those same numbers for a 340 cam in a 340? :)
What happens when dropping the compression (with shorter piston '72-'73) or similar builds where folks reduce compression to 9.5:1 or less?
 
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aj has done the numbers for 360's several times
perhaps he will post them up here
same problem with the stock dished piston 360 or late 340
 
I like the 360 because each piston has enough swept area,~737cc, and enough piston selections, that you can pretty much achieve any Scr goal you need. 340s are 696, still doable. But by 318 and 658cc you gotta pay attention to parts selection and machinings; but it's getting better with some of te new heads,etc..
As for strokers; a 408 is 823.7cc so now the scales is tipping the other way, and you need dished pistons, so you are again paying a lot of attention to chamber sizes and machinings.
The 360s just seem to fall together fairly close to perfect.
 
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Here's what I get for a stock 340.
4.04" Bore, 3.13" stroke, 6.13" rod.
Using: 279* Intake Duration, 112 Installed Centerline
Intake Closing Angle (after bdc) 71.5*
Using Static compression ratio of 10.0:1.
Effective stroke is 2.24 inches.
Your dynamic compression ratio is 7.44:1 .
Your dynamic cranking pressure is 146.05 PSI.
Your effective boost compression ratio, reflecting static c.r., cam timing, altitude of 500' is 7.34 :1.
V/P (Volume to Pressure Index) is 101

same stock 340.
4.04" Bore, 3.13" stroke, 6.13" rod.
Using: 268* Intake Duration, 112 Installed Centerline
Intake Closing Angle (after bdc) 66*
Static compression ratio of 10.0:1.
Effective stroke is 2.37 inches.
Your dynamic compression ratio is 7.81:1 .
Your dynamic cranking pressure is 155.82 PSI.
Your effective boost compression ratio, reflecting static c.r., cam timing, altitude of 500' is 7.71 :1.
V/P (Volume to Pressure Index) is 114

So that's the difference between using the Chrysler advertised duration and the .004 seat to seat duration.


Stock 340 with less compression.
Using: 279* Intake Duration, 112 Installed Centerline
Using Static compression ratio of 9.0:1.
Effective stroke is 2.24 inches.
Your dynamic compression ratio is 6.73:1 .
Your dynamic cranking pressure is 127.58 PSI.
Your effective boost compression ratio, reflecting static c.r., cam timing, and altitude of 500' is 6.63 :1.
V/P (Volume to Pressure Index) is 88
 
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Sounds about right.
And that's about what I remember about my 340s: with a manual trans and 3.55s, I always had to use the flywheel to get moving, and mine had to be wound up to pull. And my stockers (69 and 70),quit pulling around 85mph. Shifting to Fourth was sorta dead. Still, the stockers went almost 100 mph in the quarter.
Those VPs suck. I always had to keep the Rs on the cam; the right hand was always on the shifter. It was better after I got the 4.10s,lol.
But I've only got about 10 years driving experience on three of those early models after which I switched to 360s.The Dart was peppier than the BarracudaFB, I guess because of the approximate 300 pound difference in the chassis weights.
 
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