Valve spring limitations vs Cam selection

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THANKS nm
you just prevented a way less than optimal build
all new ball
what gaskets are we estimating with?
 
And BTW, I am pretty sure on the 62 cc chambers for the EQ heads. But let's make 100% sure on that.

Dang here are the pistons I would really want to use: Icon IC742.

SCR works out to 10.3 with the Felpro 1008 head gasket with .037" nominal quench gap, or 10.0 with the standard Felpro kit gasket, PN 8553PT, and a nominal .047" quench gap. Not bad on either one, and you can bump up that cam a step or 2 and keep good DCR for the low RPM torque.

BUT, the downside is that they weight is 548 + 118 = 666 grams. So some crank balance work would be needed. I am 98% certain it can be all done externally.... start with LA 360 external parts (damper and flywheel/flexplate) and then you ought to be able to reduce those external weights to make it balance out.

Just another option....
 
Wyrmrider said:
THANKS nm
you just prevented a way less than optimal build
all new ball
what gaskets are we estimating with?
Click to expand...
Hey wyrm.... that's why we have this forum, right?

I did the initial computations above with the Felpro 1008's..... .039" thick.
 
nm can he swap pins?
or take some out of the pistons
side grind the rods thats a diy with a good kitchen scale and I'll tell him how to hang them
 
I read on Allpar that the factory 5.9 CR was 8.9 and Evan (who put together the Magnum-swap website) stated "I have checked many Magnums and all are between 8.8-9.3 factory. it all depends on how deep the pistons are, .040-.08".
Mine were .050 down. Perhaps I was being hopeful at 9.4 using the .028 Mr gasket and the EQ's 62cc.
Without measuring these numbers are guestimates and I can't measure until I get my parts back.
BTW.....I sure do appreciate all of your input.
 
Don't forget that when you start dicking with gaskets and such, the pushrod length, and lifter preloads, may have to be revisited

I'm not a fan of wide LSAs.

Understood on the 279 cam, and the new, lower probable factory Scr only makes the bottom end worse with that cam, which further proves the opinion you got from it.
 
Also......a LOT of people forget when calculating compression on the Magnum, they have a shorter deck height than the LA. So if you use the LA deck height figure, it won't come out right.
 
JoePole1 said:
I read on Allpar that the factory 5.9 CR was 8.9 and Evan (who put together the Magnum-swap website) stated "I have checked many Magnums and all are between 8.8-9.3 factory. it all depends on how deep the pistons are, .040-.08".
Mine were .050 down. Perhaps I was being hopeful at 9.4 using the .028 Mr gasket and the EQ's 62cc.
Without measuring these numbers are guestimates and I can't measure until I get my parts back.
BTW.....I sure do appreciate all of your input.
Click to expand...
No problemo, JP1.... good to go into this with all the data. I was figuring the piston depth at .060" which is the book spec on the FME Catalog website for the H655CP, and assuming the nominal deck height of the Magnum. The .028" thick head gasket would help about 0.2 point on SCR/ and DCR.

If you want good low RPM torque when you drop below 2800-3000 RPM or thereabouts, then SCR/DCR become your key to that. You're transitioing from the higher RPM's, where the exhaust draw-through reeeealy is working well to fill the cylinders, to the lower RPM's where that draw-through effect just plain craps out, and the higher compressions are all you have to make cylinder filling decent, to keep your torque up.

Wyrmrider said:
nm can he swap pins?
or take some out of the pistons
side grind the rods thats a diy with a good kitchen scale and I'll tell him how to hang them
Click to expand...

He could get some weight out of the pistons, but how much is hard for me to say, not seeing them. 50 grams out of that is very tough unless you start shaving the crowns down a lot, and the crowns are probably not the old style thick ones, so maybe not much there to remove.... and it would destroy the CR again LOL. Grinding down the rod's beams and small ends would get a fair amount out, but then you really ought to weigh them end to end to keep things reasonably equalized. Maybe 10-12 grams out of the pins max; those are already pretty light, and not very cost-effective for those few grams IMHO; a new set will cost more than a simple balance job of the crank and LA damper/flexplate to a new bobweight.

Of course, using an LA damper may be a different pulley so that is a possible issue; IDK if the is OP planning on the serpentine belt pulley or the earlier V-belt type. The flexplate ought to be interchangeable as long as the weight is corrected.

IMHO, this is the most cost effective to get back to balance: rework the external weights. If that becomes a possible route, then speak up JP1 and we'll see what can be done. I have some ideas already on how to do it.
 
The front end of my build is another unknown at this point due to the fact that I am running AC and for serp I would need a 1 year only 91 5.9 Dakota AC/ALT bracket with the LA style intake I am using. I will most likely stay with LA front because I already have it but I do like the idea of the serpentine set-up.

I like the idea of the KB362's and a mid 9 CR with some quench and minimal rod work. Again.....My machinist has a good rep with piston mfg's and is digging into options as well. Unfortunately there aren't that many for Magnum 360. As far as removing piston and rod mass and messing with external balancing....I have no clue as to how you would know when you are back IN balance and feel that is better left to professionals and that is not me for sure.

Also. I am aware of the lifter preload change and I will be using a checking pushrod to measure and order a new set.
 
JoePole1 said:
The front end of my build is another unknown at this point due to the fact that I am running AC and for serp I would need a 1 year only 91 5.9 Dakota AC/ALT bracket with the LA style intake I am using. I will most likely stay with LA front because I already have it but I do like the idea of the serpentine set-up.

I like the idea of the KB362's and a mid 9 CR with some quench and minimal rod work. Again.....My machinist has a good rep with piston mfg's and is digging into options as well. Unfortunately there aren't that many for Magnum 360. As far as removing piston and rod mass and messing with external balancing....I have no clue as to how you would know when you are back IN balance and feel that is better left to professionals and that is not me for sure.

Also. I am aware of the lifter preload change and I will be using a checking pushrod to measure and order a new set.
Click to expand...
Good deal, JP1. I'll be interested to hear what other pistons may work..... always something to learn. I did look at SRP's and nothing better there.

As 'for getting back in balance', that is indeed for the machinist to do. But what I always like to do is understand the balance situation & bobweights up front and then I can come up with a plan for the balance work that will be easy and straightforward for the machinist, and will get you there with least cost. That is where I am heading with the suggestions offered: make it so the machinist just has to take weight off of the external parts or the main counterweights of the crank to get it there, and not have to add weight.

If it helps, here is some more detail:
  • The 362's are so close to the stock bobweight that it ought to just take a touch of work on the main crank counterweights to achieve the primary balance with the stock Magnum damper and flexplate (or TC)weights. In reality , they are so close you would very, very probably have a 'within-factory-tolerance' balance just to leave it as-is. )It would only be 'out' if the rods or crank were on the edge of balance tolerances to start with.)
  • The Icon 742's are a bit heavier but not all that far off of factory 5.9L Magnum bobweight. From my own data, the factory 5.9L Magnum bobweight is nominally 2004 grams. If you put in these Icons, then the bobweight becomes 2066 grams nominal. That is too far off for even factory balance tolerance, so you need to add some weight somewhere.... either with heavy metal in the crankshaft or with more external weight in front and back. The LA360 external weights are already heavier than the Magnum external weights and should be more than enough external weight to make this work. So you would start with those LA parts and take off some of that external weight to get to balance. Or, you can even use the LA parts unmodified and take the weight off of the crankshaft counterweights. (which makes it easy-peasy for the machinist....) You can even do this with the B&M flexplate for the LA360 and make it work.
Boy, I hope that makes some sense! It all works in my head LOL, and I've been down a similar road with figuring up how to manage balance with similar weight changes, and it was no problemo in execution at the shop.
 
Thanks Mark. Earlier in the week someone on FABO posted a link to EngineLabs. They have some very interesting information there and also have a newsletter that I subscribed to. They don't seem to be pushing anything even though they do have advertisers (someone's gotta pay for it...right?). Anyway...looky what I got today.
Taking It For A Spin: Why Are Some Cranks Externally Balanced?

edit.....I think they offer a lot of good information especially for a novice like myself.
 
Hey Guys I'm back with more questions but this is turning into more of a dreaded cam selection deal at this point.
I have contacted Ken at Oregon and he gave me his suggested grind and I have a couple of other cams in mind but first...
AJ and Mark have pointed out the importance of Intake closing Angle to raise cylinder pressure on my calculated 9.3:1 Magnum mill but that number is not listed by the cam manufacturers. How is ICA calculated?
 
Wyrmrider said:
so what did you end up with mechanically?

I already mentioned that Jones has superior roller profiles
are you thinking new or regrind?
Street Performance | Jones Cams
and pm dart19777@crower he gives dealer prices to fabo members
Click to expand...
Not sure what you mean by "what did I wind up with mechanically" but I am looking at regrind. Ken at Oregon sent me his grind list and there are plenty to choose from. He did make a recommendation for my vehicle set-up and I have a few from members here but I also see some interesting Dyno graphs but they don't take specific vehicle into consideration. With that said, I know I need an ICA around 53 so I would like to understand how to calculate that and then I can narrow down my cam choice.
 
oops sorry about the typo shane tiny chromebook keypad
mechanical compression
are you thinking of a regrind?
My close by fellow fabo member slantsix64 got an Oregon regrind
check out his thread -good service- budget build
stock cores limit what you can do- greatly
I'd contact Jones and Shane- companies that develop their own masters
"How is ICA calculated?"
you really need to work with these guys and do what they suggest
do not try and pick your own cam but know enough to be in the ballpark and keep asking questions
 
Still waiting for my block from the machine shop so my CR is calculated from piston manufacturer. Comes in at 9.27.

" "How is ICA calculated?"
you really need to work with these guys and do what they suggest
do not try and pick your own cam but know enough to be in the ballpark and keep asking questions"
......This is what I am trying to do and that is why I'd want to calculate an ICA with some of the cams suggested.
Sure, I could just post the choices here and maybe I will at some point.
 
ICA (seat timing)is unfortunatly givenat different heights
.050 s worthless unless you know the "intensity"
Mopar and Engle use .008 and Isky is higher but varies by cam series
Comp and many others are .006
Crane, cam dynamics, Summit, Elgin, Sealed Power use .004 which is an SAE standard
Crower may be .005- I forget
so comparing takes a cam doc or lots of experience
Another thing is that factory cams are really long below the advertised timing
The DC cams are not as long
for example I posted Mike Jones Mopar Hyd 256@.006 cam at different heights in the 318 cam stickie
Turns out it is shorter at actual seat timing than any other cam in the 250 class but it is 50% larger than the DC/MP 260 @ .275, cant measure at .300 as the DC cam does not lift that high or neither i open very long at that lift That's the power spec
The seat timing gives you your low end
keep us posted when you actually measure your compression but as of 9:1 think around 54 ABDC @.006 later you loose more low end (a choice)
 
IN the past, I have used the .005" or .006" lift angles, which in most cases are the angles that fall out of the advertised duration for a hydraulic cam, to get accurate results. And when I say accurate, the cranking compression comes out within 3-4% of the predicted value. So the seat timing is not of value, that I have found.

So for a hydrualic, I use a program where I can plug in the advertised durations, the LSA, and the ICL and it pops out the ICA. It is program by Pat Kelley, and can be downloaded here: Dynamic CR

Or, to compute the ICA based on the advertised duration at .005 to .006", from the typical data for a symmetical lobe cam:
  1. Divide the advertised duration by 2
  2. Add that to the ICL
  3. Subtract 180 to get ICA ABDC
Solids are a different matter, as their advertised numbers are based on very different lift values, and then you have to account for lash.

BTW, from running a lot of these numbers, an ICA of 53 is a pretty small cam if the ramps are the older style, milder ramps. Of course, you have a roller, so that could be a source of things being better. For one with the small an ICA, I would be looking at something like a Voodoo or the Howards. Those will get the valve open more quickly after the initial opening and keep the valve open as much as you can before the valve closing, to get the 'area under the curve' up. I don't usually think of Oregon as a source for cams like that.
 
Thanks Mark. I am leaning towards an Oregon regrind that was recommended by a couple of members using them and the cost savings. Plus I have a good blank. I do understand that the Lunati and Howards have MoPar friendly lobes. I also see notations on the Oregon grind sheet with cam profiles that they copy (ie XR270HR) in some cases.
 
JoePole1 said:
Thanks Mark. I am leaning towards an Oregon regrind that was recommended by a couple of members using them and the cost savings. Plus I have a good blank. I do understand that the Lunati and Howards have MoPar friendly lobes. I also see notations on the Oregon grind sheet with cam profiles that they copy (ie XR270HR) in some cases.
Click to expand...
Your core should also be Mopar friendly.... whether they can put a Chevy grind on your Mopar core I don't know.
 
JoePole1 said:
Thanks Mark. I am leaning towards an Oregon regrind that was recommended by a couple of members using them and the cost savings. Plus I have a good blank. I do understand that the Lunati and Howards have MoPar friendly lobes. I also see notations on the Oregon grind sheet with cam profiles that they copy (ie XR270HR) in some cases.
Click to expand...
Yes, the cost factor is something I figured you were looking at. Nothing wrong with that.

Looking at the Oregon grind HR sheet online (which is pretty od so may not have all their grinds), I can see the 1393 grind which is pretty close in terms of ICA (56* installed as in their listing), and the valve lift at .500". The 'intensity' based on the duration difference in Advertised duration - .050" duration alone (which is not a 100% sure way to look at it), looks almost as strong as Howards or Voodoo. This Oregon grind is 54* while a comparable Voodoo is 51*. What I cannot tell you is what these do at .100" or .200"; Howard's lobe list will show some of that but not Oregon and I have never seen a Lunati lobe list.

Now having said that, I have never been unhappy with a milder intensity cam like the standard Cranes. But I don't go for all-out maximal HP. So that Oregon grind may suit you just fine. And I have not looked back a springs and such with these; the less intense, the less spring is needed in general.

Do you have any Oregon specs or a grind number to share? As said, a lot of their online info looks old.
 
Thanks Mark. The grind Oregon Ken recommended is 1341 - 218/224@ .050, 270/276@.060, 110/106, 482/482. There is also an identical grind-1634 that has a lift of 528/536. The lift is using 1.6. Notation says XR270HR. Since that is a Comp grind I looked at the dyno chart on their site which uses a very similar (displacement, CR, head, intake, carb), albeit chebby engine. The chart looked good but noticed their XR276HR (SBM cam XR274HR) that had slightly more power and nice, flat torque curve. The Oregon grind for that cam is 1990. 224/230@.050, 276/282@.060, 112/108, 510/510 -1.6. The 1990 was something based on another member @TrailBeast running the 1341 stating he would have bumped to the 224/230. The other two I was looking at were the Lunati 715 (Truestreet) @motorpirate 213/219, 264/270@.050, 112/106, 485/485.
Another interesting cam is the Howards 77195-10 221/225, 274/278, 110/106, 507/533@.050. I'll have to run the numbers and see what I get for cylinder pressure.
 
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