|
Re: Magnum Conversion Woes
[Re: John_M]
#88886
07/16/08 10:30 AM
07/16/08 10:30 AM
|
Joined: May 2008
Posts: 5,399
Aurora, Colorado
451Mopar
master
|
master
Joined: May 2008
Posts: 5,399
Aurora, Colorado
|
Quote:
I have an LA block, with KB107 pistons, Comp Cams XE268H with Advertised Duration 268/ 280, Lift .477/ .480. Block is bored over .030". I am using EQ Iron Ram heads with Chev springs supplied by someone on here who also drilled the new heads and supplied longer bolts and the MP oil-through pushrods and rockers (I replaced the supplied rockers with new MP ones) .
I thought I was set to go until I received this e-mail from my mechanic friend:
"The cam called for 106 and it was 108 which isn't to bad. There is a lot of coil bind in the valve springs .... the coil bind is at .465" and actual valve lift is .501" and even with a 1 1/2:1 rocker arm ratio actual valve lift would be .472" which still leaves a short fall of .009". The current lift short fall is .036" without any safety margin? We need .100" minimum to give a minimal safety margin."
Any thoughts here by anyone who has done this conversion would be greatly appreciated. Thanks.
Sounds like you have the wrong valve springs. Not sure where you even found a valve spring that coil binds at 0.465"?
2-degrees off on the cam install is not too bad, an offset cam key can correct it if you wanted.
The big thing not mentioned in the post is which lifters your using. They need to be compatable with pushrod oiling.
|
|
|
Re: Magnum Conversion Woes
[Re: John_M]
#88887
07/16/08 12:32 PM
07/16/08 12:32 PM
|
Joined: Jan 2003
Posts: 17,904
S.E. Michigan
ZIPPY
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 17,904
S.E. Michigan
|
Though I don't claim to know anything about EQ heads, if they are a close knockoff of a regular Magnum head, maybe this will apply:
Mopar Performance has sold the proper valve springs (and matching valve spring retainers) to accomodate anything less than .600 lift for quite a few years now, they're tried and true.
They're sold under P4876062 (spring), and P4452032 (retainer). Locks will vary per the application.
The parts you need aren't anything exotic or hard to find.
Rich H.
Esse Quam Videri
|
|
|
Re: Magnum Conversion Woes
[Re: ZIPPY]
#88888
07/16/08 12:51 PM
07/16/08 12:51 PM
|
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
|
ok, some questions about your heads:
1) what valve is in there? a factory style magnum 8mm stem valve, or a SBC 11/32" stem valve?
2)with your current retainers, what is your current spring installed height?
3) what are your current retainer's ID and OD?
once we get this info, we can help you find a suitable retainer/spring combo.
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
|
|
|
Re: Magnum Conversion Woes
[Re: John_M]
#88889
07/16/08 12:51 PM
07/16/08 12:51 PM
|
Joined: Jan 2003
Posts: 75,082
U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 75,082
U.S.S.A.
|
Quote:
No takers? I did come up with some valuable information on the magnum head conversion.
A warning to those, like me, who trust that some of the guys on here are the experts they appear to be. They may not be.
Do your research. Ask someone who you think is an expert for advice, then read and ask several more. Research!
And just because someone on here appears to know their stuff when they offer to do a job for you that isn't necessarily the case.
I blame myself for not doing enough research beforehand. I should know better but I got caught.
I went back to see who these EXPERTS are you are talking down to and I see the same exact thing there , as I do here .
Its not surprising that all you are hearing is crickets ...
As far as the spring bind issue , thats something you need to take up with the company you purchased those heads from .
Otherwise rotsa ruck with your project
|
|
|
Re: Magnum Conversion Woes
[Re: 451Mopar]
#88891
07/16/08 08:08 PM
07/16/08 08:08 PM
|
Joined: Aug 2004
Posts: 260
N. Ontario, Canada
John_M
OP
enthusiast
|
OP
enthusiast
Joined: Aug 2004
Posts: 260
N. Ontario, Canada
|
Quote:
.... The big thing not mentioned in the post is which lifters your using. They need to be compatable with pushrod oiling.
Comp Cams hydraulic lifters that supply oil through the pushrods.
Quote:
.... They're sold under P4876062 (spring), and P4452032 (retainer). Locks will vary per the application.
The parts you need aren't anything exotic or hard to find.
I was also advised that I could use the Magnum R/T springs P5249464 but their maximum lift is 0.525".
The parts are easy to find but I already paid for them once.
Quote:
I went back to see who these EXPERTS are you are talking down to and I see the same exact thing there , as I do here .
Its not surprising that all you are hearing is crickets ...
You have no idea. Suffice it to say I didn't get what I paid for.
|
|
|
Re: Magnum Conversion Woes
[Re: 80mirada]
#88893
07/17/08 07:41 AM
07/17/08 07:41 AM
|
Anonymous
Unregistered
|
Anonymous
Unregistered
|
I will admit I dont know anything about magnum heads but the principles are the same. you need the right installed valve height and that means you need to measure and grind the valve spring seats (to add height) or use seats (to take it away).
What is the length of the chevy springs as compared to sb springs. that coil bindig at such a low lift is weird. that would bind at stock cam heights.
|
|
|
Re: Magnum Conversion Woes
[Re: John_M]
#88895
07/17/08 08:55 AM
07/17/08 08:55 AM
|
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
|
are they chevy 11/32" stem valves or magnum 8mm valves? again, we need more info to help you out.
if they are chevy valves, you can find all kinds of different retainers to increase installed height.
if they're magnum 8mm, there not a whole lot of choices other than the LS1 keepers (that the GM V6 springs also use) 2.2L retainers (what the MP ones are basically), or stock. 2.2L retainers can be used with any spring ~1.4" OD. you might be able to find something with a short enough coil bind height and decent enough spring rate, or you're going to have to sink the valves or machine the spring seat for more installed height.
I seem to remember seeing somewhere 8mm stem magnum valves that are +.100" longer....
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
|
|
|
Re: Magnum Conversion Woes
[Re: CoyoteJack]
#88899
07/17/08 11:23 AM
07/17/08 11:23 AM
|
Joined: Aug 2004
Posts: 260
N. Ontario, Canada
John_M
OP
enthusiast
|
OP
enthusiast
Joined: Aug 2004
Posts: 260
N. Ontario, Canada
|
So if I put the 6494 MP springs in I would get enough lift before coil bind?
The wire diameter is the same on the MP and Chev springs it seems.
How could you get more spring compression if both springs start at basically the same place and have the same wire diameter? Just trying to understand - definitely not arguing.
Do you have the stock valves with the single groove locks?
Last edited by John_M; 07/17/08 11:34 AM.
|
|
|
Re: Magnum Conversion Woes
[Re: ZIPPY]
#88901
07/17/08 01:09 PM
07/17/08 01:09 PM
|
Joined: Sep 2007
Posts: 576
Escondido, CA
kick_the_reverb
mopar
|
mopar
Joined: Sep 2007
Posts: 576
Escondido, CA
|
Not trying to offend anyone, but from reading the info about the GM 3.1 springs and retainers in the past, it looked to me like it would be cutting it too close in some cases (being that there are variations in the heads). So it worked for Dave, and it was marginal for Patrick. That was enough for me to think that the Chevy 11/32 +.100" valves would be a much better solution, or just paying the price for the MP setup.
I have to note that I decided against using Magnum EQ in my specific case, so I can't provide hands on experience. Not saying there's anything wrong with them (or with using Magnums), just decided I'll use something else.
Good luck,
Ran
"Hey mister, something's wrong with your car, it idles roughly" - number one comment I got in Israel when daily driving a 70 Barracuda with a lopey cam.
Currently working on - 1966 Dodge A100 van 318/auto
Finally - disc brakes on the front.
In the plans - rear disc brakes, B&M 250 blower
|
|
|
Re: Magnum Conversion Woes
[Re: ZIPPY]
#88902
07/17/08 01:34 PM
07/17/08 01:34 PM
|
Joined: Apr 2004
Posts: 1,396
Mass
dgc333
pro stock
|
pro stock
Joined: Apr 2004
Posts: 1,396
Mass
|
Quote:
Stock valves should be multi-groove, performance (or aftermarket) valves should be single groove.
Stock magnum head valves have a single round profile groove.
|
|
|
Re: Magnum Conversion Woes
[Re: ZIPPY]
#88903
07/17/08 01:37 PM
07/17/08 01:37 PM
|
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
|
Quote:
Quote:
How could you get more spring compression if both springs start at basically the same place and have the same wire diameter? Just trying to understand - definitely not arguing.
Greater or lesser number of coils within a given area. Different/more robust material spec allows more spring pressure with a lower coil count.
actually, spring pressure is a function of the material's elastic modulus, wire diameter, coil count, and coil diamteter. smaller coil diameter, larger wire diamter and/or less coils=stiffer spring rate. all steels have the same elastic modulus essentially. different materials (in the steel family) will change the yield, ultimate tensile, and fatigue strength.
Quote:
Do you have the stock valves with the single groove locks?
Stock valves should be multi-groove, performance (or aftermarket) valves should be single groove.
the stock valves on the mag heads under my work bench are single groove. sounds like you have stock magnum valves.
if you look my findings in the "best of" post
cheap magnum spring
your installed height measurements look similar to what I found when I installed some junkyard springs on my "under the workbench" heads. I had ~1.593" IH, and having the springs tested where I used to work, they coil bind at 1.065", so for the lift you're looking at, with .060 coil bind clearance (generally the minimum you want to go), you'd want ~1.64" installed height, which means machining the spring pocket down ~ 1/16" or sinking the valve a likewise amount.
note what I said in that thread, based on my results I'd be a little leeery running them with much more than .480" measured lift on my particular heads w/o something to increase installed height.
I'm suprised your mechanic is saying they coil bind at .465", as based on my tested coil bind height, with your installed height, they should coil bind at ~.517". with the recommended .060 min clearance, you wouldn't want to run more than ~.457" lift with your installed height.
it's just the design of the retainers, unfortunately there aren't any alternative retainers for these springs out there to give more installed height (vs. say an 11/32 stem, 1.4" diameter retainer, where there's tons of different ones that give more or less installed height). comp has some retainers for their beehive springs that should work for these, but I don't know if they'll help increase installed height. conversely, comp has some beehive springs that may work with these retainers, but they don't net you anything (coil bind height is listed at 1.04-1.06" for these springs)
so it looks like you have 2 options:
1) machine the spring pocket .060 for more installed height
2) find some MP or 2.2L retainers, and measure the installed height of those. with that info, scour the catalogs for a ~1.4" OD spring who's coil bind height is short enough to give you enough lift and clearance, and have adequate spring rate and seat pressure.
Last edited by patrick; 07/17/08 01:43 PM.
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
|
|
|
|
|
